import logging
import os
import time
import re
from typing import Optional
import yt_dlp

logger = logging.getLogger(__name__)

CACHE_TTL = int(os.getenv("CACHE_TTL", 31536000))

_session_cache = {}
_cache_timestamps = {}


def _is_hls_url(url: str) -> bool:
    return url.endswith(".m3u8") or "m3u8" in url


def _get_cache_key(video_url: str) -> str:
    return video_url


def _is_cache_expired(video_url: str) -> bool:
    key = _get_cache_key(video_url)
    if key not in _cache_timestamps:
        return True
    return time.time() - _cache_timestamps[key] > CACHE_TTL


def _get_cached_session(video_url: str) -> Optional[dict]:
    key = _get_cache_key(video_url)
    if key in _session_cache and not _is_cache_expired(video_url):
        return _session_cache[key]
    return None


def _set_cached_session(video_url: str, session_data: dict) -> None:
    key = _get_cache_key(video_url)
    _session_cache[key] = session_data
    _cache_timestamps[key] = time.time()


def clear_expired_cache() -> None:
    expired_keys = [
        key for key in _session_cache
        if _is_cache_expired(key)
    ]
    for key in expired_keys:
        del _session_cache[key]
        del _cache_timestamps[key]


def get_hls_playlist(video_url: str) -> str:
    cached = _get_cached_session(video_url)
    if cached and "hls_playlist" in cached:
        return cached["hls_playlist"]

    if _is_hls_url(video_url):
        hls_url = video_url
    else:
        ydl_opts = {
            "quiet": True,
            "no_warnings": True,
            "socket_timeout": int(os.getenv("SOCKET_TIMEOUT", 30)),
        }

        with yt_dlp.YoutubeDL(ydl_opts) as ydl:
            info = ydl.extract_info(video_url, download=False)

            if not info or "hls" not in info or not info["hls"]:
                raise ValueError("No HLS stream available for this video")

            hls_url = info["hls"]

    import urllib.request
    with urllib.request.urlopen(hls_url, timeout=30) as response:
        playlist_content = response.read().decode("utf-8")

    session_data = {
        "hls_playlist": playlist_content,
        "hls_url": hls_url,
        "video_url": video_url,
    }
    _set_cached_session(video_url, session_data)

    return playlist_content


def get_hls_segment(video_url: str, segment_name: str) -> bytes:
    cached = _get_cached_session(video_url)
    if not cached or "hls_url" not in cached:
        get_hls_playlist(video_url)
        cached = _get_cached_session(video_url)

    hls_url = cached["hls_url"]
    base_url = hls_url.rsplit("/", 1)[0]

    if segment_name.startswith("/"):
        segment_name = segment_name[1:]

    segment_url = f"{base_url}/{segment_name}"

    import urllib.request
    with urllib.request.urlopen(segment_url, timeout=30) as response:
        return response.read()


def get_stream_info(video_url: str) -> dict:
    cached = _get_cached_session(video_url)
    if cached:
        return cached

    if _is_hls_url(video_url):
        return {
            "title": "Test Video",
            "hls_url": video_url,
            "thumbnail": None,
        }

    ydl_opts = {
        "quiet": True,
        "no_warnings": True,
        "socket_timeout": int(os.getenv("SOCKET_TIMEOUT", 30)),
    }

    with yt_dlp.YoutubeDL(ydl_opts) as ydl:
        info = ydl.extract_info(video_url, download=False)

        if not info:
            raise ValueError("Could not extract video info")

        return {
            "title": info.get("title", "Unknown"),
            "hls_url": info.get("hls"),
            "thumbnail": info.get("thumbnail"),
        }