/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @format
 * @flow strict-local
 * @emails oncall+draft_js
 */
'use strict';

const UserAgent = require("fbjs/lib/UserAgent");

const invariant = require("fbjs/lib/invariant");

const isChrome = UserAgent.isBrowser('Chrome'); // In Chrome, the client rects will include the entire bounds of all nodes that
// begin (have a start tag) within the selection, even if the selection does
// not overlap the entire node. To resolve this, we split the range at each
// start tag and join the client rects together.
// https://code.google.com/p/chromium/issues/detail?id=324437

/* eslint-disable consistent-return */

function getRangeClientRectsChrome(range: Range): Array<ClientRect> {
  const tempRange = range.cloneRange();
  const clientRects = [];

  for (let ancestor = range.endContainer; ancestor != null; ancestor = ancestor.parentNode) {
    // If we've climbed up to the common ancestor, we can now use the
    // original start point and stop climbing the tree.
    const atCommonAncestor = ancestor === range.commonAncestorContainer;

    if (atCommonAncestor) {
      tempRange.setStart(range.startContainer, range.startOffset);
    } else {
      tempRange.setStart(tempRange.endContainer, 0);
    }

    const rects = Array.from(tempRange.getClientRects());
    clientRects.push(rects);

    if (atCommonAncestor) {
      clientRects.reverse();
      return [].concat(...clientRects);
    }

    tempRange.setEndBefore(ancestor);
  }

  invariant(false, 'Found an unexpected detached subtree when getting range client rects.');
}
/* eslint-enable consistent-return */

/**
 * Like range.getClientRects() but normalizes for browser bugs.
 */


const getRangeClientRects = (isChrome ? getRangeClientRectsChrome : function (range: Range): Array<ClientRect> {
  return Array.from(range.getClientRects());
}: (range: Range) => Array<ClientRect>);
module.exports = getRangeClientRects;