import os
import subprocess
import sys
import tempfile
import asyncio
import signal
import threading

# Set up temp directories FIRST, before any imports that might use temp files
def setup_early_temp_directories():
    """Set up temp directories before Quart imports."""
    backend_dir = os.path.dirname(os.path.abspath(__file__))
    temp_dir = os.path.join(backend_dir, 'temp')
    
    try:
        os.makedirs(temp_dir, exist_ok=True)
        os.chmod(temp_dir, 0o755)
        
        # Test write permissions
        test_file = os.path.join(temp_dir, 'test_write_early')
        with open(test_file, 'w') as f:
            f.write('test')
        os.remove(test_file)
        
        # Set environment variables BEFORE any imports that use tempfile
        os.environ['TMPDIR'] = temp_dir
        os.environ['TEMP'] = temp_dir  
        os.environ['TMP'] = temp_dir
        tempfile.tempdir = temp_dir
        
        print(f"✓ Early temp directory setup: {temp_dir}")
        return temp_dir
    except Exception as e:
        print(f"Warning: Early temp directory setup failed: {e}")
        return None

# Set up temp directories before importing app
setup_early_temp_directories()

from app import create_app
from app.models.user import User

# Create the ASGI app (which wraps Quart + SocketIO)
asgi_app = create_app()
# Extract the Quart app from the ASGI wrapper
quart_app = asgi_app.quart_app

# Initialize database on startup
async def initialize_database():
    pass  # Default user creation removed (security: use populate_db.py script instead)

# Use the ASGI app for the server
app = asgi_app

async def startup():
    """Initialize the application on startup."""
    await initialize_database()

# Signal handlers are now managed within the asyncio event loop for proper async shutdown

async def run_server():
    """Run the server with enhanced shutdown pattern and diagnostics."""
    import hypercorn.asyncio
    from hypercorn import Config
    import faulthandler
    import threading
    
    # Enable fault handler for debugging
    faulthandler.register(signal.SIGUSR1 if hasattr(signal, 'SIGUSR1') else signal.SIGBREAK)
    
    print("Starting Quart + SocketIO app with hypercorn ASGI server...")
    print("📡 WebSocket functionality enabled")
    print("🤖 AI Runner active for autonomous conversations") 
    print("⚡ All operations async and non-blocking")
    print("🛑 Use Ctrl-C for graceful shutdown")
    print("🔍 Debug: Send SIGUSR1 for stack dump if it hangs")
    print("Started Semblance back end service")
    
    # Create hypercorn config with debug settings
    config = Config()
    config.bind = ["0.0.0.0:5137"]
    config.debug = False
    config.use_reloader = False
    config.loglevel = "info"  # Enable more logging
    config.lifespan = "on"    # Ensure lifespan is enabled
    config.startup_timeout = 60
    config.shutdown_timeout = 5   # Shorter for faster shutdown
    config.graceful_timeout = 3   # Shorter for faster shutdown
    config.keep_alive_timeout = 2 # Cut lingering connections faster
    
    # Add startup tasks to Quart app
    @quart_app.before_serving
    async def startup_task():
        await startup()
    
    # Add shutdown tasks to Quart app with timeout protection
    @quart_app.after_serving
    async def shutdown_task():
        print("🛑 Quart app shutting down...")
        
        # 1. Shutdown SocketIO first to stop WebSocket tasks
        try:
            print("🔌 Shutting down SocketIO...")
            from app.extensions import socketio_server
            
            # First disconnect all clients
            print("🔌 Disconnecting all SocketIO clients...")
            try:
                # Get all sessions and disconnect them
                for sid in list(socketio_server.manager.get_participants('/', None) or []):
                    try:
                        await socketio_server.disconnect(sid, namespace='/')
                    except Exception as disconnect_err:
                        print(f"Error disconnecting {sid}: {disconnect_err}")
                print("✅ All SocketIO clients disconnected")
            except Exception as disconnect_err:
                print(f"Error during client disconnection: {disconnect_err}")
            
            # Then shutdown the server
            try:
                if hasattr(socketio_server, 'shutdown'):
                    await socketio_server.shutdown()
                    print("✅ SocketIO server shutdown complete")
                else:
                    # Try shutting down the underlying engine.io server
                    if hasattr(socketio_server, 'eio') and hasattr(socketio_server.eio, 'shutdown'):
                        await socketio_server.eio.shutdown()
                        print("✅ EngineIO shutdown complete")
                    else:
                        print("⚠️  No shutdown method available - relying on task cancellation")
            except Exception as shutdown_err:
                print(f"SocketIO shutdown error: {shutdown_err}")
                
        except Exception as e:
            print(f"⚠️  Overall SocketIO shutdown error: {e}")
        
        # 2. Shutdown AI Runner
        try:
            await asyncio.wait_for(
                asyncio.to_thread(shutdown_ai_runner_safe),
                timeout=3.0  # Shorter timeout
            )
            print("✅ AI Runner shutdown complete")
        except asyncio.TimeoutError:
            print("⏱️  AI Runner shutdown timed out; continuing")
        except Exception as e:
            print(f"⚠️  AI Runner shutdown error: {e}")
        
        # 3. Close database connections
        try:
            print("🗄️  Closing database connections...")
            await close_database_connections()
            print("✅ Database connections closed")
        except Exception as e:
            print(f"⚠️  Database close error: {e}")
        
        # 4. Cancel any remaining engineio/socketio tasks
        await cancel_socketio_tasks()
    
    def shutdown_ai_runner_safe():
        """Safe AI Runner shutdown that doesn't block the main event loop."""
        try:
            from app.services.ai_runner_service import shutdown_ai_runner
            shutdown_ai_runner()
        except Exception as e:
            print(f"Error in AI Runner shutdown: {e}")
    
    async def close_database_connections():
        """Close all database connections to stop PyMongo background threads."""
        try:
            # Close the global Motor client singleton
            from app.db import close_db_connections
            await asyncio.to_thread(close_db_connections)
        except Exception as e:
            print(f"Database connection close error: {e}")
    
    async def cancel_socketio_tasks():
        """Cancel any remaining SocketIO/EngineIO tasks."""
        try:
            print("🧹 Cancelling remaining SocketIO tasks...")
            cancelled_count = 0
            
            for task in list(asyncio.all_tasks()):
                if task.done() or task is asyncio.current_task():
                    continue
                
                # Check if this is a SocketIO/EngineIO related task
                try:
                    coro = task.get_coro()
                    module = getattr(coro, '__module__', '')
                    qualname = getattr(coro, '__qualname__', '')
                    full_name = f'{module}.{qualname}'
                    
                    socketio_patterns = [
                        'engineio.async_socket',
                        'engineio.async_server', 
                        'socketio.async_server',
                        'AsyncSocket._websocket_handler',
                        'AsyncSocket._send_ping',
                        'AsyncServer._service_task'
                    ]
                    
                    if any(pattern in full_name for pattern in socketio_patterns):
                        task.cancel()
                        cancelled_count += 1
                        
                except Exception:
                    pass  # Ignore task inspection errors
            
            if cancelled_count > 0:
                print(f"🧹 Cancelled {cancelled_count} SocketIO tasks")
                # Give cancellations time to complete
                await asyncio.sleep(0.5)
                
        except Exception as e:
            print(f"Task cancellation error: {e}")
    
    # Create shutdown event for Hypercorn
    shutdown_event = asyncio.Event()
    _second_signal = False  # For double Ctrl-C force exit
    
    def _raise_shutdown():
        """Signal handler with force-exit on second Ctrl-C."""
        nonlocal _second_signal
        
        if _second_signal:
            print("🔥 Second Ctrl-C - forcing exit!")
            import os
            os._exit(1)
        
        _second_signal = True
        print("\\n🛑 Shutdown signal received...")
        print("📊 Active threads:", [t.name for t in threading.enumerate()])
        shutdown_event.set()
        
        # Watchdog to ensure serve() returns
        async def shutdown_watchdog():
            await asyncio.sleep(4)  # Wait 4 seconds (should be enough with enhanced cleanup)
            if not shutdown_event.is_set():
                return  # Already completed
            print("⏱️  Shutdown taking too long - dumping diagnostics...")
            
            # Dump asyncio tasks
            print("\\n=== Active asyncio tasks ===")
            for task in asyncio.all_tasks():
                if not task.done():
                    print(f"- {task.get_name()}: {task}")
            
            # Dump threads
            print("\\n=== Active threads ===")
            for thread in threading.enumerate():
                print(f"- {thread.name}: daemon={thread.daemon}, alive={thread.is_alive()}")
            
            print("🔥 Use second Ctrl-C to force exit if needed")
        
        asyncio.create_task(shutdown_watchdog(), name="shutdown-watchdog")
    
    # Register signal handlers
    loop = asyncio.get_running_loop()
    try:
        loop.add_signal_handler(signal.SIGINT, _raise_shutdown)
        loop.add_signal_handler(signal.SIGTERM, _raise_shutdown)
    except NotImplementedError:
        # Windows fallback
        signal.signal(signal.SIGINT, lambda *_: loop.call_soon_threadsafe(_raise_shutdown))
        signal.signal(signal.SIGTERM, lambda *_: loop.call_soon_threadsafe(_raise_shutdown))
    
    # Let Hypercorn handle shutdown gracefully with the trigger
    print("🔍 Debug: Starting Hypercorn serve with shutdown_trigger...")
    await hypercorn.asyncio.serve(
        asgi_app,
        config,
        shutdown_trigger=shutdown_event.wait,
    )
    
    print("🛑 Hypercorn server stopped")

if __name__ == '__main__':
    try:
        # Check if hypercorn is available
        try:
            import hypercorn.asyncio
            from hypercorn import Config
        except ImportError as e:
            print("❌ Error: hypercorn is required for WebSocket functionality!")
            print("Please install hypercorn: pip install hypercorn")
            print(f"ImportError: {e}")
            sys.exit(1)
        
        # Run the server with proper shutdown handling
        asyncio.run(run_server())
                
    except KeyboardInterrupt:
        print("\\n🛑 Keyboard interrupt - shutting down...")
    except Exception as e:
        print(f"❌ Unexpected error: {e}")
        try:
            from app.services.ai_runner_service import shutdown_ai_runner
            shutdown_ai_runner()
        except:
            pass
        sys.exit(1)
    
    print("👋 Server stopped")