import {ElementFinder, by, element, ProtractorBy, browser} from 'protractor';
import {Point} from './actions';

/**
 * Normalizes either turning a selector into an
 * ElementFinder or returning the finder itself.
 */
export function getElement(el: FinderResult): ElementFinder {
  return typeof el === 'string' ? element(by.css(el)) : el;
}

/**
 * Waits for an element to be rendered.
 */
export function waitForElement(selector: string) {
  return browser.isElementPresent(by.css(selector) as ProtractorBy);
}

/**
 * Determines the current scroll position of the page.
 */
export async function getScrollPosition(): Promise<Point> {
  const snippet = `
    var documentRect = document.documentElement.getBoundingClientRect();
    var x = -documentRect.left || document.body.scrollLeft || window.scrollX ||
             document.documentElement.scrollLeft || 0;
    var y = -documentRect.top || document.body.scrollTop || window.scrollY ||
             document.documentElement.scrollTop || 0;

    return {x: x, y: y};
  `;

  return await browser.executeScript<Point>(snippet);
}

export type FinderResult = ElementFinder | string;