Add statistics handler and endpoint

cmd/http-server/main.go

@@ -133,6 +133,10 @@ func main() {
 		{
 			currencyRoutes.GET("/all", handlers.CurrencyGetAll)
 		}
+		statisticRoute := api.Group("/statistics", middleware.AuthMiddleware())
+		{
+			statisticRoute.GET("/type", handlers.StatisticsGetAllSpendingsForTypes)
+		}
 	}
 
 	r.GET("/swagger/*any", ginSwagger.WrapHandler(swaggerFiles.Handler))

handlers/statistics.go

@@ -0,0 +1,90 @@
+package handlers
+
+import (
+	"fmt"
+	"log"
+	"slices"
+
+	"git.qowevisa.me/Qowevisa/fin-check-api/db"
+	"git.qowevisa.me/Qowevisa/fin-check-api/types"
+	"github.com/gin-gonic/gin"
+)
+
+// @Summary Get all statisticss for user
+// @Description Get all statisticss for user
+// @Tags type
+// @Produce json
+// @Param Authorization header string true "Bearer token"
+// @Success 200 {object} []types.StatsTypeCurrencyChart
+// @Failure 401 {object} types.ErrorResponse
+// @Failure 500 {object} types.ErrorResponse
+// @Security ApiKeyAuth
+// @Router /statistics/type [get]
+func StatisticsGetAllSpendingsForTypes(c *gin.Context) {
+	userID, err := GetUserID(c)
+	if err != nil {
+		c.JSON(500, types.ErrorResponse{Message: err.Error()})
+		return
+	}
+	dbc := db.Connect()
+	var userTypes []*db.Type
+	if err := dbc.Find(&userTypes, db.Type{UserID: userID}).Error; err != nil {
+		c.JSON(500, types.ErrorResponse{Message: err.Error()})
+		return
+	}
+	var userExpenses []*db.Expense
+	if err := dbc.Preload("Card.Currency").Find(&userExpenses, db.Expense{UserID: userID}).Error; err != nil {
+		c.JSON(500, types.ErrorResponse{Message: err.Error()})
+		return
+	}
+	currToChart := make(map[uint][]*db.Expense)
+
+	for _, expense := range userExpenses {
+		if expense.Card == nil || expense.Card.Currency == nil {
+			log.Printf("ERROR: db.Preload DID NOT WORKED OUT!\n")
+			c.JSON(500, types.ErrorResponse{Message: "Internal error. E.S.T.1"})
+			return
+		}
+		if val, exists := currToChart[expense.Card.CurrencyID]; !exists {
+			currToChart[expense.Card.CurrencyID] = []*db.Expense{}
+			currToChart[expense.Card.CurrencyID] = append(currToChart[expense.Card.CurrencyID], expense)
+		} else {
+			currToChart[expense.Card.CurrencyID] = append(val, expense)
+		}
+	}
+	var ret []types.StatsTypeCurrencyChart
+	for _, expenseArray := range currToChart {
+		if expenseArray[0].Card == nil || expenseArray[0].Card.Currency == nil {
+			log.Printf("ERROR: db.Preload DID NOT WORKED OUT!\n")
+			c.JSON(500, types.ErrorResponse{Message: "Internal error. E.S.T.2"})
+			return
+		}
+		currency := expenseArray[0].Card.Currency
+		typeToValue := make(map[uint]types.StatsType)
+
+		for _, expense := range expenseArray {
+			if val, exists := typeToValue[expense.TypeID]; !exists {
+				idx := slices.IndexFunc(userTypes, func(t *db.Type) bool { return t.ID == expense.TypeID })
+				typeForChart := userTypes[idx]
+				typeToValue[expense.TypeID] = types.StatsType{
+					Value: expense.Value,
+					Name:  typeForChart.Name,
+					Color: typeForChart.Color,
+				}
+			} else {
+				val.Value += expense.Value
+				typeToValue[expense.TypeID] = val
+			}
+		}
+		var elements []types.StatsType
+		for _, val := range typeToValue {
+			elements = append(elements, val)
+		}
+
+		ret = append(ret, types.StatsTypeCurrencyChart{
+			CurrencyLabel: fmt.Sprintf("%s (%s)", currency.Symbol, currency.ISOName),
+			Elements:      elements,
+		})
+	}
+	c.JSON(200, ret)
+}

types/types.go

@@ -180,3 +180,20 @@ type DbItemBought struct {
 	MetricValue uint64 `json:"metric_value" example:"100"`
 	Item        DbItem `json:"itme"`
 }
+
+// User Spendings that are connected by types:
+//
+//	-- DbExpense
+//	-- DbItemBought -> DbItem
+type StatsType struct {
+	Value uint64 `json:"value" example:"20015"`
+	Name  string `json:"name" example:"Meat"`
+	Color string `json:"color" example:"#1e2e3e"`
+}
+
+// Contains a number of StatsType
+// StatsTypeCurrencyChart is like a struct for chart with specific Currency bound
+type StatsTypeCurrencyChart struct {
+	CurrencyLabel string      `json:"label" example:"$ (USD)"`
+	Elements      []StatsType `json:"elements"`
+}