Add POST /user/{userId}/goals (#26)

Closes #4

Reviewed-on: #26

backend/db.go

@@ -2,8 +2,9 @@ package main
 
 import (
 	"errors"
-	"gitea.seeseepuff.be/seeseemelk/mysqlite"
 	"log"
+
+	"gitea.seeseepuff.be/seeseemelk/mysqlite"
 )
 
 type Db struct {
@@ -86,3 +87,44 @@ func (db *Db) GetUserGoals(userId int) ([]Goal, error) {
 	}
 	return goals, nil
 }
+
+func (db *Db) CreateGoal(userId int, goal *CreateGoalRequest) (int, error) {
+	// Check if user exists before attempting to create a goal
+	exists, err := db.UserExists(userId)
+	if err != nil {
+		return 0, err
+	}
+	if !exists {
+		return 0, errors.New("user does not exist")
+	}
+
+	tx, err := db.db.Begin()
+	if err != nil {
+		return 0, err
+	}
+	defer tx.Rollback()
+
+	// Insert the new goal
+	err = tx.Query("insert into goals (user_id, name, target, progress, weight) values (?, ?, ?, 0, ?)").
+		Bind(userId, goal.Name, goal.Target, goal.Weight).
+		Exec()
+
+	if err != nil {
+		return 0, err
+	}
+
+	// Get the last inserted ID
+	var lastId int
+	err = tx.Query("select last_insert_rowid()").ScanSingle(&lastId)
+	if err != nil {
+		return 0, err
+	}
+
+	// Commit the transaction
+	err = tx.Commit()
+	if err != nil {
+		return 0, err
+	}
+
+	return lastId, nil
+}