extern alias Instant = String;

alias UUID = String & { type: uuid };

struct Todo {
  id: UUID,
  title: String,
  createdAt: Instant,
  checkedAt: Instant?,
}

struct CreateTodoParams {
  title: String,
}

struct UpdateTodoParams {
  title: String?,
}

service TodoService {
  create(params: CreateTodoParams) -> Todo,
  get(id: UUID) -> Todo,
  getAll() -> List<Todo>,
  update(id: UUID, params: UpdateTodoParams) -> Todo,
  delete(id: UUID) -> Unit,
}