fix: address code review findings

internal/routing/graph.go

@@ -1068,7 +1068,7 @@ func (g *Graph) checkRouteForChanges(itinerary *Itinerary) bool {
 					break
 				}
 				// Check for significant delay (more than 2x normal duration)
-				if edge.Duration > leg.Cost*2 && leg.Cost > 0 { // simplified delay check
+				if edge.Duration > leg.Duration*2 && leg.Duration > 0 {
 					if !needsReSearch || itinerary.ReSearchReason == string(reasonNone) {
 						needsReSearch = true
 						itinerary.NeedsReSearch = true

internal/routing/graph_test.go

@@ -325,9 +325,6 @@ func TestLazyExpansionDepthLimit(t *testing.T) {
 // 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.
-// 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.
 func TestRouteReSearchOnChange(t *testing.T) {
 	graph := NewGraph()
 

internal/routing/search_cache.go

@@ -2,6 +2,7 @@ package routing
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 
 	"trip-planner/internal/cache"
@@ -74,19 +75,23 @@ func (s *SearchCacheService) performYandexSearch(ctx context.Context, from, to,
 
 // parseItineraryFromBytes parses an itinerary from byte data.
 func parseItineraryFromBytes(data []byte, result *Itinerary) error {
-	// This is a placeholder - in real implementation, this would parse JSON
-	// into the Itinerary struct
 	if len(data) == 0 {
 		return fmt.Errorf("empty data")
 	}
+	if err := json.Unmarshal(data, result); err != nil {
+		return fmt.Errorf("failed to parse itinerary from bytes: %w", err)
+	}
 	return nil
 }
 
 // convertResponseToBytes converts Yandex API response to bytes for caching.
 func convertResponseToBytes(resp *yandex.Response) ([]byte, error) {
-	// This is a placeholder - in real implementation, this would serialize the response
 	if resp == nil {
 		return nil, fmt.Errorf("nil response")
 	}
-	return []byte(`{"search":{"from":"%s","to":"%s"},"segments":[]}`), nil
+	data, err := json.Marshal(resp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal response: %w", err)
+	}
+	return data, nil
 }

internal/routing/search_cache_test.go

@@ -77,10 +77,10 @@ func TestParseItineraryFromBytes(t *testing.T) {
 		t.Error("expected error for empty data")
 	}
 
-	// Test with non-empty data (placeholder implementation returns nil error)
-	err = parseItineraryFromBytes([]byte("test"), &result)
-	if err != nil {
-		t.Errorf("expected no error for non-empty data, got %v", err)
+	// Test with invalid JSON data
+	err = parseItineraryFromBytes([]byte("invalid json data"), &result)
+	if err == nil {
+		t.Error("expected error for invalid JSON data")
 	}
 }