import { Task, TaskList, TaskStatus } from '../types/task.js';
export declare class TaskService {
    private static instance;
    private taskLists;
    private cleanupInterval;
    private readonly CLEANUP_INTERVAL;
    private readonly MAX_AGE;
    private constructor();
    static getInstance(): TaskService;
    createTaskList(sessionId: string, initialTasks?: Array<{
        title: string;
        acceptanceCriteria: string;
    }>): TaskList;
    getTaskList(taskListId: string): TaskList | null;
    updateTask(taskListId: string, taskId: string, updates: {
        title?: string;
        status?: TaskStatus;
        acceptanceCriteria?: string;
        evaluation?: number;
    }): Task | null;
    getTask(taskListId: string, taskId: string): Task | null;
    getAllTasks(taskListId: string): Task[] | null;
    deleteTaskList(taskListId: string): boolean;
    deleteTaskListBySession(sessionId: string): number;
    private cleanupOldTaskLists;
    getStats(): {
        totalTaskLists: number;
        totalTasks: number;
    };
    destroy(): void;
}