Implement POST task (#28)

Closes #21

Reviewed-on: #28

backend/main.go

@@ -183,6 +183,44 @@ func deleteUserGoal(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"message": "Goal deleted successfully"})
 }
 
+func createTask(c *gin.Context) {
+	var taskRequest CreateTaskRequest
+	if err := c.ShouldBindJSON(&taskRequest); err != nil {
+		log.Printf("Error parsing request body: %v", err)
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request body"})
+		return
+	}
+
+	if taskRequest.Name == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Task name cannot be empty"})
+		return
+	}
+
+	// If assigned is not nil, check if user exists
+	if taskRequest.Assigned != nil {
+		exists, err := db.UserExists(*taskRequest.Assigned)
+		if err != nil {
+			log.Printf("Error checking user existence: %v", err)
+			c.JSON(http.StatusInternalServerError, gin.H{"error": ErrInternalServerError})
+			return
+		}
+		if !exists {
+			c.JSON(http.StatusNotFound, gin.H{"error": ErrUserNotFound})
+			return
+		}
+	}
+
+	taskId, err := db.CreateTask(&taskRequest)
+	if err != nil {
+		log.Printf("Error creating task: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Could not create task"})
+		return
+	}
+
+	response := CreateTaskResponse{ID: taskId}
+	c.IndentedJSON(http.StatusCreated, response)
+}
+
 /*
 *
 Initialises the database, and then starts the server.
@@ -198,6 +236,7 @@ func start(ctx context.Context, config *ServerConfig) {
 	router.GET("/api/user/:userId/goals", getUserGoals)
 	router.POST("/api/user/:userId/goals", createUserGoal)
 	router.DELETE("/api/user/:userId/goal/:goalId", deleteUserGoal)
+	router.POST("/api/tasks", createTask)
 
 	srv := &http.Server{
 		Addr:    ":" + config.Port,