/**
 * 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 modifyBlockForContentState
 * @format
 * @flow
 */

'use strict';

import type { BlockNodeRecord } from './BlockNodeRecord';
import type ContentState from './ContentState';
import type SelectionState from './SelectionState';

const Immutable = require('immutable');

const { Map } = Immutable;

function modifyBlockForContentState(contentState: ContentState, selectionState: SelectionState, operation: (block: BlockNodeRecord) => BlockNodeRecord): ContentState {
  var startKey = selectionState.getStartKey();
  var endKey = selectionState.getEndKey();
  var blockMap = contentState.getBlockMap();
  var newBlocks = blockMap.toSeq().skipUntil((_, k) => k === startKey).takeUntil((_, k) => k === endKey).concat(Map([[endKey, blockMap.get(endKey)]])).map(operation);

  return contentState.merge({
    blockMap: blockMap.merge(newBlocks),
    selectionBefore: selectionState,
    selectionAfter: selectionState
  });
}

module.exports = modifyBlockForContentState;