import asyncio
import uuid
import os
from pathlib import Path
from urllib.parse import urlparse, parse_qs, urlencode, urlunparse
from app.config import settings

AUDIO_TMP_DIR = "/tmp/apoena-audio"

# Query parameters that are tracking/share metadata and not part of the video identity
_STRIP_PARAMS = {"si", "is", "feature", "pp", "ab_channel"}


def normalize_youtube_url(url: str) -> str:
    """Normalize YouTube URLs to canonical form for yt-dlp compatibility.

    Converts youtu.be short URLs to youtube.com/watch?v= and strips
    tracking/share parameters (si=, is=, feature=, etc.).
    """
    parsed = urlparse(url)
    netloc = parsed.netloc.lower()

    if netloc in ("youtu.be", "www.youtu.be"):
        video_id = parsed.path.lstrip("/")
        if video_id:
            return f"https://www.youtube.com/watch?v={video_id}"

    if netloc in ("youtube.com", "www.youtube.com", "m.youtube.com"):
        qs = parse_qs(parsed.query, keep_blank_values=True)
        cleaned = {k: v for k, v in qs.items() if k not in _STRIP_PARAMS}
        new_query = urlencode({k: v[0] for k, v in cleaned.items()})
        return urlunparse(parsed._replace(netloc="www.youtube.com", query=new_query))

    return url


async def extract_audio(url: str) -> Path:
    """Download audio-only from a URL using yt-dlp. Returns path to an mp3 temp file."""
    url = normalize_youtube_url(url)
    job_id = str(uuid.uuid4())
    outtmpl = f"{AUDIO_TMP_DIR}/{job_id}.%(ext)s"
    expected = Path(f"{AUDIO_TMP_DIR}/{job_id}.mp3")

    cmd = [
        "yt-dlp",
        "--extract-audio",
        "--audio-format", "mp3",
        "--audio-quality", "128K",
        "--format", "bestaudio/best/b",
        "--extractor-args", "youtube:player_client=ios,web",
        "--output", outtmpl,
    ]

    if settings.yt_dlp_cookies_file:
        cmd += ["--cookies", settings.yt_dlp_cookies_file]

    cmd.append(url)

    proc = await asyncio.create_subprocess_exec(
        *cmd,
        stdout=asyncio.subprocess.PIPE,
        stderr=asyncio.subprocess.PIPE,
    )
    _, stderr = await proc.communicate()
    stderr_text = stderr.decode().strip()

    if stderr_text:
        import logging
        logging.getLogger(__name__).warning("yt-dlp stderr: %s", stderr_text)

    if proc.returncode != 0:
        raise RuntimeError(stderr_text or "yt-dlp failed with no output")

    if expected.exists():
        return expected

    # yt-dlp sometimes keeps the original extension even with --audio-format mp3
    # Find whatever file was created with this job_id prefix
    for f in Path(AUDIO_TMP_DIR).glob(f"{job_id}.*"):
        return f

    raise RuntimeError("yt-dlp produced no output file")