/**
 * 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';

import type ContentState from "./ContentState";
import type SelectionState from "./SelectionState";

function adjustBlockDepthForContentState(contentState: ContentState, selectionState: SelectionState, adjustment: number, maxDepth: number): ContentState {
  const startKey = selectionState.getStartKey();
  const endKey = selectionState.getEndKey();
  let blockMap = contentState.getBlockMap();
  const blocks = blockMap.toSeq().skipUntil((_, k) => k === startKey).takeUntil((_, k) => k === endKey).concat([[endKey, blockMap.get(endKey)]]).map(block => {
    let depth = block.getDepth() + adjustment;
    depth = Math.max(0, Math.min(depth, maxDepth));
    return block.set('depth', depth);
  });
  blockMap = blockMap.merge(blocks);
  return contentState.merge({
    blockMap,
    selectionBefore: selectionState,
    selectionAfter: selectionState
  });
}

module.exports = adjustBlockDepthForContentState;