import os
import uuid
import uvicorn
from fastapi import FastAPI, HTTPException, BackgroundTasks
from fastapi.responses import FileResponse
from pydantic import BaseModel
from yt_dlp import YoutubeDL

app = FastAPI()

# Input schema because we aren't savages
class VideoRequest(BaseModel):
    url: str

def cleanup(path: str):
    """Deletes the file after serving because I know you won't."""
    try:
        os.remove(path)
        print(f"Deleted trash: {path}")
    except Exception as e:
        print(f"Failed to delete {path}: {e}")

@app.post("/audio")
async def download_audio(req: VideoRequest, background_tasks: BackgroundTasks):
    # Random ID so concurrent requests don't overwrite each other
    file_id = str(uuid.uuid4())
    output_template = f"/tmp/{file_id}.%(ext)s"
    
    # yt-dlp config: best audio, force mp3 because whisper hates weird codecs
    ydl_opts = {
        'format': 'bestaudio/best',
        'outtmpl': output_template,
        'postprocessors': [{
            'key': 'FFmpegExtractAudio',
            'preferredcodec': 'mp3',
            'preferredquality': '192',
        }],
        'quiet': True,
        'no_warnings': True,
    }

    try:
        with YoutubeDL(ydl_opts) as ydl:
            print(f"Yoinking audio from: {req.url}")
            info = ydl.extract_info(req.url, download=True)
            # yt-dlp might change extension post-processing, so we find the actual file
            # usually it's .mp3 if we forced it, but let's be safe
            filename = ydl.prepare_filename(info).rsplit('.', 1)[0] + '.mp3'

        if not os.path.exists(filename):
            raise HTTPException(status_code=500, detail="Download failed, file missing. Blame YouTube.")

        # queue the deletion so it happens AFTER the response is sent
        background_tasks.add_task(cleanup, filename)

        return FileResponse(
            path=filename, 
            filename=f"{file_id}.mp3", 
            media_type='audio/mpeg'
        )

    except Exception as e:
        print(f"L: {str(e)}")
        raise HTTPException(status_code=400, detail=f"Failed to download: {str(e)}")

if __name__ == "__main__":
    # Host on 0.0.0.0 so your docker container isn't useless
    uvicorn.run(app, host="0.0.0.0", port=8000)