export class BatchedPromiseHandler {
  private batchSize: number;
  /**
   * max size 10
   */
  private currentBatch: Array<() => Promise<unknown>> = [];
  private waitingBatch: Array<() => Promise<unknown>> = [];

  constructor(batchSize: number = 10) {
    this.batchSize = batchSize;
  }

  private processPromises() {
    /**
     * while (this.currentBatch.length > 0) {
     * remove promise by shift
     * }
     *
     */
    while (this.currentBatch.length > 0) {
      const promise = this.currentBatch.shift();
      promise?.().then(() => {
        const waitingPromise = this.waitingBatch.shift();
        if (waitingPromise) {
          this.currentBatch.push(waitingPromise);
          this.processPromises();
        }
      });
    }
  }
  add<T>(promise: () => Promise<T>) {
    if (this.currentBatch.length < this.batchSize) {
      this.currentBatch.push(promise);
    } else {
      this.waitingBatch.push(promise);
    }
    this.processPromises();
  }
  clearPromises() {
    this.currentBatch = [];
    this.waitingBatch = [];
  }
}