implement GetExpenseSummaryHandler

api/api.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"database/sql"
+	"github.com/KKGo-Software-engineering/workshop-summer/api/summary"
 	"github.com/KKGo-Software-engineering/workshop-summer/api/transaction"
 
 	"github.com/KKGo-Software-engineering/workshop-summer/api/config"
@@ -43,5 +44,11 @@ func New(db *sql.DB, cfg config.Config, logger *zap.Logger) *Server {
 		v1.POST("/transactions", h.Create)
 	}
 
+	{
+		h := summary.New(cfg.FeatureFlag, db)
+		v1.GET("/spenders/:id/expenses/summary", h.GetExpenseSummaryHandler)
+		//v1.GET("/spenders/:id/incomes/summary", h.GetIncomeSummaryHandler)
+	}
+
 	return &Server{e}
 }

api/summary/summary.go

@@ -0,0 +1,131 @@
+package summary
+
+import (
+	"database/sql"
+	"errors"
+	"github.com/KKGo-Software-engineering/workshop-summer/api/config"
+	"github.com/kkgo-software-engineering/workshop/mlog"
+	"github.com/labstack/echo/v4"
+	"go.uber.org/zap"
+	"net/http"
+	"time"
+)
+
+const (
+	typeExpense = "expense"
+	typeIncome  = "income"
+)
+
+var (
+	ErrInvalidSpender = errors.New("invalid spender")
+)
+
+type Err struct {
+	Message string `json:"message"`
+}
+
+type Spender struct {
+	ID int `param:"id"`
+}
+
+type RawData struct {
+	Date          time.Time
+	SumAmount     float64
+	CountExpenses int
+}
+
+type Summary struct {
+	Total   float64 `json:"total_amount"`
+	Average float64 `json:"average_per_day"`
+	Count   int     `json:"count_transaction"`
+}
+
+type handler struct {
+	flag config.FeatureFlag
+	db   *sql.DB
+}
+
+func New(cfg config.FeatureFlag, db *sql.DB) *handler {
+	return &handler{cfg, db}
+}
+
+func summary(data []RawData) Summary {
+	if len(data) == 0 {
+		return Summary{}
+	}
+
+	var total float64
+	var count int
+	for _, d := range data {
+		total += d.SumAmount
+		count += d.CountExpenses
+	}
+
+	return Summary{
+		Total:   total,
+		Average: total / float64(len(data)),
+		Count:   count,
+	}
+}
+
+const (
+	sumSQL = `SELECT
+	    date_trunc('day', date)::date AS transaction_date,
+	    SUM(amount) AS total_amount,
+	    COUNT(*) AS record_count
+	FROM
+	    "transaction"
+	WHERE
+	    transaction_type = $1 AND spender_id = $2
+	GROUP BY
+	    date_trunc('day', date)::date
+	ORDER BY
+	    transaction_date;`
+)
+
+func getSummary(c echo.Context, db *sql.DB, tnxType string) error {
+	logger := mlog.L(c)
+	ctx := c.Request().Context()
+
+	var spender Spender
+	err := c.Bind(&spender)
+	if err != nil {
+		logger.Error(ErrInvalidSpender.Error(), zap.Error(err))
+		return c.JSON(http.StatusBadRequest, Err{Message: ErrInvalidSpender.Error()})
+	}
+
+	stmt, err := db.PrepareContext(ctx, sumSQL)
+	if err != nil {
+		logger.Error("prepare statement error", zap.Error(err))
+		return c.JSON(http.StatusInternalServerError, Err{Message: "prepare statement error"})
+	}
+
+	rows, err := stmt.QueryContext(ctx, tnxType, spender.ID)
+	if err != nil {
+		logger.Error("query error", zap.Error(err))
+		return c.JSON(http.StatusInternalServerError, Err{Message: "query error"})
+	}
+	defer rows.Close()
+
+	var raws []RawData
+	for rows.Next() {
+		var raw RawData
+		err := rows.Scan(&raw.Date, &raw.SumAmount, &raw.CountExpenses)
+		if err != nil {
+			logger.Error("scan error", zap.Error(err))
+			return c.JSON(http.StatusInternalServerError, Err{Message: "scan error"})
+		}
+		raws = append(raws, raw)
+	}
+
+	return c.JSON(http.StatusOK, summary(raws))
+}
+
+func (h *handler) GetExpenseSummaryHandler(c echo.Context) error {
+	return getSummary(c, h.db, typeExpense)
+}
+
+//
+//func (h *handler) GetIncomeSummaryHandler(c echo.Context) error {
+//	return getSummary(c, h.db, typeIncome)
+//}

sql/add-sample-transaction.sql

@@ -0,0 +1,35 @@
+INSERT INTO "transaction" (date, amount, category, transaction_type, note, image_url, spender_id) VALUES
+-- Day 1: 2024-05-01
+('2024-05-01 10:15:00+00', 23, 'groceries', 'expense', 'Mock transaction 1', 'http://example.com/receipt1.jpg', 1),
+('2024-05-01 12:30:00+00', 45, 'rent', 'income', 'Mock transaction 2', 'http://example.com/receipt2.jpg', 1),
+('2024-05-01 15:45:00+00', 12, 'utilities', 'expense', 'Mock transaction 3', 'http://example.com/receipt3.jpg', 1),
+('2024-05-01 18:00:00+00', 67, 'entertainment', 'income', 'Mock transaction 4', 'http://example.com/receipt4.jpg', 1),
+('2024-05-01 20:15:00+00', 54, 'transport', 'expense', 'Mock transaction 5', 'http://example.com/receipt5.jpg', 1),
+
+-- Day 2: 2024-05-02
+('2024-05-02 09:00:00+00', 31, 'groceries', 'income', 'Mock transaction 6', 'http://example.com/receipt6.jpg', 1),
+('2024-05-02 11:15:00+00', 29, 'rent', 'expense', 'Mock transaction 7', 'http://example.com/receipt7.jpg', 1),
+('2024-05-02 13:30:00+00', 46, 'utilities', 'income', 'Mock transaction 8', 'http://example.com/receipt8.jpg', 1),
+('2024-05-02 15:45:00+00', 18, 'entertainment', 'expense', 'Mock transaction 9', 'http://example.com/receipt9.jpg', 1),
+('2024-05-02 18:00:00+00', 39, 'transport', 'income', 'Mock transaction 10', 'http://example.com/receipt10.jpg', 1),
+
+-- Day 3: 2024-05-03
+('2024-05-03 08:00:00+00', 22, 'groceries', 'expense', 'Mock transaction 11', 'http://example.com/receipt11.jpg', 1),
+('2024-05-03 10:15:00+00', 53, 'rent', 'income', 'Mock transaction 12', 'http://example.com/receipt12.jpg', 1),
+('2024-05-03 12:30:00+00', 44, 'utilities', 'expense', 'Mock transaction 13', 'http://example.com/receipt13.jpg', 1),
+('2024-05-03 14:45:00+00', 19, 'entertainment', 'income', 'Mock transaction 14', 'http://example.com/receipt14.jpg', 1),
+('2024-05-03 17:00:00+00', 61, 'transport', 'expense', 'Mock transaction 15', 'http://example.com/receipt15.jpg', 1),
+
+-- Day 4: 2024-05-04
+('2024-05-04 07:00:00+00', 38, 'groceries', 'income', 'Mock transaction 16', 'http://example.com/receipt16.jpg', 1),
+('2024-05-04 09:15:00+00', 27, 'rent', 'expense', 'Mock transaction 17', 'http://example.com/receipt17.jpg', 1),
+('2024-05-04 11:30:00+00', 49, 'utilities', 'income', 'Mock transaction 18', 'http://example.com/receipt18.jpg', 1),
+('2024-05-04 13:45:00+00', 32, 'entertainment', 'expense', 'Mock transaction 19', 'http://example.com/receipt19.jpg', 1),
+('2024-05-04 16:00:00+00', 55, 'transport', 'income', 'Mock transaction 20', 'http://example.com/receipt20.jpg', 1),
+
+-- Day 5: 2024-05-05
+('2024-05-05 06:00:00+00', 26, 'groceries', 'expense', 'Mock transaction 21', 'http://example.com/receipt21.jpg', 1),
+('2024-05-05 08:15:00+00', 48, 'rent', 'income', 'Mock transaction 22', 'http://example.com/receipt22.jpg', 1),
+('2024-05-05 10:30:00+00', 35, 'utilities', 'expense', 'Mock transaction 23', 'http://example.com/receipt23.jpg', 1),
+('2024-05-05 12:45:00+00', 43, 'entertainment', 'income', 'Mock transaction 24', 'http://example.com/receipt24.jpg', 1),
+('2024-05-05 15:00:00+00', 59, 'transport', 'expense', 'Mock transaction 25', 'http://example.com/receipt25.jpg', 1);

sql/get-raw-summary-expense.sql

@@ -0,0 +1,12 @@
+SELECT
+    date_trunc('day', date)::date AS transaction_date,
+    SUM(amount) AS total_amount,
+    COUNT(*) AS record_count
+FROM
+    "transaction"
+WHERE
+    transaction_type = 'expense' AND spender_id = 1
+GROUP BY
+    date_trunc('day', date)::date
+ORDER BY
+    transaction_date;