import { BehaviorSubject, of, Subject, Observable } from 'rxjs';

import { mergeMap } from 'rxjs/operators';

export class FieldSubscriber {
	private static _createSubject = new BehaviorSubject<any>(undefined);
	private static _createTrigger = () =>
		FieldSubscriber._createSubject.asObservable();

	private static _removeSubject = new BehaviorSubject<any>(undefined);
	private static _removeTrigger = () =>
		FieldSubscriber._removeSubject.asObservable();

	private static _changeSubject = new BehaviorSubject<any>(undefined);
	private static _changeTrigger = () =>
		FieldSubscriber._changeSubject.asObservable();

	private static _sortSubject = new BehaviorSubject<any>(undefined);
	private static _sortTrigger = () =>
		FieldSubscriber._sortSubject.asObservable();

	private static _changeDetector = new BehaviorSubject<any>(undefined);
	private static _changeDetectorTrigger = () =>
		FieldSubscriber._changeDetector.asObservable();

	private static _contactForm = new Subject<HTMLElement>();
	private static _newContactForm = (): Observable<HTMLElement> =>
		FieldSubscriber._contactForm.asObservable();

	static newContactForm(formElement: HTMLElement) {
		FieldSubscriber._contactForm.next(formElement);
	}
	static create(item: any) {
		FieldSubscriber._createSubject.next(item);
	}

	static remove(field: any) {
		FieldSubscriber._removeSubject.next(field);
	}

	static change(options: any, item: any) {
		FieldSubscriber._changeSubject.next({ options, item });
	}

	static changeDetector(form: any) {
		FieldSubscriber._changeDetector.next(form);
	}

	static sort(orders: any) {
		FieldSubscriber._sortSubject.next(orders);
	}

	static onCreate() {
		return FieldSubscriber._createTrigger().pipe(
			mergeMap((value) => {
				return of(value);
			})
		);
	}

	static onRemove() {
		return FieldSubscriber._removeTrigger().pipe(
			mergeMap((value) => {
				return of(value);
			})
		);
	}

	static onChange() {
		return FieldSubscriber._changeTrigger().pipe(
			mergeMap((value) => {
				return of(value);
			})
		);
	}

	static onChangeDetector() {
		return FieldSubscriber._changeDetectorTrigger().pipe(
			mergeMap((value) => {
				return of(value);
			})
		);
	}

	static onSort() {
		return FieldSubscriber._sortTrigger().pipe(
			mergeMap((value) => {
				return of(value);
			})
		);
	}

	static onContactForm() {
		return FieldSubscriber._newContactForm().pipe(
			mergeMap((value) => {
				return of(value);
			})
		);
	}
}