Implement AI orchestration wedding demo

backend/app/infrastructure/events.py

@@ -0,0 +1,44 @@
+import json
+import logging
+from datetime import datetime
+from typing import Any
+
+import redis
+
+from app.config import get_settings
+from app.domain.schemas import EventType
+
+logger = logging.getLogger(__name__)
+
+
+class EventPublisher:
+    """Publishes orchestration events to Redis Streams with in-memory fallback."""
+
+    def __init__(self, redis_url: str | None = None) -> None:
+        self.stream = "orchestrator.events"
+        self._fallback: list[dict[str, Any]] = []
+        self._redis = None
+        try:
+            self._redis = redis.Redis.from_url(redis_url or get_settings().redis_url, decode_responses=True)
+            self._redis.ping()
+        except Exception as exc:  # pragma: no cover - depends on local infra
+            self._redis = None
+            logger.warning("Redis unavailable, using in-memory event log: %s", exc)
+
+    def publish(self, event_type: EventType, request_id: str, payload: dict[str, Any]) -> dict[str, Any]:
+        event = {
+            "type": event_type.value,
+            "request_id": request_id,
+            "timestamp": datetime.utcnow().isoformat(),
+            "payload": payload,
+        }
+        if self._redis:
+            self._redis.xadd(self.stream, {"event": json.dumps(event, default=str)}, maxlen=500, approximate=True)
+        self._fallback.append(event)
+        return event
+
+    def recent(self, limit: int = 50) -> list[dict[str, Any]]:
+        if self._redis:
+            rows = self._redis.xrevrange(self.stream, count=limit)
+            return [json.loads(fields["event"]) for _, fields in reversed(rows)]
+        return self._fallback[-limit:]