import { BehaviorSubject, Observable, of, Subject } from 'rxjs';
import { debounceTime, mergeMap } from 'rxjs/operators';

export class SectionsSubscriber {
  private static _refSubject = new BehaviorSubject<
    { intance: any; key: string }[]
  >(undefined!);
  private static _changeRefTrigger = () =>
    SectionsSubscriber._refSubject.asObservable();

  private static _changeDetector = new Subject<string>();
  private static _changeDetectorTrigger = () =>
    SectionsSubscriber._changeDetector.asObservable();

  private static _refresh = new Subject<{ sectionId: string; action: any }>();
  private static _refreshTrigger = () =>
    SectionsSubscriber._refresh.asObservable();

  private static _elementTextSbj = new Subject<HTMLElement | undefined>();
  private static _changehElementText = () =>
    SectionsSubscriber._elementTextSbj.asObservable();

  static changeElementText(element: HTMLElement) {
    SectionsSubscriber._elementTextSbj.next(element);
  }

  static onChangeElementText() {
    return SectionsSubscriber._changehElementText().pipe(
      mergeMap((ref) => {
        return of(ref);
      })
    );
  }

  private static _itemSbj = new Subject<{
    value: string;
    element: HTMLElement;
  }>();

  static getItem = (): Observable<{
    value: string;
    element: HTMLElement;
  }> => SectionsSubscriber._itemSbj.asObservable();

  static changeSections(sections: { intance: any; key: string }[]) {
    SectionsSubscriber._refSubject.next(sections);
  }

  static getSections() {
    return SectionsSubscriber._refSubject.value;
  }

  // internal references
  static detectChange(sectionId: string) {
    return SectionsSubscriber._changeDetector.next(sectionId);
  }

  // internal references
  static refresh(sectionId: string, action: any = {}) {
    return SectionsSubscriber._refresh.next({ sectionId, action });
  }

  static change() {
    return SectionsSubscriber._changeRefTrigger().pipe(
      mergeMap((components) => {
        return of(components);
      })
    );
  }

  static onChangeDectect() {
    return SectionsSubscriber._changeDetectorTrigger()
      .pipe(debounceTime(500))
      .pipe(
        mergeMap((ref) => {
          return of(ref);
        })
      );
  }

  // internal references
  static onRefresh() {
    return SectionsSubscriber._refreshTrigger().pipe(
      mergeMap((ref) => {
        return of(ref);
      })
    );
  }

  static getSectionByKey(sectionKey: string) {
    if (!sectionKey) return;

    let currentSection = SectionsSubscriber.getSections();

    let section = currentSection.find((section) => section.key === sectionKey);

    return section;
  }

  static setItem(value: string, element: HTMLElement) {
    return SectionsSubscriber._itemSbj.next({
      value,
      element,
    });
  }
}