import asyncio
import json
import logging
from ..core.alert_queue import alert_queue
from fastapi import Request
logger = logging.getLogger(__name__)
async def alert_event_generator(request: Request):
"""
Yields server-sent events for new alerts.
This generator waits for new alerts to be placed in the alert_queue
and sends them to the client in the SSE format.
"""
try:
while True:
# Check if the client has disconnected
if await request.is_disconnected():
logger.warning("Client disconnected, stopping alert stream.")
break
try:
# Wait for a new alert from the queue, with a timeout
alert = await asyncio.wait_for(alert_queue.get(), timeout=1.0)
# Format and yield the alert as an SSE message
yield f"event: new_alert\ndata: {json.dumps(alert)}\n\n"
except asyncio.TimeoutError:
# If no alert is received, send a keep-alive comment
yield ": keep-alive\n\n"
except Exception as e:
logger.error(f"An unexpected error occurred in event generator: {e}")
# Optionally, re-raise or handle specific exceptions
finally:
logger.info("Alert event generator finished.")
