FacetManager (Search Engine)

import {
  FacetManager as HeadlessFacetManager,
  Facet as HeadlessFacet,
  FacetManagerPayload,
} from '@coveo/headless';
import {
  useEffect,
  useState,
  FunctionComponent,
  ReactElement,
  Children,
} from 'react';
 
type FacetManagerChild = ReactElement<{controller: HeadlessFacet}>;
 
interface FacetManagerProps {
  controller: HeadlessFacetManager;
  children: FacetManagerChild | FacetManagerChild[];
}
 
export const FacetManager: FunctionComponent<FacetManagerProps> = (props) => {
  const {controller} = props;
  const [, setState] = useState(controller.state);
 
  useEffect(() => controller.subscribe(() => setState(controller.state)), []);
 
  function createPayload(
    facets: FacetManagerChild[]
  ): FacetManagerPayload<FacetManagerChild>[] {
    return facets.map((facet) => ({
      facetId: facet.props.controller.state.facetId,
      payload: facet,
    }));
  }
 
  const childFacets = Children.toArray(props.children) as FacetManagerChild[];
  const payload = createPayload(childFacets);
  const sortedFacets = controller.sort(payload).map((p) => p.payload);
 
  return <div>{sortedFacets}</div>;
};
 
// usage
 
/**
 * ```tsx
 * const facetManager = buildFacetManager(engine);
 * const facetA = buildFacet(engine, {options: {field: 'abc'}});
 * const facetB = buildFacet(engine, {options: {field: 'def'}});
 *
 * <FacetManager controller={facetManager}>
 *   <Facet controller={facetA} />
 *   <Facet controller={facetB} />
 * </FacetManager>
 * ```
 */