// For some reason on expo, this file is parsed on native, and then we get an error
import { isExpo } from '../utils/misc';

class ContentHeightListener {
  public connected = false;
  private resizeObserver: ResizeObserver | null = null;
  private currentHeight: number | null = null;

  public connect(element: Element, cb: (height: number) => void) {
    this.connected = true;
    this.currentHeight = element.getBoundingClientRect().height;
    cb(this.currentHeight);

    this.resizeObserver = new ResizeObserver((entries) => {
      for (let entry of entries) {
        const newHeight = entry.target.getBoundingClientRect().height;
        if (this.currentHeight !== newHeight) {
          this.currentHeight = newHeight;
          cb(newHeight);
        }
      }
    });

    this.resizeObserver.observe(element);
  }

  public disconnect() {
    this.resizeObserver?.disconnect();
  }

  public get height() {
    return this.currentHeight;
  }
}

// when bundling because "document" does not exist. This is a hack to "shim" focusListener on expo
const shimmedHeightListener = { height: 0, connect: () => {}, connected: true };
export const contentHeightListener = isExpo()
  ? shimmedHeightListener
  : new ContentHeightListener();