backend/fastapi_app.py

"""
FastAPI backend with WebSocket support for real-time video processing
"""

from fastapi import FastAPI, WebSocket, WebSocketDisconnect, UploadFile, File, HTTPException, BackgroundTasks
from fastapi.responses import FileResponse, StreamingResponse
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
import uvicorn
import os
import uuid
import json
import asyncio
from pathlib import Path
from typing import Dict, Optional
import tempfile
import shutil

from async_processor import async_processor

app = FastAPI(title="VR180 Converter API", version="2.0.0")

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

# Create necessary directories
os.makedirs("uploads", exist_ok=True)
os.makedirs("outputs", exist_ok=True)
os.makedirs("thumbnails", exist_ok=True)
os.makedirs("static", exist_ok=True)

# Mount static files
app.mount("/static", StaticFiles(directory="static"), name="static")

@app.get("/")
async def root():
    """Health check endpoint"""
    return {"message": "VR180 Converter API is running", "version": "2.0.0"}

@app.get("/api/health")
async def health_check():
    """Detailed health check"""
    return {
        "status": "healthy",
        "message": "VR180 Converter API is running",
        "version": "2.0.0",
        "active_jobs": len(async_processor.processing_jobs),
        "active_connections": len(async_processor.active_connections)
    }

@app.post("/api/upload")
async def upload_video(file: UploadFile = File(...)):
    """Upload video file and return metadata"""
    try:
        # Validate file type
        allowed_extensions = {'.mp4', '.avi', '.mov', '.mkv', '.webm'}
        file_extension = Path(file.filename).suffix.lower()
        
        if file_extension not in allowed_extensions:
            raise HTTPException(status_code=400, detail="Invalid file type")
        
        # Generate unique filename
        file_id = str(uuid.uuid4())
        filename = f"{file_id}_{file.filename}"
        filepath = os.path.join("uploads", filename)
        
        # Save file
        with open(filepath, "wb") as buffer:
            shutil.copyfileobj(file.file, buffer)
        
        # Get video info
        video_info = async_processor.get_video_info(filepath)
        
        # Generate thumbnail
        thumbnail_path = async_processor.generate_thumbnail(filepath)
        
        return {
            "success": True,
            "file_id": file_id,
            "filename": filename,
            "original_name": file.filename,
            "video_info": video_info,
            "thumbnail": thumbnail_path,
            "file_size": os.path.getsize(filepath)
        }
        
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/api/process/{file_id}")
async def start_processing(file_id: str, background_tasks: BackgroundTasks):
    """Start video processing job"""
    try:
        # Find the uploaded file
        upload_dir = Path("uploads")
        files = list(upload_dir.glob(f"{file_id}_*"))
        
        if not files:
            raise HTTPException(status_code=404, detail="File not found")
        
        input_path = str(files[0])
        
        # Generate output path
        output_filename = f"vr180_{Path(input_path).name}"
        output_path = os.path.join("outputs", output_filename)
        
        # Start processing in background
        job_id = str(uuid.uuid4())
        background_tasks.add_task(
            async_processor.process_video_async,
            input_path,
            output_path,
            job_id
        )
        
        return {
            "success": True,
            "job_id": job_id,
            "message": "Processing started",
            "websocket_url": f"/ws/{job_id}"
        }
        
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.websocket("/ws/{job_id}")
async def websocket_endpoint(websocket: WebSocket, job_id: str):
    """WebSocket endpoint for real-time updates"""
    await async_processor.connect(websocket, job_id)
    
    try:
        while True:
            # Keep connection alive
            data = await websocket.receive_text()
            message = json.loads(data)
            
            if message.get("type") == "ping":
                await websocket.send_text(json.dumps({"type": "pong"}))
                
    except WebSocketDisconnect:
        async_processor.disconnect(job_id)

@app.get("/api/status/{job_id}")
async def get_job_status(job_id: str):
    """Get processing job status"""
    status = async_processor.get_job_status(job_id)
    
    if not status:
        raise HTTPException(status_code=404, detail="Job not found")
    
    return status

@app.get("/api/download/{filename}")
async def download_video(filename: str):
    """Download processed video"""
    filepath = os.path.join("outputs", filename)
    
    if not os.path.exists(filepath):
        raise HTTPException(status_code=404, detail="File not found")
    
    return FileResponse(
        filepath,
        media_type="video/mp4",
        filename=filename,
        headers={"Content-Disposition": f"attachment; filename={filename}"}
    )

@app.get("/api/thumbnail/{filename}")
async def get_thumbnail(filename: str):
    """Get video thumbnail"""
    thumb_path = os.path.join("thumbnails", filename)
    
    if not os.path.exists(thumb_path):
        raise HTTPException(status_code=404, detail="Thumbnail not found")
    
    return FileResponse(thumb_path, media_type="image/jpeg")

@app.delete("/api/cleanup/{file_id}")
async def cleanup_files(file_id: str):
    """Clean up uploaded and processed files"""
    try:
        # Remove uploaded file
        upload_dir = Path("uploads")
        upload_files = list(upload_dir.glob(f"{file_id}_*"))
        for file in upload_files:
            file.unlink()
        
        # Remove output file
        output_dir = Path("outputs")
        output_files = list(output_dir.glob(f"vr180_{file_id}_*"))
        for file in output_files:
            file.unlink()
        
        # Remove thumbnail
        thumb_dir = Path("thumbnails")
        thumb_files = list(thumb_dir.glob(f"{file_id}_*"))
        for file in thumb_files:
            file.unlink()
        
        return {"success": True, "message": "Files cleaned up"}
        
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/api/jobs")
async def list_jobs():
    """List all processing jobs"""
    return {
        "jobs": async_processor.processing_jobs,
        "active_connections": len(async_processor.active_connections)
    }

if __name__ == "__main__":
    uvicorn.run(
        "fastapi_app:app",
        host="0.0.0.0",
        port=8000,
        reload=True,
        workers=1  # Single worker for shared state
    )