import { ActivatedRouteSnapshot, Resolve, UrlSegment } from '@angular/router';

import { Observable, of } from 'rxjs';

export class BreadcrumbsResolver implements Resolve<IBreadcrumb[]> {
  public resolve(
    route: ActivatedRouteSnapshot
  ): Observable<IBreadcrumb[]> | Promise<IBreadcrumb[]> | IBreadcrumb[] {
    const data = route.routeConfig.data;
    const path = data.path === null ? null : this.getFullPath(route);

    const text =
      typeof data.breadcrumbs === 'string'
        ? data.breadcrumbs
        : data.breadcrumbs.text || data.text || path;

    const crumbs: IBreadcrumb[] = [{ text: text, path: path }];

    return of(crumbs);
  }

  public getFullPath(route: ActivatedRouteSnapshot): string {
    const relativePath = (segments: UrlSegment[]) =>
      segments.reduce((a, v) => (a += '/' + v.path), '');
    const fullPath = (routes: ActivatedRouteSnapshot[]) =>
      routes.reduce((a, v) => (a += relativePath(v.url)), '');

    return fullPath(route.pathFromRoot);
  }
}

export interface IBreadcrumb {
  text: string;
  path: string;
}