Enhance dashboard summary and statistics with new fields and caching improvements

- Added new field `Days` and `ScrapedTED` to `SummaryResponse` for tracking daily TED scrape counts.
- Updated `SummaryQuery` to include `Days` parameter for querying scraped TED data.
- Modified `Summary` handler to accept and process the new `Days` parameter.
- Refactored `Summary` method in the repository to support the new `Days` parameter and improved aggregation logic.
- Enhanced caching logic in the service layer to utilize a composite cache key based on `closingWindowSec` and `days`, improving cache management and retrieval efficiency.

This update improves the dashboard's functionality by providing more detailed insights into TED scraping activities and optimizing the caching strategy for better performance.

internal/dashboard/service.go

@@ -22,7 +22,8 @@ const (
 	defaultCountriesLimit     = 6
 	defaultListLimit          = 5
 	maxListLimit              = 20
-	summaryCacheTTL           = 60 * time.Second
+	summaryCacheTTL           = 5 * time.Minute
+	summaryStaleGraceTTL      = 15 * time.Minute
 	statisticsCacheTTL        = 5 * time.Minute
 	statisticsStaleGraceTTL   = 15 * time.Minute
 	// statisticsColdLoadWait bounds how long a cold-cache request waits for a fresh
@@ -54,7 +55,7 @@ type service struct {
 	logger          logger.Logger
 	redis           redis.Client
 	summaryMu       sync.Mutex
-	summary         map[int64]cacheEntry[*SummaryResponse]
+	summary         map[string]cacheEntry[*SummaryResponse]
 	summaryGroup    singleflight.Group
 	statisticsMu    sync.Mutex
 	statistics      map[int]cacheEntry[*StatisticsReportResponse]
@@ -67,32 +68,46 @@ func NewService(repo Repository, log logger.Logger, redisClient redis.Client) Se
 		repo:       repo,
 		logger:     log,
 		redis:      redisClient,
-		summary:    make(map[int64]cacheEntry[*SummaryResponse]),
+		summary:    make(map[string]cacheEntry[*SummaryResponse]),
 		statistics: make(map[int]cacheEntry[*StatisticsReportResponse]),
 	}
 	go s.warmStatisticsCache()
+	go s.warmSummaryCache()
 	return s
 }
 
 func (s *service) Summary(ctx context.Context, query SummaryQuery) (*SummaryResponse, error) {
 	windowHours := closingWindowHours(query.ClosingWindow)
 	windowSec := int64(windowHours) * 3600
+	days := trendDays(query.Days)
+	cacheKey := summaryCacheKey(windowSec, days)
 
-	if cached, ok := s.cachedSummary(windowSec); ok {
+	if cached, ok := s.cachedSummary(cacheKey); ok {
 		return cached, nil
 	}
 
-	cacheKey := strconv.FormatInt(windowSec, 10)
+	if stale, ok := s.staleSummary(cacheKey); ok {
+		go s.refreshSummary(windowSec, days)
+		return stale, nil
+	}
+
+	if redisCached, ok := s.getRedisSummary(ctx, cacheKey); ok {
+		s.storeSummary(cacheKey, redisCached)
+		go s.refreshSummary(windowSec, days)
+		return redisCached, nil
+	}
+
 	out, err, _ := s.summaryGroup.Do(cacheKey, func() (interface{}, error) {
-		if cached, ok := s.cachedSummary(windowSec); ok {
+		if cached, ok := s.cachedSummary(cacheKey); ok {
 			return cached, nil
 		}
 
 		s.logger.Info("Fetching dashboard summary", map[string]interface{}{
 			"closing_window_hours": windowHours,
+			"days":                 days,
 		})
 
-		result, err := s.repo.Summary(context.WithoutCancel(ctx), windowSec)
+		result, err := s.repo.Summary(context.WithoutCancel(ctx), windowSec, days)
 		if err != nil {
 			s.logger.Error("Failed to fetch dashboard summary", map[string]interface{}{
 				"error": err.Error(),
@@ -100,7 +115,8 @@ func (s *service) Summary(ctx context.Context, query SummaryQuery) (*SummaryResp
 			return nil, fmt.Errorf("dashboard summary: %w", err)
 		}
 
-		s.storeSummary(windowSec, result)
+		s.storeSummary(cacheKey, result)
+		s.storeRedisSummary(context.Background(), cacheKey, result)
 		return result, nil
 	})
 	if err != nil {
@@ -279,7 +295,6 @@ func emptyStatisticsReport(days int) *StatisticsReportResponse {
 		Days:        days,
 		GeneratedAt: time.Now().UTC().Unix(),
 		Daily: StatisticsDailySeries{
-			ScrapedTED:        fillTrendSeries(days, nil),
 			ScrapedDocuments:  fillTrendSeries(days, nil),
 			TranslatedNotices: fillTrendSeries(days, nil),
 		},
@@ -324,16 +339,94 @@ func (s *service) loadStatistics(ctx context.Context, days int) (*StatisticsRepo
 	return out.(*StatisticsReportResponse), nil
 }
 
-func (s *service) cachedSummary(windowSec int64) (*SummaryResponse, bool) {
+func (s *service) warmSummaryCache() {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	windowSec := int64(defaultClosingWindowHours) * 3600
+	cacheKey := summaryCacheKey(windowSec, defaultTrendDays)
+
+	if cached, ok := s.getRedisSummary(ctx, cacheKey); ok {
+		s.storeSummary(cacheKey, cached)
+		s.logger.Info("Dashboard summary cache warmed from Redis", map[string]interface{}{
+			"closing_window_hours": defaultClosingWindowHours,
+			"days":                 defaultTrendDays,
+		})
+		return
+	}
+
+	go s.refreshSummary(windowSec, defaultTrendDays)
+}
+
+func (s *service) refreshSummary(windowSec int64, days int) {
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	defer cancel()
+	_, _ = s.loadSummary(ctx, windowSec, days)
+}
+
+func (s *service) loadSummary(ctx context.Context, windowSec int64, days int) (*SummaryResponse, error) {
+	cacheKey := summaryCacheKey(windowSec, days)
+	out, err, _ := s.summaryGroup.Do(cacheKey, func() (interface{}, error) {
+		if cached, ok := s.cachedSummary(cacheKey); ok {
+			return cached, nil
+		}
+
+		s.logger.Info("Refreshing dashboard summary cache", map[string]interface{}{
+			"closing_window_sec": windowSec,
+			"days":               days,
+		})
+
+		result, err := s.repo.Summary(context.WithoutCancel(ctx), windowSec, days)
+		if err != nil {
+			s.logger.Error("Failed to refresh dashboard summary", map[string]interface{}{
+				"error": err.Error(),
+			})
+			return nil, fmt.Errorf("dashboard summary: %w", err)
+		}
+
+		s.storeSummary(cacheKey, result)
+		s.storeRedisSummary(context.Background(), cacheKey, result)
+		return result, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return out.(*SummaryResponse), nil
+}
+
+func summaryCacheKey(windowSec int64, days int) string {
+	return fmt.Sprintf("%d:%d", windowSec, days)
+}
+
+func summaryRedisKey(cacheKey string) string {
+	return fmt.Sprintf("dashboard:summary:%s", cacheKey)
+}
+
+func (s *service) cachedSummary(cacheKey string) (*SummaryResponse, bool) {
 	now := time.Now()
 
 	s.summaryMu.Lock()
 	defer s.summaryMu.Unlock()
 
-	entry, ok := s.summary[windowSec]
+	entry, ok := s.summary[cacheKey]
 	if !ok || now.After(entry.expiresAt) {
+		return nil, false
+	}
+
+	return entry.value, true
+}
+
+func (s *service) staleSummary(cacheKey string) (*SummaryResponse, bool) {
+	now := time.Now()
+
+	s.summaryMu.Lock()
+	defer s.summaryMu.Unlock()
+
+	entry, ok := s.summary[cacheKey]
+	if !ok || now.After(entry.staleUntil) {
 		if ok {
-			delete(s.summary, windowSec)
+			delete(s.summary, cacheKey)
 		}
 		return nil, false
 	}
@@ -341,17 +434,71 @@ func (s *service) cachedSummary(windowSec int64) (*SummaryResponse, bool) {
 	return entry.value, true
 }
 
-func (s *service) storeSummary(windowSec int64, value *SummaryResponse) {
+func (s *service) storeSummary(cacheKey string, value *SummaryResponse) {
+	now := time.Now()
+
 	s.summaryMu.Lock()
 	defer s.summaryMu.Unlock()
 
-	s.summary[windowSec] = cacheEntry[*SummaryResponse]{
-		expiresAt:  time.Now().Add(summaryCacheTTL),
-		staleUntil: time.Now().Add(summaryCacheTTL),
+	s.summary[cacheKey] = cacheEntry[*SummaryResponse]{
+		expiresAt:  now.Add(summaryCacheTTL),
+		staleUntil: now.Add(summaryCacheTTL + summaryStaleGraceTTL),
 		value:      value,
 	}
 }
 
+func (s *service) getRedisSummary(ctx context.Context, cacheKey string) (*SummaryResponse, bool) {
+	if s.redis == nil {
+		return nil, false
+	}
+
+	raw, err := s.redis.Get(ctx, summaryRedisKey(cacheKey))
+	if err != nil {
+		if err != goredis.Nil {
+			s.logger.Warn("Failed to read dashboard summary cache from Redis", map[string]interface{}{
+				"cache_key": cacheKey,
+				"error":     err.Error(),
+			})
+		}
+		return nil, false
+	}
+
+	var report SummaryResponse
+	if err := json.Unmarshal([]byte(raw), &report); err != nil {
+		s.logger.Warn("Failed to decode dashboard summary cache from Redis", map[string]interface{}{
+			"cache_key": cacheKey,
+			"error":     err.Error(),
+		})
+		_ = s.redis.Del(ctx, summaryRedisKey(cacheKey))
+		return nil, false
+	}
+
+	return &report, true
+}
+
+func (s *service) storeRedisSummary(ctx context.Context, cacheKey string, value *SummaryResponse) {
+	if s.redis == nil || value == nil {
+		return
+	}
+
+	encoded, err := json.Marshal(value)
+	if err != nil {
+		s.logger.Warn("Failed to encode dashboard summary for Redis", map[string]interface{}{
+			"cache_key": cacheKey,
+			"error":     err.Error(),
+		})
+		return
+	}
+
+	ttl := summaryCacheTTL + summaryStaleGraceTTL
+	if err := s.redis.Set(ctx, summaryRedisKey(cacheKey), string(encoded), ttl); err != nil {
+		s.logger.Warn("Failed to store dashboard summary in Redis", map[string]interface{}{
+			"cache_key": cacheKey,
+			"error":     err.Error(),
+		})
+	}
+}
+
 func (s *service) cachedStatistics(days int) (*StatisticsReportResponse, bool) {
 	now := time.Now()