from flask import Flask, render_template, request, jsonify
import yt_dlp
import os
import threading

app = Flask(__name__)

DOWNLOAD_DIR = os.path.join(os.path.dirname(__file__), "downloads")
os.makedirs(DOWNLOAD_DIR, exist_ok=True)

download_status = {}


def do_download(task_id, url, artist, title, album):
    try:
        download_status[task_id] = {"status": "running", "message": "Download läuft..."}

        ydl_opts = {
            "format": "bestaudio/best",
            "outtmpl": os.path.join(DOWNLOAD_DIR, "%(title)s.%(ext)s"),
            "postprocessors": [
                {
                    "key": "FFmpegExtractAudio",
                    "preferredcodec": "mp3",
                    "preferredquality": "192",
                },
                {
                    "key": "FFmpegMetadata",
                    "add_metadata": True,
                },
            ],
            # Scoped to FFmpegMetadata so tags are set correctly
            "postprocessor_args": {
                "ffmpegmetadata": [
                    "-metadata", f"artist={artist}",
                    "-metadata", f"title={title}",
                    "-metadata", f"album={album}",
                ]
            },
            "quiet": True,
            "no_warnings": True,
        }

        with yt_dlp.YoutubeDL(ydl_opts) as ydl:
            info = ydl.extract_info(url, download=True)

            # extract_info kann eine Playlist zurückgeben – dann erstes Entry nehmen
            if info is None:
                raise RuntimeError("yt-dlp hat keine Informationen zurückgegeben. Bitte URL prüfen.")
            if "entries" in info:
                info = info["entries"][0]

            filename = ydl.prepare_filename(info)
            mp3_name = os.path.splitext(os.path.basename(filename))[0] + ".mp3"

        download_status[task_id] = {
            "status": "done",
            "message": f"Fertig! Gespeichert als: {mp3_name}",
            "filename": mp3_name,
        }

    except Exception as e:
        download_status[task_id] = {
            "status": "error",
            "message": f"Fehler: {str(e)}",
        }


@app.route("/")
def index():
    return render_template("index.html")


@app.route("/download", methods=["POST"])
def download():
    data = request.get_json()
    url = data.get("url", "").strip()
    artist = data.get("artist", "").strip()
    title = data.get("title", "").strip()
    album = data.get("album", "").strip()

    if not url:
        return jsonify({"error": "URL fehlt"}), 400

    import uuid
    task_id = str(uuid.uuid4())
    thread = threading.Thread(target=do_download, args=(task_id, url, artist, title, album))
    thread.daemon = True
    thread.start()

    return jsonify({"task_id": task_id})


@app.route("/status/<task_id>")
def status(task_id):
    result = download_status.get(task_id, {"status": "unknown", "message": "Unbekannte Task-ID"})
    return jsonify(result)


if __name__ == "__main__":
    app.run(debug=True, port=5000)