import base64
import binascii
import calendar
import codecs
import collections
import collections.abc
import contextlib
import datetime as dt
import email.header
import email.utils
import enum
import errno
import functools
import hashlib
import hmac
import html.entities
import html.parser
import inspect
import io
import itertools
import json
import locale
import math
import mimetypes
import netrc
import operator
import os
import platform
import random
import re
import shlex
import socket
import ssl
import struct
import subprocess
import sys
import tempfile
import time
import traceback
import types
import unicodedata
import urllib.error
import urllib.parse
import urllib.request
import xml.etree.ElementTree

from . import traversal

from ..compat import (
    compat_datetime_from_timestamp,
    compat_etree_fromstring,
    compat_expanduser,
    compat_HTMLParseError,
)
from ..dependencies import xattr
from ..globals import IN_CLI, WINDOWS_VT_MODE

__name__ = __name__.rsplit('.', 1)[0]  # noqa: A001 # Pretend to be the parent module


class NO_DEFAULT:
    pass


def IDENTITY(x):
    return x


ENGLISH_MONTH_NAMES = [
    'January', 'February', 'March', 'April', 'May', 'June',
    'July', 'August', 'September', 'October', 'November', 'December']

MONTH_NAMES = {
    'en': ENGLISH_MONTH_NAMES,
    'fr': [
        'janvier', 'février', 'mars', 'avril', 'mai', 'juin',
        'juillet', 'août', 'septembre', 'octobre', 'novembre', 'décembre'],
    'is': [
        'janúar', 'febrúar', 'mars', 'apríl', 'maí', 'júní',
        'júlí', 'ágúst', 'september', 'október', 'nóvember', 'desember'],
    # these follow the genitive grammatical case (dopełniacz)
    # some websites might be using nominative, which will require another month list
    # https://en.wikibooks.org/wiki/Polish/Noun_cases
    'pl': ['stycznia', 'lutego', 'marca', 'kwietnia', 'maja', 'czerwca',
           'lipca', 'sierpnia', 'września', 'października', 'listopada', 'grudnia'],
}

# From https://github.com/python/cpython/blob/3.11/Lib/email/_parseaddr.py#L36-L42
TIMEZONE_NAMES = {
    'UT': 0, 'UTC': 0, 'GMT': 0, 'Z': 0,
    'AST': -4, 'ADT': -3,  # Atlantic (used in Canada)
    'EST': -5, 'EDT': -4,  # Eastern
    'CST': -6, 'CDT': -5,  # Central
    'MST': -7, 'MDT': -6,  # Mountain
    'PST': -8, 'PDT': -7,   # Pacific
}

# needed for sanitizing filenames in restricted mode
ACCENT_CHARS = dict(zip('ÂÃÄÀÁÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖŐØŒÙÚÛÜŰÝÞßàáâãäåæçèéêëìíîïðñòóôõöőøœùúûüűýþÿ',
                        itertools.chain('AAAAAA', ['AE'], 'CEEEEIIIIDNOOOOOOO', ['OE'], 'UUUUUY', ['TH', 'ss'],
                                        'aaaaaa', ['ae'], 'ceeeeiiiionooooooo', ['oe'], 'uuuuuy', ['th'], 'y'), strict=True))

DATE_FORMATS = (
    '%d %B %Y',
    '%d %b %Y',
    '%B %d %Y',
    '%B %dst %Y',
    '%B %dnd %Y',
    '%B %drd %Y',
    '%B %dth %Y',
    '%b %d %Y',
    '%b %dst %Y',
    '%b %dnd %Y',
    '%b %drd %Y',
    '%b %dth %Y',
    '%b %dst %Y %I:%M',
    '%b %dnd %Y %I:%M',
    '%b %drd %Y %I:%M',
    '%b %dth %Y %I:%M',
    '%Y %m %d',
    '%Y-%m-%d',
    '%Y.%m.%d.',
    '%Y/%m/%d',
    '%Y/%m/%d %H:%M',
    '%Y/%m/%d %H:%M:%S',
    '%Y%m%d%H%M',
    '%Y%m%d%H%M%S',
    '%Y%m%d',
    '%Y-%m-%d %H:%M',
    '%Y-%m-%d %H:%M:%S',
    '%Y-%m-%d %H:%M:%S.%f',
    '%Y-%m-%d %H:%M:%S:%f',
    '%d.%m.%Y %H:%M',
    '%d.%m.%Y %H.%M',
    '%Y-%m-%dT%H:%M:%SZ',
    '%Y-%m-%dT%H:%M:%S.%fZ',
    '%Y-%m-%dT%H:%M:%S.%f0Z',
    '%Y-%m-%dT%H:%M:%S',
    '%Y-%m-%dT%H:%M:%S.%f',
    '%Y-%m-%dT%H:%M',
    '%b %d %Y at %H:%M',
    '%b %d %Y at %H:%M:%S',
    '%B %d %Y at %H:%M',
    '%B %d %Y at %H:%M:%S',
    '%H:%M %d-%b-%Y',
)

DATE_FORMATS_DAY_FIRST = list(DATE_FORMATS)
DATE_FORMATS_DAY_FIRST.extend([
    '%d-%m-%Y',
    '%d.%m.%Y',
    '%d.%m.%y',
    '%d/%m/%Y',
    '%d/%m/%y',
    '%d/%m/%Y %H:%M:%S',
    '%d-%m-%Y %H:%M',
    '%H:%M %d/%m/%Y',
])

DATE_FORMATS_MONTH_FIRST = list(DATE_FORMATS)
DATE_FORMATS_MONTH_FIRST.extend([
    '%m-%d-%Y',
    '%m.%d.%Y',
    '%m/%d/%Y',
    '%m/%d/%y',
    '%m/%d/%Y %H:%M:%S',
])

PACKED_CODES_RE = r"}\('(.+)',(\d+),(\d+),'([^']+)'\.split\('\|'\)"
JSON_LD_RE = r'(?is)<script[^>]+type=(["\']?)application/ld\+json\1[^>]*>\s*(?P<json_ld>{.+?}|\[.+?\])\s*</script>'

NUMBER_RE = r'\d+(?:\.\d+)?'


@functools.cache
def preferredencoding():
    """Get preferred encoding.

    Returns the best encoding scheme for the system, based on
    locale.getpreferredencoding() and some further tweaks.
    """
    try:
        pref = locale.getpreferredencoding()
        'TEST'.encode(pref)
    except Exception:
        pref = 'UTF-8'

    return pref


def write_json_file(obj, fn):
    """ Encode obj as JSON and write it to fn, atomically if possible """

    tf = tempfile.NamedTemporaryFile(
        prefix=f'{os.path.basename(fn)}.', dir=os.path.dirname(fn),
        suffix='.tmp', delete=False, mode='w', encoding='utf-8')

    try:
        with tf:
            json.dump(obj, tf, ensure_ascii=False)
        if sys.platform == 'win32':
            # Need to remove existing file on Windows, else os.rename raises
            # WindowsError or FileExistsError.
            with contextlib.suppress(OSError):
                os.unlink(fn)
        with contextlib.suppress(OSError):
            mask = os.umask(0)
            os.umask(mask)
            os.chmod(tf.name, 0o666 & ~mask)
        os.rename(tf.name, fn)
    except Exception:
        with contextlib.suppress(OSError):
            os.remove(tf.name)
        raise


def partial_application(func):
    sig = inspect.signature(func)
    required_args = [
        param.name for param in sig.parameters.values()
        if param.kind in (inspect.Parameter.POSITIONAL_ONLY, inspect.Parameter.POSITIONAL_OR_KEYWORD)
        if param.default is inspect.Parameter.empty
    ]

    @functools.wraps(func)
    def wrapped(*args, **kwargs):
        if set(required_args[len(args):]).difference(kwargs):
            return functools.partial(func, *args, **kwargs)
        return func(*args, **kwargs)

    return wrapped


def find_xpath_attr(node, xpath, key, val=None):
    """ Find the xpath xpath[@key=val] """
    assert re.match(r'^[a-zA-Z_-]+$', key)
    expr = xpath + (f'[@{key}]' if val is None else f"[@{key}='{val}']")
    return node.find(expr)

# On python2.6 the xml.etree.ElementTree.Element methods don't support
# the namespace parameter


def xpath_with_ns(path, ns_map):
    components = [c.split(':') for c in path.split('/')]
    replaced = []
    for c in components:
        if len(c) == 1:
            replaced.append(c[0])
        else:
            ns, tag = c
            replaced.append(f'{{{ns_map[ns]}}}{tag}')
    return '/'.join(replaced)


def xpath_element(node, xpath, name=None, fatal=False, default=NO_DEFAULT):
    def _find_xpath(xpath):
        return node.find(xpath)

    if isinstance(xpath, str):
        n = _find_xpath(xpath)
    else:
        for xp in xpath:
            n = _find_xpath(xp)
            if n is not None:
                break

    if n is None:
        if default is not NO_DEFAULT:
            return default
        elif fatal:
            name = xpath if name is None else name
            raise ExtractorError(f'Could not find XML element {name}')
        else:
            return None
    return n


def xpath_text(node, xpath, name=None, fatal=False, default=NO_DEFAULT):
    n = xpath_element(node, xpath, name, fatal=fatal, default=default)
    if n is None or n == default:
        return n
    if n.text is None:
        if default is not NO_DEFAULT:
            return default
        elif fatal:
            name = xpath if name is None else name
            raise ExtractorError(f'Could not find XML element\'s text {name}')
        else:
            return None
    return n.text


def xpath_attr(node, xpath, key, name=None, fatal=False, default=NO_DEFAULT):
    n = find_xpath_attr(node, xpath, key)
    if n is None:
        if default is not NO_DEFAULT:
            return default
        elif fatal:
            name = f'{xpath}[@{key}]' if name is None else name
            raise ExtractorError(f'Could not find XML attribute {name}')
        else:
            return None
    return n.attrib[key]


def get_element_by_id(id, html, **kwargs):
    """Return the content of the tag with the specified ID in the passed HTML document"""
    return get_element_by_attribute('id', id, html, **kwargs)


def get_element_html_by_id(id, html, **kwargs):
    """Return the html of the tag with the specified ID in the passed HTML document"""
    return get_element_html_by_attribute('id', id, html, **kwargs)


def get_element_by_class(class_name, html):
    """Return the content of the first tag with the specified class in the passed HTML document"""
    retval = get_elements_by_class(class_name, html)
    return retval[0] if retval else None


def get_element_html_by_class(class_name, html):
    """Return the html of the first tag with the specified class in the passed HTML document"""
    retval = get_elements_html_by_class(class_name, html)
    return retval[0] if retval else None


def get_element_by_attribute(attribute, value, html, **kwargs):
    retval = get_elements_by_attribute(attribute, value, html, **kwargs)
    return retval[0] if retval else None


def get_element_html_by_attribute(attribute, value, html, **kargs):
    retval = get_elements_html_by_attribute(attribute, value, html, **kargs)
    return retval[0] if retval else None


def get_elements_by_class(class_name, html, **kargs):
    """Return the content of all tags with the specified class in the passed HTML document as a list"""
    return get_elements_by_attribute(
        'class', rf'[^\'"]*(?<=[\'"\s]){re.escape(class_name)}(?=[\'"\s])[^\'"]*',
        html, escape_value=False)


def get_elements_html_by_class(class_name, html):
    """Return the html of all tags with the specified class in the passed HTML document as a list"""
    return get_elements_html_by_attribute(
        'class', rf'[^\'"]*(?<=[\'"\s]){re.escape(class_name)}(?=[\'"\s])[^\'"]*',
        html, escape_value=False)


def get_elements_by_attribute(*args, **kwargs):
    """Return the content of the tag with the specified attribute in the passed HTML document"""
    return [content for content, _ in get_elements_text_and_html_by_attribute(*args, **kwargs)]


def get_elements_html_by_attribute(*args, **kwargs):
    """Return the html of the tag with the specified attribute in the passed HTML document"""
    return [whole for _, whole in get_elements_text_and_html_by_attribute(*args, **kwargs)]


def get_elements_text_and_html_by_attribute(attribute, value, html, *, tag=r'[\w:.-]+', escape_value=True):
    """
    Return the text (content) and the html (whole) of the tag with the specified
    attribute in the passed HTML document
    """
    if not value:
        return

    quote = '' if re.match(r'''[\s"'`=<>]''', value) else '?'

    value = re.escape(value) if escape_value else value

    partial_element_re = rf'''(?x)
        <(?P<tag>{tag})
         (?:\s(?:[^>"']|"[^"]*"|'[^']*')*)?
         \s{re.escape(attribute)}\s*=\s*(?P<_q>['"]{quote})(?-x:{value})(?P=_q)
        '''

    for m in re.finditer(partial_element_re, html):
        content, whole = get_element_text_and_html_by_tag(m.group('tag'), html[m.start():])

        yield (
            unescapeHTML(re.sub(r'^(?P<q>["\'])(?P<content>.*)(?P=q)$', r'\g<content>', content, flags=re.DOTALL)),
            whole,
        )


class HTMLBreakOnClosingTagParser(html.parser.HTMLParser):
    """
    HTML parser which raises HTMLBreakOnClosingTagException upon reaching the
    closing tag for the first opening tag it has encountered, and can be used
    as a context manager
    """

    class HTMLBreakOnClosingTagException(Exception):
        pass

    def __init__(self):
        self.tagstack = collections.deque()
        html.parser.HTMLParser.__init__(self)

    def __enter__(self):
        return self

    def __exit__(self, *_):
        self.close()

    def close(self):
        # handle_endtag does not return upon raising HTMLBreakOnClosingTagException,
        # so data remains buffered; we no longer have any interest in it, thus
        # override this method to discard it
        pass

    def handle_starttag(self, tag, _):
        self.tagstack.append(tag)

    def handle_endtag(self, tag):
        if not self.tagstack:
            raise compat_HTMLParseError('no tags in the stack')
        while self.tagstack:
            inner_tag = self.tagstack.pop()
            if inner_tag == tag:
                break
        else:
            raise compat_HTMLParseError(f'matching opening tag for closing {tag} tag not found')
        if not self.tagstack:
            raise self.HTMLBreakOnClosingTagException


# XXX: This should be far less strict
def get_element_text_and_html_by_tag(tag, html):
    """
    For the first element with the specified tag in the passed HTML document
    return its' content (text) and the whole element (html)
    """
    def find_or_raise(haystack, needle, exc):
        try:
            return haystack.index(needle)
        except ValueError:
            raise exc
    closing_tag = f'</{tag}>'
    whole_start = find_or_raise(
        html, f'<{tag}', compat_HTMLParseError(f'opening {tag} tag not found'))
    content_start = find_or_raise(
        html[whole_start:], '>', compat_HTMLParseError(f'malformed opening {tag} tag'))
    content_start += whole_start + 1
    with HTMLBreakOnClosingTagParser() as parser:
        parser.feed(html[whole_start:content_start])
        if not parser.tagstack or parser.tagstack[0] != tag:
            raise compat_HTMLParseError(f'parser did not match opening {tag} tag')
        offset = content_start
        while offset < len(html):
            next_closing_tag_start = find_or_raise(
                html[offset:], closing_tag,
                compat_HTMLParseError(f'closing {tag} tag not found'))
            next_closing_tag_end = next_closing_tag_start + len(closing_tag)
            try:
                parser.feed(html[offset:offset + next_closing_tag_end])
                offset += next_closing_tag_end
            except HTMLBreakOnClosingTagParser.HTMLBreakOnClosingTagException:
                return html[content_start:offset + next_closing_tag_start], \
                    html[whole_start:offset + next_closing_tag_end]
        raise compat_HTMLParseError('unexpected end of html')


class HTMLAttributeParser(html.parser.HTMLParser):
    """Trivial HTML parser to gather the attributes for a single element"""

    def __init__(self):
        self.attrs = {}
        html.parser.HTMLParser.__init__(self)

    def handle_starttag(self, tag, attrs):
        self.attrs = dict(attrs)
        raise compat_HTMLParseError('done')


class HTMLListAttrsParser(html.parser.HTMLParser):
    """HTML parser to gather the attributes for the elements of a list"""

    def __init__(self):
        html.parser.HTMLParser.__init__(self)
        self.items = []
        self._level = 0

    def handle_starttag(self, tag, attrs):
        if tag == 'li' and self._level == 0:
            self.items.append(dict(attrs))
        self._level += 1

    def handle_endtag(self, tag):
        self._level -= 1


def extract_attributes(html_element):
    """Given a string for an HTML element such as
    <el
         a="foo" B="bar" c="&98;az" d=boz
         empty= noval entity="&amp;"
         sq='"' dq="'"
    >
    Decode and return a dictionary of attributes.
    {
        'a': 'foo', 'b': 'bar', c: 'baz', d: 'boz',
        'empty': '', 'noval': None, 'entity': '&',
        'sq': '"', 'dq': '\''
    }.
    """
    parser = HTMLAttributeParser()
    with contextlib.suppress(compat_HTMLParseError):
        parser.feed(html_element)
        parser.close()
    return parser.attrs


def parse_list(webpage):
    """Given a string for an series of HTML <li> elements,
    return a dictionary of their attributes"""
    parser = HTMLListAttrsParser()
    parser.feed(webpage)
    parser.close()
    return parser.items


def clean_html(html):
    """Clean an HTML snippet into a readable string"""

    if html is None:  # Convenience for sanitizing descriptions etc.
        return html

    html = re.sub(r'\s+', ' ', html)
    html = re.sub(r'(?u)\s?<\s?br\s?/?\s?>\s?', '\n', html)
    html = re.sub(r'(?u)<\s?/\s?p\s?>\s?<\s?p[^>]*>', '\n', html)
    # Strip html tags
    html = re.sub('<.*?>', '', html)
    # Replace html entities
    html = unescapeHTML(html)
    return html.strip()


class LenientJSONDecoder(json.JSONDecoder):
    # TODO: Write tests
    def __init__(self, *args, transform_source=None, ignore_extra=False, close_objects=0, **kwargs):
        self.transform_source, self.ignore_extra = transform_source, ignore_extra
        self._close_attempts = 2 * close_objects
        super().__init__(*args, **kwargs)

    @staticmethod
    def _close_object(err):
        doc = err.doc[:err.pos]
        # We need to add comma first to get the correct error message
        if err.msg.startswith('Expecting \',\''):
            return doc + ','
        elif not doc.endswith(','):
            return

        if err.msg.startswith('Expecting property name'):
            return doc[:-1] + '}'
        elif err.msg.startswith('Expecting value'):
            return doc[:-1] + ']'

    def decode(self, s):
        if self.transform_source:
            s = self.transform_source(s)
        for attempt in range(self._close_attempts + 1):
            try:
                if self.ignore_extra:
                    return self.raw_decode(s.lstrip())[0]
                return super().decode(s)
            except json.JSONDecodeError as e:
                if e.pos is None:
                    raise
                elif attempt < self._close_attempts:
                    s = self._close_object(e)
                    if s is not None:
                        continue
                raise type(e)(f'{e.msg} in {s[e.pos - 10:e.pos + 10]!r}', s, e.pos)
        assert False, 'Too many attempts to decode JSON'


def sanitize_open(filename, open_mode):
    """Try to open the given filename, and slightly tweak it if this fails.

    Attempts to open the given filename. If this fails, it tries to change
    the filename slightly, step by step, until it's either able to open it
    or it fails and raises a final exception, like the standard open()
    function.

    It returns the tuple (stream, definitive_file_name).
    """
    if filename == '-':
        if sys.platform == 'win32':
            import msvcrt

            # stdout may be any IO stream, e.g. when using contextlib.redirect_stdout
            with contextlib.suppress(io.UnsupportedOperation):
                msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
        return (sys.stdout.buffer if hasattr(sys.stdout, 'buffer') else sys.stdout, filename)

    for attempt in range(2):
        try:
            try:
                if sys.platform == 'win32':
                    # FIXME: An exclusive lock also locks the file from being read.
                    # Since windows locks are mandatory, don't lock the file on windows (for now).
                    # Ref: https://github.com/yt-dlp/yt-dlp/issues/3124
                    raise LockingUnsupportedError
                stream = locked_file(filename, open_mode, block=False).__enter__()
            except OSError:
                stream = open(filename, open_mode)
            return stream, filename
        except OSError as err:
            if attempt or err.errno in (errno.EACCES,):
                raise
            old_filename, filename = filename, sanitize_path(filename)
            if old_filename == filename:
                raise


def timeconvert(timestr):
    """Convert RFC 2822 defined time string into system timestamp"""
    timestamp = None
    timetuple = email.utils.parsedate_tz(timestr)
    if timetuple is not None:
        timestamp = email.utils.mktime_tz(timetuple)
    return timestamp


def sanitize_filename(s, restricted=False, is_id=NO_DEFAULT):
    """Sanitizes a string so it could be used as part of a filename.
    @param restricted   Use a stricter subset of allowed characters
    @param is_id        Whether this is an ID that should be kept unchanged if possible.
                        If unset, yt-dlp's new sanitization rules are in effect
    """
    if s == '':
        return ''

    def replace_insane(char):
        if restricted and char in ACCENT_CHARS:
            return ACCENT_CHARS[char]
        elif not restricted and char == '\n':
            return '\0 '
        elif is_id is NO_DEFAULT and not restricted and char in '"*:<>?|/\\':
            # Replace with their full-width unicode counterparts
            return {'/': '\u29F8', '\\': '\u29f9'}.get(char, chr(ord(char) + 0xfee0))
        elif char == '?' or ord(char) < 32 or ord(char) == 127:
            return ''
        elif char == '"':
            return '' if restricted else '\''
        elif char == ':':
            return '\0_\0-' if restricted else '\0 \0-'
        elif char in '\\/|*<>':
            return '\0_'
        if restricted and (char in '!&\'()[]{}$;`^,#' or char.isspace() or ord(char) > 127):
            return '' if unicodedata.category(char)[0] in 'CM' else '\0_'
        return char

    # Replace look-alike Unicode glyphs
    if restricted and (is_id is NO_DEFAULT or not is_id):
        s = unicodedata.normalize('NFKC', s)
    s = re.sub(r'[0-9]+(?::[0-9]+)+', lambda m: m.group(0).replace(':', '_'), s)  # Handle timestamps
    result = ''.join(map(replace_insane, s))
    if is_id is NO_DEFAULT:
        result = re.sub(r'(\0.)(?:(?=\1)..)+', r'\1', result)  # Remove repeated substitute chars
        STRIP_RE = r'(?:\0.|[ _-])*'
        result = re.sub(f'^\0.{STRIP_RE}|{STRIP_RE}\0.$', '', result)  # Remove substitute chars from start/end
    result = result.replace('\0', '') or '_'

    if not is_id:
        while '__' in result:
            result = result.replace('__', '_')
        result = result.strip('_')
        # Common case of "Foreign band name - English song title"
        if restricted and result.startswith('-_'):
            result = result[2:]
        if result.startswith('-'):
            result = '_' + result[len('-'):]
        result = result.lstrip('.')
        if not result:
            result = '_'
    return result


def _sanitize_path_parts(parts):
    sanitized_parts = []
    for part in parts:
        if not part or part == '.':
            continue
        elif part == '..':
            if sanitized_parts and sanitized_parts[-1] != '..':
                sanitized_parts.pop()
            else:
                sanitized_parts.append('..')
            continue
        # Replace invalid segments with `#`
        # - trailing dots and spaces (`asdf...` => `asdf..#`)
        # - invalid chars (`<>` => `##`)
        sanitized_part = re.sub(r'[/<>:"\|\\?\*]|[\s.]$', '#', part)
        sanitized_parts.append(sanitized_part)

    return sanitized_parts


def sanitize_path(s, force=False):
    """Sanitizes and normalizes path on Windows"""
    if sys.platform != 'win32':
        if not force:
            return s
        root = '/' if s.startswith('/') else ''
        path = '/'.join(_sanitize_path_parts(s.split('/')))
        return root + path if root or path else '.'

    normed = s.replace('/', '\\')

    if normed.startswith('\\\\'):
        # UNC path (`\\SERVER\SHARE`) or device path (`\\.`, `\\?`)
        parts = normed.split('\\')
        root = '\\'.join(parts[:4]) + '\\'
        parts = parts[4:]
    elif normed[1:2] == ':':
        # absolute path or drive relative path
        offset = 3 if normed[2:3] == '\\' else 2
        root = normed[:offset]
        parts = normed[offset:].split('\\')
    else:
        # relative/drive root relative path
        root = '\\' if normed[:1] == '\\' else ''
        parts = normed.split('\\')

    path = '\\'.join(_sanitize_path_parts(parts))
    return root + path if root or path else '.'


def sanitize_url(url, *, scheme='http'):
    # Prepend protocol-less URLs with `http:` scheme in order to mitigate
    # the number of unwanted failures due to missing protocol
    if url is None:
        return
    elif url.startswith('//'):
        return f'{scheme}:{url}'
    # Fix some common typos seen so far
    COMMON_TYPOS = (
        # https://github.com/ytdl-org/youtube-dl/issues/15649
        (r'^httpss://', r'https://'),
        # https://bx1.be/lives/direct-tv/
        (r'^rmtp([es]?)://', r'rtmp\1://'),
    )
    for mistake, fixup in COMMON_TYPOS:
        if re.match(mistake, url):
            return re.sub(mistake, fixup, url)
    return url


def extract_basic_auth(url):
    parts = urllib.parse.urlsplit(url)
    if parts.username is None:
        return url, None
    url = urllib.parse.urlunsplit(parts._replace(netloc=(
        parts.hostname if parts.port is None
        else f'{parts.hostname}:{parts.port}')))
    auth_payload = base64.b64encode(
        ('{}:{}'.format(parts.username, parts.password or '')).encode())
    return url, f'Basic {auth_payload.decode()}'


def expand_path(s):
    """Expand shell variables and ~"""
    return os.path.expandvars(compat_expanduser(s))


def orderedSet(iterable, *, lazy=False):
    """Remove all duplicates from the input iterable"""
    def _iter():
        seen = []  # Do not use set since the items can be unhashable
        for x in iterable:
            if x not in seen:
                seen.append(x)
                yield x

    return _iter() if lazy else list(_iter())


def _htmlentity_transform(entity_with_semicolon):
    """Transforms an HTML entity to a character."""
    entity = entity_with_semicolon[:-1]

    # Known non-numeric HTML entity
    if entity in html.entities.name2codepoint:
        return chr(html.entities.name2codepoint[entity])

    # TODO: HTML5 allows entities without a semicolon.
    # E.g. '&Eacuteric' should be decoded as 'Éric'.
    if entity_with_semicolon in html.entities.html5:
        return html.entities.html5[entity_with_semicolon]

    mobj = re.match(r'#(x[0-9a-fA-F]+|[0-9]+)', entity)
    if mobj is not None:
        numstr = mobj.group(1)
        if numstr.startswith('x'):
            base = 16
            numstr = f'0{numstr}'
        else:
            base = 10
        # See https://github.com/ytdl-org/youtube-dl/issues/7518
        with contextlib.suppress(ValueError):
            return chr(int(numstr, base))

    # Unknown entity in name, return its literal representation
    return f'&{entity};'


def unescapeHTML(s):
    if s is None:
        return None
    assert isinstance(s, str)

    return re.sub(
        r'&([^&;]+;)', lambda m: _htmlentity_transform(m.group(1)), s)


def escapeHTML(text):
    return (
        text
        .replace('&', '&amp;')
        .replace('<', '&lt;')
        .replace('>', '&gt;')
        .replace('"', '&quot;')
        .replace("'", '&#39;')
    )


class netrc_from_content(netrc.netrc):
    def __init__(self, content):
        self.hosts, self.macros = {}, {}
        with io.StringIO(content) as stream:
            self._parse('-', stream, False)


class Popen(subprocess.Popen):
    if sys.platform == 'win32':
        _startupinfo = subprocess.STARTUPINFO()
        _startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
    else:
        _startupinfo = None

    @staticmethod
    def _fix_pyinstaller_issues(env):
        if not hasattr(sys, '_MEIPASS'):
            return

        # Force spawning independent subprocesses for exes bundled with PyInstaller>=6.10
        # Ref: https://pyinstaller.org/en/v6.10.0/CHANGES.html#incompatible-changes
        #      https://github.com/yt-dlp/yt-dlp/issues/11259
        env['PYINSTALLER_RESET_ENVIRONMENT'] = '1'

        # Restore LD_LIBRARY_PATH when using PyInstaller
        # Ref: https://pyinstaller.org/en/v6.10.0/runtime-information.html#ld-library-path-libpath-considerations
        #      https://github.com/yt-dlp/yt-dlp/issues/4573
        def _fix(key):
            orig = env.get(f'{key}_ORIG')
            if orig is None:
                env.pop(key, None)
            else:
                env[key] = orig

        _fix('LD_LIBRARY_PATH')  # Linux
        _fix('DYLD_LIBRARY_PATH')  # macOS

    def __init__(self, args, *remaining, env=None, text=False, shell=False, **kwargs):
        if env is None:
            env = os.environ.copy()
        self._fix_pyinstaller_issues(env)

        self.__text_mode = kwargs.get('encoding') or kwargs.get('errors') or text or kwargs.get('universal_newlines')
        if text is True:
            kwargs['universal_newlines'] = True  # For 3.6 compatibility
            kwargs.setdefault('encoding', 'utf-8')
            kwargs.setdefault('errors', 'replace')

        if os.name == 'nt' and kwargs.get('executable') is None:
            # Must apply shell escaping if we are trying to run a batch file
            # These conditions should be very specific to limit impact
            if not shell and isinstance(args, list) and args and args[0].lower().endswith(('.bat', '.cmd')):
                shell = True

            if shell:
                if not isinstance(args, str):
                    args = shell_quote(args, shell=True)
                shell = False
                # Set variable for `cmd.exe` newline escaping (see `utils.shell_quote`)
                env['='] = '"^\n\n"'
                args = f'{self.__comspec()} /Q /S /D /V:OFF /E:ON /C "{args}"'

        super().__init__(args, *remaining, env=env, shell=shell, **kwargs, startupinfo=self._startupinfo)

    def __comspec(self):
        comspec = os.environ.get('ComSpec') or os.path.join(
            os.environ.get('SystemRoot', ''), 'System32', 'cmd.exe')
        if os.path.isabs(comspec):
            return comspec
        raise FileNotFoundError('shell not found: neither %ComSpec% nor %SystemRoot% is set')

    def communicate_or_kill(self, *args, **kwargs):
        try:
            return self.communicate(*args, **kwargs)
        except BaseException:  # Including KeyboardInterrupt
            self.kill(timeout=None)
            raise

    def kill(self, *, timeout=0):
        super().kill()
        if timeout != 0:
            self.wait(timeout=timeout)

    @classmethod
    def run(cls, *args, timeout=None, input=None, **kwargs):
        if input is not None and kwargs.get('stdin') is None:
            kwargs['stdin'] = subprocess.PIPE
        with cls(*args, **kwargs) as proc:
            default = '' if proc.__text_mode else b''
            stdout, stderr = proc.communicate_or_kill(input=input, timeout=timeout)
            return stdout or default, stderr or default, proc.returncode


def encodeArgument(s):
    # Legacy code that uses byte strings
    # Uncomment the following line after fixing all post processors
    # assert isinstance(s, str), 'Internal error: %r should be of type %r, is %r' % (s, str, type(s))
    return s if isinstance(s, str) else s.decode('ascii')


_timetuple = collections.namedtuple('Time', ('hours', 'minutes', 'seconds', 'milliseconds'))


def timetuple_from_msec(msec):
    secs, msec = divmod(msec, 1000)
    mins, secs = divmod(secs, 60)
    hrs, mins = divmod(mins, 60)
    return _timetuple(hrs, mins, secs, msec)


def formatSeconds(secs, delim=':', msec=False):
    time = timetuple_from_msec(secs * 1000)
    if time.hours:
        ret = '%d%s%02d%s%02d' % (time.hours, delim, time.minutes, delim, time.seconds)
    elif time.minutes:
        ret = '%d%s%02d' % (time.minutes, delim, time.seconds)
    else:
        ret = '%d' % time.seconds
    return '%s.%03d' % (ret, time.milliseconds) if msec else ret


def bug_reports_message(before=';'):
    from ..update import REPOSITORY

    msg = (f'please report this issue on  https://github.com/{REPOSITORY}/issues?q= , '
           'filling out the appropriate issue template. Confirm you are on the latest version using  yt-dlp -U')

    before = before.rstrip()
    if not before or before.endswith(('.', '!', '?')):
        msg = msg[0].title() + msg[1:]

    return (before + ' ' if before else '') + msg


class YoutubeDLError(Exception):
    """Base exception for YoutubeDL errors."""
    msg = None

    def __init__(self, msg=None):
        if msg is not None:
            self.msg = msg
        elif self.msg is None:
            self.msg = type(self).__name__
        super().__init__(self.msg)


class ExtractorError(YoutubeDLError):
    """Error during info extraction."""

    def __init__(self, msg, tb=None, expected=False, cause=None, video_id=None, ie=None):
        """ tb, if given, is the original traceback (so that it can be printed out).
        If expected is set, this is a normal error message and most likely not a bug in yt-dlp.
        """
        from ..networking.exceptions import network_exceptions
        if sys.exc_info()[0] in network_exceptions:
            expected = True

        self.orig_msg = str(msg)
        self.traceback = tb
        self.expected = expected
        self.cause = cause
        self.video_id = video_id
        self.ie = ie
        self.exc_info = sys.exc_info()  # preserve original exception
        if isinstance(self.exc_info[1], ExtractorError):
            self.exc_info = self.exc_info[1].exc_info
        super().__init__(self.__msg)

    @property
    def __msg(self):
        return ''.join((
            format_field(self.ie, None, '[%s] '),
            format_field(self.video_id, None, '%s: '),
            self.orig_msg,
            format_field(self.cause, None, ' (caused by %r)'),
            '' if self.expected else bug_reports_message()))

    def format_traceback(self):
        return join_nonempty(
            self.traceback and ''.join(traceback.format_tb(self.traceback)),
            self.cause and ''.join(traceback.format_exception(None, self.cause, self.cause.__traceback__)[1:]),
            delim='\n') or None

    def __setattr__(self, name, value):
        super().__setattr__(name, value)
        if getattr(self, 'msg', None) and name not in ('msg', 'args'):
            self.msg = self.__msg or type(self).__name__
            self.args = (self.msg, )  # Cannot be property


class UnsupportedError(ExtractorError):
    def __init__(self, url):
        super().__init__(
            f'Unsupported URL: {url}', expected=True)
        self.url = url


class RegexNotFoundError(ExtractorError):
    """Error when a regex didn't match"""
    pass


class GeoRestrictedError(ExtractorError):
    """Geographic restriction Error exception.

    This exception may be thrown when a video is not available from your
    geographic location due to geographic restrictions imposed by a website.
    """

    def __init__(self, msg, countries=None, **kwargs):
        kwargs['expected'] = True
        super().__init__(msg, **kwargs)
        self.countries = countries


class UserNotLive(ExtractorError):
    """Error when a channel/user is not live"""

    def __init__(self, msg=None, **kwargs):
        kwargs['expected'] = True
        super().__init__(msg or 'The channel is not currently live', **kwargs)


class DownloadError(YoutubeDLError):
    """Download Error exception.

    This exception may be thrown by FileDownloader objects if they are not
    configured to continue on errors. They will contain the appropriate
    error message.
    """

    def __init__(self, msg, exc_info=None):
        """ exc_info, if given, is the original exception that caused the trouble (as returned by sys.exc_info()). """
        super().__init__(msg)
        self.exc_info = exc_info


class EntryNotInPlaylist(YoutubeDLError):
    """Entry not in playlist exception.

    This exception will be thrown by YoutubeDL when a requested entry
    is not found in the playlist info_dict
    """
    msg = 'Entry not found in info'


class SameFileError(YoutubeDLError):
    """Same File exception.

    This exception will be thrown by FileDownloader objects if they detect
    multiple files would have to be downloaded to the same file on disk.
    """
    msg = 'Fixed output name but more than one file to download'

    def __init__(self, filename=None):
        if filename is not None:
            self.msg += f': {filename}'
        super().__init__(self.msg)


class PostProcessingError(YoutubeDLError):
    """Post Processing exception.

    This exception may be raised by PostProcessor's .run() method to
    indicate an error in the postprocessing task.
    """


class DownloadCancelled(YoutubeDLError):
    """ Exception raised when the download queue should be interrupted """
    msg = 'The download was cancelled'


class ExistingVideoReached(DownloadCancelled):
    """ --break-on-existing triggered """
    msg = 'Encountered a video that is already in the archive, stopping due to --break-on-existing'


class RejectedVideoReached(DownloadCancelled):
    """ --break-match-filter triggered """
    msg = 'Encountered a video that did not match filter, stopping due to --break-match-filter'


class MaxDownloadsReached(DownloadCancelled):
    """ --max-downloads limit has been reached. """
    msg = 'Maximum number of downloads reached, stopping due to --max-downloads'


class ReExtractInfo(YoutubeDLError):
    """ Video info needs to be re-extracted. """

    def __init__(self, msg, expected=False):
        super().__init__(msg)
        self.expected = expected


class ThrottledDownload(ReExtractInfo):
    """ Download speed below --throttled-rate. """
    msg = 'The download speed is below throttle limit'

    def __init__(self):
        super().__init__(self.msg, expected=False)


class UnavailableVideoError(YoutubeDLError):
    """Unavailable Format exception.

    This exception will be thrown when a video is requested
    in a format that is not available for that video.
    """
    msg = 'Unable to download video'

    def __init__(self, err=None):
        if err is not None:
            self.msg += f': {err}'
        super().__init__(self.msg)


class ContentTooShortError(YoutubeDLError):
    """Content Too Short exception.

    This exception may be raised by FileDownloader objects when a file they
    download is too small for what the server announced first, indicating
    the connection was probably interrupted.
    """

    def __init__(self, downloaded, expected):
        super().__init__(f'Downloaded {downloaded} bytes, expected {expected} bytes')
        # Both in bytes
        self.downloaded = downloaded
        self.expected = expected


class XAttrMetadataError(YoutubeDLError):
    def __init__(self, code=None, msg='Unknown error'):
        super().__init__(msg)
        self.code = code
        self.msg = msg

        # Parsing code and msg
        if (self.code in (errno.ENOSPC, errno.EDQUOT)
                or 'No space left' in self.msg or 'Disk quota exceeded' in self.msg):
            self.reason = 'NO_SPACE'
        elif self.code == errno.E2BIG or 'Argument list too long' in self.msg:
            self.reason = 'VALUE_TOO_LONG'
        else:
            self.reason = 'NOT_SUPPORTED'


class XAttrUnavailableError(YoutubeDLError):
    pass


class UnsafeExecExpansionError(YoutubeDLError):
    pass


def is_path_like(f):
    return isinstance(f, (str, bytes, os.PathLike))


def extract_timezone(date_str, default=None):
    m = re.search(
        r'''(?x)
            ^.{8,}?                                              # >=8 char non-TZ prefix, if present
            (?P<tz>Z|                                            # just the UTC Z, or
                (?:(?<=.\b\d{4}|\b\d{2}:\d\d)|                   # preceded by 4 digits or hh:mm or
                   (?<!.\b[a-zA-Z]{3}|[a-zA-Z]{4}|..\b\d\d))     # not preceded by 3 alpha word or >= 4 alpha or 2 digits
                   [ ]?                                          # optional space
                (?P<sign>\+|-)                                   # +/-
                (?P<hours>[0-9]{2}):?(?P<minutes>[0-9]{2})       # hh[:]mm
            $)
        ''', date_str)
    timezone = None

    if not m:
        m = re.search(r'\d{1,2}:\d{1,2}(?:\.\d+)?(?P<tz>\s*[A-Z]+)$', date_str)
        timezone = TIMEZONE_NAMES.get(m and m.group('tz').strip())
        if timezone is not None:
            date_str = date_str[:-len(m.group('tz'))]
            timezone = dt.timedelta(hours=timezone)
    else:
        date_str = date_str[:-len(m.group('tz'))]
        if m.group('sign'):
            sign = 1 if m.group('sign') == '+' else -1
            timezone = dt.timedelta(
                hours=sign * int(m.group('hours')),
                minutes=sign * int(m.group('minutes')))

    if timezone is None and default is not NO_DEFAULT:
        timezone = default or dt.timedelta()

    return timezone, date_str


@partial_application
def parse_iso8601(date_str, delimiter='T', timezone=None):
    """ Return a UNIX timestamp from the given date """

    if date_str is None:
        return None

    date_str = re.sub(r'\.[0-9]+', '', date_str)

    timezone, date_str = extract_timezone(date_str, timezone)

    with contextlib.suppress(ValueError, TypeError):
        date_format = f'%Y-%m-%d{delimiter}%H:%M:%S'
        dt_ = dt.datetime.strptime(date_str, date_format) - timezone
        return calendar.timegm(dt_.timetuple())


def date_formats(day_first=True):
    return DATE_FORMATS_DAY_FIRST if day_first else DATE_FORMATS_MONTH_FIRST


def unified_strdate(date_str, day_first=True):
    """Return a string with the date in the format YYYYMMDD"""

    if date_str is None:
        return None
    upload_date = None
    # Replace commas
    date_str = date_str.replace(',', ' ')
    # Remove AM/PM + timezone
    date_str = re.sub(r'(?i)\s*(?:AM|PM)(?:\s+[A-Z]+)?', '', date_str)
    _, date_str = extract_timezone(date_str)

    for expression in date_formats(day_first):
        with contextlib.suppress(ValueError):
            upload_date = dt.datetime.strptime(date_str, expression).strftime('%Y%m%d')
    if upload_date is None:
        timetuple = email.utils.parsedate_tz(date_str)
        if timetuple:
            with contextlib.suppress(ValueError):
                upload_date = dt.datetime(*timetuple[:6]).strftime('%Y%m%d')
    if upload_date is not None:
        return str(upload_date)


@partial_application
def unified_timestamp(date_str, day_first=True, tz_offset=0):
    if not isinstance(date_str, str):
        return None

    date_str = re.sub(r'\s+', ' ', re.sub(
        r'(?i)[,|]|(mon|tues?|wed(nes)?|thu(rs)?|fri|sat(ur)?|sun)(day)?', '', date_str))

    pm_delta = 12 if re.search(r'(?i)PM', date_str) else 0
    timezone, date_str = extract_timezone(
        date_str, default=dt.timedelta(hours=tz_offset) if tz_offset else None)

    # Remove AM/PM + timezone
    date_str = re.sub(r'(?i)\s*(?:AM|PM)(?:\s+[A-Z]+)?', '', date_str)

    # Remove unrecognized timezones from ISO 8601 alike timestamps
    m = re.search(r'\d{1,2}:\d{1,2}(?:\.\d+)?(?P<tz>\s*[A-Z]+)$', date_str)
    if m:
        date_str = date_str[:-len(m.group('tz'))]

    # Python only supports microseconds, so remove nanoseconds
    m = re.search(r'^([0-9]{4,}-[0-9]{1,2}-[0-9]{1,2}T[0-9]{1,2}:[0-9]{1,2}:[0-9]{1,2}\.[0-9]{6})[0-9]+$', date_str)
    if m:
        date_str = m.group(1)

    for expression in date_formats(day_first):
        with contextlib.suppress(ValueError):
            dt_ = dt.datetime.strptime(date_str, expression) - timezone + dt.timedelta(hours=pm_delta)
            return calendar.timegm(dt_.timetuple())

    timetuple = email.utils.parsedate_tz(date_str)
    if timetuple:
        return calendar.timegm(timetuple) + pm_delta * 3600 - int(timezone.total_seconds())


@partial_application
def determine_ext(url, default_ext='unknown_video'):
    if url is None or '.' not in url:
        return default_ext
    guess = url.partition('?')[0].rpartition('.')[2]
    if re.match(r'^[A-Za-z0-9]+$', guess):
        return guess
    # Try extract ext from URLs like http://example.com/foo/bar.mp4/?download
    elif guess.rstrip('/') in KNOWN_EXTENSIONS:
        return guess.rstrip('/')
    else:
        return default_ext


def subtitles_filename(filename, sub_lang, sub_format, expected_real_ext=None):
    return replace_extension(filename, sub_lang + '.' + sub_format, expected_real_ext)


def datetime_from_str(date_str, precision='auto', format='%Y%m%d'):
    R"""
    Return a datetime object from a string.
    Supported format:
        (now|today|yesterday|DATE)([+-]\d+(microsecond|second|minute|hour|day|week|month|year)s?)?

    @param format       strftime format of DATE
    @param precision    Round the datetime object: auto|microsecond|second|minute|hour|day
                        auto: round to the unit provided in date_str (if applicable).
    """
    auto_precision = False
    if precision == 'auto':
        auto_precision = True
        precision = 'microsecond'
    today = datetime_round(dt.datetime.now(dt.timezone.utc), precision)
    if date_str in ('now', 'today'):
        return today
    if date_str == 'yesterday':
        return today - dt.timedelta(days=1)
    match = re.match(
        r'(?P<start>.+)(?P<sign>[+-])(?P<time>\d+)(?P<unit>microsecond|second|minute|hour|day|week|month|year)s?',
        date_str)
    if match is not None:
        start_time = datetime_from_str(match.group('start'), precision, format)
        time = int(match.group('time')) * (-1 if match.group('sign') == '-' else 1)
        unit = match.group('unit')
        if unit == 'month' or unit == 'year':
            new_date = datetime_add_months(start_time, time * 12 if unit == 'year' else time)
            unit = 'day'
        else:
            if unit == 'week':
                unit = 'day'
                time *= 7
            delta = dt.timedelta(**{unit + 's': time})
            new_date = start_time + delta
        if auto_precision:
            return datetime_round(new_date, unit)
        return new_date

    return datetime_round(dt.datetime.strptime(date_str, format), precision)


def date_from_str(date_str, format='%Y%m%d', strict=False):
    R"""
    Return a date object from a string using datetime_from_str

    @param strict  Restrict allowed patterns to "YYYYMMDD" and
                   (now|today|yesterday)(-\d+(day|week|month|year)s?)?
    """
    if strict and not re.fullmatch(r'\d{8}|(now|today|yesterday)(-\d+(day|week|month|year)s?)?', date_str):
        raise ValueError(f'Invalid date format "{date_str}"')
    return datetime_from_str(date_str, precision='microsecond', format=format).date()


def datetime_add_months(dt_, months):
    """Increment/Decrement a datetime object by months."""
    month = dt_.month + months - 1
    year = dt_.year + month // 12
    month = month % 12 + 1
    day = min(dt_.day, calendar.monthrange(year, month)[1])
    return dt_.replace(year, month, day)


def datetime_round(dt_, precision='day'):
    """
    Round a datetime object's time to a specific precision
    """
    if precision == 'microsecond':
        return dt_

    time_scale = 1_000_000
    unit_seconds = {
        'day': 86400,
        'hour': 3600,
        'minute': 60,
        'second': 1,
    }
    roundto = lambda x, n: ((x + n / 2) // n) * n
    timestamp = roundto(calendar.timegm(dt_.timetuple()) + dt_.microsecond / time_scale, unit_seconds[precision])
    return compat_datetime_from_timestamp(timestamp)


def hyphenate_date(date_str):
    """
    Convert a date in 'YYYYMMDD' format to 'YYYY-MM-DD' format"""
    match = re.match(r'^(\d\d\d\d)(\d\d)(\d\d)$', date_str)
    if match is not None:
        return '-'.join(match.groups())
    else:
        return date_str


class DateRange:
    """Represents a time interval between two dates"""

    def __init__(self, start=None, end=None):
        """start and end must be strings in the format accepted by date"""
        if start is not None:
            self.start = date_from_str(start, strict=True)
        else:
            self.start = dt.datetime.min.date()
        if end is not None:
            self.end = date_from_str(end, strict=True)
        else:
            self.end = dt.datetime.max.date()
        if self.start > self.end:
            raise ValueError(f'Date range: "{self}" , the start date must be before the end date')

    @classmethod
    def day(cls, day):
        """Returns a range that only contains the given day"""
        return cls(day, day)

    def __contains__(self, date):
        """Check if the date is in the range"""
        if not isinstance(date, dt.date):
            date = date_from_str(date)
        return self.start <= date <= self.end

    def __repr__(self):
        return f'{__name__}.{type(self).__name__}({self.start.isoformat()!r}, {self.end.isoformat()!r})'

    def __str__(self):
        return f'{self.start} to {self.end}'

    def __eq__(self, other):
        return (isinstance(other, DateRange)
                and self.start == other.start and self.end == other.end)


@functools.cache
def system_identifier():
    python_implementation = platform.python_implementation()
    if python_implementation == 'PyPy' and hasattr(sys, 'pypy_version_info'):
        python_implementation += ' version %d.%d.%d' % sys.pypy_version_info[:3]
    libc_ver = []
    with contextlib.suppress(OSError):  # We may not have access to the executable
        libc_ver = platform.libc_ver()

    return 'Python {} ({} {} {}) - {} ({}{})'.format(
        platform.python_version(),
        python_implementation,
        platform.machine(),
        platform.architecture()[0],
        platform.platform(),
        ssl.OPENSSL_VERSION,
        format_field(join_nonempty(*libc_ver, delim=' '), None, ', %s'),
    )


@functools.cache
def get_windows_version():
    """ Get Windows version. returns () if it's not running on Windows """
    if os.name == 'nt':
        return version_tuple(platform.win32_ver()[1])
    else:
        return ()


def write_string(s, out=None, encoding=None):
    assert isinstance(s, str)
    out = out or sys.stderr
    # `sys.stderr` might be `None` (Ref: https://github.com/pyinstaller/pyinstaller/pull/7217)
    if not out:
        return

    if os.name == 'nt' and supports_terminal_sequences(out):
        s = re.sub(r'([\r\n]+)', r' \1', s)

    enc, buffer = None, out
    # `mode` might be `None` (Ref: https://github.com/yt-dlp/yt-dlp/issues/8816)
    if 'b' in (getattr(out, 'mode', None) or ''):
        enc = encoding or preferredencoding()
    elif hasattr(out, 'buffer'):
        buffer = out.buffer
        enc = encoding or getattr(out, 'encoding', None) or preferredencoding()

    buffer.write(s.encode(enc, 'ignore') if enc else s)
    out.flush()


# TODO: Use global logger
def deprecation_warning(msg, *, printer=None, stacklevel=0, **kwargs):
    if IN_CLI.value:
        if msg in deprecation_warning._cache:
            return
        deprecation_warning._cache.add(msg)
        if printer:
            return printer(f'{msg}{bug_reports_message()}', **kwargs)
        return write_string(f'ERROR: {msg}{bug_reports_message()}\n', **kwargs)
    else:
        import warnings
        warnings.warn(DeprecationWarning(msg), stacklevel=stacklevel + 3)


deprecation_warning._cache = set()


class LockingUnsupportedError(OSError):
    msg = 'File locking is not supported'

    def __init__(self):
        super().__init__(self.msg)


# Cross-platform file locking
if sys.platform == 'win32':
    import ctypes
    import ctypes.wintypes
    import msvcrt

    class OVERLAPPED(ctypes.Structure):
        _fields_ = [
            ('Internal', ctypes.wintypes.LPVOID),
            ('InternalHigh', ctypes.wintypes.LPVOID),
            ('Offset', ctypes.wintypes.DWORD),
            ('OffsetHigh', ctypes.wintypes.DWORD),
            ('hEvent', ctypes.wintypes.HANDLE),
        ]

    kernel32 = ctypes.WinDLL('kernel32')
    LockFileEx = kernel32.LockFileEx
    LockFileEx.argtypes = [
        ctypes.wintypes.HANDLE,     # hFile
        ctypes.wintypes.DWORD,      # dwFlags
        ctypes.wintypes.DWORD,      # dwReserved
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
        ctypes.POINTER(OVERLAPPED),  # Overlapped
    ]
    LockFileEx.restype = ctypes.wintypes.BOOL
    UnlockFileEx = kernel32.UnlockFileEx
    UnlockFileEx.argtypes = [
        ctypes.wintypes.HANDLE,     # hFile
        ctypes.wintypes.DWORD,      # dwReserved
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockLow
        ctypes.wintypes.DWORD,      # nNumberOfBytesToLockHigh
        ctypes.POINTER(OVERLAPPED),  # Overlapped
    ]
    UnlockFileEx.restype = ctypes.wintypes.BOOL
    whole_low = 0xffffffff
    whole_high = 0x7fffffff

    def _lock_file(f, exclusive, block):
        overlapped = OVERLAPPED()
        overlapped.Offset = 0
        overlapped.OffsetHigh = 0
        overlapped.hEvent = 0
        f._lock_file_overlapped_p = ctypes.pointer(overlapped)

        if not LockFileEx(msvcrt.get_osfhandle(f.fileno()),
                          (0x2 if exclusive else 0x0) | (0x0 if block else 0x1),
                          0, whole_low, whole_high, f._lock_file_overlapped_p):
            # NB: No argument form of "ctypes.FormatError" does not work on PyPy
            raise BlockingIOError(f'Locking file failed: {ctypes.FormatError(ctypes.GetLastError())!r}')

    def _unlock_file(f):
        assert f._lock_file_overlapped_p
        handle = msvcrt.get_osfhandle(f.fileno())
        if not UnlockFileEx(handle, 0, whole_low, whole_high, f._lock_file_overlapped_p):
            raise OSError(f'Unlocking file failed: {ctypes.FormatError()!r}')

else:
    try:
        import fcntl

        def _lock_file(f, exclusive, block):
            flags = fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH
            if not block:
                flags |= fcntl.LOCK_NB
            try:
                fcntl.flock(f, flags)
            except BlockingIOError:
                raise
            except OSError:  # AOSP does not have flock()
                fcntl.lockf(f, flags)

        def _unlock_file(f):
            with contextlib.suppress(OSError):
                return fcntl.flock(f, fcntl.LOCK_UN)
            with contextlib.suppress(OSError):
                return fcntl.lockf(f, fcntl.LOCK_UN)  # AOSP does not have flock()
            return fcntl.flock(f, fcntl.LOCK_UN | fcntl.LOCK_NB)  # virtiofs needs LOCK_NB on unlocking

    except ImportError:

        def _lock_file(f, exclusive, block):
            raise LockingUnsupportedError

        def _unlock_file(f):
            raise LockingUnsupportedError


class locked_file:
    locked = False

    def __init__(self, filename, mode, block=True, encoding=None):
        if mode not in {'r', 'rb', 'a', 'ab', 'w', 'wb'}:
            raise NotImplementedError(mode)
        self.mode, self.block = mode, block

        writable = any(f in mode for f in 'wax+')
        readable = any(f in mode for f in 'r+')
        flags = functools.reduce(operator.ior, (
            getattr(os, 'O_CLOEXEC', 0),  # UNIX only
            getattr(os, 'O_BINARY', 0),  # Windows only
            getattr(os, 'O_NOINHERIT', 0),  # Windows only
            os.O_CREAT if writable else 0,  # O_TRUNC only after locking
            os.O_APPEND if 'a' in mode else 0,
            os.O_EXCL if 'x' in mode else 0,
            os.O_RDONLY if not writable else os.O_RDWR if readable else os.O_WRONLY,
        ))

        self.f = os.fdopen(os.open(filename, flags, 0o666), mode, encoding=encoding)

    def __enter__(self):
        exclusive = 'r' not in self.mode
        try:
            _lock_file(self.f, exclusive, self.block)
            self.locked = True
        except OSError:
            self.f.close()
            raise
        if 'w' in self.mode:
            try:
                self.f.truncate()
            except OSError as e:
                if e.errno not in (
                    errno.ESPIPE,  # Illegal seek - expected for FIFO
                    errno.EINVAL,  # Invalid argument - expected for /dev/null
                ):
                    raise
        return self

    def unlock(self):
        if not self.locked:
            return
        try:
            _unlock_file(self.f)
        finally:
            self.locked = False

    def __exit__(self, *_):
        try:
            self.unlock()
        finally:
            self.f.close()

    open = __enter__
    close = __exit__

    def __getattr__(self, attr):
        return getattr(self.f, attr)

    def __iter__(self):
        return iter(self.f)


@functools.cache
def get_filesystem_encoding():
    encoding = sys.getfilesystemencoding()
    return encoding if encoding is not None else 'utf-8'


_WINDOWS_QUOTE_TRANS = str.maketrans({'"': R'\"'})
_CMD_QUOTE_TRANS = str.maketrans({
    # Keep quotes balanced by replacing them with `""` instead of `\\"`
    '"': '""',
    # These require an env-variable `=` containing `"^\n\n"` (set in `utils.Popen`)
    # `=` should be unique since variables containing `=` cannot be set using cmd
    '\n': '%=%',
    '\r': '%=%',
    # Use zero length variable replacement so `%` doesn't get expanded
    # `cd` is always set as long as extensions are enabled (`/E:ON` in `utils.Popen`)
    '%': '%%cd:~,%',
})


def shell_quote(args, *, shell=False):
    args = list(variadic(args))

    if os.name != 'nt':
        return shlex.join(args)

    trans = _CMD_QUOTE_TRANS if shell else _WINDOWS_QUOTE_TRANS
    return ' '.join(
        s if re.fullmatch(r'[\w#$*\-+./:?@\\]+', s, re.ASCII)
        else re.sub(r'(\\+)("|$)', r'\1\1\2', s).translate(trans).join('""')
        for s in args)


def smuggle_url(url, data):
    """ Pass additional data in a URL for internal use. """

    url, idata = unsmuggle_url(url, {})
    data.update(idata)
    sdata = urllib.parse.urlencode(
        {'__youtubedl_smuggle': json.dumps(data)})
    return url + '#' + sdata


def unsmuggle_url(smug_url, default=None):
    if '#__youtubedl_smuggle' not in smug_url:
        return smug_url, default
    url, _, sdata = smug_url.rpartition('#')
    jsond = urllib.parse.parse_qs(sdata)['__youtubedl_smuggle'][0]
    data = json.loads(jsond)
    return url, data


def format_decimal_suffix(num, fmt='%d%s', *, factor=1000):
    """ Formats numbers with decimal sufixes like K, M, etc """
    num, factor = float_or_none(num), float(factor)
    if num is None or num < 0:
        return None
    POSSIBLE_SUFFIXES = 'kMGTPEZY'
    exponent = 0 if num == 0 else min(int(math.log(num, factor)), len(POSSIBLE_SUFFIXES))
    suffix = ['', *POSSIBLE_SUFFIXES][exponent]
    if factor == 1024:
        suffix = {'k': 'Ki', '': ''}.get(suffix, f'{suffix}i')
    converted = num / (factor ** exponent)
    return fmt % (converted, suffix)


def format_bytes(bytes):
    return format_decimal_suffix(bytes, '%.2f%sB', factor=1024) or 'N/A'


def lookup_unit_table(unit_table, s, strict=False):
    num_re = NUMBER_RE if strict else NUMBER_RE.replace(R'\.', '[,.]')
    units_re = '|'.join(re.escape(u) for u in unit_table)
    m = (re.fullmatch if strict else re.match)(
        rf'(?P<num>{num_re})\s*(?P<unit>{units_re})\b', s)
    if not m:
        return None

    num = float(m.group('num').replace(',', '.'))
    mult = unit_table[m.group('unit')]
    return round(num * mult)


def parse_bytes(s):
    """Parse a string indicating a byte quantity into an integer"""
    return lookup_unit_table(
        {u: 1024**i for i, u in enumerate(['', *'KMGTPEZY'])},
        s.upper(), strict=True)


def parse_filesize(s):
    if s is None:
        return None

    # The lower-case forms are of course incorrect and unofficial,
    # but we support those too
    _UNIT_TABLE = {
        'B': 1,
        'b': 1,
        'bytes': 1,
        'KiB': 1024,
        'KB': 1000,
        'kB': 1024,
        'Kb': 1000,
        'kb': 1000,
        'kilobytes': 1000,
        'kibibytes': 1024,
        'MiB': 1024 ** 2,
        'MB': 1000 ** 2,
        'mB': 1024 ** 2,
        'Mb': 1000 ** 2,
        'mb': 1000 ** 2,
        'megabytes': 1000 ** 2,
        'mebibytes': 1024 ** 2,
        'GiB': 1024 ** 3,
        'GB': 1000 ** 3,
        'gB': 1024 ** 3,
        'Gb': 1000 ** 3,
        'gb': 1000 ** 3,
        'gigabytes': 1000 ** 3,
        'gibibytes': 1024 ** 3,
        'TiB': 1024 ** 4,
        'TB': 1000 ** 4,
        'tB': 1024 ** 4,
        'Tb': 1000 ** 4,
        'tb': 1000 ** 4,
        'terabytes': 1000 ** 4,
        'tebibytes': 1024 ** 4,
        'PiB': 1024 ** 5,
        'PB': 1000 ** 5,
        'pB': 1024 ** 5,
        'Pb': 1000 ** 5,
        'pb': 1000 ** 5,
        'petabytes': 1000 ** 5,
        'pebibytes': 1024 ** 5,
        'EiB': 1024 ** 6,
        'EB': 1000 ** 6,
        'eB': 1024 ** 6,
        'Eb': 1000 ** 6,
        'eb': 1000 ** 6,
        'exabytes': 1000 ** 6,
        'exbibytes': 1024 ** 6,
        'ZiB': 1024 ** 7,
        'ZB': 1000 ** 7,
        'zB': 1024 ** 7,
        'Zb': 1000 ** 7,
        'zb': 1000 ** 7,
        'zettabytes': 1000 ** 7,
        'zebibytes': 1024 ** 7,
        'YiB': 1024 ** 8,
        'YB': 1000 ** 8,
        'yB': 1024 ** 8,
        'Yb': 1000 ** 8,
        'yb': 1000 ** 8,
        'yottabytes': 1000 ** 8,
        'yobibytes': 1024 ** 8,
    }

    return lookup_unit_table(_UNIT_TABLE, s)


def parse_count(s):
    if s is None:
        return None

    s = re.sub(r'^[^\d]+\s', '', s).strip()

    if re.match(r'^[\d,.]+$', s):
        return str_to_int(s)

    _UNIT_TABLE = {
        'k': 1000,
        'K': 1000,
        'm': 1000 ** 2,
        'M': 1000 ** 2,
        'kk': 1000 ** 2,
        'KK': 1000 ** 2,
        'b': 1000 ** 3,
        'B': 1000 ** 3,
    }

    ret = lookup_unit_table(_UNIT_TABLE, s)
    if ret is not None:
        return ret

    mobj = re.match(r'([\d,.]+)(?:$|\s)', s)
    if mobj:
        return str_to_int(mobj.group(1))


def parse_resolution(s, *, lenient=False):
    if s is None:
        return {}

    if lenient:
        mobj = re.search(r'(?P<w>\d+)\s*[xX×,]\s*(?P<h>\d+)', s)
    else:
        mobj = re.search(r'(?<![a-zA-Z0-9])(?P<w>\d+)\s*[xX×,]\s*(?P<h>\d+)(?![a-zA-Z0-9])', s)
    if mobj:
        return {
            'width': int(mobj.group('w')),
            'height': int(mobj.group('h')),
        }

    mobj = re.search(r'(?<![a-zA-Z0-9])(\d+)[pPiI](?![a-zA-Z0-9])', s)
    if mobj:
        return {'height': int(mobj.group(1))}

    mobj = re.search(r'\b([48])[kK]\b', s)
    if mobj:
        return {'height': int(mobj.group(1)) * 540}

    if lenient:
        mobj = re.search(r'(?<!\d)(\d{2,5})w(?![a-zA-Z0-9])', s)
        if mobj:
            return {'width': int(mobj.group(1))}

    return {}


def parse_bitrate(s):
    if not isinstance(s, str):
        return
    mobj = re.search(r'\b(\d+)\s*kbps', s)
    if mobj:
        return int(mobj.group(1))


def month_by_name(name, lang='en'):
    """ Return the number of a month by (locale-independently) English name """

    month_names = MONTH_NAMES.get(lang, MONTH_NAMES['en'])

    try:
        return month_names.index(name) + 1
    except ValueError:
        return None


def month_by_abbreviation(abbrev):
    """ Return the number of a month by (locale-independently) English
        abbreviations """

    try:
        return [s[:3] for s in ENGLISH_MONTH_NAMES].index(abbrev) + 1
    except ValueError:
        return None


def fix_xml_ampersands(xml_str):
    """Replace all the '&' by '&amp;' in XML"""
    return re.sub(
        r'&(?!amp;|lt;|gt;|apos;|quot;|#x[0-9a-fA-F]{,4};|#[0-9]{,4};)',
        '&amp;',
        xml_str)


def setproctitle(title):
    assert isinstance(title, str)

    # Workaround for https://github.com/yt-dlp/yt-dlp/issues/4541
    try:
        import ctypes
    except ImportError:
        return

    try:
        libc = ctypes.cdll.LoadLibrary('libc.so.6')
    except OSError:
        return
    except TypeError:
        # LoadLibrary in Windows Python 2.7.13 only expects
        # a bytestring, but since unicode_literals turns
        # every string into a unicode string, it fails.
        return
    title_bytes = title.encode()
    buf = ctypes.create_string_buffer(len(title_bytes))
    buf.value = title_bytes
    try:
        # PR_SET_NAME = 15      Ref: /usr/include/linux/prctl.h
        libc.prctl(15, buf, 0, 0, 0)
    except AttributeError:
        return  # Strange libc, just skip this


def remove_start(s, start):
    return s[len(start):] if s is not None and s.startswith(start) else s


def remove_end(s, end):
    return s[:-len(end)] if s is not None and end and s.endswith(end) else s


def remove_quotes(s):
    if s is None or len(s) < 2:
        return s
    for quote in ('"', "'"):
        if s[0] == quote and s[-1] == quote:
            return s[1:-1]
    return s


def get_domain(url):
    """
    This implementation is inconsistent, but is kept for compatibility.
    Use this only for "webpage_url_domain"
    """
    return remove_start(urllib.parse.urlparse(url).netloc, 'www.') or None


def url_basename(url):
    path = urllib.parse.urlparse(url).path
    return path.strip('/').split('/')[-1]


def base_url(url):
    return re.match(r'https?://[^?#]+/', url).group()


@partial_application
def urljoin(base, path):
    if isinstance(path, bytes):
        path = path.decode()
    if not isinstance(path, str) or not path:
        return None
    if re.match(r'(?:[a-zA-Z][a-zA-Z0-9+-.]*:)?//', path):
        return path
    if isinstance(base, bytes):
        base = base.decode()
    if not isinstance(base, str) or not re.match(
            r'^(?:https?:)?//', base):
        return None
    return urllib.parse.urljoin(base, path)


@partial_application
def int_or_none(v, scale=1, default=None, get_attr=None, invscale=1, base=None):
    if get_attr and v is not None:
        v = getattr(v, get_attr, None)
    if invscale == 1 and scale < 1:
        invscale = int(1 / scale)
        scale = 1
    try:
        return (int(v) if base is None else int(v, base=base)) * invscale // scale
    except (ValueError, TypeError, OverflowError):
        return default


def str_or_none(v, default=None):
    return default if v is None else str(v)


def str_to_int(int_str):
    """ A more relaxed version of int_or_none """
    if isinstance(int_str, int):
        return int_str
    elif isinstance(int_str, str):
        int_str = re.sub(r'[,\.\+]', '', int_str)
        return int_or_none(int_str)


@partial_application
def float_or_none(v, scale=1, invscale=1, default=None):
    if v is None:
        return default
    if invscale == 1 and scale < 1:
        invscale = int(1 / scale)
        scale = 1
    try:
        return float(v) * invscale / scale
    except (ValueError, TypeError):
        return default


def bool_or_none(v, default=None):
    return v if isinstance(v, bool) else default


def strip_or_none(v, default=None):
    return v.strip() if isinstance(v, str) else default


def url_or_none(url):
    if not url or not isinstance(url, str):
        return None
    url = url.strip()
    return url if re.match(r'(?:(?:https?|rt(?:m(?:pt?[es]?|fp)|sp[su]?)|mms|ftps?|wss?):)?//', url) else None


def strftime_or_none(timestamp, date_format='%Y%m%d', default=None):
    datetime_object = None
    try:
        if isinstance(timestamp, (int, float)):  # unix timestamp
            datetime_object = compat_datetime_from_timestamp(timestamp)
        elif isinstance(timestamp, str):  # assume YYYYMMDD
            datetime_object = dt.datetime.strptime(timestamp, '%Y%m%d')
        date_format = re.sub(  # Support %s on windows
            r'(?<!%)(%%)*%s', rf'\g<1>{int(datetime_object.timestamp())}', date_format)
        return datetime_object.strftime(date_format)
    except (ValueError, TypeError, AttributeError, OverflowError, OSError):
        return default


def parse_duration(s):
    if not isinstance(s, str):
        return None
    s = s.strip()
    if not s:
        return None

    days, hours, mins, secs, ms = [None] * 5
    m = re.match(r'''(?x)
            (?P<before_secs>
                (?:(?:(?P<days>[0-9]+):)?(?P<hours>[0-9]+):)?(?P<mins>[0-9]+):)?
            (?P<secs>(?(before_secs)[0-9]{1,2}|[0-9]+))
            (?P<ms>[.:][0-9]+)?Z?$
        ''', s)
    if m:
        days, hours, mins, secs, ms = m.group('days', 'hours', 'mins', 'secs', 'ms')
    else:
        m = re.match(
            r'''(?ix)(?:P?
                (?:
                    [0-9]+\s*y(?:ears?)?,?\s*
                )?
                (?:
                    [0-9]+\s*m(?:onths?)?,?\s*
                )?
                (?:
                    [0-9]+\s*w(?:eeks?)?,?\s*
                )?
                (?:
                    (?P<days>[0-9]+)\s*d(?:ays?)?,?\s*
                )?
                T)?
                (?:
                    (?P<hours>[0-9]+)\s*h(?:(?:ou)?rs?)?,?\s*
                )?
                (?:
                    (?P<mins>[0-9]+)\s*m(?:in(?:ute)?s?)?,?\s*
                )?
                (?:
                    (?P<secs>[0-9]+)(?P<ms>\.[0-9]+)?\s*s(?:ec(?:ond)?s?)?\s*
                )?Z?$''', s)
        if m:
            days, hours, mins, secs, ms = m.groups()
        else:
            m = re.match(r'(?i)(?:(?P<hours>[0-9.]+)\s*(?:hours?)|(?P<mins>[0-9.]+)\s*(?:mins?\.?|minutes?)\s*)Z?$', s)
            if m:
                hours, mins = m.groups()
            else:
                return None

    if ms:
        ms = ms.replace(':', '.')
    return sum(float(part or 0) * mult for part, mult in (
        (days, 86400), (hours, 3600), (mins, 60), (secs, 1), (ms, 1)))


def _change_extension(prepend, filename, ext, expected_real_ext=None, *, _allowed_exts=()):
    name, real_ext = os.path.splitext(filename)

    if not expected_real_ext or real_ext[1:] == expected_real_ext:
        filename = name
        if prepend and real_ext:
            _UnsafeExtensionError.sanitize_extension(ext, prepend=True, _allowed_exts=_allowed_exts)
            return f'{filename}.{ext}{real_ext}'

    return f'{filename}.{_UnsafeExtensionError.sanitize_extension(ext, _allowed_exts=_allowed_exts)}'


prepend_extension = functools.partial(_change_extension, True)
replace_extension = functools.partial(_change_extension, False)


def check_executable(exe, args=[]):
    """ Checks if the given binary is installed somewhere in PATH, and returns its name.
    args can be a list of arguments for a short output (like -version) """
    try:
        Popen.run([exe, *args], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    except OSError:
        return False
    return exe


def _get_exe_version_output(exe, args, ignore_return_code=False):
    try:
        # STDIN should be redirected too. On UNIX-like systems, ffmpeg triggers
        # SIGTTOU if yt-dlp is run in the background.
        # See https://github.com/ytdl-org/youtube-dl/issues/955#issuecomment-209789656
        stdout, _, ret = Popen.run([encodeArgument(exe), *args], text=True,
                                   stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
        if not ignore_return_code and ret:
            return None
    except OSError:
        return False
    return stdout


def detect_exe_version(output, version_re=None, unrecognized='present'):
    assert isinstance(output, str)
    if version_re is None:
        version_re = r'version\s+([-0-9._a-zA-Z]+)'
    m = re.search(version_re, output)
    if m:
        return m.group(1)
    else:
        return unrecognized


def get_exe_version(exe, args=['--version'],
                    version_re=None, unrecognized=('present', 'broken')):
    """ Returns the version of the specified executable,
    or False if the executable is not present """
    unrecognized = variadic(unrecognized)
    assert len(unrecognized) in (1, 2)
    out = _get_exe_version_output(exe, args)
    if out is None:
        return unrecognized[-1]
    return out and detect_exe_version(out, version_re, unrecognized[0])


def frange(start=0, stop=None, step=1):
    """Float range"""
    if stop is None:
        start, stop = 0, start
    sign = [-1, 1][step > 0] if step else 0
    while sign * start < sign * stop:
        yield start
        start += step


class LazyList(collections.abc.Sequence):
    """Lazy immutable list from an iterable
    Note that slices of a LazyList are lists and not LazyList"""

    class IndexError(IndexError):  # noqa: A001
        pass

    def __init__(self, iterable, *, reverse=False, _cache=None):
        self._iterable = iter(iterable)
        self._cache = [] if _cache is None else _cache
        self._reversed = reverse

    def __iter__(self):
        if self._reversed:
            # We need to consume the entire iterable to iterate in reverse
            yield from self.exhaust()
            return
        yield from self._cache
        for item in self._iterable:
            self._cache.append(item)
            yield item

    def _exhaust(self):
        self._cache.extend(self._iterable)
        self._iterable = []  # Discard the emptied iterable to make it pickle-able
        return self._cache

    def exhaust(self):
        """Evaluate the entire iterable"""
        return self._exhaust()[::-1 if self._reversed else 1]

    @staticmethod
    def _reverse_index(x):
        return None if x is None else ~x

    def __getitem__(self, idx):
        if isinstance(idx, slice):
            if self._reversed:
                idx = slice(self._reverse_index(idx.start), self._reverse_index(idx.stop), -(idx.step or 1))
            start, stop, step = idx.start, idx.stop, idx.step or 1
        elif isinstance(idx, int):
            if self._reversed:
                idx = self._reverse_index(idx)
            start, stop, step = idx, idx, 0
        else:
            raise TypeError('indices must be integers or slices')
        if ((start or 0) < 0 or (stop or 0) < 0
                or (start is None and step < 0)
                or (stop is None and step > 0)):
            # We need to consume the entire iterable to be able to slice from the end
            # Obviously, never use this with infinite iterables
            self._exhaust()
            try:
                return self._cache[idx]
            except IndexError as e:
                raise self.IndexError(e) from e
        n = max(start or 0, stop or 0) - len(self._cache) + 1
        if n > 0:
            self._cache.extend(itertools.islice(self._iterable, n))
        try:
            return self._cache[idx]
        except IndexError as e:
            raise self.IndexError(e) from e

    def __bool__(self):
        try:
            self[-1] if self._reversed else self[0]
        except self.IndexError:
            return False
        return True

    def __len__(self):
        self._exhaust()
        return len(self._cache)

    def __reversed__(self):
        return type(self)(self._iterable, reverse=not self._reversed, _cache=self._cache)

    def __copy__(self):
        return type(self)(self._iterable, reverse=self._reversed, _cache=self._cache)

    def __repr__(self):
        # repr and str should mimic a list. So we exhaust the iterable
        return repr(self.exhaust())

    def __str__(self):
        return repr(self.exhaust())


class PagedList:

    class IndexError(IndexError):  # noqa: A001
        pass

    def __len__(self):
        # This is only useful for tests
        return len(self.getslice())

    def __init__(self, pagefunc, pagesize, use_cache=True):
        self._pagefunc = pagefunc
        self._pagesize = pagesize
        self._pagecount = float('inf')
        self._use_cache = use_cache
        self._cache = {}

    def getpage(self, pagenum):
        page_results = self._cache.get(pagenum)
        if page_results is None:
            page_results = [] if pagenum > self._pagecount else list(self._pagefunc(pagenum))
        if self._use_cache:
            self._cache[pagenum] = page_results
        return page_results

    def getslice(self, start=0, end=None):
        return list(self._getslice(start, end))

    def _getslice(self, start, end):
        raise NotImplementedError('This method must be implemented by subclasses')

    def __getitem__(self, idx):
        assert self._use_cache, 'Indexing PagedList requires cache'
        if not isinstance(idx, int) or idx < 0:
            raise TypeError('indices must be non-negative integers')
        entries = self.getslice(idx, idx + 1)
        if not entries:
            raise self.IndexError
        return entries[0]

    def __bool__(self):
        return bool(self.getslice(0, 1))


class OnDemandPagedList(PagedList):
    """Download pages until a page with less than maximum results"""

    def _getslice(self, start, end):
        for pagenum in itertools.count(start // self._pagesize):
            firstid = pagenum * self._pagesize
            nextfirstid = pagenum * self._pagesize + self._pagesize
            if start >= nextfirstid:
                continue

            startv = (
                start % self._pagesize
                if firstid <= start < nextfirstid
                else 0)
            endv = (
                ((end - 1) % self._pagesize) + 1
                if (end is not None and firstid <= end <= nextfirstid)
                else None)

            try:
                page_results = self.getpage(pagenum)
            except Exception:
                self._pagecount = pagenum - 1
                raise
            if startv != 0 or endv is not None:
                page_results = page_results[startv:endv]
            yield from page_results

            # A little optimization - if current page is not "full", ie. does
            # not contain page_size videos then we can assume that this page
            # is the last one - there are no more ids on further pages -
            # i.e. no need to query again.
            if len(page_results) + startv < self._pagesize:
                break

            # If we got the whole page, but the next page is not interesting,
            # break out early as well
            if end == nextfirstid:
                break


class InAdvancePagedList(PagedList):
    """PagedList with total number of pages known in advance"""

    def __init__(self, pagefunc, pagecount, pagesize):
        PagedList.__init__(self, pagefunc, pagesize, True)
        self._pagecount = pagecount

    def _getslice(self, start, end):
        start_page = start // self._pagesize
        end_page = self._pagecount if end is None else min(self._pagecount, end // self._pagesize + 1)
        skip_elems = start - start_page * self._pagesize
        only_more = None if end is None else end - start
        for pagenum in range(start_page, end_page):
            page_results = self.getpage(pagenum)
            if skip_elems:
                page_results = page_results[skip_elems:]
                skip_elems = None
            if only_more is not None:
                if len(page_results) < only_more:
                    only_more -= len(page_results)
                else:
                    yield from page_results[:only_more]
                    break
            yield from page_results


class PlaylistEntries:
    MissingEntry = object()
    is_exhausted = False

    def __init__(self, ydl, info_dict):
        self.ydl = ydl

        # _entries must be assigned now since infodict can change during iteration
        entries = info_dict.get('entries')
        if entries is None:
            raise EntryNotInPlaylist('There are no entries')
        elif isinstance(entries, list):
            self.is_exhausted = True

        requested_entries = info_dict.get('requested_entries')
        self.is_incomplete = requested_entries is not None
        if self.is_incomplete:
            assert self.is_exhausted
            self._entries = [self.MissingEntry] * max(requested_entries or [0])
            for i, entry in zip(requested_entries, entries):  # noqa: B905
                self._entries[i - 1] = entry
        elif isinstance(entries, (list, PagedList, LazyList)):
            self._entries = entries
        else:
            self._entries = LazyList(entries)

    PLAYLIST_ITEMS_RE = re.compile(r'''(?x)
        (?P<start>[+-]?\d+)?
        (?P<range>[:-]
            (?P<end>[+-]?\d+|inf(?:inite)?)?
            (?::(?P<step>[+-]?\d+))?
        )?''')

    @classmethod
    def parse_playlist_items(cls, string):
        for segment in string.split(','):
            if not segment:
                raise ValueError('There is two or more consecutive commas')
            mobj = cls.PLAYLIST_ITEMS_RE.fullmatch(segment)
            if not mobj:
                raise ValueError(f'{segment!r} is not a valid specification')
            start, end, step, has_range = mobj.group('start', 'end', 'step', 'range')
            if int_or_none(step) == 0:
                raise ValueError(f'Step in {segment!r} cannot be zero')
            yield slice(int_or_none(start), float_or_none(end), int_or_none(step)) if has_range else int(start)

    def get_requested_items(self):
        playlist_items = self.ydl.params.get('playlist_items')
        playlist_start = self.ydl.params.get('playliststart', 1)
        playlist_end = self.ydl.params.get('playlistend')
        # For backwards compatibility, interpret -1 as whole list
        if playlist_end in (-1, None):
            playlist_end = ''
        if not playlist_items:
            playlist_items = f'{playlist_start}:{playlist_end}'
        elif playlist_start != 1 or playlist_end:
            self.ydl.report_warning('Ignoring playliststart and playlistend because playlistitems was given', only_once=True)

        for index in self.parse_playlist_items(playlist_items):
            for i, entry in self[index]:
                yield i, entry
                if not entry:
                    continue
                try:
                    # The item may have just been added to archive. Don't break due to it
                    if not self.ydl.params.get('lazy_playlist'):
                        # TODO: Add auto-generated fields
                        self.ydl._match_entry(entry, incomplete=True, silent=True)
                except (ExistingVideoReached, RejectedVideoReached):
                    return

    def get_full_count(self):
        if self.is_exhausted and not self.is_incomplete:
            return len(self)
        elif isinstance(self._entries, InAdvancePagedList):
            if self._entries._pagesize == 1:
                return self._entries._pagecount

    @functools.cached_property
    def _getter(self):
        if isinstance(self._entries, list):
            def get_entry(i):
                try:
                    entry = self._entries[i]
                except IndexError:
                    entry = self.MissingEntry
                    if not self.is_incomplete:
                        raise self.IndexError
                if entry is self.MissingEntry:
                    raise EntryNotInPlaylist(f'Entry {i + 1} cannot be found')
                return entry
        else:
            def get_entry(i):
                try:
                    return type(self.ydl)._handle_extraction_exceptions(lambda _, i: self._entries[i])(self.ydl, i)
                except (LazyList.IndexError, PagedList.IndexError):
                    raise self.IndexError
        return get_entry

    def __getitem__(self, idx):
        if isinstance(idx, int):
            idx = slice(idx, idx)

        # NB: PlaylistEntries[1:10] => (0, 1, ... 9)
        step = 1 if idx.step is None else idx.step
        if idx.start is None:
            start = 0 if step > 0 else len(self) - 1
        else:
            start = idx.start - 1 if idx.start >= 0 else len(self) + idx.start

        # NB: Do not call len(self) when idx == [:]
        if idx.stop is None:
            stop = 0 if step < 0 else float('inf')
        else:
            stop = idx.stop - 1 if idx.stop >= 0 else len(self) + idx.stop
        stop += [-1, 1][step > 0]

        for i in frange(start, stop, step):
            if i < 0:
                continue
            try:
                entry = self._getter(i)
            except self.IndexError:
                self.is_exhausted = True
                if step > 0:
                    break
                continue
            yield i + 1, entry

    def __len__(self):
        return len(tuple(self[:]))

    class IndexError(IndexError):  # noqa: A001
        pass


def uppercase_escape(s):
    unicode_escape = codecs.getdecoder('unicode_escape')
    return re.sub(
        r'\\U[0-9a-fA-F]{8}',
        lambda m: unicode_escape(m.group(0))[0],
        s)


def lowercase_escape(s):
    unicode_escape = codecs.getdecoder('unicode_escape')
    return re.sub(
        r'\\u[0-9a-fA-F]{4}',
        lambda m: unicode_escape(m.group(0))[0],
        s)


def parse_qs(url, **kwargs):
    return urllib.parse.parse_qs(urllib.parse.urlparse(url).query, **kwargs)


def read_batch_urls(batch_fd):
    def fixup(url):
        if not isinstance(url, str):
            url = url.decode('utf-8', 'replace')
        BOM_UTF8 = ('\xef\xbb\xbf', '\ufeff')
        for bom in BOM_UTF8:
            if url.startswith(bom):
                url = url[len(bom):]
        url = url.lstrip()
        if not url or url.startswith(('#', ';', ']')):
            return False
        # "#" cannot be stripped out since it is part of the URI
        # However, it can be safely stripped out if following a whitespace
        return re.split(r'\s#', url, maxsplit=1)[0].rstrip()

    with contextlib.closing(batch_fd) as fd:
        return [url for url in map(fixup, fd) if url]


def urlencode_postdata(*args, **kargs):
    return urllib.parse.urlencode(*args, **kargs).encode('ascii')


@partial_application
def update_url(url, *, query_update=None, **kwargs):
    """Replace URL components specified by kwargs
       @param url           str or parse url tuple
       @param query_update  update query
       @returns             str
    """
    if isinstance(url, str):
        if not kwargs and not query_update:
            return url
        else:
            url = urllib.parse.urlparse(url)
    if query_update:
        assert 'query' not in kwargs, 'query_update and query cannot be specified at the same time'
        kwargs['query'] = urllib.parse.urlencode({
            **urllib.parse.parse_qs(url.query),
            **query_update,
        }, True)
    return urllib.parse.urlunparse(url._replace(**kwargs))


@partial_application
def update_url_query(url, query):
    return update_url(url, query_update=query)


def _multipart_encode_impl(data, boundary):
    content_type = f'multipart/form-data; boundary={boundary}'

    out = b''
    for k, v in data.items():
        out += b'--' + boundary.encode('ascii') + b'\r\n'
        if isinstance(k, str):
            k = k.encode()
        if isinstance(v, str):
            v = v.encode()
        # RFC 2047 requires non-ASCII field names to be encoded, while RFC 7578
        # suggests sending UTF-8 directly. Firefox sends UTF-8, too
        content = b'Content-Disposition: form-data; name="' + k + b'"\r\n\r\n' + v + b'\r\n'
        if boundary.encode('ascii') in content:
            raise ValueError('Boundary overlaps with data')
        out += content

    out += b'--' + boundary.encode('ascii') + b'--\r\n'

    return out, content_type


def multipart_encode(data, boundary=None):
    """
    Encode a dict to RFC 7578-compliant form-data

    data:
        A dict where keys and values can be either Unicode or bytes-like
        objects.
    boundary:
        If specified a Unicode object, it's used as the boundary. Otherwise
        a random boundary is generated.

    Reference: https://tools.ietf.org/html/rfc7578
    """
    has_specified_boundary = boundary is not None

    while True:
        if boundary is None:
            boundary = '---------------' + str(random.randrange(0x0fffffff, 0xffffffff))

        try:
            out, content_type = _multipart_encode_impl(data, boundary)
            break
        except ValueError:
            if has_specified_boundary:
                raise
            boundary = None

    return out, content_type


def is_iterable_like(x, allowed_types=collections.abc.Iterable, blocked_types=NO_DEFAULT):
    if blocked_types is NO_DEFAULT:
        blocked_types = (str, bytes, collections.abc.Mapping)
    return isinstance(x, allowed_types) and not isinstance(x, blocked_types)


def variadic(x, allowed_types=NO_DEFAULT):
    if not isinstance(allowed_types, (tuple, type)):
        deprecation_warning('allowed_types should be a tuple or a type')
        allowed_types = tuple(allowed_types)
    return x if is_iterable_like(x, blocked_types=allowed_types) else (x, )


def try_call(*funcs, expected_type=None, args=[], kwargs={}):
    for f in funcs:
        try:
            val = f(*args, **kwargs)
        except (AttributeError, KeyError, TypeError, IndexError, ValueError, ZeroDivisionError):
            pass
        else:
            if expected_type is None or isinstance(val, expected_type):
                return val


def try_get(src, getter, expected_type=None):
    return try_call(*variadic(getter), args=(src,), expected_type=expected_type)


def filter_dict(dct, cndn=lambda _, v: v is not None):
    return {k: v for k, v in dct.items() if cndn(k, v)}


def merge_dicts(*dicts):
    merged = {}
    for a_dict in dicts:
        for k, v in a_dict.items():
            if ((v is not None and k not in merged)
                    or (isinstance(v, str) and merged[k] == '')):
                merged[k] = v
    return merged


def encode_compat_str(string, encoding=preferredencoding(), errors='strict'):
    return string if isinstance(string, str) else str(string, encoding, errors)


US_RATINGS = {
    'G': 0,
    'PG': 10,
    'PG-13': 13,
    'R': 16,
    'NC': 18,
}


TV_PARENTAL_GUIDELINES = {
    'TV-Y': 0,
    'TV-Y7': 7,
    'TV-G': 0,
    'TV-PG': 0,
    'TV-14': 14,
    'TV-MA': 17,
}


def parse_age_limit(s):
    # isinstance(False, int) is True. So type() must be used instead
    if type(s) is int:  # noqa: E721
        return s if 0 <= s <= 21 else None
    elif not isinstance(s, str):
        return None
    m = re.match(r'^(?P<age>\d{1,2})\+?$', s)
    if m:
        return int(m.group('age'))
    s = s.upper()
    if s in US_RATINGS:
        return US_RATINGS[s]
    m = re.match(r'^TV[_-]?({})$'.format('|'.join(k[3:] for k in TV_PARENTAL_GUIDELINES)), s)
    if m:
        return TV_PARENTAL_GUIDELINES['TV-' + m.group(1)]
    return None


def strip_jsonp(code):
    return re.sub(
        r'''(?sx)^
            (?:window\.)?(?P<func_name>[a-zA-Z0-9_.$]*)
            (?:\s*&&\s*(?P=func_name))?
            \s*\(\s*(?P<callback_data>.*)\);?
            \s*?(?://[^\n]*)*$''',
        r'\g<callback_data>', code)


def js_to_json(code, vars={}, *, strict=False):
    # vars is a dict of var, val pairs to substitute
    STRING_QUOTES = '\'"`'
    STRING_RE = '|'.join(rf'{q}(?:\\.|[^\\{q}])*{q}' for q in STRING_QUOTES)
    COMMENT_RE = r'/\*(?:(?!\*/).)*?\*/|//[^\n]*\n'
    SKIP_RE = fr'\s*(?:{COMMENT_RE})?\s*'
    INTEGER_TABLE = (
        (fr'(?s)^(0[xX][0-9a-fA-F]+){SKIP_RE}:?$', 16),
        (fr'(?s)^(0+[0-7]+){SKIP_RE}:?$', 8),
    )

    def process_escape(match):
        JSON_PASSTHROUGH_ESCAPES = R'"\bfnrtu'
        escape = match.group(1) or match.group(2)

        return (Rf'\{escape}' if escape in JSON_PASSTHROUGH_ESCAPES
                else R'\u00' if escape == 'x'
                else '' if escape == '\n'
                else escape)

    def template_substitute(match):
        evaluated = js_to_json(match.group(1), vars, strict=strict)
        if evaluated[0] == '"':
            with contextlib.suppress(json.JSONDecodeError):
                return json.loads(evaluated)
        return evaluated

    def fix_kv(m):
        v = m.group(0)
        if v in ('true', 'false', 'null'):
            return v
        elif v in ('undefined', 'void 0'):
            return 'null'
        elif v.startswith(('/*', '//', '!')) or v == ',':
            return ''

        if v[0] in STRING_QUOTES:
            v = re.sub(r'(?s)\${([^}]+)}', template_substitute, v[1:-1]) if v[0] == '`' else v[1:-1]
            escaped = re.sub(r'(?s)(")|\\(.)', process_escape, v)
            return f'"{escaped}"'

        for regex, base in INTEGER_TABLE:
            im = re.match(regex, v)
            if im:
                i = int(im.group(1), base)
                return f'"{i}":' if v.endswith(':') else str(i)

        if v in vars:
            try:
                if not strict:
                    json.loads(vars[v])
            except json.JSONDecodeError:
                return json.dumps(vars[v])
            else:
                return vars[v]

        if not strict:
            return f'"{v}"'

        raise ValueError(f'Unknown value: {v}')

    def create_map(mobj):
        return json.dumps(dict(json.loads(js_to_json(mobj.group(1) or '[]', vars=vars))))

    code = re.sub(r'(?:new\s+)?Array\((.*?)\)', r'[\g<1>]', code)
    code = re.sub(r'new Map\((\[.*?\])?\)', create_map, code)
    if not strict:
        code = re.sub(rf'new Date\(({STRING_RE})\)', r'\g<1>', code)
        code = re.sub(r'new \w+\((.*?)\)', lambda m: json.dumps(m.group(0)), code)
        code = re.sub(r'parseInt\([^\d]+(\d+)[^\d]+\)', r'\1', code)
        code = re.sub(r'\(function\([^)]*\)\s*\{[^}]*\}\s*\)\s*\(\s*(["\'][^)]*["\'])\s*\)', r'\1', code)

    return re.sub(rf'''(?sx)
        {STRING_RE}|
        {COMMENT_RE}|,(?={SKIP_RE}[\]}}])|
        void\s0|(?:(?<![0-9])[eE]|[a-df-zA-DF-Z_$])[.a-zA-Z_$0-9]*|
        \b(?:0[xX][0-9a-fA-F]+|(?<!\.)0+[0-7]+)(?:{SKIP_RE}:)?|
        [0-9]+(?={SKIP_RE}:)|
        !+
        ''', fix_kv, code)


def qualities(quality_ids):
    """ Get a numeric quality value out of a list of possible values """
    def q(qid):
        try:
            return quality_ids.index(qid)
        except ValueError:
            return -1
    return q


POSTPROCESS_WHEN = ('pre_process', 'after_filter', 'video', 'before_dl', 'post_process', 'after_move', 'after_video', 'playlist')


DEFAULT_OUTTMPL = {
    'default': '%(title)s [%(id)s].%(ext)s',
    'chapter': '%(title)s - %(section_number)03d %(section_title)s [%(id)s].%(ext)s',
}
OUTTMPL_TYPES = {
    'chapter': None,
    'subtitle': None,
    'thumbnail': None,
    'description': 'description',
    'annotation': 'annotations.xml',
    'infojson': 'info.json',
    'link': None,
    'pl_video': None,
    'pl_thumbnail': None,
    'pl_description': 'description',
    'pl_infojson': 'info.json',
}

# As of [1] format syntax is:
#  %[mapping_key][conversion_flags][minimum_width][.precision][length_modifier]type
# 1. https://docs.python.org/2/library/stdtypes.html#string-formatting
STR_FORMAT_RE_TMPL = r'''(?x)
    (?<!%)(?P<prefix>(?:%%)*)
    %
    (?P<has_key>\((?P<key>{0})\))?
    (?P<format>
        (?P<conversion>[#0\-+ ]+)?
        (?P<min_width>\d+)?
        (?P<precision>\.\d+)?
        (?P<len_mod>[hlL])?  # unused in python
        {1}  # conversion type
    )
'''


STR_FORMAT_TYPES = 'diouxXeEfFgGcrsa'


def limit_length(s, length):
    """ Add ellipses to overly long strings """
    if s is None:
        return None
    ELLIPSES = '...'
    if len(s) > length:
        return s[:length - len(ELLIPSES)] + ELLIPSES
    return s


def version_tuple(v, *, lenient=False):
    parse = int_or_none(default=-1) if lenient else int
    return tuple(parse(e) for e in re.split(r'[-.]', v))


def is_outdated_version(version, limit, assume_new=True):
    if not version:
        return not assume_new
    try:
        return version_tuple(version) < version_tuple(limit)
    except ValueError:
        return not assume_new


def ytdl_is_updateable():
    """ Returns if yt-dlp can be updated with -U """

    from ..update import is_non_updateable

    return not is_non_updateable()


def args_to_str(args):
    # Get a short string representation for a subprocess command
    return shell_quote(args)


def error_to_str(err):
    return f'{type(err).__name__}: {err}'


@partial_application
def mimetype2ext(mt, default=NO_DEFAULT):
    if not isinstance(mt, str):
        if default is not NO_DEFAULT:
            return default
        return None

    MAP = {
        # video
        '3gpp': '3gp',
        'mp2t': 'ts',
        'mp4': 'mp4',
        'mpeg': 'mpeg',
        'mpegurl': 'm3u8',
        'quicktime': 'mov',
        'webm': 'webm',
        'vp9': 'vp9',
        'video/ogg': 'ogv',
        'x-flv': 'flv',
        'x-m4v': 'm4v',
        'x-matroska': 'mkv',
        'x-mng': 'mng',
        'x-mp4-fragmented': 'mp4',
        'x-ms-asf': 'asf',
        'x-ms-wmv': 'wmv',
        'x-msvideo': 'avi',
        'vnd.dlna.mpeg-tts': 'mpeg',

        # application (streaming playlists)
        'dash+xml': 'mpd',
        'f4m+xml': 'f4m',
        'hds+xml': 'f4m',
        'vnd.apple.mpegurl': 'm3u8',
        'vnd.ms-sstr+xml': 'ism',
        'x-mpegurl': 'm3u8',

        # audio
        'audio/mp4': 'm4a',
        # Per RFC 3003, audio/mpeg can be .mp1, .mp2 or .mp3.
        # Using .mp3 as it's the most popular one
        'audio/mpeg': 'mp3',
        'audio/webm': 'webm',
        'audio/x-matroska': 'mka',
        'audio/x-mpegurl': 'm3u',
        'aacp': 'aac',
        'flac': 'flac',
        'midi': 'mid',
        'ogg': 'ogg',
        'wav': 'wav',
        'wave': 'wav',
        'x-aac': 'aac',
        'x-flac': 'flac',
        'x-m4a': 'm4a',
        'x-realaudio': 'ra',
        'x-wav': 'wav',

        # image
        'avif': 'avif',
        'bmp': 'bmp',
        'gif': 'gif',
        'jpeg': 'jpg',
        'png': 'png',
        'svg+xml': 'svg',
        'tiff': 'tif',
        'vnd.wap.wbmp': 'wbmp',
        'webp': 'webp',
        'x-icon': 'ico',
        'x-jng': 'jng',
        'x-ms-bmp': 'bmp',

        # caption
        'filmstrip+json': 'fs',
        'smptett+xml': 'tt',
        'ttaf+xml': 'dfxp',
        'ttml+xml': 'ttml',
        'x-ms-sami': 'sami',
        'x-subrip': 'srt',
        'x-srt': 'srt',

        # misc
        'gzip': 'gz',
        'json': 'json',
        'xml': 'xml',
        'zip': 'zip',
    }

    mimetype = mt.partition(';')[0].strip().lower()
    _, _, subtype = mimetype.rpartition('/')

    ext = traversal.traverse_obj(MAP, mimetype, subtype, subtype.rsplit('+')[-1])
    if ext:
        return ext
    elif default is not NO_DEFAULT:
        return default
    return subtype.replace('+', '.')


def ext2mimetype(ext_or_url):
    if not ext_or_url:
        return None
    if '.' not in ext_or_url:
        ext_or_url = f'file.{ext_or_url}'
    return mimetypes.guess_type(ext_or_url)[0]


def parse_codecs(codecs_str):
    # http://tools.ietf.org/html/rfc6381
    if not codecs_str:
        return {}
    split_codecs = list(filter(None, map(
        str.strip, codecs_str.strip().strip(',').split(','))))
    vcodec, acodec, scodec, hdr = None, None, None, None
    for full_codec in split_codecs:
        full_codec = re.sub(r'^([^.]+)', lambda m: m.group(1).lower(), full_codec)
        parts = re.sub(r'0+(?=\d)', '', full_codec).split('.')
        if parts[0] in ('avc1', 'avc2', 'avc3', 'avc4', 'vp9', 'vp8', 'hev1', 'hev2',
                        'h263', 'h264', 'mp4v', 'hvc1', 'av1', 'theora', 'dvh1', 'dvhe'):
            if vcodec:
                continue
            vcodec = full_codec
            if parts[0] in ('dvh1', 'dvhe'):
                hdr = 'DV'
            elif parts[0] == 'av1' and traversal.traverse_obj(parts, 3) == '10':
                hdr = 'HDR10'
            elif parts[:2] == ['vp9', '2']:
                hdr = 'HDR10'
        elif parts[0] in ('flac', 'mp4a', 'opus', 'vorbis', 'mp3', 'aac', 'ac-4',
                          'ac-3', 'ec-3', 'eac3', 'dtsc', 'dtse', 'dtsh', 'dtsl'):
            acodec = acodec or full_codec
        elif parts[0] in ('stpp', 'wvtt'):
            scodec = scodec or full_codec
        else:
            write_string(f'WARNING: Unknown codec {full_codec}\n')
    if vcodec or acodec or scodec:
        return {
            'vcodec': vcodec or 'none',
            'acodec': acodec or 'none',
            'dynamic_range': hdr,
            **({'scodec': scodec} if scodec is not None else {}),
        }
    elif len(split_codecs) == 2:
        return {
            'vcodec': split_codecs[0],
            'acodec': split_codecs[1],
        }
    return {}


def get_compatible_ext(*, vcodecs, acodecs, vexts, aexts, preferences=None):
    assert len(vcodecs) == len(vexts) and len(acodecs) == len(aexts)

    allow_mkv = not preferences or 'mkv' in preferences

    if allow_mkv and max(len(acodecs), len(vcodecs)) > 1:
        return 'mkv'  # TODO: any other format allows this?

    # TODO: All codecs supported by parse_codecs isn't handled here
    COMPATIBLE_CODECS = {
        'mp4': {
            'av1', 'hevc', 'avc1', 'mp4a', 'ac-4',  # fourcc (m3u8, mpd)
            'h264', 'aacl', 'ec-3',  # Set in ISM
        },
        'webm': {
            'av1', 'vp9', 'vp8', 'opus', 'vrbs',
            'vp9x', 'vp8x',  # in the webm spec
        },
    }

    sanitize_codec = functools.partial(
        try_get, getter=lambda x: x[0].split('.')[0].replace('0', '').lower())
    vcodec, acodec = sanitize_codec(vcodecs), sanitize_codec(acodecs)

    for ext in preferences or COMPATIBLE_CODECS.keys():
        codec_set = COMPATIBLE_CODECS.get(ext, set())
        if ext == 'mkv' or codec_set.issuperset((vcodec, acodec)):
            return ext

    COMPATIBLE_EXTS = (
        {'mp3', 'mp4', 'm4a', 'm4p', 'm4b', 'm4r', 'm4v', 'ismv', 'isma', 'mov'},
        {'webm', 'weba'},
    )
    for ext in preferences or vexts:
        current_exts = {ext, *vexts, *aexts}
        if ext == 'mkv' or current_exts == {ext} or any(
                ext_sets.issuperset(current_exts) for ext_sets in COMPATIBLE_EXTS):
            return ext
    return 'mkv' if allow_mkv else preferences[-1]


def urlhandle_detect_ext(url_handle, default=NO_DEFAULT):
    getheader = url_handle.headers.get

    if cd := getheader('Content-Disposition'):
        if m := re.match(r'attachment;\s*filename="(?P<filename>[^"]+)"', cd):
            if ext := determine_ext(m.group('filename'), default_ext=None):
                return ext

    return (
        determine_ext(getheader('x-amz-meta-name'), default_ext=None)
        or getheader('x-amz-meta-file-type')
        or mimetype2ext(getheader('Content-Type'), default=default))


def encode_data_uri(data, mime_type):
    return 'data:{};base64,{}'.format(mime_type, base64.b64encode(data).decode('ascii'))


def age_restricted(content_limit, age_limit):
    """ Returns True iff the content should be blocked """

    if age_limit is None:  # No limit set
        return False
    if content_limit is None:
        return False  # Content available for everyone
    return age_limit < content_limit


# List of known byte-order-marks (BOM)
BOMS = [
    (b'\xef\xbb\xbf', 'utf-8'),
    (b'\x00\x00\xfe\xff', 'utf-32-be'),
    (b'\xff\xfe\x00\x00', 'utf-32-le'),
    (b'\xff\xfe', 'utf-16-le'),
    (b'\xfe\xff', 'utf-16-be'),
]


def is_html(first_bytes):
    """ Detect whether a file contains HTML by examining its first bytes. """

    encoding = 'utf-8'
    for bom, enc in BOMS:
        while first_bytes.startswith(bom):
            encoding, first_bytes = enc, first_bytes[len(bom):]

    return re.match(r'\s*<', first_bytes.decode(encoding, 'replace'))


def determine_protocol(info_dict):
    protocol = info_dict.get('protocol')
    if protocol is not None:
        return protocol

    url = sanitize_url(info_dict['url'])
    if url.startswith('rtmp'):
        return 'rtmp'
    elif url.startswith('mms'):
        return 'mms'
    elif url.startswith('rtsp'):
        return 'rtsp'

    ext = determine_ext(url)
    if ext == 'm3u8':
        return 'm3u8' if info_dict.get('is_live') else 'm3u8_native'
    elif ext == 'f4m':
        return 'f4m'

    return urllib.parse.urlparse(url).scheme


def render_table(header_row, data, delim=False, extra_gap=0, hide_empty=False):
    """ Render a list of rows, each as a list of values.
    Text after a \t will be right aligned """
    def width(string):
        return len(remove_terminal_sequences(string).replace('\t', ''))

    def get_max_lens(table):
        return [max(width(str(v)) for v in col) for col in zip(*table, strict=True)]

    def filter_using_list(row, filter_array):
        return [col for take, col in itertools.zip_longest(filter_array, row, fillvalue=True) if take]

    max_lens = get_max_lens(data) if hide_empty else []
    header_row = filter_using_list(header_row, max_lens)
    data = [filter_using_list(row, max_lens) for row in data]

    table = [header_row, *data]
    max_lens = get_max_lens(table)
    extra_gap += 1
    if delim:
        table = [header_row, [delim * (ml + extra_gap) for ml in max_lens], *data]
        table[1][-1] = table[1][-1][:-extra_gap * len(delim)]  # Remove extra_gap from end of delimiter
    for row in table:
        for pos, text in enumerate(map(str, row)):
            if '\t' in text:
                row[pos] = text.replace('\t', ' ' * (max_lens[pos] - width(text))) + ' ' * extra_gap
            else:
                row[pos] = text + ' ' * (max_lens[pos] - width(text) + extra_gap)
    return '\n'.join(''.join(row).rstrip() for row in table)


def _match_one(filter_part, dct, incomplete):
    # TODO: Generalize code with YoutubeDL._build_format_filter
    STRING_OPERATORS = {
        '*=': operator.contains,
        '^=': lambda attr, value: attr.startswith(value),
        '$=': lambda attr, value: attr.endswith(value),
        '~=': lambda attr, value: re.search(value, attr),
    }
    COMPARISON_OPERATORS = {
        **STRING_OPERATORS,
        '<=': operator.le,  # "<=" must be defined above "<"
        '<': operator.lt,
        '>=': operator.ge,
        '>': operator.gt,
        '=': operator.eq,
    }

    if isinstance(incomplete, bool):
        is_incomplete = lambda _: incomplete
    else:
        is_incomplete = lambda k: k in incomplete

    operator_rex = re.compile(r'''(?x)
        (?P<key>[a-z_]+)
        \s*(?P<negation>!\s*)?(?P<op>{})(?P<none_inclusive>\s*\?)?\s*
        (?:
            (?P<quote>["\'])(?P<quotedstrval>.+?)(?P=quote)|
            (?P<strval>.+?)
        )
        '''.format('|'.join(map(re.escape, COMPARISON_OPERATORS.keys()))))
    m = operator_rex.fullmatch(filter_part.strip())
    if m:
        m = m.groupdict()
        unnegated_op = COMPARISON_OPERATORS[m['op']]
        if m['negation']:
            op = lambda attr, value: not unnegated_op(attr, value)
        else:
            op = unnegated_op
        comparison_value = m['quotedstrval'] or m['strval']
        if m['quote']:
            comparison_value = comparison_value.replace(r'\{}'.format(m['quote']), m['quote'])
        actual_value = dct.get(m['key'])
        numeric_comparison = None
        if isinstance(actual_value, (int, float)):
            # If the original field is a string and matching comparisonvalue is
            # a number we should respect the origin of the original field
            # and process comparison value as a string (see
            # https://github.com/ytdl-org/youtube-dl/issues/11082)
            try:
                numeric_comparison = int(comparison_value)
            except ValueError:
                numeric_comparison = parse_filesize(comparison_value)
                if numeric_comparison is None:
                    numeric_comparison = parse_filesize(f'{comparison_value}B')
                if numeric_comparison is None:
                    numeric_comparison = parse_duration(comparison_value)
        if numeric_comparison is not None and m['op'] in STRING_OPERATORS:
            raise ValueError('Operator {} only supports string values!'.format(m['op']))
        if actual_value is None:
            return is_incomplete(m['key']) or m['none_inclusive']
        return op(actual_value, comparison_value if numeric_comparison is None else numeric_comparison)

    UNARY_OPERATORS = {
        '': lambda v: (v is True) if isinstance(v, bool) else (v is not None),
        '!': lambda v: (v is False) if isinstance(v, bool) else (v is None),
    }
    operator_rex = re.compile(r'''(?x)
        (?P<op>{})\s*(?P<key>[a-z_]+)
        '''.format('|'.join(map(re.escape, UNARY_OPERATORS.keys()))))
    m = operator_rex.fullmatch(filter_part.strip())
    if m:
        op = UNARY_OPERATORS[m.group('op')]
        actual_value = dct.get(m.group('key'))
        if is_incomplete(m.group('key')) and actual_value is None:
            return True
        return op(actual_value)

    raise ValueError(f'Invalid filter part {filter_part!r}')


def match_str(filter_str, dct, incomplete=False):
    """ Filter a dictionary with a simple string syntax.
    @returns           Whether the filter passes
    @param incomplete  Set of keys that is expected to be missing from dct.
                       Can be True/False to indicate all/none of the keys may be missing.
                       All conditions on incomplete keys pass if the key is missing
    """
    return all(
        _match_one(filter_part.replace(r'\&', '&'), dct, incomplete)
        for filter_part in re.split(r'(?<!\\)&', filter_str))


def match_filter_func(filters, breaking_filters=None):
    if not filters and not breaking_filters:
        return None
    repr_ = f'{match_filter_func.__module__}.{match_filter_func.__qualname__}({filters}, {breaking_filters})'

    breaking_filters = match_filter_func(breaking_filters) or (lambda _, __: None)
    filters = set(variadic(filters or []))

    interactive = '-' in filters
    if interactive:
        filters.remove('-')

    @function_with_repr.set_repr(repr_)
    def _match_func(info_dict, incomplete=False):
        ret = breaking_filters(info_dict, incomplete)
        if ret is not None:
            raise RejectedVideoReached(ret)

        if not filters or any(match_str(f, info_dict, incomplete) for f in filters):
            return NO_DEFAULT if interactive and not incomplete else None
        else:
            video_title = info_dict.get('title') or info_dict.get('id') or 'entry'
            filter_str = ') | ('.join(map(str.strip, filters))
            return f'{video_title} does not pass filter ({filter_str}), skipping ..'
    return _match_func


class download_range_func:
    def __init__(self, chapters, ranges, from_info=False):
        self.chapters, self.ranges, self.from_info = chapters, ranges, from_info

    def __call__(self, info_dict, ydl):

        warning = ('There are no chapters matching the regex' if info_dict.get('chapters')
                   else 'Cannot match chapters since chapter information is unavailable')
        for regex in self.chapters or []:
            for i, chapter in enumerate(info_dict.get('chapters') or []):
                if re.search(regex, chapter['title']):
                    warning = None
                    yield {**chapter, 'index': i}
        if self.chapters and warning:
            ydl.to_screen(f'[info] {info_dict["id"]}: {warning}')

        for start, end in self.ranges or []:
            yield {
                'start_time': self._handle_negative_timestamp(start, info_dict),
                'end_time': self._handle_negative_timestamp(end, info_dict),
            }

        if self.from_info and (info_dict.get('start_time') or info_dict.get('end_time')):
            yield {
                'start_time': info_dict.get('start_time') or 0,
                'end_time': info_dict.get('end_time') or float('inf'),
            }
        elif not self.ranges and not self.chapters:
            yield {}

    @staticmethod
    def _handle_negative_timestamp(time, info):
        return max(info['duration'] + time, 0) if info.get('duration') and time < 0 else time

    def __eq__(self, other):
        return (isinstance(other, download_range_func)
                and self.chapters == other.chapters and self.ranges == other.ranges)

    def __repr__(self):
        return f'{__name__}.{type(self).__name__}({self.chapters}, {self.ranges})'


def parse_dfxp_time_expr(time_expr):
    if not time_expr:
        return

    mobj = re.match(rf'^(?P<time_offset>{NUMBER_RE})s?$', time_expr)
    if mobj:
        return float(mobj.group('time_offset'))

    mobj = re.match(r'^(\d+):(\d\d):(\d\d(?:(?:\.|:)\d+)?)$', time_expr)
    if mobj:
        return 3600 * int(mobj.group(1)) + 60 * int(mobj.group(2)) + float(mobj.group(3).replace(':', '.'))


def srt_subtitles_timecode(seconds):
    return '%02d:%02d:%02d,%03d' % timetuple_from_msec(seconds * 1000)


def ass_subtitles_timecode(seconds):
    time = timetuple_from_msec(seconds * 1000)
    return '%01d:%02d:%02d.%02d' % (*time[:-1], time.milliseconds / 10)


def dfxp2srt(dfxp_data):
    """
    @param dfxp_data A bytes-like object containing DFXP data
    @returns A unicode object containing converted SRT data
    """
    LEGACY_NAMESPACES = (
        (b'http://www.w3.org/ns/ttml', [
            b'http://www.w3.org/2004/11/ttaf1',
            b'http://www.w3.org/2006/04/ttaf1',
            b'http://www.w3.org/2006/10/ttaf1',
        ]),
        (b'http://www.w3.org/ns/ttml#styling', [
            b'http://www.w3.org/ns/ttml#style',
        ]),
    )

    SUPPORTED_STYLING = [
        'color',
        'fontFamily',
        'fontSize',
        'fontStyle',
        'fontWeight',
        'textDecoration',
    ]

    _x = functools.partial(xpath_with_ns, ns_map={
        'xml': 'http://www.w3.org/XML/1998/namespace',
        'ttml': 'http://www.w3.org/ns/ttml',
        'tts': 'http://www.w3.org/ns/ttml#styling',
    })

    styles = {}
    default_style = {}

    class TTMLPElementParser:
        _out = ''
        _unclosed_elements = []
        _applied_styles = []

        def start(self, tag, attrib):
            if tag in (_x('ttml:br'), 'br'):
                self._out += '\n'
            else:
                unclosed_elements = []
                style = {}
                element_style_id = attrib.get('style')
                if default_style:
                    style.update(default_style)
                if element_style_id:
                    style.update(styles.get(element_style_id, {}))
                for prop in SUPPORTED_STYLING:
                    prop_val = attrib.get(_x('tts:' + prop))
                    if prop_val:
                        style[prop] = prop_val
                if style:
                    font = ''
                    for k, v in sorted(style.items()):
                        if self._applied_styles and self._applied_styles[-1].get(k) == v:
                            continue
                        if k == 'color':
                            font += f' color="{v}"'
                        elif k == 'fontSize':
                            font += f' size="{v}"'
                        elif k == 'fontFamily':
                            font += f' face="{v}"'
                        elif k == 'fontWeight' and v == 'bold':
                            self._out += '<b>'
                            unclosed_elements.append('b')
                        elif k == 'fontStyle' and v == 'italic':
                            self._out += '<i>'
                            unclosed_elements.append('i')
                        elif k == 'textDecoration' and v == 'underline':
                            self._out += '<u>'
                            unclosed_elements.append('u')
                    if font:
                        self._out += '<font' + font + '>'
                        unclosed_elements.append('font')
                    applied_style = {}
                    if self._applied_styles:
                        applied_style.update(self._applied_styles[-1])
                    applied_style.update(style)
                    self._applied_styles.append(applied_style)
                self._unclosed_elements.append(unclosed_elements)

        def end(self, tag):
            if tag not in (_x('ttml:br'), 'br'):
                unclosed_elements = self._unclosed_elements.pop()
                for element in reversed(unclosed_elements):
                    self._out += f'</{element}>'
                if unclosed_elements and self._applied_styles:
                    self._applied_styles.pop()

        def data(self, data):
            self._out += data

        def close(self):
            return self._out.strip()

    # Fix UTF-8 encoded file wrongly marked as UTF-16. See https://github.com/yt-dlp/yt-dlp/issues/6543#issuecomment-1477169870
    # This will not trigger false positives since only UTF-8 text is being replaced
    dfxp_data = dfxp_data.replace(b'encoding=\'UTF-16\'', b'encoding=\'UTF-8\'')

    def parse_node(node):
        target = TTMLPElementParser()
        parser = xml.etree.ElementTree.XMLParser(target=target)
        parser.feed(xml.etree.ElementTree.tostring(node))
        return parser.close()

    for k, v in LEGACY_NAMESPACES:
        for ns in v:
            dfxp_data = dfxp_data.replace(ns, k)

    dfxp = compat_etree_fromstring(dfxp_data)
    out = []
    paras = dfxp.findall(_x('.//ttml:p')) or dfxp.findall('.//p')

    if not paras:
        raise ValueError('Invalid dfxp/TTML subtitle')

    repeat = False
    while True:
        for style in dfxp.findall(_x('.//ttml:style')):
            style_id = style.get('id') or style.get(_x('xml:id'))
            if not style_id:
                continue
            parent_style_id = style.get('style')
            if parent_style_id:
                if parent_style_id not in styles:
                    repeat = True
                    continue
                styles[style_id] = styles[parent_style_id].copy()
            for prop in SUPPORTED_STYLING:
                prop_val = style.get(_x('tts:' + prop))
                if prop_val:
                    styles.setdefault(style_id, {})[prop] = prop_val
        if repeat:
            repeat = False
        else:
            break

    for p in ('body', 'div'):
        ele = xpath_element(dfxp, [_x('.//ttml:' + p), './/' + p])
        if ele is None:
            continue
        style = styles.get(ele.get('style'))
        if not style:
            continue
        default_style.update(style)

    for para, index in zip(paras, itertools.count(1), strict=False):
        begin_time = parse_dfxp_time_expr(para.attrib.get('begin'))
        end_time = parse_dfxp_time_expr(para.attrib.get('end'))
        dur = parse_dfxp_time_expr(para.attrib.get('dur'))
        if begin_time is None:
            continue
        if not end_time:
            if not dur:
                continue
            end_time = begin_time + dur
        out.append('%d\n%s --> %s\n%s\n\n' % (
            index,
            srt_subtitles_timecode(begin_time),
            srt_subtitles_timecode(end_time),
            parse_node(para)))

    return ''.join(out)


def cli_option(params, command_option, param, separator=None):
    param = params.get(param)
    return ([] if param is None
            else [command_option, str(param)] if separator is None
            else [f'{command_option}{separator}{param}'])


def cli_bool_option(params, command_option, param, true_value='true', false_value='false', separator=None):
    param = params.get(param)
    assert param in (True, False, None)
    return cli_option({True: true_value, False: false_value}, command_option, param, separator)


def cli_valueless_option(params, command_option, param, expected_value=True):
    return [command_option] if params.get(param) == expected_value else []


def cli_configuration_args(argdict, keys, default=[], use_compat=True):
    if isinstance(argdict, (list, tuple)):  # for backward compatibility
        if use_compat:
            return argdict
        else:
            argdict = None
    if argdict is None:
        return default
    assert isinstance(argdict, dict)

    assert isinstance(keys, (list, tuple))
    for key_list in keys:
        arg_list = list(filter(
            lambda x: x is not None,
            [argdict.get(key.lower()) for key in variadic(key_list)]))
        if arg_list:
            return [arg for args in arg_list for arg in args]
    return default


def _configuration_args(main_key, argdict, exe, keys=None, default=[], use_compat=True):
    main_key, exe = main_key.lower(), exe.lower()
    root_key = exe if main_key == exe else f'{main_key}+{exe}'
    keys = [f'{root_key}{k}' for k in (keys or [''])]
    if root_key in keys:
        if main_key != exe:
            keys.append((main_key, exe))
        keys.append('default')
    else:
        use_compat = False
    return cli_configuration_args(argdict, keys, default, use_compat)


class ISO639Utils:
    # See http://www.loc.gov/standards/iso639-2/ISO-639-2_utf-8.txt
    _lang_map = {
        'aa': 'aar',
        'ab': 'abk',
        'ae': 'ave',
        'af': 'afr',
        'ak': 'aka',
        'am': 'amh',
        'an': 'arg',
        'ar': 'ara',
        'as': 'asm',
        'av': 'ava',
        'ay': 'aym',
        'az': 'aze',
        'ba': 'bak',
        'be': 'bel',
        'bg': 'bul',
        'bh': 'bih',
        'bi': 'bis',
        'bm': 'bam',
        'bn': 'ben',
        'bo': 'bod',
        'br': 'bre',
        'bs': 'bos',
        'ca': 'cat',
        'ce': 'che',
        'ch': 'cha',
        'co': 'cos',
        'cr': 'cre',
        'cs': 'ces',
        'cu': 'chu',
        'cv': 'chv',
        'cy': 'cym',
        'da': 'dan',
        'de': 'deu',
        'dv': 'div',
        'dz': 'dzo',
        'ee': 'ewe',
        'el': 'ell',
        'en': 'eng',
        'eo': 'epo',
        'es': 'spa',
        'et': 'est',
        'eu': 'eus',
        'fa': 'fas',
        'ff': 'ful',
        'fi': 'fin',
        'fj': 'fij',
        'fo': 'fao',
        'fr': 'fra',
        'fy': 'fry',
        'ga': 'gle',
        'gd': 'gla',
        'gl': 'glg',
        'gn': 'grn',
        'gu': 'guj',
        'gv': 'glv',
        'ha': 'hau',
        'he': 'heb',
        'iw': 'heb',  # Replaced by he in 1989 revision
        'hi': 'hin',
        'ho': 'hmo',
        'hr': 'hrv',
        'ht': 'hat',
        'hu': 'hun',
        'hy': 'hye',
        'hz': 'her',
        'ia': 'ina',
        'id': 'ind',
        'in': 'ind',  # Replaced by id in 1989 revision
        'ie': 'ile',
        'ig': 'ibo',
        'ii': 'iii',
        'ik': 'ipk',
        'io': 'ido',
        'is': 'isl',
        'it': 'ita',
        'iu': 'iku',
        'ja': 'jpn',
        'jv': 'jav',
        'ka': 'kat',
        'kg': 'kon',
        'ki': 'kik',
        'kj': 'kua',
        'kk': 'kaz',
        'kl': 'kal',
        'km': 'khm',
        'kn': 'kan',
        'ko': 'kor',
        'kr': 'kau',
        'ks': 'kas',
        'ku': 'kur',
        'kv': 'kom',
        'kw': 'cor',
        'ky': 'kir',
        'la': 'lat',
        'lb': 'ltz',
        'lg': 'lug',
        'li': 'lim',
        'ln': 'lin',
        'lo': 'lao',
        'lt': 'lit',
        'lu': 'lub',
        'lv': 'lav',
        'mg': 'mlg',
        'mh': 'mah',
        'mi': 'mri',
        'mk': 'mkd',
        'ml': 'mal',
        'mn': 'mon',
        'mr': 'mar',
        'ms': 'msa',
        'mt': 'mlt',
        'my': 'mya',
        'na': 'nau',
        'nb': 'nob',
        'nd': 'nde',
        'ne': 'nep',
        'ng': 'ndo',
        'nl': 'nld',
        'nn': 'nno',
        'no': 'nor',
        'nr': 'nbl',
        'nv': 'nav',
        'ny': 'nya',
        'oc': 'oci',
        'oj': 'oji',
        'om': 'orm',
        'or': 'ori',
        'os': 'oss',
        'pa': 'pan',
        'pe': 'per',
        'pi': 'pli',
        'pl': 'pol',
        'ps': 'pus',
        'pt': 'por',
        'qu': 'que',
        'rm': 'roh',
        'rn': 'run',
        'ro': 'ron',
        'ru': 'rus',
        'rw': 'kin',
        'sa': 'san',
        'sc': 'srd',
        'sd': 'snd',
        'se': 'sme',
        'sg': 'sag',
        'si': 'sin',
        'sk': 'slk',
        'sl': 'slv',
        'sm': 'smo',
        'sn': 'sna',
        'so': 'som',
        'sq': 'sqi',
        'sr': 'srp',
        'ss': 'ssw',
        'st': 'sot',
        'su': 'sun',
        'sv': 'swe',
        'sw': 'swa',
        'ta': 'tam',
        'te': 'tel',
        'tg': 'tgk',
        'th': 'tha',
        'ti': 'tir',
        'tk': 'tuk',
        'tl': 'tgl',
        'tn': 'tsn',
        'to': 'ton',
        'tr': 'tur',
        'ts': 'tso',
        'tt': 'tat',
        'tw': 'twi',
        'ty': 'tah',
        'ug': 'uig',
        'uk': 'ukr',
        'ur': 'urd',
        'uz': 'uzb',
        've': 'ven',
        'vi': 'vie',
        'vo': 'vol',
        'wa': 'wln',
        'wo': 'wol',
        'xh': 'xho',
        'yi': 'yid',
        'ji': 'yid',  # Replaced by yi in 1989 revision
        'yo': 'yor',
        'za': 'zha',
        'zh': 'zho',
        'zu': 'zul',
    }

    @classmethod
    def short2long(cls, code):
        """Convert language code from ISO 639-1 to ISO 639-2/T"""
        return cls._lang_map.get(code[:2])

    @classmethod
    def long2short(cls, code):
        """Convert language code from ISO 639-2/T to ISO 639-1"""
        for short_name, long_name in cls._lang_map.items():
            if long_name == code:
                return short_name


class ISO3166Utils:
    # From http://data.okfn.org/data/core/country-list
    _country_map = {
        'AF': 'Afghanistan',
        'AX': 'Åland Islands',
        'AL': 'Albania',
        'DZ': 'Algeria',
        'AS': 'American Samoa',
        'AD': 'Andorra',
        'AO': 'Angola',
        'AI': 'Anguilla',
        'AQ': 'Antarctica',
        'AG': 'Antigua and Barbuda',
        'AR': 'Argentina',
        'AM': 'Armenia',
        'AW': 'Aruba',
        'AU': 'Australia',
        'AT': 'Austria',
        'AZ': 'Azerbaijan',
        'BS': 'Bahamas',
        'BH': 'Bahrain',
        'BD': 'Bangladesh',
        'BB': 'Barbados',
        'BY': 'Belarus',
        'BE': 'Belgium',
        'BZ': 'Belize',
        'BJ': 'Benin',
        'BM': 'Bermuda',
        'BT': 'Bhutan',
        'BO': 'Bolivia, Plurinational State of',
        'BQ': 'Bonaire, Sint Eustatius and Saba',
        'BA': 'Bosnia and Herzegovina',
        'BW': 'Botswana',
        'BV': 'Bouvet Island',
        'BR': 'Brazil',
        'IO': 'British Indian Ocean Territory',
        'BN': 'Brunei Darussalam',
        'BG': 'Bulgaria',
        'BF': 'Burkina Faso',
        'BI': 'Burundi',
        'KH': 'Cambodia',
        'CM': 'Cameroon',
        'CA': 'Canada',
        'CV': 'Cape Verde',
        'KY': 'Cayman Islands',
        'CF': 'Central African Republic',
        'TD': 'Chad',
        'CL': 'Chile',
        'CN': 'China',
        'CX': 'Christmas Island',
        'CC': 'Cocos (Keeling) Islands',
        'CO': 'Colombia',
        'KM': 'Comoros',
        'CG': 'Congo',
        'CD': 'Congo, the Democratic Republic of the',
        'CK': 'Cook Islands',
        'CR': 'Costa Rica',
        'CI': 'Côte d\'Ivoire',
        'HR': 'Croatia',
        'CU': 'Cuba',
        'CW': 'Curaçao',
        'CY': 'Cyprus',
        'CZ': 'Czech Republic',
        'DK': 'Denmark',
        'DJ': 'Djibouti',
        'DM': 'Dominica',
        'DO': 'Dominican Republic',
        'EC': 'Ecuador',
        'EG': 'Egypt',
        'SV': 'El Salvador',
        'GQ': 'Equatorial Guinea',
        'ER': 'Eritrea',
        'EE': 'Estonia',
        'ET': 'Ethiopia',
        'FK': 'Falkland Islands (Malvinas)',
        'FO': 'Faroe Islands',
        'FJ': 'Fiji',
        'FI': 'Finland',
        'FR': 'France',
        'GF': 'French Guiana',
        'PF': 'French Polynesia',
        'TF': 'French Southern Territories',
        'GA': 'Gabon',
        'GM': 'Gambia',
        'GE': 'Georgia',
        'DE': 'Germany',
        'GH': 'Ghana',
        'GI': 'Gibraltar',
        'GR': 'Greece',
        'GL': 'Greenland',
        'GD': 'Grenada',
        'GP': 'Guadeloupe',
        'GU': 'Guam',
        'GT': 'Guatemala',
        'GG': 'Guernsey',
        'GN': 'Guinea',
        'GW': 'Guinea-Bissau',
        'GY': 'Guyana',
        'HT': 'Haiti',
        'HM': 'Heard Island and McDonald Islands',
        'VA': 'Holy See (Vatican City State)',
        'HN': 'Honduras',
        'HK': 'Hong Kong',
        'HU': 'Hungary',
        'IS': 'Iceland',
        'IN': 'India',
        'ID': 'Indonesia',
        'IR': 'Iran, Islamic Republic of',
        'IQ': 'Iraq',
        'IE': 'Ireland',
        'IM': 'Isle of Man',
        'IL': 'Israel',
        'IT': 'Italy',
        'JM': 'Jamaica',
        'JP': 'Japan',
        'JE': 'Jersey',
        'JO': 'Jordan',
        'KZ': 'Kazakhstan',
        'KE': 'Kenya',
        'KI': 'Kiribati',
        'KP': 'Korea, Democratic People\'s Republic of',
        'KR': 'Korea, Republic of',
        'KW': 'Kuwait',
        'KG': 'Kyrgyzstan',
        'LA': 'Lao People\'s Democratic Republic',
        'LV': 'Latvia',
        'LB': 'Lebanon',
        'LS': 'Lesotho',
        'LR': 'Liberia',
        'LY': 'Libya',
        'LI': 'Liechtenstein',
        'LT': 'Lithuania',
        'LU': 'Luxembourg',
        'MO': 'Macao',
        'MK': 'Macedonia, the Former Yugoslav Republic of',
        'MG': 'Madagascar',
        'MW': 'Malawi',
        'MY': 'Malaysia',
        'MV': 'Maldives',
        'ML': 'Mali',
        'MT': 'Malta',
        'MH': 'Marshall Islands',
        'MQ': 'Martinique',
        'MR': 'Mauritania',
        'MU': 'Mauritius',
        'YT': 'Mayotte',
        'MX': 'Mexico',
        'FM': 'Micronesia, Federated States of',
        'MD': 'Moldova, Republic of',
        'MC': 'Monaco',
        'MN': 'Mongolia',
        'ME': 'Montenegro',
        'MS': 'Montserrat',
        'MA': 'Morocco',
        'MZ': 'Mozambique',
        'MM': 'Myanmar',
        'NA': 'Namibia',
        'NR': 'Nauru',
        'NP': 'Nepal',
        'NL': 'Netherlands',
        'NC': 'New Caledonia',
        'NZ': 'New Zealand',
        'NI': 'Nicaragua',
        'NE': 'Niger',
        'NG': 'Nigeria',
        'NU': 'Niue',
        'NF': 'Norfolk Island',
        'MP': 'Northern Mariana Islands',
        'NO': 'Norway',
        'OM': 'Oman',
        'PK': 'Pakistan',
        'PW': 'Palau',
        'PS': 'Palestine, State of',
        'PA': 'Panama',
        'PG': 'Papua New Guinea',
        'PY': 'Paraguay',
        'PE': 'Peru',
        'PH': 'Philippines',
        'PN': 'Pitcairn',
        'PL': 'Poland',
        'PT': 'Portugal',
        'PR': 'Puerto Rico',
        'QA': 'Qatar',
        'RE': 'Réunion',
        'RO': 'Romania',
        'RU': 'Russian Federation',
        'RW': 'Rwanda',
        'BL': 'Saint Barthélemy',
        'SH': 'Saint Helena, Ascension and Tristan da Cunha',
        'KN': 'Saint Kitts and Nevis',
        'LC': 'Saint Lucia',
        'MF': 'Saint Martin (French part)',
        'PM': 'Saint Pierre and Miquelon',
        'VC': 'Saint Vincent and the Grenadines',
        'WS': 'Samoa',
        'SM': 'San Marino',
        'ST': 'Sao Tome and Principe',
        'SA': 'Saudi Arabia',
        'SN': 'Senegal',
        'RS': 'Serbia',
        'SC': 'Seychelles',
        'SL': 'Sierra Leone',
        'SG': 'Singapore',
        'SX': 'Sint Maarten (Dutch part)',
        'SK': 'Slovakia',
        'SI': 'Slovenia',
        'SB': 'Solomon Islands',
        'SO': 'Somalia',
        'ZA': 'South Africa',
        'GS': 'South Georgia and the South Sandwich Islands',
        'SS': 'South Sudan',
        'ES': 'Spain',
        'LK': 'Sri Lanka',
        'SD': 'Sudan',
        'SR': 'Suriname',
        'SJ': 'Svalbard and Jan Mayen',
        'SZ': 'Swaziland',
        'SE': 'Sweden',
        'CH': 'Switzerland',
        'SY': 'Syrian Arab Republic',
        'TW': 'Taiwan, Province of China',
        'TJ': 'Tajikistan',
        'TZ': 'Tanzania, United Republic of',
        'TH': 'Thailand',
        'TL': 'Timor-Leste',
        'TG': 'Togo',
        'TK': 'Tokelau',
        'TO': 'Tonga',
        'TT': 'Trinidad and Tobago',
        'TN': 'Tunisia',
        'TR': 'Turkey',
        'TM': 'Turkmenistan',
        'TC': 'Turks and Caicos Islands',
        'TV': 'Tuvalu',
        'UG': 'Uganda',
        'UA': 'Ukraine',
        'AE': 'United Arab Emirates',
        'GB': 'United Kingdom',
        'US': 'United States',
        'UM': 'United States Minor Outlying Islands',
        'UY': 'Uruguay',
        'UZ': 'Uzbekistan',
        'VU': 'Vanuatu',
        'VE': 'Venezuela, Bolivarian Republic of',
        'VN': 'Viet Nam',
        'VG': 'Virgin Islands, British',
        'VI': 'Virgin Islands, U.S.',
        'WF': 'Wallis and Futuna',
        'EH': 'Western Sahara',
        'YE': 'Yemen',
        'ZM': 'Zambia',
        'ZW': 'Zimbabwe',
        # Not ISO 3166 codes, but used for IP blocks
        'AP': 'Asia/Pacific Region',
        'EU': 'Europe',
    }

    @classmethod
    def short2full(cls, code):
        """Convert an ISO 3166-2 country code to the corresponding full name"""
        return cls._country_map.get(code.upper())


class GeoUtils:
    # Major IPv4 address blocks per country
    _country_ip_map = {
        'AD': '46.172.224.0/19',
        'AE': '94.200.0.0/13',
        'AF': '149.54.0.0/17',
        'AG': '209.59.64.0/18',
        'AI': '204.14.248.0/21',
        'AL': '46.99.0.0/16',
        'AM': '46.70.0.0/15',
        'AO': '105.168.0.0/13',
        'AP': '182.50.184.0/21',
        'AQ': '23.154.160.0/24',
        'AR': '181.0.0.0/12',
        'AS': '202.70.112.0/20',
        'AT': '77.116.0.0/14',
        'AU': '1.128.0.0/11',
        'AW': '181.41.0.0/18',
        'AX': '185.217.4.0/22',
        'AZ': '5.197.0.0/16',
        'BA': '31.176.128.0/17',
        'BB': '65.48.128.0/17',
        'BD': '114.130.0.0/16',
        'BE': '57.0.0.0/8',
        'BF': '102.178.0.0/15',
        'BG': '95.42.0.0/15',
        'BH': '37.131.0.0/17',
        'BI': '154.117.192.0/18',
        'BJ': '137.255.0.0/16',
        'BL': '185.212.72.0/23',
        'BM': '196.12.64.0/18',
        'BN': '156.31.0.0/16',
        'BO': '161.56.0.0/16',
        'BQ': '161.0.80.0/20',
        'BR': '191.128.0.0/12',
        'BS': '24.51.64.0/18',
        'BT': '119.2.96.0/19',
        'BW': '168.167.0.0/16',
        'BY': '178.120.0.0/13',
        'BZ': '179.42.192.0/18',
        'CA': '99.224.0.0/11',
        'CD': '41.243.0.0/16',
        'CF': '197.242.176.0/21',
        'CG': '160.113.0.0/16',
        'CH': '85.0.0.0/13',
        'CI': '102.136.0.0/14',
        'CK': '202.65.32.0/19',
        'CL': '152.172.0.0/14',
        'CM': '102.244.0.0/14',
        'CN': '36.128.0.0/10',
        'CO': '181.240.0.0/12',
        'CR': '201.192.0.0/12',
        'CU': '152.206.0.0/15',
        'CV': '165.90.96.0/19',
        'CW': '190.88.128.0/17',
        'CY': '31.153.0.0/16',
        'CZ': '88.100.0.0/14',
        'DE': '53.0.0.0/8',
        'DJ': '197.241.0.0/17',
        'DK': '87.48.0.0/12',
        'DM': '192.243.48.0/20',
        'DO': '152.166.0.0/15',
        'DZ': '41.96.0.0/12',
        'EC': '186.68.0.0/15',
        'EE': '90.190.0.0/15',
        'EG': '156.160.0.0/11',
        'ER': '196.200.96.0/20',
        'ES': '88.0.0.0/11',
        'ET': '196.188.0.0/14',
        'EU': '2.16.0.0/13',
        'FI': '91.152.0.0/13',
        'FJ': '144.120.0.0/16',
        'FK': '80.73.208.0/21',
        'FM': '119.252.112.0/20',
        'FO': '88.85.32.0/19',
        'FR': '90.0.0.0/9',
        'GA': '41.158.0.0/15',
        'GB': '25.0.0.0/8',
        'GD': '74.122.88.0/21',
        'GE': '31.146.0.0/16',
        'GF': '161.22.64.0/18',
        'GG': '62.68.160.0/19',
        'GH': '154.160.0.0/12',
        'GI': '95.164.0.0/16',
        'GL': '88.83.0.0/19',
        'GM': '160.182.0.0/15',
        'GN': '197.149.192.0/18',
        'GP': '104.250.0.0/19',
        'GQ': '105.235.224.0/20',
        'GR': '94.64.0.0/13',
        'GT': '168.234.0.0/16',
        'GU': '168.123.0.0/16',
        'GW': '197.214.80.0/20',
        'GY': '181.41.64.0/18',
        'HK': '113.252.0.0/14',
        'HN': '181.210.0.0/16',
        'HR': '93.136.0.0/13',
        'HT': '148.102.128.0/17',
        'HU': '84.0.0.0/14',
        'ID': '39.192.0.0/10',
        'IE': '87.32.0.0/12',
        'IL': '79.176.0.0/13',
        'IM': '5.62.80.0/20',
        'IN': '117.192.0.0/10',
        'IO': '203.83.48.0/21',
        'IQ': '37.236.0.0/14',
        'IR': '2.176.0.0/12',
        'IS': '82.221.0.0/16',
        'IT': '79.0.0.0/10',
        'JE': '87.244.64.0/18',
        'JM': '72.27.0.0/17',
        'JO': '176.29.0.0/16',
        'JP': '133.0.0.0/8',
        'KE': '105.48.0.0/12',
        'KG': '158.181.128.0/17',
        'KH': '36.37.128.0/17',
        'KI': '103.25.140.0/22',
        'KM': '197.255.224.0/20',
        'KN': '198.167.192.0/19',
        'KP': '175.45.176.0/22',
        'KR': '175.192.0.0/10',
        'KW': '37.36.0.0/14',
        'KY': '64.96.0.0/15',
        'KZ': '2.72.0.0/13',
        'LA': '115.84.64.0/18',
        'LB': '178.135.0.0/16',
        'LC': '24.92.144.0/20',
        'LI': '82.117.0.0/19',
        'LK': '112.134.0.0/15',
        'LR': '102.183.0.0/16',
        'LS': '129.232.0.0/17',
        'LT': '78.56.0.0/13',
        'LU': '188.42.0.0/16',
        'LV': '46.109.0.0/16',
        'LY': '41.252.0.0/14',
        'MA': '105.128.0.0/11',
        'MC': '88.209.64.0/18',
        'MD': '37.246.0.0/16',
        'ME': '178.175.0.0/17',
        'MF': '74.112.232.0/21',
        'MG': '154.126.0.0/17',
        'MH': '117.103.88.0/21',
        'MK': '77.28.0.0/15',
        'ML': '154.118.128.0/18',
        'MM': '37.111.0.0/17',
        'MN': '49.0.128.0/17',
        'MO': '60.246.0.0/16',
        'MP': '202.88.64.0/20',
        'MQ': '109.203.224.0/19',
        'MR': '41.188.64.0/18',
        'MS': '208.90.112.0/22',
        'MT': '46.11.0.0/16',
        'MU': '105.16.0.0/12',
        'MV': '27.114.128.0/18',
        'MW': '102.70.0.0/15',
        'MX': '187.192.0.0/11',
        'MY': '175.136.0.0/13',
        'MZ': '197.218.0.0/15',
        'NA': '41.182.0.0/16',
        'NC': '101.101.0.0/18',
        'NE': '197.214.0.0/18',
        'NF': '203.17.240.0/22',
        'NG': '105.112.0.0/12',
        'NI': '186.76.0.0/15',
        'NL': '145.96.0.0/11',
        'NO': '84.208.0.0/13',
        'NP': '36.252.0.0/15',
        'NR': '203.98.224.0/19',
        'NU': '49.156.48.0/22',
        'NZ': '49.224.0.0/14',
        'OM': '5.36.0.0/15',
        'PA': '186.72.0.0/15',
        'PE': '186.160.0.0/14',
        'PF': '123.50.64.0/18',
        'PG': '124.240.192.0/19',
        'PH': '49.144.0.0/13',
        'PK': '39.32.0.0/11',
        'PL': '83.0.0.0/11',
        'PM': '70.36.0.0/20',
        'PR': '66.50.0.0/16',
        'PS': '188.161.0.0/16',
        'PT': '85.240.0.0/13',
        'PW': '202.124.224.0/20',
        'PY': '181.120.0.0/14',
        'QA': '37.210.0.0/15',
        'RE': '102.35.0.0/16',
        'RO': '79.112.0.0/13',
        'RS': '93.86.0.0/15',
        'RU': '5.136.0.0/13',
        'RW': '41.186.0.0/16',
        'SA': '188.48.0.0/13',
        'SB': '202.1.160.0/19',
        'SC': '154.192.0.0/11',
        'SD': '102.120.0.0/13',
        'SE': '78.64.0.0/12',
        'SG': '8.128.0.0/10',
        'SI': '188.196.0.0/14',
        'SK': '78.98.0.0/15',
        'SL': '102.143.0.0/17',
        'SM': '89.186.32.0/19',
        'SN': '41.82.0.0/15',
        'SO': '154.115.192.0/18',
        'SR': '186.179.128.0/17',
        'SS': '105.235.208.0/21',
        'ST': '197.159.160.0/19',
        'SV': '168.243.0.0/16',
        'SX': '190.102.0.0/20',
        'SY': '5.0.0.0/16',
        'SZ': '41.84.224.0/19',
        'TC': '65.255.48.0/20',
        'TD': '154.68.128.0/19',
        'TG': '196.168.0.0/14',
        'TH': '171.96.0.0/13',
        'TJ': '85.9.128.0/18',
        'TK': '27.96.24.0/21',
        'TL': '180.189.160.0/20',
        'TM': '95.85.96.0/19',
        'TN': '197.0.0.0/11',
        'TO': '175.176.144.0/21',
        'TR': '78.160.0.0/11',
        'TT': '186.44.0.0/15',
        'TV': '202.2.96.0/19',
        'TW': '120.96.0.0/11',
        'TZ': '156.156.0.0/14',
        'UA': '37.52.0.0/14',
        'UG': '102.80.0.0/13',
        'US': '6.0.0.0/8',
        'UY': '167.56.0.0/13',
        'UZ': '84.54.64.0/18',
        'VA': '212.77.0.0/19',
        'VC': '207.191.240.0/21',
        'VE': '186.88.0.0/13',
        'VG': '66.81.192.0/20',
        'VI': '146.226.0.0/16',
        'VN': '14.160.0.0/11',
        'VU': '202.80.32.0/20',
        'WF': '117.20.32.0/21',
        'WS': '202.4.32.0/19',
        'YE': '134.35.0.0/16',
        'YT': '41.242.116.0/22',
        'ZA': '41.0.0.0/11',
        'ZM': '102.144.0.0/13',
        'ZW': '102.177.192.0/18',
    }

    @classmethod
    def random_ipv4(cls, code_or_block):
        if len(code_or_block) == 2:
            block = cls._country_ip_map.get(code_or_block.upper())
            if not block:
                return None
        else:
            block = code_or_block
        addr, preflen = block.split('/')
        addr_min = struct.unpack('!L', socket.inet_aton(addr))[0]
        addr_max = addr_min | (0xffffffff >> int(preflen))
        return str(socket.inet_ntoa(
            struct.pack('!L', random.randint(addr_min, addr_max))))


# Both long_to_bytes and bytes_to_long are adapted from PyCrypto, which is
# released into Public Domain
# https://github.com/dlitz/pycrypto/blob/master/lib/Crypto/Util/number.py#L387

def long_to_bytes(n, blocksize=0):
    """long_to_bytes(n:long, blocksize:int) : string
    Convert a long integer to a byte string.

    If optional blocksize is given and greater than zero, pad the front of the
    byte string with binary zeros so that the length is a multiple of
    blocksize.
    """
    # after much testing, this algorithm was deemed to be the fastest
    s = b''
    n = int(n)
    while n > 0:
        s = struct.pack('>I', n & 0xffffffff) + s
        n = n >> 32
    # strip off leading zeros
    for i in range(len(s)):
        if s[i] != b'\000'[0]:
            break
    else:
        # only happens when n == 0
        s = b'\000'
        i = 0
    s = s[i:]
    # add back some pad bytes.  this could be done more efficiently w.r.t. the
    # de-padding being done above, but sigh...
    if blocksize > 0 and len(s) % blocksize:
        s = (blocksize - len(s) % blocksize) * b'\000' + s
    return s


def bytes_to_long(s):
    """bytes_to_long(string) : long
    Convert a byte string to a long integer.

    This is (essentially) the inverse of long_to_bytes().
    """
    acc = 0
    length = len(s)
    if length % 4:
        extra = (4 - length % 4)
        s = b'\000' * extra + s
        length = length + extra
    for i in range(0, length, 4):
        acc = (acc << 32) + struct.unpack('>I', s[i:i + 4])[0]
    return acc


def ohdave_rsa_encrypt(data, exponent, modulus):
    """
    Implement OHDave's RSA algorithm. See http://www.ohdave.com/rsa/

    Input:
        data: data to encrypt, bytes-like object
        exponent, modulus: parameter e and N of RSA algorithm, both integer
    Output: hex string of encrypted data

    Limitation: supports one block encryption only
    """

    payload = int(binascii.hexlify(data[::-1]), 16)
    encrypted = pow(payload, exponent, modulus)
    return f'{encrypted:x}'


def pkcs1pad(data, length):
    """
    Padding input data with PKCS#1 scheme

    @param {int[]} data        input data
    @param {int}   length      target length
    @returns {int[]}           padded data
    """
    if len(data) > length - 11:
        raise ValueError('Input data too long for PKCS#1 padding')

    pseudo_random = [random.randint(0, 254) for _ in range(length - len(data) - 3)]
    return [0, 2, *pseudo_random, 0, *data]


def _base_n_table(n, table):
    if not table and not n:
        raise ValueError('Either table or n must be specified')
    table = (table or '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')[:n]

    if n and n != len(table):
        raise ValueError(f'base {n} exceeds table length {len(table)}')
    return table


def encode_base_n(num, n=None, table=None):
    """Convert given int to a base-n string"""
    table = _base_n_table(n, table)
    if not num:
        return table[0]

    result, base = '', len(table)
    while num:
        result = table[num % base] + result
        num = num // base
    return result


def decode_base_n(string, n=None, table=None):
    """Convert given base-n string to int"""
    table = {char: index for index, char in enumerate(_base_n_table(n, table))}
    result, base = 0, len(table)
    for char in string:
        result = result * base + table[char]
    return result


def decode_packed_codes(code):
    mobj = re.search(PACKED_CODES_RE, code)
    obfuscated_code, base, count, symbols = mobj.groups()
    base = int(base)
    count = int(count)
    symbols = symbols.split('|')
    symbol_table = {}

    while count:
        count -= 1
        base_n_count = encode_base_n(count, base)
        symbol_table[base_n_count] = symbols[count] or base_n_count

    return re.sub(
        r'\b(\w+)\b', lambda m: symbol_table.get(m.group(0), m.group(0)),
        obfuscated_code)


def caesar(s, alphabet, shift):
    if shift == 0:
        return s
    l = len(alphabet)
    return ''.join(
        alphabet[(alphabet.index(c) + shift) % l] if c in alphabet else c
        for c in s)


def rot47(s):
    return caesar(s, r'''!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~''', 47)


def parse_m3u8_attributes(attrib):
    info = {}
    for (key, val) in re.findall(r'(?P<key>[A-Z0-9-]+)=(?P<val>"[^"]+"|[^",]+)(?:,|$)', attrib):
        if val.startswith('"'):
            val = val[1:-1]
        info[key] = val
    return info


def urshift(val, n):
    return val >> n if val >= 0 else (val + 0x100000000) >> n


def write_xattr(path, key, value):
    # Windows: Write xattrs to NTFS Alternate Data Streams:
    # http://en.wikipedia.org/wiki/NTFS#Alternate_data_streams_.28ADS.29
    if os.name == 'nt':
        assert ':' not in key
        assert os.path.exists(path)

        try:
            with open(f'{path}:{key}', 'wb') as f:
                f.write(value)
        except OSError as e:
            raise XAttrMetadataError(e.errno, e.strerror)
        return

    # UNIX Method 1. Use os.setxattr/xattrs/pyxattrs modules

    setxattr = None
    if callable(getattr(os, 'setxattr', None)):
        setxattr = os.setxattr
    elif getattr(xattr, '_yt_dlp__identifier', None) == 'pyxattr':
        # Unicode arguments are not supported in pyxattr until version 0.5.0
        # See https://github.com/ytdl-org/youtube-dl/issues/5498
        if version_tuple(xattr.__version__) >= (0, 5, 0):
            setxattr = xattr.set
    elif xattr:
        setxattr = xattr.setxattr

    if setxattr:
        try:
            setxattr(path, key, value)
        except OSError as e:
            raise XAttrMetadataError(e.errno, e.strerror)
        return

    # UNIX Method 2. Use setfattr/xattr executables
    exe = ('setfattr' if check_executable('setfattr', ['--version'])
           else 'xattr' if check_executable('xattr', ['-h']) else None)
    if not exe:
        raise XAttrUnavailableError(
            'Couldn\'t find a tool to set the xattrs. Install either the "xattr" or "pyxattr" Python modules or the '
            + ('"xattr" binary' if sys.platform != 'linux' else 'GNU "attr" package (which contains the "setfattr" tool)'))

    value = value.decode()
    try:
        _, stderr, returncode = Popen.run(
            [exe, '-w', key, value, path] if exe == 'xattr' else [exe, '-n', key, '-v', value, path],
            text=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
    except OSError as e:
        raise XAttrMetadataError(e.errno, e.strerror)
    if returncode:
        raise XAttrMetadataError(returncode, stderr)


def random_birthday(year_field, month_field, day_field):
    start_date = dt.date(1950, 1, 1)
    end_date = dt.date(1995, 12, 31)
    offset = random.randint(0, (end_date - start_date).days)
    random_date = start_date + dt.timedelta(offset)
    return {
        year_field: str(random_date.year),
        month_field: str(random_date.month),
        day_field: str(random_date.day),
    }


def find_available_port(interface=''):
    try:
        with socket.socket() as sock:
            sock.bind((interface, 0))
            return sock.getsockname()[1]
    except OSError:
        return None


# Templates for internet shortcut files, which are plain text files.
DOT_URL_LINK_TEMPLATE = '''\
[InternetShortcut]
URL=%(url)s
'''

DOT_WEBLOC_LINK_TEMPLATE = '''\
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
\t<key>URL</key>
\t<string>%(url)s</string>
</dict>
</plist>
'''

DOT_DESKTOP_LINK_TEMPLATE = '''\
[Desktop Entry]
Encoding=UTF-8
Name=%(filename)s
Type=Link
URL=%(url)s
Icon=text-html
'''

LINK_TEMPLATES = {
    'url': DOT_URL_LINK_TEMPLATE,
    'desktop': DOT_DESKTOP_LINK_TEMPLATE,
    'webloc': DOT_WEBLOC_LINK_TEMPLATE,
}


def iri_to_uri(iri):
    """
    Converts an IRI (Internationalized Resource Identifier, allowing Unicode characters) to a URI (Uniform Resource Identifier, ASCII-only).

    The function doesn't add an additional layer of escaping; e.g., it doesn't escape `%3C` as `%253C`. Instead, it percent-escapes characters with an underlying UTF-8 encoding *besides* those already escaped, leaving the URI intact.
    """

    iri_parts = urllib.parse.urlparse(iri)

    if '[' in iri_parts.netloc:
        raise ValueError('IPv6 URIs are not, yet, supported.')
        # Querying `.netloc`, when there's only one bracket, also raises a ValueError.

    # The `safe` argument values, that the following code uses, contain the characters that should not be percent-encoded. Everything else but letters, digits and '_.-' will be percent-encoded with an underlying UTF-8 encoding. Everything already percent-encoded will be left as is.

    net_location = ''
    if iri_parts.username:
        net_location += urllib.parse.quote(iri_parts.username, safe=r"!$%&'()*+,~")
        if iri_parts.password is not None:
            net_location += ':' + urllib.parse.quote(iri_parts.password, safe=r"!$%&'()*+,~")
        net_location += '@'

    net_location += iri_parts.hostname.encode('idna').decode()  # Punycode for Unicode hostnames.
    # The 'idna' encoding produces ASCII text.
    if iri_parts.port is not None and iri_parts.port != 80:
        net_location += ':' + str(iri_parts.port)

    return urllib.parse.urlunparse(
        (iri_parts.scheme,
            net_location,

            urllib.parse.quote_plus(iri_parts.path, safe=r"!$%&'()*+,/:;=@|~"),

            # Unsure about the `safe` argument, since this is a legacy way of handling parameters.
            urllib.parse.quote_plus(iri_parts.params, safe=r"!$%&'()*+,/:;=@|~"),

            # Not totally sure about the `safe` argument, since the source does not explicitly mention the query URI component.
            urllib.parse.quote_plus(iri_parts.query, safe=r"!$%&'()*+,/:;=?@{|}~"),

            urllib.parse.quote_plus(iri_parts.fragment, safe=r"!#$%&'()*+,/:;=?@{|}~")))

    # Source for `safe` arguments: https://url.spec.whatwg.org/#percent-encoded-bytes.


def to_high_limit_path(path):
    if sys.platform in ['win32', 'cygwin']:
        # Work around MAX_PATH limitation on Windows. The maximum allowed length for the individual path segments may still be quite limited.
        return '\\\\?\\' + os.path.abspath(path)

    return path


@partial_application
def format_field(obj, field=None, template='%s', ignore=NO_DEFAULT, default='', func=IDENTITY):
    val = traversal.traverse_obj(obj, *variadic(field))
    if not val if ignore is NO_DEFAULT else val in variadic(ignore):
        return default
    return template % func(val)


def clean_podcast_url(url):
    url = re.sub(r'''(?x)
        (?:
            (?:
                chtbl\.com/track|
                media\.blubrry\.com| # https://create.blubrry.com/resources/podcast-media-download-statistics/getting-started/
                play\.podtrac\.com|
                chrt\.fm/track|
                mgln\.ai/e
            )(?:/[^/.]+)?|
            (?:dts|www)\.podtrac\.com/(?:pts/)?redirect\.[0-9a-z]{3,4}| # http://analytics.podtrac.com/how-to-measure
            flex\.acast\.com|
            pd(?:
                cn\.co| # https://podcorn.com/analytics-prefix/
                st\.fm # https://podsights.com/docs/
            )/e|
            [0-9]\.gum\.fm|
            pscrb\.fm/rss/p
        )/''', '', url)
    return re.sub(r'^\w+://(\w+://)', r'\1', url)


_HEX_TABLE = '0123456789abcdef'


def random_uuidv4():
    return re.sub(r'[xy]', lambda x: _HEX_TABLE[random.randint(0, 15)], 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx')


def make_dir(path, to_screen=None):
    try:
        dn = os.path.dirname(path)
        if dn:
            os.makedirs(dn, exist_ok=True)
        return True
    except OSError as err:
        if callable(to_screen) is not None:
            to_screen(f'unable to create directory {err}')
        return False


def get_executable_path():
    from ..update import _get_variant_and_executable_path

    return os.path.dirname(os.path.abspath(_get_variant_and_executable_path()[1]))


def get_user_config_dirs(package_name):
    # .config (e.g. ~/.config/package_name)
    xdg_config_home = os.getenv('XDG_CONFIG_HOME') or compat_expanduser('~/.config')
    yield os.path.join(xdg_config_home, package_name)

    # appdata (%APPDATA%/package_name)
    appdata_dir = os.getenv('appdata')
    if appdata_dir:
        yield os.path.join(appdata_dir, package_name)

    # home (~/.package_name)
    yield os.path.join(compat_expanduser('~'), f'.{package_name}')


def get_system_config_dirs(package_name):
    # /etc/package_name
    yield os.path.join('/etc', package_name)


def time_seconds(**kwargs):
    """
    Returns TZ-aware time in seconds since the epoch (1970-01-01T00:00:00Z)
    """
    return time.time() + dt.timedelta(**kwargs).total_seconds()


# implemented following JWT https://www.rfc-editor.org/rfc/rfc7519.html
# implemented following JWS https://www.rfc-editor.org/rfc/rfc7515.html
def jwt_encode(payload_data, key, *, alg='HS256', headers=None):
    assert alg in ('HS256',), f'Unsupported algorithm "{alg}"'

    def jwt_json_bytes(obj):
        return json.dumps(obj, separators=(',', ':')).encode()

    def jwt_b64encode(bytestring):
        return base64.urlsafe_b64encode(bytestring).rstrip(b'=')

    header_data = {
        'alg': alg,
        'typ': 'JWT',
    }
    if headers:
        # Allow re-ordering of keys if both 'alg' and 'typ' are present
        if 'alg' in headers and 'typ' in headers:
            header_data = headers
        else:
            header_data.update(headers)

    header_b64 = jwt_b64encode(jwt_json_bytes(header_data))
    payload_b64 = jwt_b64encode(jwt_json_bytes(payload_data))

    # HS256 is the only algorithm currently supported
    h = hmac.new(key.encode(), header_b64 + b'.' + payload_b64, hashlib.sha256)
    signature_b64 = jwt_b64encode(h.digest())

    return (header_b64 + b'.' + payload_b64 + b'.' + signature_b64).decode()


# can be extended in future to verify the signature and parse header and return the algorithm used if it's not HS256
def jwt_decode_hs256(jwt):
    _header_b64, payload_b64, _signature_b64 = jwt.split('.')
    # add trailing ='s that may have been stripped, superfluous ='s are ignored
    return json.loads(base64.urlsafe_b64decode(f'{payload_b64}==='))


@functools.cache
def supports_terminal_sequences(stream):
    if os.name == 'nt':
        if not WINDOWS_VT_MODE.value:
            return False
    elif not os.getenv('TERM'):
        return False
    try:
        return stream.isatty()
    except BaseException:
        return False


def windows_enable_vt_mode():
    """Ref: https://bugs.python.org/issue30075 """
    if get_windows_version() < (10, 0, 10586):
        return

    import ctypes
    import ctypes.wintypes
    import msvcrt

    ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004

    dll = ctypes.WinDLL('kernel32', use_last_error=False)
    handle = os.open('CONOUT$', os.O_RDWR)
    try:
        h_out = ctypes.wintypes.HANDLE(msvcrt.get_osfhandle(handle))
        dw_original_mode = ctypes.wintypes.DWORD()
        success = dll.GetConsoleMode(h_out, ctypes.byref(dw_original_mode))
        if not success:
            raise Exception('GetConsoleMode failed')

        success = dll.SetConsoleMode(h_out, ctypes.wintypes.DWORD(
            dw_original_mode.value | ENABLE_VIRTUAL_TERMINAL_PROCESSING))
        if not success:
            raise Exception('SetConsoleMode failed')
    finally:
        os.close(handle)

    WINDOWS_VT_MODE.value = True
    supports_terminal_sequences.cache_clear()


_terminal_sequences_re = re.compile('\033\\[[^m]+m')


def remove_terminal_sequences(string):
    return _terminal_sequences_re.sub('', string)


def number_of_digits(number):
    return len('%d' % number)


def join_nonempty(*values, delim='-', from_dict=None):
    if from_dict is not None:
        values = (traversal.traverse_obj(from_dict, variadic(v)) for v in values)
    return delim.join(map(str, filter(None, values)))


def scale_thumbnails_to_max_format_width(formats, thumbnails, url_width_re):
    """
    Find the largest format dimensions in terms of video width and, for each thumbnail:
    * Modify the URL: Match the width with the provided regex and replace with the former width
    * Update dimensions

    This function is useful with video services that scale the provided thumbnails on demand
    """
    _keys = ('width', 'height')
    max_dimensions = max(
        (tuple(fmt.get(k) or 0 for k in _keys) for fmt in formats),
        default=(0, 0))
    if not max_dimensions[0]:
        return thumbnails
    return [
        merge_dicts(
            {'url': re.sub(url_width_re, str(max_dimensions[0]), thumbnail['url'])},
            dict(zip(_keys, max_dimensions, strict=True)), thumbnail)
        for thumbnail in thumbnails
    ]


def parse_http_range(range):
    """ Parse value of "Range" or "Content-Range" HTTP header into tuple. """
    if not range:
        return None, None, None
    crg = re.search(r'bytes[ =](\d+)-(\d+)?(?:/(\d+))?', range)
    if not crg:
        return None, None, None
    return int(crg.group(1)), int_or_none(crg.group(2)), int_or_none(crg.group(3))


def read_stdin(what):
    if what:
        eof = 'Ctrl+Z' if os.name == 'nt' else 'Ctrl+D'
        write_string(f'Reading {what} from STDIN - EOF ({eof}) to end:\n')
    return sys.stdin


def determine_file_encoding(data):
    """
    Detect the text encoding used
    @returns (encoding, bytes to skip)
    """

    # BOM marks are given priority over declarations
    for bom, enc in BOMS:
        if data.startswith(bom):
            return enc, len(bom)

    # Strip off all null bytes to match even when UTF-16 or UTF-32 is used.
    # We ignore the endianness to get a good enough match
    data = data.replace(b'\0', b'')
    mobj = re.match(rb'(?m)^#\s*coding\s*:\s*(\S+)\s*$', data)
    return mobj.group(1).decode() if mobj else None, 0


class Config:
    own_args = None
    parsed_args = None
    filename = None
    __initialized = False

    def __init__(self, parser, label=None):
        self.parser, self.label = parser, label
        self._loaded_paths, self.configs = set(), []

    def init(self, args=None, filename=None):
        assert not self.__initialized
        self.own_args, self.filename = args, filename
        return self.load_configs()

    def load_configs(self):
        directory = ''
        if self.filename:
            location = os.path.realpath(self.filename)
            directory = os.path.dirname(location)
            if location in self._loaded_paths:
                return False
            self._loaded_paths.add(location)

        self.__initialized = True
        opts, _ = self.parser.parse_known_args(self.own_args)
        self.parsed_args = self.own_args
        for location in opts.config_locations or []:
            if location == '-':
                if location in self._loaded_paths:
                    continue
                self._loaded_paths.add(location)
                self.append_config(shlex.split(read_stdin('options'), comments=True), label='stdin')
                continue
            location = os.path.join(directory, expand_path(location))
            if os.path.isdir(location):
                location = os.path.join(location, 'yt-dlp.conf')
            if not os.path.exists(location):
                self.parser.error(f'config location {location} does not exist')
            self.append_config(self.read_file(location), location)
        return True

    def __str__(self):
        label = join_nonempty(
            self.label, 'config', f'"{self.filename}"' if self.filename else '',
            delim=' ')
        return join_nonempty(
            self.own_args is not None and f'{label[0].upper()}{label[1:]}: {self.hide_login_info(self.own_args)}',
            *(f'\n{c}'.replace('\n', '\n| ')[1:] for c in self.configs),
            delim='\n')

    @staticmethod
    def read_file(filename, default=[]):
        try:
            optionf = open(filename, 'rb')
        except OSError:
            return default  # silently skip if file is not present
        try:
            enc, skip = determine_file_encoding(optionf.read(512))
            optionf.seek(skip, io.SEEK_SET)
        except OSError:
            enc = None  # silently skip read errors
        try:
            # FIXME: https://github.com/ytdl-org/youtube-dl/commit/dfe5fa49aed02cf36ba9f743b11b0903554b5e56
            contents = optionf.read().decode(enc or preferredencoding())
            res = shlex.split(contents, comments=True)
        except Exception as err:
            raise ValueError(f'Unable to parse "{filename}": {err}')
        finally:
            optionf.close()
        return res

    @staticmethod
    def hide_login_info(opts):
        PRIVATE_OPTS = {'-p', '--password', '-u', '--username', '--video-password', '--ap-password', '--ap-username'}
        eqre = re.compile('^(?P<key>' + ('|'.join(re.escape(po) for po in PRIVATE_OPTS)) + ')=.+$')

        def _scrub_eq(o):
            m = eqre.match(o)
            if m:
                return m.group('key') + '=PRIVATE'
            else:
                return o

        opts = list(map(_scrub_eq, opts))
        for idx, opt in enumerate(opts):
            if opt in PRIVATE_OPTS and idx + 1 < len(opts):
                opts[idx + 1] = 'PRIVATE'
        return opts

    def append_config(self, *args, label=None):
        config = type(self)(self.parser, label)
        config._loaded_paths = self._loaded_paths
        if config.init(*args):
            self.configs.append(config)

    @property
    def all_args(self):
        for config in reversed(self.configs):
            yield from config.all_args
        yield from self.parsed_args or []

    def parse_known_args(self, **kwargs):
        return self.parser.parse_known_args(self.all_args, **kwargs)

    def parse_args(self):
        return self.parser.parse_args(self.all_args)


def merge_headers(*dicts):
    """Merge dicts of http headers case insensitively, prioritizing the latter ones"""
    return {k.title(): v for k, v in itertools.chain.from_iterable(map(dict.items, dicts))}


def cached_method(f):
    """Cache a method"""
    signature = inspect.signature(f)

    @functools.wraps(f)
    def wrapper(self, *args, **kwargs):
        bound_args = signature.bind(self, *args, **kwargs)
        bound_args.apply_defaults()
        key = tuple(bound_args.arguments.values())[1:]

        cache = vars(self).setdefault('_cached_method__cache', {}).setdefault(f.__name__, {})
        if key not in cache:
            cache[key] = f(self, *args, **kwargs)
        return cache[key]
    return wrapper


class classproperty:
    """property access for class methods with optional caching"""
    def __new__(cls, func=None, *args, **kwargs):
        if not func:
            return functools.partial(cls, *args, **kwargs)
        return super().__new__(cls)

    def __init__(self, func, *, cache=False):
        functools.update_wrapper(self, func)
        self.func = func
        self._cache = {} if cache else None

    def __get__(self, _, cls):
        if self._cache is None:
            return self.func(cls)
        elif cls not in self._cache:
            self._cache[cls] = self.func(cls)
        return self._cache[cls]


class function_with_repr:
    def __init__(self, func, repr_=None):
        functools.update_wrapper(self, func)
        self.func, self.__repr = func, repr_

    def __call__(self, *args, **kwargs):
        return self.func(*args, **kwargs)

    @classmethod
    def set_repr(cls, repr_):
        return functools.partial(cls, repr_=repr_)

    def __repr__(self):
        if self.__repr:
            return self.__repr
        return f'{self.func.__module__}.{self.func.__qualname__}'


class Namespace(types.SimpleNamespace):
    """Immutable namespace"""

    def __iter__(self):
        return iter(self.__dict__.values())

    @property
    def items_(self):
        return self.__dict__.items()


MEDIA_EXTENSIONS = Namespace(
    common_video=('avi', 'flv', 'mkv', 'mov', 'mp4', 'webm'),
    video=('3g2', '3gp', 'f4v', 'mk3d', 'divx', 'mpg', 'ogv', 'm4v', 'wmv'),
    common_audio=('aiff', 'alac', 'flac', 'm4a', 'mka', 'mp3', 'ogg', 'opus', 'wav'),
    audio=('aac', 'ape', 'asf', 'f4a', 'f4b', 'm4b', 'm4r', 'oga', 'ogx', 'spx', 'vorbis', 'wma', 'weba'),
    thumbnails=('jpg', 'png', 'webp'),
    storyboards=('mhtml', ),
    subtitles=('srt', 'vtt', 'ass', 'lrc'),
    manifests=('f4f', 'f4m', 'm3u8', 'smil', 'mpd'),
)
MEDIA_EXTENSIONS.video += MEDIA_EXTENSIONS.common_video
MEDIA_EXTENSIONS.audio += MEDIA_EXTENSIONS.common_audio

KNOWN_EXTENSIONS = (*MEDIA_EXTENSIONS.video, *MEDIA_EXTENSIONS.audio, *MEDIA_EXTENSIONS.manifests)


class _UnsafeExtensionError(Exception):
    """
    Mitigation exception for uncommon/malicious file extensions
    This should be caught in YoutubeDL.py alongside a warning

    Ref: https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-79w7-vh3h-8g4j
    """
    ALLOWED_EXTENSIONS = frozenset([
        # internal
        'description',
        'json',
        'meta',
        'orig',
        'part',
        'temp',
        'uncut',
        'unknown_video',
        'ytdl',

        # video
        *MEDIA_EXTENSIONS.video,
        'asx',
        'ismv',
        'm2t',
        'm2ts',
        'm2v',
        'm4s',
        'mng',
        'mp2v',
        'mp4v',
        'mpe',
        'mpeg',
        'mpeg1',
        'mpeg2',
        'mpeg4',
        'mxf',
        'ogm',
        'qt',
        'rm',
        'swf',
        'ts',
        'vid',
        'vob',
        'vp9',

        # audio
        *MEDIA_EXTENSIONS.audio,
        '3ga',
        'ac3',
        'adts',
        'aif',
        'au',
        'dts',
        'isma',
        'it',
        'mid',
        'mod',
        'mpga',
        'mp1',
        'mp2',
        'mp4a',
        'mpa',
        'ra',
        'shn',
        'xm',

        # image
        *MEDIA_EXTENSIONS.thumbnails,
        'avif',
        'bmp',
        'gif',
        'heic',
        'ico',
        'image',
        'jfif',
        'jng',
        'jpe',
        'jpeg',
        'jxl',
        'svg',
        'tif',
        'tiff',
        'wbmp',

        # subtitle
        *MEDIA_EXTENSIONS.subtitles,
        'dfxp',
        'fs',
        'ismt',
        'json3',
        'sami',
        'scc',
        'srv1',
        'srv2',
        'srv3',
        'ssa',
        'tt',
        'ttml',
        'xml',

        # others
        *MEDIA_EXTENSIONS.manifests,
        *MEDIA_EXTENSIONS.storyboards,
        'ism',
        'm3u',
        'sbv',
    ])

    def __init__(self, extension, /):
        super().__init__(f'unsafe file extension: {extension!r}')
        self.extension = extension

    @classmethod
    def sanitize_extension(cls, extension, /, *, prepend=False, _allowed_exts=()):
        if extension is None:
            return None

        if '/' in extension or '\\' in extension:
            raise cls(extension)

        if not prepend:
            _, _, last = extension.rpartition('.')
            if last == 'bin':
                extension = last = 'unknown_video'
            allowed = _allowed_exts or cls.ALLOWED_EXTENSIONS
            if last.lower() not in allowed:
                raise cls(extension)

        return extension


class RetryManager:
    """Usage:
        for retry in RetryManager(...):
            try:
                ...
            except SomeException as err:
                retry.error = err
                continue
    """
    attempt, _error = 0, None

    def __init__(self, _retries, _error_callback, **kwargs):
        self.retries = _retries or 0
        self.error_callback = functools.partial(_error_callback, **kwargs)

    def _should_retry(self):
        return self._error is not NO_DEFAULT and self.attempt <= self.retries

    @property
    def error(self):
        if self._error is NO_DEFAULT:
            return None
        return self._error

    @error.setter
    def error(self, value):
        self._error = value

    def __iter__(self):
        while self._should_retry():
            self.error = NO_DEFAULT
            self.attempt += 1
            yield self
            if self.error:
                self.error_callback(self.error, self.attempt, self.retries)

    @staticmethod
    def report_retry(e, count, retries, *, sleep_func, info, warn, error=None, suffix=None):
        """Utility function for reporting retries"""
        if count > retries:
            if error:
                return error(f'{e}. Giving up after {count - 1} retries') if count > 1 else error(str(e))
            raise e

        if not count:
            return warn(e)
        elif isinstance(e, ExtractorError):
            e = remove_end(str_or_none(e.cause) or e.orig_msg, '.')
        warn(f'{e}. Retrying{format_field(suffix, None, " %s")} ({count}/{retries})...')

        delay = float_or_none(sleep_func(n=count - 1)) if callable(sleep_func) else sleep_func
        if delay:
            info(f'Sleeping {delay:.2f} seconds ...')
            time.sleep(delay)


@partial_application
def make_archive_id(ie, video_id):
    ie_key = ie if isinstance(ie, str) else ie.ie_key()
    return f'{ie_key.lower()} {video_id}'


@partial_application
def truncate_string(s, left, right=0):
    assert left > 3 and right >= 0
    if s is None or len(s) <= left + right:
        return s
    return f'{s[:left - 3]}...{s[-right:] if right else ""}'


def orderedSet_from_options(options, alias_dict, *, use_regex=False, start=None):
    assert 'all' in alias_dict, '"all" alias is required'
    requested = list(start or [])
    for val in options:
        discard = val.startswith('-')
        if discard:
            val = val[1:]

        if val in alias_dict:
            val = alias_dict[val] if not discard else [
                i[1:] if i.startswith('-') else f'-{i}' for i in alias_dict[val]]
            # NB: Do not allow regex in aliases for performance
            requested = orderedSet_from_options(val, alias_dict, start=requested)
            continue

        current = (filter(re.compile(val, re.I).fullmatch, alias_dict['all']) if use_regex
                   else [val] if val in alias_dict['all'] else None)
        if current is None:
            raise ValueError(val)

        if discard:
            for item in current:
                while item in requested:
                    requested.remove(item)
        else:
            requested.extend(current)

    return orderedSet(requested)


# TODO: Rewrite
class FormatSorter:
    regex = r' *((?P<reverse>\+)?(?P<field>[a-zA-Z0-9_]+)((?P<separator>[~:])(?P<limit>.*?))?)? *$'

    default = ('hidden', 'aud_or_vid', 'hasvid', 'ie_pref', 'lang', 'quality',
               'res', 'fps', 'hdr:12', 'vcodec', 'channels', 'acodec',
               'size', 'br', 'asr', 'proto', 'ext', 'hasaud', 'source', 'id')  # These must not be aliases
    _prefer_vp9_sort = ('hidden', 'aud_or_vid', 'hasvid', 'ie_pref', 'lang', 'quality',
                        'res', 'fps', 'hdr:12', 'vcodec:vp9.2', 'channels', 'acodec',
                        'size', 'br', 'asr', 'proto', 'ext', 'hasaud', 'source', 'id')
    ytdl_default = ('hasaud', 'lang', 'quality', 'tbr', 'filesize', 'vbr',
                    'height', 'width', 'proto', 'vext', 'abr', 'aext',
                    'fps', 'fs_approx', 'source', 'id')

    settings = {
        'vcodec': {'type': 'ordered', 'regex': True,
                   'order': ['av0?1', r'vp0?9\.0?2', 'vp0?9', '[hx]265|he?vc?', '[hx]264|avc', 'vp0?8', 'mp4v|h263', 'theora', '', None, 'none']},
        'acodec': {'type': 'ordered', 'regex': True,
                   'order': ['[af]lac', 'wav|aiff', 'opus', 'vorbis|ogg', 'aac', 'mp?4a?', 'mp3', 'ac-?4', 'e-?a?c-?3', 'ac-?3', 'dts', '', None, 'none']},
        'hdr': {'type': 'ordered', 'regex': True, 'field': 'dynamic_range',
                'order': ['dv', '(hdr)?12', r'(hdr)?10\+', '(hdr)?10', 'hlg', '', 'sdr', None]},
        'proto': {'type': 'ordered', 'regex': True, 'field': 'protocol',
                  'order': ['(ht|f)tps', '(ht|f)tp$', 'm3u8.*', '.*dash', 'websocket_frag', 'rtmpe?', '', 'mms|rtsp', 'ws|websocket', 'f4']},
        'vext': {'type': 'ordered', 'field': 'video_ext',
                 'order': ('mp4', 'mov', 'webm', 'flv', '', 'none'),
                 'order_free': ('webm', 'mp4', 'mov', 'flv', '', 'none')},
        'aext': {'type': 'ordered', 'regex': True, 'field': 'audio_ext',
                 'order': ('m4a', 'aac', 'mp3', 'ogg', 'opus', 'web[am]', '', 'none'),
                 'order_free': ('ogg', 'opus', 'web[am]', 'mp3', 'm4a', 'aac', '', 'none')},
        'hidden': {'visible': False, 'forced': True, 'type': 'extractor', 'max': -1000},
        'aud_or_vid': {'visible': False, 'forced': True, 'type': 'multiple',
                       'field': ('vcodec', 'acodec'),
                       'function': lambda it: int(any(v != 'none' for v in it))},
        'ie_pref': {'priority': True, 'type': 'extractor'},
        'hasvid': {'priority': True, 'field': 'vcodec', 'type': 'boolean', 'not_in_list': ('none',)},
        'hasaud': {'field': 'acodec', 'type': 'boolean', 'not_in_list': ('none',)},
        'lang': {'convert': 'float', 'field': 'language_preference', 'default': -1},
        'quality': {'convert': 'float', 'default': -1},
        'filesize': {'convert': 'bytes'},
        'fs_approx': {'convert': 'bytes', 'field': 'filesize_approx'},
        'id': {'convert': 'string', 'field': 'format_id'},
        'height': {'convert': 'float_none'},
        'width': {'convert': 'float_none'},
        'fps': {'convert': 'float_none'},
        'channels': {'convert': 'float_none', 'field': 'audio_channels'},
        'tbr': {'convert': 'float_none'},
        'vbr': {'convert': 'float_none'},
        'abr': {'convert': 'float_none'},
        'asr': {'convert': 'float_none'},
        'source': {'convert': 'float', 'field': 'source_preference', 'default': -1},

        'codec': {'type': 'combined', 'field': ('vcodec', 'acodec')},
        'br': {'type': 'multiple', 'field': ('tbr', 'vbr', 'abr'), 'convert': 'float_none',
               'function': lambda it: next(filter(None, it), None)},
        'size': {'type': 'multiple', 'field': ('filesize', 'fs_approx'), 'convert': 'bytes',
                 'function': lambda it: next(filter(None, it), None)},
        'ext': {'type': 'combined', 'field': ('vext', 'aext')},
        'res': {'type': 'multiple', 'field': ('height', 'width'),
                'function': lambda it: min(filter(None, it), default=0)},

        # Actual field names
        'format_id': {'type': 'alias', 'field': 'id'},
        'preference': {'type': 'alias', 'field': 'ie_pref'},
        'language_preference': {'type': 'alias', 'field': 'lang'},
        'source_preference': {'type': 'alias', 'field': 'source'},
        'protocol': {'type': 'alias', 'field': 'proto'},
        'filesize_approx': {'type': 'alias', 'field': 'fs_approx'},
        'audio_channels': {'type': 'alias', 'field': 'channels'},

        # Deprecated
        'dimension': {'type': 'alias', 'field': 'res', 'deprecated': True},
        'resolution': {'type': 'alias', 'field': 'res', 'deprecated': True},
        'extension': {'type': 'alias', 'field': 'ext', 'deprecated': True},
        'bitrate': {'type': 'alias', 'field': 'br', 'deprecated': True},
        'total_bitrate': {'type': 'alias', 'field': 'tbr', 'deprecated': True},
        'video_bitrate': {'type': 'alias', 'field': 'vbr', 'deprecated': True},
        'audio_bitrate': {'type': 'alias', 'field': 'abr', 'deprecated': True},
        'framerate': {'type': 'alias', 'field': 'fps', 'deprecated': True},
        'filesize_estimate': {'type': 'alias', 'field': 'size', 'deprecated': True},
        'samplerate': {'type': 'alias', 'field': 'asr', 'deprecated': True},
        'video_ext': {'type': 'alias', 'field': 'vext', 'deprecated': True},
        'audio_ext': {'type': 'alias', 'field': 'aext', 'deprecated': True},
        'video_codec': {'type': 'alias', 'field': 'vcodec', 'deprecated': True},
        'audio_codec': {'type': 'alias', 'field': 'acodec', 'deprecated': True},
        'video': {'type': 'alias', 'field': 'hasvid', 'deprecated': True},
        'has_video': {'type': 'alias', 'field': 'hasvid', 'deprecated': True},
        'audio': {'type': 'alias', 'field': 'hasaud', 'deprecated': True},
        'has_audio': {'type': 'alias', 'field': 'hasaud', 'deprecated': True},
        'extractor': {'type': 'alias', 'field': 'ie_pref', 'deprecated': True},
        'extractor_preference': {'type': 'alias', 'field': 'ie_pref', 'deprecated': True},
    }

    def __init__(self, ydl, field_preference):
        self.ydl = ydl
        self._order = []
        self.evaluate_params(self.ydl.params, field_preference)
        if ydl.params.get('verbose'):
            self.print_verbose_info(self.ydl.write_debug)

    def _get_field_setting(self, field, key):
        if field not in self.settings:
            if key in ('forced', 'priority'):
                return False
            self.ydl.deprecated_feature(f'Using arbitrary fields ({field}) for format sorting is '
                                        'deprecated and may be removed in a future version')
            self.settings[field] = {}
        prop_obj = self.settings[field]
        if key not in prop_obj:
            type_ = prop_obj.get('type')
            if key == 'field':
                default = 'preference' if type_ == 'extractor' else (field,) if type_ in ('combined', 'multiple') else field
            elif key == 'convert':
                default = 'order' if type_ == 'ordered' else 'float_string' if field else 'ignore'
            else:
                default = {'type': 'field', 'visible': True, 'order': [], 'not_in_list': (None,)}.get(key)
            prop_obj[key] = default
        return prop_obj[key]

    def _resolve_field_value(self, field, value, convert_none=False):
        if value is None:
            if not convert_none:
                return None
        else:
            value = value.lower()
        conversion = self._get_field_setting(field, 'convert')
        if conversion == 'ignore':
            return None
        if conversion == 'string':
            return value
        elif conversion == 'float_none':
            return float_or_none(value)
        elif conversion == 'bytes':
            return parse_bytes(value)
        elif conversion == 'order':
            order_list = (self._use_free_order and self._get_field_setting(field, 'order_free')) or self._get_field_setting(field, 'order')
            use_regex = self._get_field_setting(field, 'regex')
            list_length = len(order_list)
            empty_pos = order_list.index('') if '' in order_list else list_length + 1
            if use_regex and value is not None:
                for i, regex in enumerate(order_list):
                    if regex and re.match(regex, value):
                        return list_length - i
                return list_length - empty_pos  # not in list
            else:  # not regex or  value = None
                return list_length - (order_list.index(value) if value in order_list else empty_pos)
        else:
            if value.isnumeric():
                return float(value)
            else:
                self.settings[field]['convert'] = 'string'
                return value

    def evaluate_params(self, params, sort_extractor):
        self._use_free_order = params.get('prefer_free_formats', False)
        self._sort_user = params.get('format_sort', [])
        self._sort_extractor = sort_extractor

        def add_item(field, reverse, closest, limit_text):
            field = field.lower()
            if field in self._order:
                return
            self._order.append(field)
            limit = self._resolve_field_value(field, limit_text)
            data = {
                'reverse': reverse,
                'closest': False if limit is None else closest,
                'limit_text': limit_text,
                'limit': limit}
            if field in self.settings:
                self.settings[field].update(data)
            else:
                self.settings[field] = data

        sort_list = (
            tuple(field for field in self.default if self._get_field_setting(field, 'forced'))
            + (tuple() if params.get('format_sort_force', False)
                else tuple(field for field in self.default if self._get_field_setting(field, 'priority')))
            + tuple(self._sort_user) + tuple(sort_extractor) + self.default)

        for item in sort_list:
            match = re.match(self.regex, item)
            if match is None:
                raise ExtractorError(f'Invalid format sort string "{item}" given by extractor')
            field = match.group('field')
            if field is None:
                continue
            if self._get_field_setting(field, 'type') == 'alias':
                alias, field = field, self._get_field_setting(field, 'field')
                if self._get_field_setting(alias, 'deprecated'):
                    self.ydl.deprecated_feature(f'Format sorting alias {alias} is deprecated and may '
                                                f'be removed in a future version. Please use {field} instead')
            reverse = match.group('reverse') is not None
            closest = match.group('separator') == '~'
            limit_text = match.group('limit')

            has_limit = limit_text is not None
            has_multiple_fields = self._get_field_setting(field, 'type') == 'combined'
            has_multiple_limits = has_limit and has_multiple_fields and not self._get_field_setting(field, 'same_limit')

            fields = self._get_field_setting(field, 'field') if has_multiple_fields else (field,)
            limits = limit_text.split(':') if has_multiple_limits else (limit_text,) if has_limit else tuple()
            limit_count = len(limits)
            for (i, f) in enumerate(fields):
                add_item(f, reverse, closest,
                         limits[i] if i < limit_count
                         else limits[0] if has_limit and not has_multiple_limits
                         else None)

    def print_verbose_info(self, write_debug):
        if self._sort_user:
            write_debug('Sort order given by user: {}'.format(', '.join(self._sort_user)))
        if self._sort_extractor:
            write_debug('Sort order given by extractor: {}'.format(', '.join(self._sort_extractor)))
        write_debug('Formats sorted by: {}'.format(', '.join(['{}{}{}'.format(
            '+' if self._get_field_setting(field, 'reverse') else '', field,
            '{}{}({})'.format('~' if self._get_field_setting(field, 'closest') else ':',
                              self._get_field_setting(field, 'limit_text'),
                              self._get_field_setting(field, 'limit'))
            if self._get_field_setting(field, 'limit_text') is not None else '')
            for field in self._order if self._get_field_setting(field, 'visible')])))

    def _calculate_field_preference_from_value(self, format_, field, type_, value):
        reverse = self._get_field_setting(field, 'reverse')
        closest = self._get_field_setting(field, 'closest')
        limit = self._get_field_setting(field, 'limit')

        if type_ == 'extractor':
            maximum = self._get_field_setting(field, 'max')
            if value is None or (maximum is not None and value >= maximum):
                value = -1
        elif type_ == 'boolean':
            in_list = self._get_field_setting(field, 'in_list')
            not_in_list = self._get_field_setting(field, 'not_in_list')
            value = 0 if ((in_list is None or value in in_list) and (not_in_list is None or value not in not_in_list)) else -1
        elif type_ == 'ordered':
            value = self._resolve_field_value(field, value, True)

        # try to convert to number
        val_num = float_or_none(value, default=self._get_field_setting(field, 'default'))
        is_num = self._get_field_setting(field, 'convert') != 'string' and val_num is not None
        if is_num:
            value = val_num

        return ((-10, 0) if value is None
                else (1, value, 0) if not is_num  # if a field has mixed strings and numbers, strings are sorted higher
                else (0, -abs(value - limit), value - limit if reverse else limit - value) if closest
                else (0, value, 0) if not reverse and (limit is None or value <= limit)
                else (0, -value, 0) if limit is None or (reverse and value == limit) or value > limit
                else (-1, value, 0))

    def _calculate_field_preference(self, format_, field):
        type_ = self._get_field_setting(field, 'type')  # extractor, boolean, ordered, field, multiple
        get_value = lambda f: format_.get(self._get_field_setting(f, 'field'))
        if type_ == 'multiple':
            type_ = 'field'  # Only 'field' is allowed in multiple for now
            actual_fields = self._get_field_setting(field, 'field')

            value = self._get_field_setting(field, 'function')(get_value(f) for f in actual_fields)
        else:
            value = get_value(field)
        return self._calculate_field_preference_from_value(format_, field, type_, value)

    @staticmethod
    def _fill_sorting_fields(format):
        # Determine missing protocol
        if not format.get('protocol'):
            format['protocol'] = determine_protocol(format)

        # Determine missing ext
        if not format.get('ext') and 'url' in format:
            format['ext'] = determine_ext(format['url']).lower()
        if format.get('vcodec') == 'none':
            format['audio_ext'] = format['ext'] if format.get('acodec') != 'none' else 'none'
            format['video_ext'] = 'none'
        else:
            format['video_ext'] = format['ext']
            format['audio_ext'] = 'none'
        # if format.get('preference') is None and format.get('ext') in ('f4f', 'f4m'):  # Not supported?
        #    format['preference'] = -1000

        if format.get('preference') is None and format.get('ext') == 'flv' and re.match('[hx]265|he?vc?', format.get('vcodec') or ''):
            # HEVC-over-FLV is out-of-spec by FLV's original spec
            # ref. https://trac.ffmpeg.org/ticket/6389
            # ref. https://github.com/yt-dlp/yt-dlp/pull/5821
            format['preference'] = -100

        # Determine missing bitrates
        if format.get('vcodec') == 'none':
            format['vbr'] = 0
        if format.get('acodec') == 'none':
            format['abr'] = 0
        if not format.get('vbr') and format.get('vcodec') != 'none':
            format['vbr'] = try_call(lambda: format['tbr'] - format['abr']) or None
        if not format.get('abr') and format.get('acodec') != 'none':
            format['abr'] = try_call(lambda: format['tbr'] - format['vbr']) or None
        if not format.get('tbr'):
            format['tbr'] = try_call(lambda: format['vbr'] + format['abr']) or None

    def calculate_preference(self, format):
        self._fill_sorting_fields(format)
        return tuple(self._calculate_field_preference(format, field) for field in self._order)


def filesize_from_tbr(tbr, duration):
    """
    @param tbr:      Total bitrate in kbps (1000 bits/sec)
    @param duration: Duration in seconds
    @returns         Filesize in bytes
    """
    if tbr is None or duration is None:
        return None
    return int(duration * tbr * (1000 / 8))


def _request_dump_filename(url, video_id, data=None, trim_length=None):
    if data is not None:
        data = hashlib.md5(data).hexdigest()
    basen = join_nonempty(video_id, data, url, delim='_')
    trim_length = trim_length or 240
    if len(basen) > trim_length:
        h = '___' + hashlib.md5(basen.encode()).hexdigest()
        basen = basen[:trim_length - len(h)] + h
    filename = sanitize_filename(f'{basen}.dump', restricted=True)
    # Working around MAX_PATH limitation on Windows (see
    # http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx)
    if os.name == 'nt':
        absfilepath = os.path.abspath(filename)
        if len(absfilepath) > 259:
            filename = fR'\\?\{absfilepath}'
    return filename


# XXX: Temporary
class _YDLLogger:
    def __init__(self, ydl=None):
        self._ydl = ydl

    def debug(self, message):
        if self._ydl:
            self._ydl.write_debug(message)

    def info(self, message):
        if self._ydl:
            self._ydl.to_screen(message)

    def warning(self, message, *, once=False):
        if self._ydl:
            self._ydl.report_warning(message, once)

    def error(self, message, *, is_error=True):
        if self._ydl:
            self._ydl.report_error(message, is_error=is_error)

    def stdout(self, message):
        if self._ydl:
            self._ydl.to_stdout(message)

    def stderr(self, message):
        if self._ydl:
            self._ydl.to_stderr(message)


class _ProgressState(enum.Enum):
    """
    Represents a state for a progress bar.

    See: https://conemu.github.io/en/AnsiEscapeCodes.html#ConEmu_specific_OSC
    """

    HIDDEN = 0
    INDETERMINATE = 3
    VISIBLE = 1
    WARNING = 4
    ERROR = 2

    @classmethod
    def from_dict(cls, s, /):
        if s['status'] == 'finished':
            return cls.INDETERMINATE

        # Not currently used
        if s['status'] == 'error':
            return cls.ERROR

        return cls.INDETERMINATE if s.get('_percent') is None else cls.VISIBLE

    def get_ansi_escape(self, /, percent=None):
        percent = 0 if percent is None else int(percent)
        return f'\033]9;4;{self.value};{percent}\007'
