/**
 * 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 getRangesForDraftEntity
 * @format
 * @flow
 */

'use strict';

import type { BlockNodeRecord } from './BlockNodeRecord';
import type { DraftRange } from './DraftRange';

var invariant = require('fbjs/lib/invariant');

/**
 * Obtain the start and end positions of the range that has the
 * specified entity applied to it.
 *
 * Entity keys are applied only to contiguous stretches of text, so this
 * method searches for the first instance of the entity key and returns
 * the subsequent range.
 */
function getRangesForDraftEntity(block: BlockNodeRecord, key: string): Array<DraftRange> {
  var ranges = [];
  block.findEntityRanges(c => c.getEntity() === key, (start, end) => {
    ranges.push({ start, end });
  });

  invariant(!!ranges.length, 'Entity key not found in this range.');

  return ranges;
}

module.exports = getRangesForDraftEntity;