import os
import shutil
import uuid
from pathlib import Path
from fastapi import APIRouter, UploadFile, HTTPException, BackgroundTasks
from fastapi.responses import FileResponse
import ffmpeg

router = APIRouter()

TEMP_DIR = Path("temp_uploads")
TEMP_DIR.mkdir(exist_ok=True)

def cleanup_file(path: Path):
    try:
        if path.exists():
            path.unlink()
    except Exception as e:
        print(f"Error cleaning up file {path}: {e}")

@router.post("/gif")
async def convert_video_to_gif(file: UploadFile, background_tasks: BackgroundTasks):
    if not (file.content_type or "").startswith("video/"):
        raise HTTPException(status_code=400, detail="File must be a video")

    file_id = str(uuid.uuid4())
    input_path = TEMP_DIR / f"{file_id}_{file.filename}"
    output_filename = f"{file_id}.gif"
    output_path = TEMP_DIR / output_filename

    try:
        with input_path.open("wb") as buffer:
            shutil.copyfileobj(file.file, buffer)
            
        stream = ffmpeg.input(str(input_path))
        stream = ffmpeg.filter(stream, 'fps', fps=10)
        stream = ffmpeg.filter(stream, 'scale', 320, -1)
        stream = ffmpeg.output(stream, str(output_path))
        ffmpeg.run(stream, capture_stdout=True, capture_stderr=True)
        
        background_tasks.add_task(cleanup_file, input_path)
        background_tasks.add_task(cleanup_file, output_path)

        return FileResponse(
            output_path, 
            media_type="image/gif", 
            filename="converted.gif"
        )

    except ffmpeg.Error as e:
        cleanup_file(input_path)
        if output_path.exists():
            cleanup_file(output_path)
        print(e.stderr.decode('utf8'))
        raise HTTPException(status_code=500, detail="FFmpeg conversion failed")
    except Exception as e:
        cleanup_file(input_path)
        if output_path.exists():
            cleanup_file(output_path)
        raise HTTPException(status_code=500, detail=str(e))