/**
 * Copyright (c) 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule getRangeBoundingClientRect
 * @format
 * @flow
 */

'use strict';

var getRangeClientRects = require('getRangeClientRects');

export type FakeClientRect = {
  left: number,
  width: number,
  right: number,
  top: number,
  bottom: number,
  height: number,
};

/**
 * Like range.getBoundingClientRect() but normalizes for browser bugs.
 */
function getRangeBoundingClientRect(range: Range): FakeClientRect {
  // "Return a DOMRect object describing the smallest rectangle that includes
  // the first rectangle in list and all of the remaining rectangles of which
  // the height or width is not zero."
  // http://www.w3.org/TR/cssom-view/#dom-range-getboundingclientrect
  var rects = getRangeClientRects(range);
  var top = 0;
  var right = 0;
  var bottom = 0;
  var left = 0;

  if (rects.length) {
    // If the first rectangle has 0 width, we use the second, this is needed
    // because Chrome renders a 0 width rectangle when the selection contains
    // a line break.
    if (rects.length > 1 && rects[0].width === 0) {
      ({top, right, bottom, left} = rects[1]);
    } else {
      ({top, right, bottom, left} = rects[0]);
    }

    for (var ii = 1; ii < rects.length; ii++) {
      var rect = rects[ii];
      if (rect.height !== 0 && rect.width !== 0) {
        top = Math.min(top, rect.top);
        right = Math.max(right, rect.right);
        bottom = Math.max(bottom, rect.bottom);
        left = Math.min(left, rect.left);
      }
    }
  }

  return {
    top,
    right,
    bottom,
    left,
    width: right - left,
    height: bottom - top,
  };
}

module.exports = getRangeBoundingClientRect;
