/**
 * Get bounding client rect of given element
 */
import { getStyleComputedProperty } from './getStyleComputedProperty';
import { getBordersSize } from './getBordersSize';
import { getWindowSizes } from './getWindowSizes';
import { getScroll } from './getScroll';
import { getClientRect } from './getClientRect';
import { isIE } from './isIE';
import { Offsets } from '../models';

export function getBoundingClientRect(element: HTMLElement): Offsets {
  let rect: any = {};

  // IE10 10 FIX: Please, don't ask, the element isn't
  // considered in DOM in some circumstances...
  // This isn't reproducible in IE10 compatibility mode of IE11
  try {
    if (isIE(10)) {
      rect = element.getBoundingClientRect();
      const scrollTop = getScroll(element, 'top');
      const scrollLeft = getScroll(element, 'left');
      rect.top += scrollTop;
      rect.left += scrollLeft;
      rect.bottom += scrollTop;
      rect.right += scrollLeft;
    } else {
      rect = element.getBoundingClientRect();
    }
  } catch (e) {
    return undefined;
  }

  const result: any = {
    left: rect.left,
    top: rect.top,
    width: rect.right - rect.left,
    height: rect.bottom - rect.top
  };

  // subtract scrollbar size from sizes
  const sizes: any = element.nodeName === 'HTML' ? getWindowSizes(element.ownerDocument) : {};
  const width =
    sizes.width || element.clientWidth || result.right - result.left;
  const height =
    sizes.height || element.clientHeight || result.bottom - result.top;

  let horizScrollbar = element.offsetWidth - width;
  let vertScrollbar = element.offsetHeight - height;

  // if an hypothetical scrollbar is detected, we must be sure it's not a `border`
  // we make this check conditional for performance reasons
  if (horizScrollbar || vertScrollbar) {
    const styles = getStyleComputedProperty(element);
    horizScrollbar -= getBordersSize(styles, 'x');
    vertScrollbar -= getBordersSize(styles, 'y');

    result.width -= horizScrollbar;
    result.height -= vertScrollbar;
  }

  return getClientRect(result);
}