""" WebSocket message handling and protocol implementation. """ import asyncio import json import logging from typing import Optional from fastapi import WebSocket, WebSocketDisconnect from websockets.exceptions import ConnectionClosedError from .messages import ( parse_incoming_message, serialize_outgoing_message, MessageTypes, create_state_report ) from .models import ( SetSubscriptionListMessage, SetSessionIdMessage, SetProgressionStageMessage, RequestStateMessage, PatchSessionResultMessage ) from .state import worker_state, SystemMetrics logger = logging.getLogger(__name__) # Constants HEARTBEAT_INTERVAL = 2.0 # seconds WORKER_TIMEOUT_MS = 10000 class WebSocketHandler: """ Handles WebSocket connection lifecycle and message processing. """ def __init__(self, websocket: WebSocket): self.websocket = websocket self.connected = False self._heartbeat_task: Optional[asyncio.Task] = None self._message_task: Optional[asyncio.Task] = None async def handle_connection(self) -> None: """ Main connection handler that manages the WebSocket lifecycle. Based on the original architecture from archive/app.py """ client_info = f"{self.websocket.client.host}:{self.websocket.client.port}" if self.websocket.client else "unknown" logger.info(f"Starting WebSocket handler for {client_info}") stream_task = None try: logger.info(f"Accepting WebSocket connection from {client_info}") await self.websocket.accept() self.connected = True logger.info(f"WebSocket connection accepted and established for {client_info}") # Send immediate heartbeat to show connection is alive await self._send_immediate_heartbeat() # Start background tasks (matching original architecture) stream_task = asyncio.create_task(self._process_streams()) heartbeat_task = asyncio.create_task(self._send_heartbeat()) message_task = asyncio.create_task(self._handle_messages()) logger.info(f"WebSocket background tasks started for {client_info} (stream + heartbeat + message handler)") # Wait for heartbeat and message tasks (stream runs independently) await asyncio.gather(heartbeat_task, message_task) except Exception as e: logger.error(f"Error in WebSocket connection for {client_info}: {e}", exc_info=True) finally: logger.info(f"Cleaning up connection for {client_info}") # Cancel stream task if stream_task and not stream_task.done(): stream_task.cancel() try: await stream_task except asyncio.CancelledError: logger.debug(f"Stream task cancelled for {client_info}") await self._cleanup() async def _send_immediate_heartbeat(self) -> None: """Send immediate heartbeat on connection to show we're alive.""" try: cpu_usage = SystemMetrics.get_cpu_usage() memory_usage = SystemMetrics.get_memory_usage() gpu_usage = SystemMetrics.get_gpu_usage() gpu_memory_usage = SystemMetrics.get_gpu_memory_usage() camera_connections = worker_state.get_camera_connections() state_report = create_state_report( cpu_usage=cpu_usage, memory_usage=memory_usage, gpu_usage=gpu_usage, gpu_memory_usage=gpu_memory_usage, camera_connections=camera_connections ) await self._send_message(state_report) logger.info(f"[TX → Backend] stateReport: CPU {cpu_usage:.1f}%, Memory {memory_usage:.1f}%, " f"GPU {gpu_usage or 'N/A'}, {len(camera_connections)} cameras") except Exception as e: logger.error(f"Error sending immediate heartbeat: {e}") async def _send_heartbeat(self) -> None: """Send periodic state reports as heartbeat.""" while self.connected: try: # Collect system metrics cpu_usage = SystemMetrics.get_cpu_usage() memory_usage = SystemMetrics.get_memory_usage() gpu_usage = SystemMetrics.get_gpu_usage() gpu_memory_usage = SystemMetrics.get_gpu_memory_usage() camera_connections = worker_state.get_camera_connections() # Create and send state report state_report = create_state_report( cpu_usage=cpu_usage, memory_usage=memory_usage, gpu_usage=gpu_usage, gpu_memory_usage=gpu_memory_usage, camera_connections=camera_connections ) await self._send_message(state_report) logger.info(f"[TX → Backend] Heartbeat: CPU {cpu_usage:.1f}%, Memory {memory_usage:.1f}%, " f"GPU {gpu_usage or 'N/A'}, {len(camera_connections)} cameras") await asyncio.sleep(HEARTBEAT_INTERVAL) except Exception as e: logger.error(f"Error sending heartbeat: {e}") break async def _handle_messages(self) -> None: """Handle incoming WebSocket messages.""" while self.connected: try: raw_message = await self.websocket.receive_text() logger.info(f"[RX ← Backend] {raw_message}") # Parse incoming message message = parse_incoming_message(raw_message) if not message: logger.warning("Failed to parse incoming message") continue # Route message to appropriate handler await self._route_message(message) except (WebSocketDisconnect, ConnectionClosedError) as e: logger.warning(f"WebSocket disconnected: {e}") break except json.JSONDecodeError: logger.error("Received invalid JSON message") except Exception as e: logger.error(f"Error handling message: {e}") break async def _route_message(self, message) -> None: """Route parsed message to appropriate handler.""" message_type = message.type try: if message_type == MessageTypes.SET_SUBSCRIPTION_LIST: await self._handle_set_subscription_list(message) elif message_type == MessageTypes.SET_SESSION_ID: await self._handle_set_session_id(message) elif message_type == MessageTypes.SET_PROGRESSION_STAGE: await self._handle_set_progression_stage(message) elif message_type == MessageTypes.REQUEST_STATE: await self._handle_request_state(message) elif message_type == MessageTypes.PATCH_SESSION_RESULT: await self._handle_patch_session_result(message) else: logger.warning(f"Unknown message type: {message_type}") except Exception as e: logger.error(f"Error handling {message_type} message: {e}") async def _handle_set_subscription_list(self, message: SetSubscriptionListMessage) -> None: """Handle setSubscriptionList message for declarative subscription management.""" logger.info(f"[RX Processing] setSubscriptionList with {len(message.subscriptions)} subscriptions") # Update worker state with new subscriptions worker_state.set_subscriptions(message.subscriptions) # TODO: Phase 2 - Integrate with model management and streaming # For now, just log the subscription changes for subscription in message.subscriptions: logger.info(f" Subscription: {subscription.subscriptionIdentifier} -> " f"Model {subscription.modelId} ({subscription.modelName})") if subscription.rtspUrl: logger.debug(f" RTSP: {subscription.rtspUrl}") if subscription.snapshotUrl: logger.debug(f" Snapshot: {subscription.snapshotUrl} ({subscription.snapshotInterval}ms)") if subscription.modelUrl: logger.debug(f" Model: {subscription.modelUrl}") logger.info("Subscription list updated successfully") async def _handle_set_session_id(self, message: SetSessionIdMessage) -> None: """Handle setSessionId message.""" display_identifier = message.payload.displayIdentifier session_id = message.payload.sessionId logger.info(f"[RX Processing] setSessionId for display {display_identifier}: {session_id}") # Update worker state worker_state.set_session_id(display_identifier, session_id) async def _handle_set_progression_stage(self, message: SetProgressionStageMessage) -> None: """Handle setProgressionStage message.""" display_identifier = message.payload.displayIdentifier stage = message.payload.progressionStage logger.info(f"[RX Processing] setProgressionStage for display {display_identifier}: {stage}") # Update worker state worker_state.set_progression_stage(display_identifier, stage) async def _handle_request_state(self, message: RequestStateMessage) -> None: """Handle requestState message by sending immediate state report.""" logger.debug("[RX Processing] requestState - sending immediate state report") # Collect metrics and send state report cpu_usage = SystemMetrics.get_cpu_usage() memory_usage = SystemMetrics.get_memory_usage() gpu_usage = SystemMetrics.get_gpu_usage() gpu_memory_usage = SystemMetrics.get_gpu_memory_usage() camera_connections = worker_state.get_camera_connections() state_report = create_state_report( cpu_usage=cpu_usage, memory_usage=memory_usage, gpu_usage=gpu_usage, gpu_memory_usage=gpu_memory_usage, camera_connections=camera_connections ) await self._send_message(state_report) async def _handle_patch_session_result(self, message: PatchSessionResultMessage) -> None: """Handle patchSessionResult message.""" payload = message.payload logger.info(f"[RX Processing] patchSessionResult for session {payload.sessionId}: " f"success={payload.success}, message='{payload.message}'") # TODO: Handle patch session result if needed # For now, just log the response async def _send_message(self, message) -> None: """Send message to backend via WebSocket.""" if not self.connected: logger.warning("Cannot send message: WebSocket not connected") return try: json_message = serialize_outgoing_message(message) await self.websocket.send_text(json_message) # Log heartbeats at INFO level with simplified format if hasattr(message, 'type') and message.type == 'stateReport': logger.info(f"[TX → Backend] {message.type}") else: logger.info(f"[TX → Backend] {json_message}") except Exception as e: logger.error(f"Failed to send WebSocket message: {e}") raise async def _process_streams(self) -> None: """ Stream processing task that handles frame processing and detection. This is a placeholder for Phase 2 - currently just logs that it's running. """ logger.info("Stream processing task started") try: while self.connected: # Get current subscriptions subscriptions = worker_state.get_all_subscriptions() # TODO: Phase 2 - Add actual frame processing logic here # This will include: # - Frame reading from RTSP/HTTP streams # - Model inference using loaded pipelines # - Detection result sending via WebSocket # Sleep to prevent excessive CPU usage (similar to old poll_interval) await asyncio.sleep(0.1) # 100ms polling interval except asyncio.CancelledError: logger.info("Stream processing task cancelled") except Exception as e: logger.error(f"Error in stream processing: {e}", exc_info=True) async def _cleanup(self) -> None: """Clean up resources when connection closes.""" logger.info("Cleaning up WebSocket connection") self.connected = False # Cancel background tasks if self._heartbeat_task and not self._heartbeat_task.done(): self._heartbeat_task.cancel() if self._message_task and not self._message_task.done(): self._message_task.cancel() # Clear worker state worker_state.set_subscriptions([]) worker_state.session_ids.clear() worker_state.progression_stages.clear() logger.info("WebSocket connection cleanup completed") # Factory function for FastAPI integration async def websocket_endpoint(websocket: WebSocket) -> None: """ FastAPI WebSocket endpoint handler. Args: websocket: FastAPI WebSocket connection """ handler = WebSocketHandler(websocket) await handler.handle_connection()