fix: address code review findings

cmd/api/handlers.go

@@ -239,6 +239,30 @@ func RouteSearch(hc *HandlerContext, w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	// Detect closed stations by checking if they have real edges in the graph
+	for _, cityID := range []string{req.FromCityID, req.ToCityID} {
+		// Get stations for this city
+		stations := getStationsForCity(cityID)
+		for _, station := range stations {
+			if len(station) > 0 {
+				stationID := station[0]
+				// Check if this station has real edges
+				hasRealEdges := false
+				for _, edge := range hc.Router.Edges() {
+					if edge.From.ID == stationID || edge.To.ID == stationID {
+						if edge.Kind == routing.EdgeKindReal {
+							hasRealEdges = true
+							break
+						}
+					}
+				}
+				if !hasRealEdges {
+					closedStationsMap[stationID] = true
+				}
+			}
+		}
+	}
+
 	// Run Pareto-optimal route search using the graph
 	results := hc.Router.FindRoutesPareto(req.FromCityID, req.ToCityID, opts, closedStationsMap, neighborsMap)
 

internal/cache/store.go

@@ -116,10 +116,16 @@ func keyString(k *CacheKey) string {
 	case k.Kind == "station":
 		return fmt.Sprintf("stations:%s", sanitizeKeyComponent(k.Code))
 	case k.Kind == "search":
-		return fmt.Sprintf("search:%s:%s:%s",
+		// Include far-term flag in cache key to distinguish near-term (3-hour TTL) from far-term (7-day TTL)
+		farTermFlag := "near"
+		if k.Request != "" {
+			farTermFlag = k.Request
+		}
+		return fmt.Sprintf("search:%s:%s:%s:%s",
 			sanitizeKeyComponent(k.From),
 			sanitizeKeyComponent(k.To),
-			sanitizeKeyComponent(k.Date))
+			sanitizeKeyComponent(k.Date),
+			farTermFlag)
 	default:
 		return fmt.Sprintf("unknown:%s", sanitizeKeyComponent(k.Kind))
 	}

internal/cache/store_test.go

@@ -72,10 +72,17 @@ func TestCacheKeyString(t *testing.T) {
 
 	// Search key
 	searchKey := &CacheKey{Kind: "search", From: "c146", To: "c213", Date: "2026-08-15"}
-	expectedSearchKey := "search:c146:c213:2026-08-15"
+	expectedSearchKey := "search:c146:c213:2026-08-15:near"
 	if keyString(searchKey) != expectedSearchKey {
 		t.Errorf("expected %s, got %s", expectedSearchKey, keyString(searchKey))
 	}
+
+	// Search key with far-term flag
+	searchKeyFarTerm := &CacheKey{Kind: "search", From: "c146", To: "c213", Date: "2026-08-30", Request: "far"}
+	expectedSearchKeyFarTerm := "search:c146:c213:2026-08-30:far"
+	if keyString(searchKeyFarTerm) != expectedSearchKeyFarTerm {
+		t.Errorf("expected %s, got %s", expectedSearchKeyFarTerm, keyString(searchKeyFarTerm))
+	}
 }
 
 // TestCacheAsideGetOrSet tests the cache-aside GetOrSetFuncPattern.