import { TodoItem, CreateTodoInput, UpdateTodoInput, TodoFilter, TodoStatus } from './types.js';
/**
* Manages todo items with simple ordered list functionality
*/
export class TodoManager {
private readonly todos: Map<string, TodoItem> = new Map();
private nextId: number = 1;
private nextOrder: number = 1;
/**
* Creates a new todo item
*/
public createTodo(input: CreateTodoInput): TodoItem {
const now = new Date();
const id = this.generateId();
const todo: TodoItem = {
id,
title: input.title,
...(input.description !== undefined && { description: input.description }),
status: 'pending',
createdAt: now,
updatedAt: now,
order: this.nextOrder++,
};
this.todos.set(id, todo);
return todo;
}
/**
* Retrieves a todo item by ID
*/
public getTodo(id: string): TodoItem | undefined {
return this.todos.get(id);
}
/**
* Retrieves all todo items with optional filtering, ordered by creation
*/
public getTodos(filter?: TodoFilter): readonly TodoItem[] {
const todos = Array.from(this.todos.values());
if (!filter) {
return this.sortTodos(todos);
}
const filtered = todos.filter(todo => {
if (filter.status && todo.status !== filter.status) {
return false;
}
return true;
});
return this.sortTodos(filtered);
}
/**
* Gets the next todo item (first pending item in order)
*/
public getNextTodo(): TodoItem | undefined {
const pendingTodos = this.getTodos({ status: 'pending' });
return pendingTodos.length > 0 ? pendingTodos[0] : undefined;
}
/**
* Updates an existing todo item
*/
public updateTodo(id: string, updates: UpdateTodoInput): TodoItem | undefined {
const existingTodo = this.todos.get(id);
if (!existingTodo) {
return undefined;
}
const updatedTodo: TodoItem = {
...existingTodo,
...updates,
id: existingTodo.id, // Ensure ID cannot be changed
createdAt: existingTodo.createdAt, // Ensure createdAt cannot be changed
order: existingTodo.order, // Ensure order cannot be changed
updatedAt: new Date(),
};
this.todos.set(id, updatedTodo);
return updatedTodo;
}
/**
* Marks a todo item as completed
*/
public completeTodo(id: string): TodoItem | undefined {
return this.updateTodo(id, { status: 'completed' });
}
/**
* Deletes a todo item
*/
public deleteTodo(id: string): boolean {
return this.todos.delete(id);
}
/**
* Gets the total count of todos
*/
public getTodoCount(): number {
return this.todos.size;
}
/**
* Gets count of todos by status
*/
public getTodoCountByStatus(status: TodoStatus): number {
return Array.from(this.todos.values()).filter(todo => todo.status === status).length;
}
/**
* Clears all todos
*/
public clearAll(): void {
this.todos.clear();
this.nextId = 1;
this.nextOrder = 1;
}
/**
* Generates a unique ID for a todo item
*/
private generateId(): string {
return `todo-${this.nextId++}`;
}
/**
* Sorts todos by order (creation order)
*/
private sortTodos(todos: TodoItem[]): readonly TodoItem[] {
return todos.sort((a, b) => a.order - b.order);
}
}
