import os
from typing import Callable

import yt_dlp


class YtDlpClient:
    """Real YtClient backed by yt_dlp. Not unit-tested offline; see test_youtube_live.py."""

    def search_album(self, artist: str, album: str) -> list[dict]:
        query = f"ytsearch5:{artist} {album} full album"
        opts = {
            "quiet": True,
            "no_warnings": True,
            "extract_flat": "in_playlist",
            "skip_download": True,
        }
        with yt_dlp.YoutubeDL(opts) as ydl:
            info = ydl.extract_info(query, download=False)
        results: list[dict] = []
        for e in (info.get("entries") or []):
            if not e:
                continue
            results.append(
                {
                    "source_ref": e.get("url") or e.get("webpage_url") or e.get("id"),
                    "title": e.get("title") or "",
                    "artist": e.get("uploader") or e.get("channel") or "",
                    "track_count": e.get("playlist_count") or 1,
                }
            )
        return results

    def download(self, source_ref: str, dest: str, on_progress: Callable[[float], None]) -> dict:
        os.makedirs(dest, exist_ok=True)

        def hook(d: dict) -> None:
            if d.get("status") == "downloading":
                total = d.get("total_bytes") or d.get("total_bytes_estimate")
                if total:
                    on_progress(min(1.0, d.get("downloaded_bytes", 0) / total))
            elif d.get("status") == "finished":
                on_progress(1.0)

        opts = {
            "quiet": True,
            "no_warnings": True,
            "format": "bestaudio/best",
            "outtmpl": os.path.join(dest, "%(playlist_index)s-%(title)s.%(ext)s"),
            "progress_hooks": [hook],
            "postprocessors": [{"key": "FFmpegExtractAudio", "preferredcodec": "opus"}],
        }
        with yt_dlp.YoutubeDL(opts) as ydl:
            info = ydl.extract_info(source_ref, download=True)
        entries = info.get("entries") if info.get("entries") is not None else [info]
        return {"track_count": len([e for e in entries if e]), "path": dest}