import { Gesture, THRESHOLD } from './gesture';

class Pan extends Gesture {
  isSingleFigure = true;
  holdTimeout = null;
  startTime = 0;
  isHold = false;
  constructor(handler) {
    super('drag', handler);
  }

  handleTouchStart(event) {
    this.isSingleFigure = event.touches.length === 1;
    if (!this.isSingleFigure) return;

    this.holdTimeout && clearTimeout(this.holdTimeout);

    this.startTime = Date.now();

    this.holdTimeout = setTimeout(() => {
      this.isHold = true;
    }, THRESHOLD.PAN_BEFORE_HOLD);
  }

  handleTouchMove(event) {
    if (!this.isSingleFigure) return;
    const currentTime = Date.now();
    if (currentTime - this.startTime < THRESHOLD.PAN_BEFORE_HOLD) {
      clearTimeout(this.holdTimeout);
    } else {
      if (this.isHold) {
        this.dispatchEvent(event);
      }
    }
  }

  handleTouchEnd(_event) {
    if (!this.isSingleFigure) return;
    clearTimeout(this.holdTimeout);
    this.startTime = 0;
    this.holdTimeout = null;
    this.isHold = false;
  }
}

export default Pan;