from fastapi import FastAPI, HTTPException, Query
from fastapi.responses import FileResponse, JSONResponse
import os
import traceback
from processor import process_video_to_panorama

app = FastAPI(title="Video Density Estimation API")

@app.get("/process")
async def process_video(
    input_video: str = Query(..., description="Path to input video file"),
    output_dir: str = Query(..., description="Output directory path")
):
    """
    Process video to generate density estimation result
    
    Args:
        input_video: Path to input video file (e.g., /path/to/video.mp4)
        output_dir: Output directory path (e.g., /path/to/output)
    
    Returns:
        JSON with result path or error message
    """
    try:
        # Validate input video
        if not os.path.exists(input_video):
            raise HTTPException(status_code=400, detail=f"Input video not found: {input_video}")
        
        # Process video
        result_path,total_count = process_video_to_panorama(input_video, output_dir)
        
        return JSONResponse({
            "status": "success",
            "result_path": result_path,
	    "total_count": int(total_count), 
            "message": "Processing completed successfully"
        })
    
    except Exception as e:
        error_msg = f"Processing failed: {str(e)}"
        print(f"Error traceback:\n{traceback.format_exc()}")
        raise HTTPException(status_code=500, detail=error_msg)

@app.get("/result")
async def get_result(result_path: str = Query(..., description="Path to result image")):
    """Download result image"""
    if not os.path.exists(result_path):
        raise HTTPException(status_code=404, detail="Result image not found")
    return FileResponse(result_path)

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)