from fastapi import FastAPI, UploadFile, File
from fastapi.responses import FileResponse
from starlette.middleware.base import BaseHTTPMiddleware
import cv2
import subprocess
import uuid
import os
import shutil
import tempfile

app = FastAPI()

os.umask(0o077)

def detect_product_in_frame(frame):
    return (100, 50, 400, 400)

@app.post("/process_video/")
async def process_video(file: UploadFile = File(...)):
    temp_dir = tempfile.mkdtemp()
    input_filename = os.path.join(temp_dir, f"input_{uuid.uuid4()}.mp4")
    output_filename = os.path.join(temp_dir, f"output_{uuid.uuid4()}.mp4")
    
    try:
        with open(input_filename, "wb") as f:
            f.write(await file.read())
    except Exception as e:
        shutil.rmtree(temp_dir)
        return {"error": f"Erro ao salvar o vídeo de entrada: {str(e)}"}

    cap = cv2.VideoCapture(input_filename)
    success, frame = cap.read()
    cap.release()
    if not success:
        shutil.rmtree(temp_dir)
        return {"error": "Não foi possível ler o vídeo."}
    
    roi_box = detect_product_in_frame(frame)

    if roi_box:
        x, y, w, h = roi_box
        crop_cmd = [
            'ffmpeg',
            '-i', input_filename,
            '-vf', f"crop={w}:{h}:{x}:{y}",
            '-c:a', 'copy',
            output_filename
        ]
        try:
            result = subprocess.run(crop_cmd, check=True, capture_output=True, text=True)
            print("FFmpeg output:", result.stdout)
            print("FFmpeg error (if any):", result.stderr)
        except subprocess.CalledProcessError as e:
            shutil.rmtree(temp_dir)
            return {"error": f"Erro ao processar o vídeo com FFmpeg: {e.stderr}"}

        os.remove(input_filename)

        if os.path.exists(output_filename):
            response = FileResponse(output_filename, media_type="video/mp4", filename="cropped_video.mp4")
            response.headers["X-Delete-Dir"] = temp_dir
            return response
        else:
            shutil.rmtree(temp_dir)
            return {"error": "O arquivo de saída não foi gerado pelo FFmpeg."}
    else:
        shutil.rmtree(temp_dir)
        return {"error": "Não foi possível detectar o produto para realizar o crop."}

class CleanupMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request, call_next):
        response = await call_next(request)
        temp_dir_to_delete = response.headers.get("X-Delete-Dir")
        if temp_dir_to_delete and os.path.exists(temp_dir_to_delete):
            shutil.rmtree(temp_dir_to_delete)
        return response

app.add_middleware(CleanupMiddleware)