feat(backend): 增强使用统计和API密钥功能

- 优化使用统计处理逻辑
- 增强API密钥仓储层功能
- 改进账户使用服务
- 完善API契约测试覆盖

backend/internal/handler/usage_handler.go

@@ -371,24 +371,16 @@ func (h *UsageHandler) DashboardApiKeysUsage(c *gin.Context) {
 		return
 	}
 
-	// Verify ownership of all requested API keys
-	userApiKeys, _, err := h.apiKeyService.List(c.Request.Context(), subject.UserID, pagination.PaginationParams{Page: 1, PageSize: 1000})
-	if err != nil {
-		response.ErrorFrom(c, err)
+	// Limit the number of API key IDs to prevent SQL parameter overflow
+	if len(req.ApiKeyIDs) > 100 {
+		response.BadRequest(c, "Too many API key IDs (maximum 100 allowed)")
 		return
 	}
 
-	userApiKeyIDs := make(map[int64]bool)
-	for _, key := range userApiKeys {
-		userApiKeyIDs[key.ID] = true
-	}
-
-	// Filter to only include user's own API keys
-	validApiKeyIDs := make([]int64, 0)
-	for _, id := range req.ApiKeyIDs {
-		if userApiKeyIDs[id] {
-			validApiKeyIDs = append(validApiKeyIDs, id)
-		}
+	validApiKeyIDs, err := h.apiKeyService.VerifyOwnership(c.Request.Context(), subject.UserID, req.ApiKeyIDs)
+	if err != nil {
+		response.ErrorFrom(c, err)
+		return
 	}
 
 	if len(validApiKeyIDs) == 0 {

backend/internal/repository/api_key_repo.go

@@ -81,6 +81,22 @@ func (r *apiKeyRepository) ListByUserID(ctx context.Context, userID int64, param
 	return outKeys, paginationResultFromTotal(total, params), nil
 }
 
+func (r *apiKeyRepository) VerifyOwnership(ctx context.Context, userID int64, apiKeyIDs []int64) ([]int64, error) {
+	if len(apiKeyIDs) == 0 {
+		return []int64{}, nil
+	}
+
+	ids := make([]int64, 0, len(apiKeyIDs))
+	err := r.db.WithContext(ctx).
+		Model(&apiKeyModel{}).
+		Where("user_id = ? AND id IN ?", userID, apiKeyIDs).
+		Pluck("id", &ids).Error
+	if err != nil {
+		return nil, err
+	}
+	return ids, nil
+}
+
 func (r *apiKeyRepository) CountByUserID(ctx context.Context, userID int64) (int64, error) {
 	var count int64
 	err := r.db.WithContext(ctx).Model(&apiKeyModel{}).Where("user_id = ?", userID).Count(&count).Error

backend/internal/server/api_contract_test.go

@@ -788,6 +788,25 @@ func (r *stubApiKeyRepo) ListByUserID(ctx context.Context, userID int64, params
 	}, nil
 }
 
+func (r *stubApiKeyRepo) VerifyOwnership(ctx context.Context, userID int64, apiKeyIDs []int64) ([]int64, error) {
+	if len(apiKeyIDs) == 0 {
+		return []int64{}, nil
+	}
+	seen := make(map[int64]struct{}, len(apiKeyIDs))
+	out := make([]int64, 0, len(apiKeyIDs))
+	for _, id := range apiKeyIDs {
+		if _, ok := seen[id]; ok {
+			continue
+		}
+		seen[id] = struct{}{}
+		key, ok := r.byID[id]
+		if ok && key.UserID == userID {
+			out = append(out, id)
+		}
+	}
+	return out, nil
+}
+
 func (r *stubApiKeyRepo) CountByUserID(ctx context.Context, userID int64) (int64, error) {
 	var count int64
 	for _, key := range r.byID {

backend/internal/service/account_usage_service.go

@@ -48,6 +48,10 @@ type UsageLogRepository interface {
 
 	// Account stats
 	GetAccountUsageStats(ctx context.Context, accountID int64, startTime, endTime time.Time) (*usagestats.AccountUsageStatsResponse, error)
+
+	// Aggregated stats (optimized)
+	GetUserStatsAggregated(ctx context.Context, userID int64, startTime, endTime time.Time) (*usagestats.UsageStats, error)
+	GetApiKeyStatsAggregated(ctx context.Context, apiKeyID int64, startTime, endTime time.Time) (*usagestats.UsageStats, error)
 }
 
 // usageCache 用于缓存usage数据

backend/internal/service/api_key_service.go

@@ -34,6 +34,7 @@ type ApiKeyRepository interface {
 	Delete(ctx context.Context, id int64) error
 
 	ListByUserID(ctx context.Context, userID int64, params pagination.PaginationParams) ([]ApiKey, *pagination.PaginationResult, error)
+	VerifyOwnership(ctx context.Context, userID int64, apiKeyIDs []int64) ([]int64, error)
 	CountByUserID(ctx context.Context, userID int64) (int64, error)
 	ExistsByKey(ctx context.Context, key string) (bool, error)
 	ListByGroupID(ctx context.Context, groupID int64, params pagination.PaginationParams) ([]ApiKey, *pagination.PaginationResult, error)
@@ -256,6 +257,18 @@ func (s *ApiKeyService) List(ctx context.Context, userID int64, params paginatio
 	return keys, pagination, nil
 }
 
+func (s *ApiKeyService) VerifyOwnership(ctx context.Context, userID int64, apiKeyIDs []int64) ([]int64, error) {
+	if len(apiKeyIDs) == 0 {
+		return []int64{}, nil
+	}
+
+	validIDs, err := s.apiKeyRepo.VerifyOwnership(ctx, userID, apiKeyIDs)
+	if err != nil {
+		return nil, fmt.Errorf("verify api key ownership: %w", err)
+	}
+	return validIDs, nil
+}
+
 // GetByID 根据ID获取API Key
 func (s *ApiKeyService) GetByID(ctx context.Context, id int64) (*ApiKey, error) {
 	apiKey, err := s.apiKeyRepo.GetByID(ctx, id)

backend/internal/service/usage_service.go

@@ -148,22 +148,40 @@ func (s *UsageService) ListByAccount(ctx context.Context, accountID int64, param
 
 // GetStatsByUser 获取用户的使用统计
 func (s *UsageService) GetStatsByUser(ctx context.Context, userID int64, startTime, endTime time.Time) (*UsageStats, error) {
-	logs, _, err := s.usageRepo.ListByUserAndTimeRange(ctx, userID, startTime, endTime)
+	stats, err := s.usageRepo.GetUserStatsAggregated(ctx, userID, startTime, endTime)
 	if err != nil {
-		return nil, fmt.Errorf("list usage logs: %w", err)
+		return nil, fmt.Errorf("get user stats: %w", err)
 	}
 
-	return s.calculateStats(logs), nil
+	return &UsageStats{
+		TotalRequests:     stats.TotalRequests,
+		TotalInputTokens:  stats.TotalInputTokens,
+		TotalOutputTokens: stats.TotalOutputTokens,
+		TotalCacheTokens:  stats.TotalCacheTokens,
+		TotalTokens:       stats.TotalTokens,
+		TotalCost:         stats.TotalCost,
+		TotalActualCost:   stats.TotalActualCost,
+		AverageDurationMs: stats.AverageDurationMs,
+	}, nil
 }
 
 // GetStatsByApiKey 获取API Key的使用统计
 func (s *UsageService) GetStatsByApiKey(ctx context.Context, apiKeyID int64, startTime, endTime time.Time) (*UsageStats, error) {
-	logs, _, err := s.usageRepo.ListByApiKeyAndTimeRange(ctx, apiKeyID, startTime, endTime)
+	stats, err := s.usageRepo.GetApiKeyStatsAggregated(ctx, apiKeyID, startTime, endTime)
 	if err != nil {
-		return nil, fmt.Errorf("list usage logs: %w", err)
+		return nil, fmt.Errorf("get api key stats: %w", err)
 	}
 
-	return s.calculateStats(logs), nil
+	return &UsageStats{
+		TotalRequests:     stats.TotalRequests,
+		TotalInputTokens:  stats.TotalInputTokens,
+		TotalOutputTokens: stats.TotalOutputTokens,
+		TotalCacheTokens:  stats.TotalCacheTokens,
+		TotalTokens:       stats.TotalTokens,
+		TotalCost:         stats.TotalCost,
+		TotalActualCost:   stats.TotalActualCost,
+		AverageDurationMs: stats.AverageDurationMs,
+	}, nil
 }
 
 // GetStatsByAccount 获取账号的使用统计