/**
 * 管理浏览器scale
 */
import { getStorage, setStorage } from '@/Storage';
import { ObserverStateManager } from '../observerStateManager';

const defaultScale = 1;

class ZoomManagerClass {
  private scale = defaultScale;

  setSacle(scale: number) {
    this.preprocess(scale);

    ObserverStateManager.update(scale);

    this.scale = scale;
  }

  getScale() {
    return getStorage('zoom-proportion') ?? defaultScale;
  }

  initScale() {
    this.setSacle(this.getScale());
  }

  /**
   * 抵消body scale
   *
   * @param {(number | string | null)} size
   * @return {*}
   * @memberof ZoomManagerClass
   */
  negativeScale(size: number | string | null) {
    if (!size) {
      return 0;
    }

    const bodyScale = Number(this.getScale());
    const numberVal = Number(size);

    if (bodyScale && numberVal) {
      size = numberVal / bodyScale;
    }

    return size;
  }

  private preprocess(scale: number) {
    // 执行副作用
    (document.body.style as any).zoom = scale;
    setStorage('zoom-proportion', scale);
  }
}

export const ZoomManager = new ZoomManagerClass();