from fastapi import FastAPI, File, UploadFile, Form
from fastapi.responses import JSONResponse, FileResponse
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
import shutil, os

app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

app.mount("/", StaticFiles(directory=".", html=True), name="static")

@app.post("/process")
async def process_music(
    music: UploadFile = File(...),
    vocal: UploadFile = File(...),
    lyrics: str = Form(...),
    model: str = Form(...)
):
    os.makedirs("temp", exist_ok=True)
    music_path = f"temp/{music.filename}"
    vocal_path = f"temp/{vocal.filename}"
    with open(music_path, "wb") as f:
        shutil.copyfileobj(music.file, f)
    with open(vocal_path, "wb") as f:
        shutil.copyfileobj(vocal.file, f)

    # 模擬選擇模型結果處理
    result_file = "demo/ai_sing_sample.mp3"
    if os.path.exists(result_file):
        shutil.copy(result_file, "temp/output_demo.mp3")
        return JSONResponse({ "status": "success", "download_url": "/download/output_demo.mp3" })
    return JSONResponse({ "status": "failed", "error": "No output file." })

@app.get("/download/{filename}")
async def download_file(filename: str):
    path = f"temp/{filename}"
    if os.path.exists(path):
        return FileResponse(path, media_type="audio/mpeg", filename=filename)
    return JSONResponse({ "error": "File not found" }, status_code=404)