/**
 * @license
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import { DomScope } from './types';

export function ownerDocument(scope: DomScope): Document {
  const node = isRange(scope)
    ? scope.commonAncestorContainer
    : scope;
  return node.ownerDocument || node as Document;
}

export function rangeFromScope(scope: DomScope): Range {
  if (isRange(scope)) {
    return scope;
  }
  const range = ownerDocument(scope).createRange();
  range.selectNodeContents(scope);
  return range;
}

function isRange(scope: DomScope): scope is Range {
  return 'collapsed' in scope;
}