import { LogLevel } from '../../../helper/logger';
import { Result } from '../../../types/types';
export interface TaskState {
    retryCount: number;
    status: TaskStatus;
}
declare type ProgressNotice = () => void;
export declare type OnError = () => void;
export declare type OnCancel = () => void;
export declare type OnProgress = () => void;
export declare type OnComplete = () => void;
export declare type TaskStatus = 'waiting' | 'processing' | 'canceled' | 'error' | 'success';
export interface Task {
    cancel(): Promise<Result>;
    process(notice: ProgressNotice): Promise<Result>;
}
declare type TaskCreator = () => Promise<Result<Task[]>>;
interface LoggerOptions {
    level: LogLevel;
    prefix: string;
}
interface TaskQueueOptions {
    logger?: LoggerOptions;
    concurrentLimit?: number;
    tasksCreator?: TaskCreator;
}
export declare class TaskQueue {
    private options?;
    private logger;
    /** 取消标记 */
    private canceled;
    /** 队列正在处理中 */
    private processing;
    /** 队列错误信息； */
    private error?;
    /** 队列并发标记 */
    private concurrentTicket;
    /** 用户传入的任务 */
    private tasks;
    /** 动态创建任务方法 */
    private tasksCreator?;
    /** 通过 tasksCreator 动态创建的任务 */
    private dynamicTasks;
    /** 任务的状态表 */
    private taskStates;
    /** 状态订阅函数表 */
    private errorListeners;
    private cancelListeners;
    private progressListeners;
    private completeListeners;
    constructor(options?: TaskQueueOptions | undefined);
    private handleProgress;
    private handleComplete;
    private handleError;
    private handleCancel;
    onProgress(listener: OnProgress): () => boolean;
    onComplete(listener: OnComplete): () => boolean;
    onError(listener: OnError): () => boolean;
    onCancel(listener: OnCancel): () => boolean;
    private getTaskState;
    /** 任务处理函数；递归取出任务并执行，除非遇到 canceled 或 error 状态 */
    private process;
    /** 添加任务 */
    enqueue(...tasks: Array<Task | TaskQueue>): void;
    /** 开始处理 */
    start(): Promise<Result>;
    /** 取消任务 */
    cancel(): Promise<Result>;
}
export {};