eksplicit mapping af envs

backend/app/services/session_service.py

@@ -0,0 +1,39 @@
+import json
+import uuid
+from datetime import UTC, datetime, timedelta
+
+from app.core.config import settings
+from app.core.redis import get_client
+
+
+async def create_session(ble_token: str, interests: list[str]) -> dict:
+    """Store an ephemeral BLE session in Redis with TTL."""
+    client = get_client()
+    session_id = str(uuid.uuid4())
+    expires_at = datetime.now(UTC) + timedelta(seconds=settings.session_ttl_seconds)
+
+    payload = json.dumps({
+        "session_id": session_id,
+        "interests": interests,
+        "created_at": datetime.now(UTC).isoformat(),
+    })
+
+    await client.setex(f"session:{ble_token}", settings.session_ttl_seconds, payload)
+
+    return {"session_id": session_id, "expires_at": expires_at}
+
+
+async def get_session(ble_token: str) -> dict | None:
+    """Retrieve a session by BLE token. Returns None if expired or not found."""
+    client = get_client()
+    raw = await client.get(f"session:{ble_token}")
+    if raw is None:
+        return None
+    return json.loads(raw)
+
+
+async def count_active_sessions() -> int:
+    """Return number of active (non-expired) sessions."""
+    client = get_client()
+    keys = await client.keys("session:*")
+    return len(keys)