/*
 * 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 { App } from '../../app/App';
import { PageLinkedMap } from '../../app/map';
import Page from '../../page';

const pageMap: PageLinkedMap = App.pageMap;

/**
 * Get an element tree of a page.
 * @param  {string} id - Page id.
 * @return {Object} A virtual dom tree.
 */
export function getRoot(id: string): object {
  const page: Page = pageMap[id];
  let result: any;
  if (page) {
    const doc: any = page.doc || {};
    const body = doc.body || {};
    result = body.toJSON ? body.toJSON() : {};
  } else {
    result = new Error(`invalid page id "${id}"`);
  }
  return result;
}