From 2d6726dcd7c32dc0f4be2b73418f0798e3bac4d3 Mon Sep 17 00:00:00 2001
From: Viktor Barzin <viktorbarzin@meta.com>
Date: Tue, 17 Feb 2026 19:54:15 +0000
Subject: [PATCH] Show last listing update time next to connection status in
 header

Add last_updated timestamp to /api/status endpoint by querying
MAX(last_seen) across both listing tables. Display it in the
HealthIndicator as relative time (e.g. "2h ago") with full
date/time in the tooltip on hover.
---
 api/app.py                                  |  9 +++++--
 frontend/src/components/HealthIndicator.tsx | 30 +++++++++++++++++++--
 frontend/src/services/healthService.ts      |  2 ++
 repositories/listing_repository.py          | 16 +++++++++++
 tests/integration/test_api.py               |  3 ++-
 5 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/api/app.py b/api/app.py
index 2ddee0f..8cefbea 100644
--- a/api/app.py
+++ b/api/app.py
@@ -139,8 +139,13 @@ async def unhandled_exception_handler(request: Request, exc: Exception) -> JSONR
 
 
 @app.get("/api/status")
-async def get_status() -> dict[str, str]:
-    return {"status": "OK"}
+async def get_status() -> dict[str, str | None]:
+    repository = ListingRepository(engine)
+    last_updated = repository.get_last_updated()
+    return {
+        "status": "OK",
+        "last_updated": last_updated.isoformat() if last_updated else None,
+    }
 
 
 @app.get("/api/listing")
diff --git a/frontend/src/components/HealthIndicator.tsx b/frontend/src/components/HealthIndicator.tsx
index d511b02..cd224e3 100644
--- a/frontend/src/components/HealthIndicator.tsx
+++ b/frontend/src/components/HealthIndicator.tsx
@@ -8,6 +8,20 @@ interface HealthIndicatorProps {
   interval?: number;
 }
 
+function formatRelativeTime(isoString: string): string {
+  const date = new Date(isoString);
+  const now = new Date();
+  const diffMs = now.getTime() - date.getTime();
+  const diffMins = Math.floor(diffMs / 60000);
+  const diffHours = Math.floor(diffMs / 3600000);
+  const diffDays = Math.floor(diffMs / 86400000);
+
+  if (diffMins < 1) return 'just now';
+  if (diffMins < 60) return `${diffMins}m ago`;
+  if (diffHours < 24) return `${diffHours}h ago`;
+  return `${diffDays}d ago`;
+}
+
 export function HealthIndicator({ interval = 30000 }: HealthIndicatorProps) {
   const [health, setHealth] = useState<HealthCheckResult>({ status: 'checking' });
 
@@ -46,12 +60,19 @@ export function HealthIndicator({ interval = 30000 }: HealthIndicatorProps) {
   };
 
   const getTooltipContent = () => {
+    const lines: string[] = [];
+
     if (health.status === 'checking') {
       return 'Checking backend connection...';
     }
 
     if (health.status === 'healthy') {
-      return `Backend connected (${health.latencyMs}ms)`;
+      lines.push(`Backend connected (${health.latencyMs}ms)`);
+      if (health.lastUpdated) {
+        const date = new Date(health.lastUpdated);
+        lines.push(`Last update: ${date.toLocaleString()}`);
+      }
+      return lines.join('\n');
     }
 
     return `Backend unavailable: ${health.error || 'Unknown error'}`;
@@ -72,10 +93,15 @@ export function HealthIndicator({ interval = 30000 }: HealthIndicatorProps) {
             <span className={`text-xs ${getStatusColor(health.status)} hidden sm:inline`}>
               {getStatusLabel(health.status)}
             </span>
+            {health.status === 'healthy' && health.lastUpdated && (
+              <span className="text-xs text-muted-foreground hidden sm:inline">
+                · {formatRelativeTime(health.lastUpdated)}
+              </span>
+            )}
           </div>
         </TooltipTrigger>
         <TooltipContent side="bottom">
-          <p>{getTooltipContent()}</p>
+          <p className="whitespace-pre-line">{getTooltipContent()}</p>
         </TooltipContent>
       </Tooltip>
     </TooltipProvider>
diff --git a/frontend/src/services/healthService.ts b/frontend/src/services/healthService.ts
index b5fb382..a913b7c 100644
--- a/frontend/src/services/healthService.ts
+++ b/frontend/src/services/healthService.ts
@@ -6,6 +6,7 @@ export interface HealthCheckResult {
   status: HealthStatus;
   latencyMs?: number;
   error?: string;
+  lastUpdated?: string;
 }
 
 /**
@@ -39,6 +40,7 @@ export async function checkBackendHealth(): Promise<HealthCheckResult> {
       return {
         status: 'healthy',
         latencyMs,
+        lastUpdated: data.last_updated ?? undefined,
       };
     }
 
diff --git a/repositories/listing_repository.py b/repositories/listing_repository.py
index ac74200..3823847 100644
--- a/repositories/listing_repository.py
+++ b/repositories/listing_repository.py
@@ -359,6 +359,22 @@ class ListingRepository:
 
         return model_listing
 
+    def get_last_updated(self) -> datetime | None:
+        """Get the most recent last_seen timestamp across all listings.
+
+        Checks both RentListing and BuyListing tables and returns the latest.
+        """
+        with Session(self.engine) as session:
+            rent_max = session.execute(
+                sa_select(func.max(RentListing.last_seen))
+            ).scalar()
+            buy_max = session.execute(
+                sa_select(func.max(BuyListing.last_seen))
+            ).scalar()
+
+        candidates = [t for t in (rent_max, buy_max) if t is not None]
+        return max(candidates) if candidates else None
+
     def get_listing_ids(
         self,
         listing_type: ListingType = ListingType.RENT,
diff --git a/tests/integration/test_api.py b/tests/integration/test_api.py
index 2002884..1d79fb6 100644
--- a/tests/integration/test_api.py
+++ b/tests/integration/test_api.py
@@ -16,7 +16,8 @@ class TestStatusEndpoint:
         """Test that status endpoint returns OK status."""
         response = await async_client.get("/api/status")
         assert response.status_code == 200
-        assert response.json() == {"status": "OK"}
+        assert response.json()["status"] == "OK"
+        assert "last_updated" in response.json()
 
 
 class TestListingEndpoint: