Add GET /user/:userId/allowance/:allowanceId (#50)

Reviewed-on: #50

backend/api_test.go

@@ -421,6 +421,47 @@ func TestGetHistory(t *testing.T) {
 	response.Value(2).Object().Value("allowance").Number().IsEqual(-10)
 }
 
+func TestGetUserAllowanceById(t *testing.T) {
+	e := startServer(t)
+
+	// Create a new allowance
+	requestBody := map[string]interface{}{
+		"name":   TestAllowanceName,
+		"target": 5000,
+		"weight": 10,
+	}
+	resp := e.POST("/user/1/allowance").WithJSON(requestBody).Expect().Status(201).JSON().Object()
+	allowanceId := int(resp.Value("id").Number().Raw())
+
+	// Retrieve the created allowance by ID
+	result := e.GET("/user/1/allowance/" + strconv.Itoa(allowanceId)).Expect().Status(200).JSON().Object()
+	result.Value("id").IsEqual(allowanceId)
+	result.Value("name").IsEqual(TestAllowanceName)
+	result.Value("target").IsEqual(5000)
+	result.Value("weight").IsEqual(10)
+	result.Value("progress").IsEqual(0)
+}
+
+func TestGetUserByAllowanceIdInvalidAllowance(t *testing.T) {
+	e := startServer(t)
+	e.GET("/user/1/allowance/9999").Expect().Status(404)
+}
+
+func TestGetUserByAllowanceByIdInvalidUserId(t *testing.T) {
+	e := startServer(t)
+	e.GET("/user/999/allowance/1").Expect().Status(404)
+}
+
+func TestGetUserByAllowanceByIdBadUserId(t *testing.T) {
+	e := startServer(t)
+	e.GET("/user/bad/allowance/1").Expect().Status(400)
+}
+
+func TestGetUserByAllowanceByIdBadAllowanceId(t *testing.T) {
+	e := startServer(t)
+	e.GET("/user/1/allowance/bad").Expect().Status(400)
+}
+
 func getDelta(base time.Time, delta float64) (time.Time, time.Time) {
 	start := base.Add(-time.Duration(delta) * time.Second)
 	end := base.Add(time.Duration(delta) * time.Second)

backend/db.go

@@ -86,6 +86,17 @@ func (db *Db) GetUserAllowances(userId int) ([]Allowance, error) {
 	return allowances, nil
 }
 
+func (db *Db) GetUserAllowanceById(userId int, allowanceId int) (*Allowance, error) {
+	allowance := &Allowance{}
+	err := db.db.Query("select id, name, target, progress, weight from allowances where user_id = ? and id = ?").
+		Bind(userId, allowanceId).
+		ScanSingle(&allowance.ID, &allowance.Name, &allowance.Target, &allowance.Progress, &allowance.Weight)
+	if err != nil {
+		return nil, err
+	}
+	return allowance, nil
+}
+
 func (db *Db) CreateAllowance(userId int, allowance *CreateAllowanceRequest) (int, error) {
 	// Check if user exists before attempting to create an allowance
 	exists, err := db.UserExists(userId)

backend/main.go

@@ -106,6 +106,49 @@ func getUserAllowance(c *gin.Context) {
 	c.IndentedJSON(http.StatusOK, allowances)
 }
 
+func getUserAllowanceById(c *gin.Context) {
+	userIdStr := c.Param("userId")
+	allowanceIdStr := c.Param("allowanceId")
+
+	userId, err := strconv.Atoi(userIdStr)
+	if err != nil {
+		log.Printf(ErrInvalidUserID+": %v", err)
+		c.JSON(http.StatusBadRequest, gin.H{"error": ErrInvalidUserID})
+		return
+	}
+
+	allowanceId, err := strconv.Atoi(allowanceIdStr)
+	if err != nil {
+		log.Printf("Invalid allowance ID: %v", err)
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid allowance ID"})
+		return
+	}
+
+	exists, err := db.UserExists(userId)
+	if err != nil {
+		log.Printf(ErrCheckingUserExist, err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": ErrInternalServerError})
+		return
+	}
+	if !exists {
+		c.JSON(http.StatusNotFound, gin.H{"error": ErrUserNotFound})
+		return
+	}
+
+	allowance, err := db.GetUserAllowanceById(userId, allowanceId)
+	if errors.Is(err, mysqlite.ErrNoRows) {
+		c.JSON(http.StatusNotFound, gin.H{"error": "Allowance not found"})
+		return
+	}
+	if err != nil {
+		log.Printf("Error getting allowance: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": ErrInternalServerError})
+		return
+	}
+
+	c.IndentedJSON(http.StatusOK, allowance)
+}
+
 func createUserAllowance(c *gin.Context) {
 	userIdStr := c.Param("userId")
 	userId, err := strconv.Atoi(userIdStr)
@@ -363,6 +406,7 @@ func start(ctx context.Context, config *ServerConfig) {
 	router.GET("/api/user/:userId/history", getHistory)
 	router.GET("/api/user/:userId/allowance", getUserAllowance)
 	router.POST("/api/user/:userId/allowance", createUserAllowance)
+	router.GET("/api/user/:userId/allowance/:allowanceId", getUserAllowanceById)
 	router.DELETE("/api/user/:userId/allowance/:allowanceId", deleteUserAllowance)
 	router.POST("/api/tasks", createTask)
 	router.GET("/api/tasks", getTasks)