Initial commit

task.go

@@ -0,0 +1,128 @@
+package main
+
+import "context"
+
+type Item struct {
+	ID        int
+	Title     string
+	Completed bool
+}
+
+type Tasks struct {
+	Items          []Item
+	Count          int
+	CompletedCount int
+}
+
+func fetchTasks() ([]Item, error) {
+	var items []Item
+	rows, err := DB.Query("select id, title, completed from tasks order by postition;")
+	if err != nil {
+		return []Item{}, err
+	}
+	defer rows.Close()
+	for rows.Next() {
+		item := Item{}
+		err := rows.Scan(&item.ID, &item.Title, &item.Completed)
+		if err != nil {
+			return []Item{}, err
+		}
+		items = append(items, item)
+	}
+	return items, nil
+}
+
+func fetchTask(ID int) (Item, error) {
+	var item Item
+	err := DB.QueryRow("select id, title, completed from tasks where id = (?)", ID).Scan(&item.ID, &item.Title, &item.Completed)
+	if err != nil {
+		return Item{}, err
+	}
+	return item, nil
+}
+
+func updateTask(ID int, title string) (Item, error) {
+	var item Item
+	err := DB.QueryRow("update tasks set title = (?) where id = (?) returning id, title, completed", title, ID).Scan(&item.ID, &item.Title, &item.Completed)
+	if err != nil {
+		return Item{}, err
+	}
+	return item, nil
+}
+
+func fetchCount() (int, error) {
+	var count int
+	err := DB.QueryRow("select count(*) from tasks;").Scan(&count)
+	if err != nil {
+		return 0, err
+	}
+	return count, nil
+}
+
+func insertTask(title string) (Item, error) {
+	count, err := fetchCount()
+	if err != nil {
+		return Item{}, err
+	}
+	var id int
+	err = DB.QueryRow("insert into tasks (title, position) values (?, ?) returning id", title, count).Scan(&id)
+	if err != nil {
+		return Item{}, err
+	}
+	item := Item{ID: id, Title: title, Completed: false}
+	return item, nil
+}
+
+func deleteTask(ctx context.Context, ID int) error {
+	_, err := DB.Exec("delete from tasks where id = (?)", ID)
+	if err != nil {
+		return err
+	}
+	rows, err := DB.Query("select id from tasks order by position")
+	if err != nil {
+		return err
+	}
+	var ids []int
+	for rows.Next() {
+		var id int
+		err := rows.Scan(&id)
+		if err != nil {
+			return err
+		}
+		ids = append(ids, id)
+	}
+	tx, err := DB.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	for idx, id := range ids {
+		_, err := DB.Exec("update tasks set position = (?) where id = (?)", idx, id)
+		if err != nil {
+			return err
+		}
+	}
+	err = tx.Commit()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func orderTasks(ctx context.Context, values []int) error {
+	tx, err := DB.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	for i, v := range values {
+		_, err := tx.Exec("update tasks set position = (?) where id = (?)", i, v)
+		if err != nil {
+			return err
+		}
+	}
+	if err := tx.Commit(); err != nil {
+		return err
+	}
+	return nil
+}