superset-frontend/packages/superset-frontend/src/dashboard/components/nativeFilters/FilterBar/utils.ts

import { Filter } from '../types';
import { CascadeFilter } from './types';

/**
 * 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.
 */

export function mapParentFiltersToChildren(
  filters: Filter[],
): { [id: string]: Filter[] } {
  const cascadeChildren = {};
  filters.forEach(filter => {
    const [parentId] = filter.cascadeParentIds || [];
    if (parentId) {
      if (!cascadeChildren[parentId]) {
        cascadeChildren[parentId] = [];
      }
      cascadeChildren[parentId].push(filter);
    }
  });
  return cascadeChildren;
}

export function buildCascadeFiltersTree(filters: Filter[]): CascadeFilter[] {
  const cascadeChildren = mapParentFiltersToChildren(filters);

  const getCascadeFilter = (filter: Filter): CascadeFilter => {
    const children = cascadeChildren[filter.id] || [];
    return {
      ...filter,
      cascadeChildren: children.map(getCascadeFilter),
    };
  };

  return filters
    .filter(filter => !filter.cascadeParentIds?.length)
    .map(getCascadeFilter);
}