main.py

from fastapi import FastAPI, UploadFile, File, Form
from fastapi.responses import FileResponse
import tempfile
import shutil
import os
import logging

# Import your existing merge functions here
# from your_module import merge_videos_and_audios  # if separated, or define inline

app = FastAPI()
logger = logging.getLogger("uvicorn.error")

@app.post("/merge")
async def merge_endpoint(
    files: list[UploadFile] = File(...),
    orig_vol: float = Form(1.0),
    music_vol: float = Form(0.5),
):
    temp_dir = tempfile.mkdtemp()
    try:
        saved_files = []
        for uploaded_file in files:
            # Save each uploaded file to disk
            file_location = os.path.join(temp_dir, uploaded_file.filename)
            with open(file_location, "wb") as out_file:
                content = await uploaded_file.read()
                out_file.write(content)
            saved_files.append(file_location)

        if len(saved_files) < 2:
            return {"error": "Please upload at least 2 video/audio files."}

        # Call your existing merge function
        output_path = merge_videos_and_audios(
            video_files=[f for f in saved_files if f.lower().endswith(".mp4")],
            audio_files=[f for f in saved_files if f.lower().endswith((".mp3", ".wav"))],
            orig_vol=orig_vol,
            music_vol=music_vol,
            temp_dir=temp_dir,
        )

        if isinstance(output_path, str) and output_path.startswith("Error"):
            return {"error": output_path}
        
        # Return the merged file with appropriate media type
        media_type = "video/mp4" if output_path.lower().endswith(".mp4") else "audio/mpeg"
        file_name = os.path.basename(output_path)
        return FileResponse(output_path, media_type=media_type, filename=file_name)

    finally:
        # Clean up uploaded files after response is sent
        shutil.rmtree(temp_dir)