fix: address code review findings

- Fix type mismatch in search_cache.go: SearchWithCache now returns *yandex.Response instead of *Itinerary
- Fix token bucket refill logic in yandex/client.go to properly accumulate tokens based on refillPerSec
- Fix hardcoded API key in main.go to load from YANDEX_API_KEY environment variable
- Fix missing error handling for JSON encoding in handlers.go RouteGeoJSON function
- Fix incorrect redis.Nil handling in cache/store.go CacheAside.Exists method
- Fix incorrect error return type in station_status.go updateStationStatus to return newStatus instead of empty string

internal/routing/graph_test.go

@@ -18,25 +18,25 @@ func TestFindRouteMaxTransfers(t *testing.T) {
 
 	// Add direct edge s1 -> s6 (0 transfers)
 	graph.AddEdge(&Edge{
-		From:       graph.Nodes()[0], // s1
-		To:         graph.Nodes()[5], // s6
-		Kind:       EdgeKindReal,
-		Duration:   3600,
-		Transport:  "train",
+		From:          graph.Nodes()[0], // s1
+		To:            graph.Nodes()[5], // s6
+		Kind:          EdgeKindReal,
+		Duration:      3600,
+		Transport:     "train",
 		TransportType: TransportTypeTrain,
-		IsTransfer: false,
+		IsTransfer:    false,
 	})
 
 	// Add chain edges s1->s2->s3->s4->s5->s6 (each is a transfer edge)
 	for i := 0; i < 5; i++ {
 		graph.AddEdge(&Edge{
-			From:       graph.Nodes()[i],
-			To:         graph.Nodes()[i+1],
-			Kind:       EdgeKindReal,
-			Duration:   1000,
-			Transport:  "train",
+			From:          graph.Nodes()[i],
+			To:            graph.Nodes()[i+1],
+			Kind:          EdgeKindReal,
+			Duration:      1000,
+			Transport:     "train",
 			TransportType: TransportTypeTrain,
-			IsTransfer: true,
+			IsTransfer:    true,
 		})
 	}
 
@@ -105,68 +105,68 @@ func TestParetoFrontGeneration(t *testing.T) {
 
 	// Add direct edge s1 -> s8 (0 transfers, higher cost)
 	graph.AddEdge(&Edge{
-		From:       graph.Nodes()[0], // s1
-		To:         graph.Nodes()[7], // s8
-		Kind:       EdgeKindReal,
-		Duration:   600, // 10 min
-		Transport:  "train",
+		From:          graph.Nodes()[0], // s1
+		To:            graph.Nodes()[7], // s8
+		Kind:          EdgeKindReal,
+		Duration:      600, // 10 min
+		Transport:     "train",
 		TransportType: TransportTypeTrain,
-		IsTransfer: false,
-		Cost:        500, // expensive direct
+		IsTransfer:    false,
+		Cost:          500, // expensive direct
 	})
 
 	// Add 1-transfer route s1->s3->s8 (lower cost, more time)
 	graph.AddEdge(&Edge{
-		From:       graph.Nodes()[0], // s1
-		To:         graph.Nodes()[2], // s3
-		Kind:       EdgeKindReal,
-		Duration:   200, // 3 min
-		Transport:  "train",
+		From:          graph.Nodes()[0], // s1
+		To:            graph.Nodes()[2], // s3
+		Kind:          EdgeKindReal,
+		Duration:      200, // 3 min
+		Transport:     "train",
 		TransportType: TransportTypeTrain,
-		IsTransfer: true,
-		Cost:        200,
+		IsTransfer:    true,
+		Cost:          200,
 	})
 	graph.AddEdge(&Edge{
-		From:       graph.Nodes()[2], // s3
-		To:         graph.Nodes()[7], // s8
-		Kind:       EdgeKindReal,
-		Duration:   300, // 5 min
-		Transport:  "train",
+		From:          graph.Nodes()[2], // s3
+		To:            graph.Nodes()[7], // s8
+		Kind:          EdgeKindReal,
+		Duration:      300, // 5 min
+		Transport:     "train",
 		TransportType: TransportTypeTrain,
-		IsTransfer: true,
-		Cost:        100,
+		IsTransfer:    true,
+		Cost:          100,
 	})
 
 	// Add 2-transfer route s1->s5->s6->s8 (even lower cost, more transfers)
 	graph.AddEdge(&Edge{
-		From:       graph.Nodes()[0], // s1
-		To:         graph.Nodes()[4], // s5
-		Kind:       EdgeKindReal,
-		Duration:   100, // 2 min
-		Transport:  "train",
+		From:          graph.Nodes()[0], // s1
+		To:            graph.Nodes()[4], // s5
+		Kind:          EdgeKindReal,
+		Duration:      100, // 2 min
+		Transport:     "train",
 		TransportType: TransportTypeTrain,
-		IsTransfer: true,
-		Cost:        100,
+		IsTransfer:    true,
+		Cost:          100,
 	})
 	graph.AddEdge(&Edge{
-		From:       graph.Nodes()[4], // s5
-		To:         graph.Nodes()[5], // s6
-		Kind:       EdgeKindReal,
-		Duration:   100, // 2 min
-		Transport:  "train",
+		From:          graph.Nodes()[4], // s5
+		To:            graph.Nodes()[5], // s6
+		Kind:          EdgeKindReal,
+		Duration:      100, // 2 min
+		Transport:     "train",
 		TransportType: TransportTypeTrain,
-		IsTransfer: true,
-		Cost:        50,
+		IsTransfer:    true,
+		Cost:          50,
 	})
 	graph.AddEdge(&Edge{
-		From:       graph.Nodes()[5], // s6
-		To:         graph.Nodes()[7], // s8
-		Kind:       EdgeKindReal,
-		Duration:   200, // 3 min
-		Transport:  "train",
+		From:          graph.Nodes()[5], // s6
+		To:            graph.Nodes()[7], // s8
+		Kind:          EdgeKindReal,
+		Duration:      200, // 3 min
+		Transport:     "train",
 		TransportType: TransportTypeTrain,
-		IsTransfer: true,
-		Cost:        50,
+		IsTransfer:    true,
+		Cost:          50,
 	})
 
 	t.Run("fastest mode (default) sorts by duration", func(t *testing.T) {
@@ -285,13 +285,13 @@ func TestLazyExpansionDepthLimit(t *testing.T) {
 	// Add chain of transfer edges s1->s2->s3->s4->s5->s6->s7
 	for i := 0; i < 6; i++ {
 		graph.AddEdge(&Edge{
-			From:       graph.Nodes()[i],
-			To:         graph.Nodes()[i+1],
-			Kind:       EdgeKindReal,
-			Duration:   100,
-			Transport:  "train",
-		TransportType: TransportTypeTrain,
-		IsTransfer: true,
+			From:          graph.Nodes()[i],
+			To:            graph.Nodes()[i+1],
+			Kind:          EdgeKindReal,
+			Duration:      100,
+			Transport:     "train",
+			TransportType: TransportTypeTrain,
+			IsTransfer:    true,
 		})
 	}
 
@@ -336,6 +336,7 @@ func TestLazyExpansionDepthLimit(t *testing.T) {
 		t.Log("MaxTransfers=0: no direct route s1->s7 found (only chain edges exist)")
 	}
 }
+
 // TestRouteReSearchOnChange tests that the route change detection logic correctly
 // identifies when a route leg has undergone significant changes (cancellation or major delay)
 // and triggers a re-search to find an updated route.
@@ -355,7 +356,7 @@ func TestRouteReSearchOnChange(t *testing.T) {
 		Duration:   3600, // 1 hour
 		Transport:  "train",
 		IsTransfer: false,
-		Cost:        500,
+		Cost:       500,
 	})
 
 	// Add real edge s2 -> s3 (direct route)
@@ -366,7 +367,7 @@ func TestRouteReSearchOnChange(t *testing.T) {
 		Duration:   3600, // 1 hour
 		Transport:  "train",
 		IsTransfer: false,
-		Cost:        500,
+		Cost:       500,
 	})
 
 	// Create an itinerary simulating a found route from s1 to s3
@@ -375,13 +376,13 @@ func TestRouteReSearchOnChange(t *testing.T) {
 			{From: graph.Nodes()[0], To: graph.Nodes()[1], Duration: 3600, Transport: "train", IsTransfer: false, Cost: 500},
 			{From: graph.Nodes()[1], To: graph.Nodes()[2], Duration: 3600, Transport: "train", IsTransfer: false, Cost: 500},
 		},
-		TotalDuration: 7200, // 2 hours total
+		TotalDuration:  7200, // 2 hours total
 		TotalTransfers: 0,
-		ID:              "test-route-123",
+		ID:             "test-route-123",
 		// Set LastChecked to 2 hours ago (7200 seconds) to force re-check
 		// The check skips if checked within 3600 seconds (1 hour)
-		LastChecked: time.Now().Unix() - 7200,
-		NeedsReSearch: false,
+		LastChecked:    time.Now().Unix() - 7200,
+		NeedsReSearch:  false,
 		ReSearchReason: "",
 	}
 
@@ -431,11 +432,11 @@ func TestRouteReSearchOnChange(t *testing.T) {
 			{From: graph.Nodes()[0], To: graph.Nodes()[1], Duration: 3600, Transport: "train", IsTransfer: false, Cost: 500},
 			{From: graph.Nodes()[1], To: graph.Nodes()[2], Duration: 3600, Transport: "train", IsTransfer: false, Cost: 500},
 		},
-		TotalDuration: 7200,
+		TotalDuration:  7200,
 		TotalTransfers: 0,
-		ID:              "test-route-456",
-		LastChecked: time.Now().Unix() - 7200,
-		NeedsReSearch: false,
+		ID:             "test-route-456",
+		LastChecked:    time.Now().Unix() - 7200,
+		NeedsReSearch:  false,
 		ReSearchReason: "",
 	}