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

export function getBoundingClientRect(element: HTMLElement): Offsets {
  const rect: Offsets = element.getBoundingClientRect();

  // 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)) {
  //     const scrollTop = getScroll(element, 'top');
  //     const scrollLeft = getScroll(element, 'left');
  //     if (rect && isNumber(rect.top) && isNumber(rect.left) && isNumber(rect.bottom) && isNumber(rect.right)) {
  //       rect.top += scrollTop;
  //       rect.left += scrollLeft;
  //       rect.bottom += scrollTop;
  //       rect.right += scrollLeft;
  //     }
  //   }
  // } catch (e) {
  //   return rect;
  // }

  if (!(rect && isNumber(rect.top) && isNumber(rect.left) && isNumber(rect.bottom) && isNumber(rect.right))) {
    return rect;
  }

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

  // subtract scrollbar size from sizes
  const sizes = element.nodeName === 'HTML' ? getWindowSizes(element.ownerDocument) : undefined;
  const width = sizes?.width || element.clientWidth
    || isNumber(rect.right) && isNumber(result.left) && rect.right - result.left || 0;
  const height = sizes?.height || element.clientHeight
    || isNumber(rect.bottom) && isNumber(result.top) && rect.bottom - result.top || 0;

  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);
}