export class ISchedule {
  // 进程锁
  isLocked = false;
  private t: number | null = null;

  constructor(public idle: number, public start: () => Promise<void> | void) {
    this.start = start;
    this.idle = idle;
    this.t = window.setInterval(() => {
      this._start();
    }, this.idle);
  }

  private async _start() {
    if (this.isLocked) {
      return;
    } else {
      this.isLocked = true;
      try {
        // 失败不退出队列
        await this.start();
      } catch (e) {
        console.error(e);
      } finally {
        this.isLocked = false;
      }
    }
  }

  get isAvailable() {
    return this.t !== null;
  }

  stop() {
    if (this.t !== null) {
      window.clearInterval(this.t);
      this.t = null;
    }
  }
}

export class IQueue<T> {
  data: T[] = [];

  lpush(...data: T[]) {
    this.data.unshift(...data);
  }

  rpop(n: number) {
    const result: T[] = [];
    for (let i = 0; i < n; i++) {
      const o = this.data.pop();
      o !== undefined && result.push(o);
    }
    return result;
  }

  rpopAll() {
    const result: T[] = [];
    while (true) {
      const o = this.data.pop();
      if (o !== undefined) {
        result.push(o);
      } else {
        break;
      }
    }
    return result;
  }
}