fix: address code review findings

cmd/api/handlers.go

@@ -205,6 +205,18 @@ func RouteSearch(hc *HandlerContext, w http.ResponseWriter, r *http.Request) {
 		RankingMode: rankingMode,
 	}
 
+	// Determine if this is a far-term search (date is more than 7 days in the future)
+	if req.Date != "" {
+		requestDate, err := time.Parse("2006-01-02", req.Date)
+		if err == nil {
+			now := time.Now()
+			daysDiff := int(requestDate.Sub(now).Hours() / 24)
+			if daysDiff >= 7 {
+				opts.FarTerm = true
+			}
+		}
+	}
+
 	// Detect closed stations and get neighbors for fallback
 	closedStationsMap := make(map[string]bool)
 	neighborsMap := make(map[string][]storage.StationNeighbor)
@@ -431,7 +443,7 @@ func StationStatus(hc *HandlerContext, w http.ResponseWriter, r *http.Request) {
 func adminAuth(hc *HandlerContext, w http.ResponseWriter, r *http.Request) bool {
 	expectedAPIKey := os.Getenv("TRIP_PLANNER_ADMIN_API_KEY")
 	if expectedAPIKey == "" {
-		http.Error(w, "unauthorized", http.StatusUnauthorized)
+		http.Error(w, "server configuration error: TRIP_PLANNER_ADMIN_API_KEY is not set", http.StatusInternalServerError)
 		return false
 	}
 	providedAPIKey := r.Header.Get("X-Admin-Api-Key")

cmd/cron/station_status.go

@@ -131,12 +131,17 @@ func (sm *StationMonitor) updateStationStatus(ctx context.Context, tripCount int
 	zeroSinceData, err := sm.Cache.Get(ctx, zeroSinceKey)
 	var zeroSince time.Time
 	if err == nil && zeroSinceData != nil {
-		var zeroSinceUnix int64
-		_, parseErr := fmt.Sscanf(string(zeroSinceData), "%d", &zeroSinceUnix)
-		if parseErr == nil {
-			zeroSince = time.Unix(zeroSinceUnix, 0)
-		} else {
+		// Handle "0" marker for time.Time{} (no zero-since)
+		if string(zeroSinceData) == "0" {
 			zeroSince = time.Time{}
+		} else {
+			var zeroSinceUnix int64
+			_, parseErr := fmt.Sscanf(string(zeroSinceData), "%d", &zeroSinceUnix)
+			if parseErr == nil {
+				zeroSince = time.Unix(zeroSinceUnix, 0)
+			} else {
+				zeroSince = time.Time{}
+			}
 		}
 	}
 
@@ -184,7 +189,12 @@ func (sm *StationMonitor) updateStationStatus(ctx context.Context, tripCount int
 	}
 
 	// Write updated zero-since timestamp to cache with 24h TTL
-	if err := sm.Cache.Set(ctx, zeroSinceKey, []byte(fmt.Sprintf("%d", zeroSince.Unix())), 24*time.Hour); err != nil {
+	// Use "0" marker for time.Time{} to indicate no zero-since
+	zeroSinceStr := "0"
+	if !zeroSince.IsZero() {
+		zeroSinceStr = fmt.Sprintf("%d", zeroSince.Unix())
+	}
+	if err := sm.Cache.Set(ctx, zeroSinceKey, []byte(zeroSinceStr), 24*time.Hour); err != nil {
 		return newStatus, fmt.Errorf("cache set zero since: %w", err)
 	}
 

internal/cache/preferences.go

@@ -107,15 +107,6 @@ func (p *Preferences) AddSavedCity(ctx context.Context, userID, cityCode, cityNa
 
 // RemoveSavedCity removes a city from the user's saved cities.
 func (p *Preferences) RemoveSavedCity(ctx context.Context, userID, cityCode string) error {
-	key := &CacheKey{
-		Kind:    "prefs:saved_city:" + userID,
-		Code:    userID,
-		From:    "",
-		To:      "",
-		Date:    "",
-		Request: "",
-	}
-
 	// Load existing cities
 	cities, err := p.GetSavedCities(ctx, userID)
 	if err != nil {
@@ -132,6 +123,10 @@ func (p *Preferences) RemoveSavedCity(ctx context.Context, userID, cityCode stri
 
 	if len(result) == 0 {
 		// If no cities left, delete the key
+		key := &CacheKey{
+			Kind: "prefs:saved_city:" + userID,
+			Code: userID,
+		}
 		return p.store.Delete(ctx, key)
 	}
 
@@ -141,6 +136,10 @@ func (p *Preferences) RemoveSavedCity(ctx context.Context, userID, cityCode stri
 		return err
 	}
 
+	key := &CacheKey{
+		Kind: "prefs:saved_city:" + userID,
+		Code: userID,
+	}
 	return p.store.Set(ctx, key, data, PreferenceTTL)
 }
 

internal/cache/store.go

@@ -167,6 +167,11 @@ func GetSearchKey(from, to, date string) *CacheKey {
 	return &CacheKey{Kind: "search", From: from, To: to, Date: date}
 }
 
+// GetSearchKeyWithFarTerm returns the cache key for a search query with far-term flag.
+func GetSearchKeyWithFarTerm(from, to, date, farTermFlag string) *CacheKey {
+	return &CacheKey{Kind: "search", From: from, To: to, Date: date, Request: farTermFlag}
+}
+
 // CacheAside represents the cache-aside pattern implementation.
 // It follows the pattern: Redis → miss → Postgres/API → write-back to Redis.
 type CacheAside struct {

internal/routing/graph.go

@@ -2,6 +2,7 @@ package routing
 
 import (
 	"context"
+	"log"
 	"sort"
 	"time"
 	"trip-planner/internal/storage"
@@ -626,9 +627,10 @@ func (g *Graph) FindRoute(originID, destID string, opts SearchOptions, closedSta
 				"date": time.Now().Format("2006-01-02"),
 			}
 
-			resp, err := yandexClient.Do(context.Background(), "GET", "/v3.0/search/", query)
+			resp, err := yandexClient.Do(context.TODO(), "GET", "/v3.0/search/", query)
 			if err != nil {
-				// If API call fails, return nil (no route found)
+				// If API call fails, log the error and return nil (no route found)
+				log.Printf("WARNING: yandex search failed for route expansion: %v", err)
 				return nil
 			}
 
@@ -1106,9 +1108,9 @@ func (g *Graph) checkRouteForChanges(itinerary *Itinerary) bool {
 
 // rescheduleRoute performs a re-search for the route with updated graph data.
 // This is called when significant changes are detected in the route legs.
-func (g *Graph) rescheduleRoute(originID, destID string, opts SearchOptions, closedStations map[string]bool, neighbors map[string][]storage.StationNeighbor) *Itinerary {
+func (g *Graph) rescheduleRoute(originID, destID string, opts SearchOptions, closedStations map[string]bool, neighbors map[string][]storage.StationNeighbor, yclient ...*yandex.Client) *Itinerary {
 	// Re-run the search with the same options to get an updated route
-	result := g.FindRoute(originID, destID, opts, closedStations, neighbors)
+	result := g.FindRoute(originID, destID, opts, closedStations, neighbors, yclient...)
 	if result != nil {
 		result.LastChecked = time.Now().Unix()
 		result.NeedsReSearch = false
@@ -1119,9 +1121,9 @@ func (g *Graph) rescheduleRoute(originID, destID string, opts SearchOptions, clo
 
 // CheckAndRescheduleRoute checks a route for changes and returns an updated route if needed.
 // This is the main entry point for flight change notification logic.
-func (g *Graph) CheckAndRescheduleRoute(itinerary *Itinerary, originID, destID string, opts SearchOptions, closedStations map[string]bool, neighbors map[string][]storage.StationNeighbor) *Itinerary {
+func (g *Graph) CheckAndRescheduleRoute(itinerary *Itinerary, originID, destID string, opts SearchOptions, closedStations map[string]bool, neighbors map[string][]storage.StationNeighbor, yclient ...*yandex.Client) *Itinerary {
 	if g.checkRouteForChanges(itinerary) {
-		return g.rescheduleRoute(originID, destID, opts, closedStations, neighbors)
+		return g.rescheduleRoute(originID, destID, opts, closedStations, neighbors, yclient...)
 	}
 	return itinerary
 }

internal/routing/search_cache.go

@@ -29,8 +29,12 @@ func NewSearchCacheService(cacheStore cache.Cache, yclient *yandex.Client, m *me
 // SearchWithCache performs a route search with caching support.
 // It uses the cache-aside pattern: try cache first, then Yandex API, then write back to cache.
 func (s *SearchCacheService) SearchWithCache(ctx context.Context, from, to, date string, opts SearchOptions) (*yandex.Response, error) {
-	// Generate cache key
-	searchKey := cache.GetSearchKey(from, to, date)
+	// Generate cache key including far-term flag to distinguish near-term vs far-term searches
+	farTermFlag := "near"
+	if opts.FarTerm {
+		farTermFlag = "far"
+	}
+	searchKey := cache.GetSearchKeyWithFarTerm(from, to, date, farTermFlag)
 
 	// Try to get from cache first
 	fetchFunc := func() ([]byte, error) {