/**
 * 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
 * @emails oncall+draft_js
 *
 * This is unstable and not part of the public API and should not be used by
 * production systems. This file may be update/removed without notice.
 */

import type { BlockMap } from "./BlockMap";
import type { BlockNodeRecord } from "./BlockNodeRecord";
const ContentBlockNode = require("./ContentBlockNode");
const getNextDelimiterBlockKey = (block: BlockNodeRecord, blockMap: BlockMap): ?string => {
  const isExperimentalTreeBlock = block instanceof ContentBlockNode;
  if (!isExperimentalTreeBlock) {
    return null;
  }
  const nextSiblingKey = block.getNextSiblingKey();
  if (nextSiblingKey) {
    return nextSiblingKey;
  }
  const parent = block.getParentKey();
  if (!parent) {
    return null;
  }
  let nextNonDescendantBlock = blockMap.get(parent);
  while (nextNonDescendantBlock && !nextNonDescendantBlock.getNextSiblingKey()) {
    const parentKey = nextNonDescendantBlock.getParentKey();
    nextNonDescendantBlock = parentKey ? blockMap.get(parentKey) : null;
  }
  if (!nextNonDescendantBlock) {
    return null;
  }
  return nextNonDescendantBlock.getNextSiblingKey();
};
module.exports = getNextDelimiterBlockKey;