from fastapi import FastAPI, HTTPException, Query
from fastapi.responses import RedirectResponse
import subprocess

app = FastAPI(
    title="YouTube Audio Streamer",
    description="Stream best audio of a YouTube video using yt-dlp.",
    version="1.0.1",
    docs_url="/docs",
    redoc_url="/redoc"
)

@app.get("/", tags=["Health"])
async def root():
    return {"status": "FastAPI working", "message": "YT-DLP backend ready"}

@app.get("/stream", tags=["Stream"])
async def stream_audio(url: str = Query(..., description="Full YouTube video URL")):
    if "youtube.com/watch?v=" not in url and "youtu.be/" not in url:
        raise HTTPException(status_code=400, detail="Invalid YouTube URL.")

    try:
        result = subprocess.run(
            ["yt-dlp", "-f", "bestaudio", "--get-url", url],
            capture_output=True, text=True
        )
        audio_url = result.stdout.strip()
        if not audio_url:
            raise HTTPException(status_code=404, detail="No audio URL found.")
        return RedirectResponse(audio_url)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error: {str(e)}")