"""Safe Uqload URL validation and Dean Edwards packer decoding."""

from __future__ import annotations

import re
from urllib.parse import urlparse


UQLOAD_ROOT_DOMAINS = (
    "uqload.is",
    "uqload.bz",
    "uqload.cx",
    "uqload.com",
    "uqload.net",
    "uqload.org",
    "uqload.to",
    "uqload.io",
    "uqload.co",
)

PACKER_SIGNATURE_RE = re.compile(
    r"eval\s*\(\s*function\s*\(\s*p\s*,\s*a\s*,\s*c\s*,\s*k\s*,"
    r"\s*e\s*,\s*d\s*\)"
)
PACKER_SINGLE_QUOTE_RE = re.compile(
    r"\}\s*\(\s*'((?:[^'\\]|\\.)*)'\s*,\s*(\d+)\s*,\s*(\d+)\s*,"
    r"\s*'((?:[^'\\]|\\.)*)'\s*\.split",
    re.DOTALL,
)
PACKER_DOUBLE_QUOTE_RE = re.compile(
    r'\}\s*\(\s*"((?:[^"\\]|\\.)*)"\s*,\s*(\d+)\s*,\s*(\d+)\s*,'
    r'\s*"((?:[^"\\]|\\.)*)"\s*\.split',
    re.DOTALL,
)
HTTPS_URL_RE = re.compile(r"""https://[^\s"'\\<>]+""", re.IGNORECASE)
VIDEO_ID_RE = re.compile(r"^[a-z0-9_-]+$", re.IGNORECASE)


def get_uqload_root_domain(hostname: str | None) -> str | None:
    host = str(hostname or "").lower().rstrip(".")
    return next(
        (
            root
            for root in UQLOAD_ROOT_DOMAINS
            if host == root or host.endswith(f".{root}")
        ),
        None,
    )


def parse_allowed_uqload_url(raw_url: str):
    try:
        parsed = urlparse(str(raw_url or "").strip())
        port = parsed.port
    except (TypeError, ValueError):
        raise ValueError("Invalid Uqload URL") from None

    if (
        parsed.scheme != "https"
        or not parsed.hostname
        or parsed.username
        or parsed.password
        or (port is not None and port != 443)
        or not get_uqload_root_domain(parsed.hostname)
    ):
        raise ValueError("Invalid Uqload URL")
    return parsed


def normalize_uqload_embed_url(raw_url: str) -> str:
    parsed = parse_allowed_uqload_url(raw_url)
    last_part = next(
        (part for part in reversed(parsed.path.split("/")) if part),
        "",
    )
    video_id = re.sub(r"^embed-", "", last_part, flags=re.IGNORECASE)
    video_id = re.sub(r"\.html$", "", video_id, flags=re.IGNORECASE)
    if not VIDEO_ID_RE.fullmatch(video_id):
        raise ValueError("Invalid Uqload URL")

    authority = parsed.hostname
    if parsed.port:
        authority = f"{authority}:{parsed.port}"
    return f"https://{authority}/embed-{video_id}.html"


def get_uqload_site_origin(raw_url: str) -> str:
    parsed = parse_allowed_uqload_url(raw_url)
    return f"https://{get_uqload_root_domain(parsed.hostname)}"


def _number_to_base(number: int, radix: int) -> str:
    quotient, remainder = divmod(number, radix)
    if remainder > 35:
        digit = chr(remainder + 29)
    else:
        digit = "0123456789abcdefghijklmnopqrstuvwxyz"[remainder]
    return (_number_to_base(quotient, radix) if quotient else "") + digit


def unpack_dean_edwards(
    packed_script: str,
    radix: int,
    keyword_count: int,
    keywords: list[str],
) -> str:
    if (
        radix < 2
        or radix > 62
        or keyword_count < 0
        or keyword_count > 10_000
        or keyword_count > len(keywords)
    ):
        raise ValueError("Invalid packed script")

    lookup = {}
    for index in range(keyword_count - 1, -1, -1):
        token = _number_to_base(index, radix)
        lookup[token] = keywords[index] if index < len(keywords) and keywords[index] else token

    return re.sub(
        r"\b\w+\b",
        lambda match: lookup.get(match.group(0), match.group(0)),
        packed_script,
    )


def decode_packed_script_from_html(html: str) -> str | None:
    content = str(html or "")
    signature = PACKER_SIGNATURE_RE.search(content)
    if not signature:
        return None

    split_match = re.search(r"""\.split\s*\(\s*(['"])\|\1\s*\)""", content[signature.start() :])
    if not split_match:
        return None
    split_end = signature.start() + split_match.end()
    section = content[signature.start() : split_end]

    match = PACKER_SINGLE_QUOTE_RE.search(section) or PACKER_DOUBLE_QUOTE_RE.search(section)
    if not match:
        return None

    payload = match.group(1).replace("\\'", "'").replace('\\"', '"')
    radix = int(match.group(2))
    keyword_count = int(match.group(3))
    keywords = match.group(4).split("|")
    try:
        return unpack_dean_edwards(payload, radix, keyword_count, keywords)
    except ValueError:
        return None


def extract_uqload_media_url(html: str) -> str | None:
    candidates: list[str] = []

    def collect(value: str | None) -> None:
        normalized = str(value or "").replace("\\/", "/")
        for match in HTTPS_URL_RE.finditer(normalized):
            candidate = match.group(0).rstrip("),;")
            try:
                parse_allowed_uqload_url(candidate)
            except ValueError:
                continue
            candidates.append(candidate)

    collect(html)
    collect(decode_packed_script_from_html(html))

    for pattern in (
        re.compile(r"/master\.m3u8(?:[?#]|$)", re.IGNORECASE),
        re.compile(r"\.m3u8(?:[?#]|$)", re.IGNORECASE),
        re.compile(r"/v\.mp4(?:[?#]|$)", re.IGNORECASE),
    ):
        match = next((url for url in candidates if pattern.search(url)), None)
        if match:
            return match
    return None