Added analytics by transactions

backend/src/api/routers/transactions.go

@@ -25,6 +25,7 @@ func (router *TransactionsRouter) RegisterRoutes(r *gin.RouterGroup) {
 	{
 		transactions.POST("", router.Create)
 		transactions.GET("", router.List)
+		transactions.GET("/analytics", router.Analytics)
 		transactions.GET("/:id", router.Read)
 		transactions.PATCH("/:id", router.Update)
 		transactions.DELETE("/:id", router.Delete)
@@ -114,6 +115,53 @@ func (router *TransactionsRouter) List(c *gin.Context) {
 	c.JSON(http.StatusOK, dto.TransactionsToListResponse(transactions))
 }
 
+// Analytics GoDoc
+// @Summary Получить аналитику по транзакциям
+// @Description Возвращает расходы, доходы и total за период. При фильтре по type второй тип возвращается как 0.
+// @Tags Transactions
+// @Accept json
+// @Produce json
+// @Param family_id query int false "Family ID"
+// @Param type query string false "Transaction type: income or expense"
+// @Param date_from query string true "RFC3339 start datetime"
+// @Param date_to query string true "RFC3339 end datetime"
+// @Success 200 {object} dto.TransactionAnalyticsResponse
+// @Failure 400 {object} dto.ErrorResponse
+// @Failure 500 {object} dto.ErrorResponse
+// @Router /transactions/analytics [get]
+func (router *TransactionsRouter) Analytics(c *gin.Context) {
+	var query dto.TransactionAnalyticsQuery
+	if err := c.ShouldBindQuery(&query); err != nil {
+		c.JSON(http.StatusBadRequest, dto.ErrorResponse{Message: err.Error()})
+		return
+	}
+
+	dateFrom, err := time.Parse(time.RFC3339, query.DateFrom)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, dto.ErrorResponse{Message: "date_from must be RFC3339"})
+		return
+	}
+
+	dateTo, err := time.Parse(time.RFC3339, query.DateTo)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, dto.ErrorResponse{Message: "date_to must be RFC3339"})
+		return
+	}
+
+	analytics, err := router.service.Analytics(c.Request.Context(), domain.TransactionAnalyticsFilter{
+		FamilyID: query.FamilyID,
+		Type:     query.Type,
+		DateFrom: dateFrom,
+		DateTo:   dateTo,
+	})
+	if err != nil {
+		handleTransactionError(c, err)
+		return
+	}
+
+	c.JSON(http.StatusOK, dto.TransactionAnalyticsToResponse(analytics))
+}
+
 // Read GoDoc
 // @Summary Получить транзакцию по ID
 // @Description Возвращает транзакцию по ее внутреннему ID
@@ -228,7 +276,8 @@ func handleTransactionError(c *gin.Context, err error) {
 		c.JSON(http.StatusNotFound, dto.ErrorResponse{Message: err.Error()})
 	case errors.Is(err, services.ErrTransactionPatch),
 		errors.Is(err, services.ErrReceiptLinkConflict),
-		errors.Is(err, services.ErrInvalidTransaction):
+		errors.Is(err, services.ErrInvalidTransaction),
+		errors.Is(err, services.ErrInvalidAnalytics):
 		c.JSON(http.StatusBadRequest, dto.ErrorResponse{Message: err.Error()})
 	case errors.Is(err, services.ErrReceiptNotFound):
 		c.JSON(http.StatusNotFound, dto.ErrorResponse{Message: err.Error()})