AudiOhm/backend/app/services/youtube_service.py

"""YouTube service using yt-dlp."""
import asyncio
import json
import subprocess
from pathlib import Path
from typing import List, Optional, Dict, Any
from uuid import uuid4

from app.core.config import settings


class YouTubeService:
    """Service for YouTube operations using yt-dlp."""

    def __init__(self):
        self.ytdlp_path = settings.YTDLP_PATH
        self.cache_dir = Path(settings.AUDIO_CACHE_PATH)
        self.cache_dir.mkdir(parents=True, exist_ok=True)

    async def search(
        self,
        query: str,
        max_results: int = 20,
        search_type: str = "videos",
    ) -> List[Dict[str, Any]]:
        """
        Search YouTube for videos.

        Args:
            query: Search query
            max_results: Maximum number of results
            search_type: Type of search (videos, playlists, etc.)

        Returns:
            List of search results
        """
        cmd = [
            self.ytdlp_path,
            "ytsearch" + str(max_results) + ":" + query,
            "--dump-json",
            "--flat-playlist",
            "--skip-download",
            "--no-warnings",
        ]

        try:
            process = await asyncio.create_subprocess_exec(
                *cmd,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
            )
            stdout, stderr = await process.communicate()

            if process.returncode != 0:
                error_msg = stderr.decode() if stderr else "Unknown error"
                print(f"yt-dlp search error: {error_msg}")
                return []

            # Parse JSON output (one line per video)
            results = []
            for line in stdout.decode().split("\n"):
                if not line.strip():
                    continue
                try:
                    data = json.loads(line)
                    results.append(self._parse_search_result(data))
                except json.JSONDecodeError:
                    continue

            return results

        except Exception as e:
            print(f"Error searching YouTube: {e}")
            return []

    def _parse_search_result(self, data: Dict[str, Any]) -> Dict[str, Any]:
        """Parse yt-dlp search result."""
        youtube_id = data.get("id", "")

        # Generate thumbnail URL manually since --flat-playlist doesn't fetch them
        # Try multiple YouTube thumbnail formats in order of quality
        thumbnail = f"https://i.ytimg.com/vi/{youtube_id}/maxresdefault.jpg"

        return {
            "youtube_id": youtube_id,
            "title": data.get("title", ""),
            "artist": data.get("artist", data.get("uploader", "")),
            "duration": self._parse_duration(data.get("duration")),
            "thumbnail": thumbnail,
            "url": f"https://www.youtube.com/watch?v={youtube_id}",
        }

    def _parse_duration(self, duration: Optional[int]) -> Optional[int]:
        """Parse duration in seconds."""
        if duration is None:
            return None
        return int(duration)

    async def get_video_info(self, video_id: str) -> Optional[Dict[str, Any]]:
        """
        Get detailed information about a video.

        Args:
            video_id: YouTube video ID

        Returns:
            Video information or None
        """
        url = f"https://www.youtube.com/watch?v={video_id}"

        cmd = [
            self.ytdlp_path,
            url,
            "--dump-json",
            "--skip-download",
            "--no-warnings",
        ]

        try:
            process = await asyncio.create_subprocess_exec(
                *cmd,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
            )
            stdout, stderr = await process.communicate()

            if process.returncode != 0:
                return None

            data = json.loads(stdout.decode())
            return self._parse_video_info(data)

        except Exception as e:
            print(f"Error getting video info: {e}")
            return None

    def _parse_video_info(self, data: Dict[str, Any]) -> Dict[str, Any]:
        """Parse yt-dlp video info."""
        youtube_id = data.get("id", "")
        # Convert webp thumbnails to jpg for better browser compatibility
        thumbnail = data.get("thumbnail", "")
        if "vi_webp" in thumbnail:
            thumbnail = f"https://i.ytimg.com/vi/{youtube_id}/maxresdefault.jpg"

        return {
            "youtube_id": youtube_id,
            "title": data.get("title", ""),
            "artist": data.get("artist", data.get("uploader", "")),
            "album": data.get("album", ""),
            "duration": self._parse_duration(data.get("duration")),
            "thumbnail": thumbnail,
            "description": data.get("description"),
            "genres": data.get("genres", []),
            "upload_date": data.get("upload_date"),
        }

    async def get_stream_url(self, video_id: str) -> Optional[str]:
        """
        Get direct stream URL for a video.

        Args:
            video_id: YouTube video ID

        Returns:
            Stream URL or None
        """
        url = f"https://www.youtube.com/watch?v={video_id}"

        cmd = [
            self.ytdlp_path,
            url,
            "--get-url",
            "--format",
            "bestaudio[ext=m4a]/bestaudio/best",
            "--no-warnings",
        ]

        try:
            process = await asyncio.create_subprocess_exec(
                *cmd,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
            )
            stdout, stderr = await process.communicate()

            if process.returncode != 0:
                return None

            stream_url = stdout.decode().strip()
            return stream_url if stream_url else None

        except Exception as e:
            print(f"Error getting stream URL: {e}")
            return None

    async def download_audio(
        self,
        video_id: str,
        quality: str = "high",
    ) -> Optional[Path]:
        """
        Download audio from YouTube and cache it.

        Args:
            video_id: YouTube video ID
            quality: Audio quality (low, medium, high)

        Returns:
            Path to downloaded file or None
        """
        url = f"https://www.youtube.com/watch?v={video_id}"
        cache_path = self.cache_dir / f"{video_id}.mp3"

        # Check if already cached
        if cache_path.exists():
            return cache_path

        # Determine format based on quality
        if quality == "high":
            audio_format = "320"
        elif quality == "medium":
            audio_format = "192"
        else:
            audio_format = "128"

        cmd = [
            self.ytdlp_path,
            url,
            "--extract-audio",
            "--audio-format",
            "mp3",
            "--audio-quality",
            audio_format,
            "--output",
            str(cache_path),
            "--no-warnings",
        ]

        try:
            process = await asyncio.create_subprocess_exec(
                *cmd,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
            )
            stdout, stderr = await process.communicate()

            if process.returncode != 0:
                error_msg = stderr.decode() if stderr else "Unknown error"
                print(f"Error downloading audio: {error_msg}")
                return None

            return cache_path if cache_path.exists() else None

        except Exception as e:
            print(f"Error downloading audio: {e}")
            return None

    async def get_related_videos(self, video_id: str, max_results: int = 10) -> List[Dict[str, Any]]:
        """
        Get related videos for a video.

        Args:
            video_id: YouTube video ID
            max_results: Maximum number of results

        Returns:
            List of related videos
        """
        url = f"https://www.youtube.com/watch?v={video_id}"

        cmd = [
            self.ytdlp_path,
            url,
            "--flat-playlist",
            "--playlist-end",
            str(max_results),
            "--dump-json",
            "--no-warnings",
        ]

        try:
            process = await asyncio.create_subprocess_exec(
                *cmd,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE,
            )
            stdout, stderr = await process.communicate()

            if process.returncode != 0:
                return []

            results = []
            for line in stdout.decode().split("\n"):
                if not line.strip():
                    continue
                try:
                    data = json.loads(line)
                    if data.get("id") != video_id:  # Exclude the video itself
                        results.append(self._parse_search_result(data))
                except json.JSONDecodeError:
                    continue

            return results

        except Exception as e:
            print(f"Error getting related videos: {e}")
            return []