sort.ts

/*
 * Copyright 2019 LABOR.digital
 *
 * Licensed 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.
 *
 * Last modified: 2019.02.01 at 18:58
 */
import type {List, ListPath, ReadList} from '../Interfaces/List';
import {isNull} from '../Types/isNull';
import {isUndefined} from '../Types/isUndefined';
import {forEach} from './forEach';
import {getListType, getNewList, setListValue} from './listAccess';
import {getPath} from './Paths/getPath';

/**
 * Can be used to sort arrays containing objects by a property of said objects
 * Can also be used to sort plain objects, containing other objects in the same way
 *
 * @param list the list to sort
 * @param by The property of the child objects to sort by
 * @param desc If set to true the result will be sorted descending instead of the default which is ascending
 */
export function sort<V, K>(list: ReadList<V, K>, by?: ListPath | null, desc?: boolean): List<V, K>
{
    // Build the sorter
    let sorter: Array<{ by: V | ListPath | any, k: any, v: any }> = [];
    forEach(list, (v, k) => {
        sorter.push({
            by: isNull(by) || isUndefined(by) ? v : getPath(v, by),
            k, v
        });
    });
    
    // Sort the sorter array
    sorter = sorter.sort((a, b) =>
        desc ?
            ((a.by > b.by) ? -1 : ((a.by < b.by) ? 1 : 0)) :
            ((a.by < b.by) ? -1 : ((a.by > b.by) ? 1 : 0)));
    
    // Build result
    const result = getNewList<V, K>(getListType(list));
    forEach(sorter, (o) => setListValue(result, o.v, o.k));
    return result;
}