import {Directive, ElementRef, EventEmitter, Input, OnDestroy, OnInit, Output} from '@angular/core';
import {fromEvent, Subscriber} from 'rxjs';
import {delay, tap} from 'rxjs/operators';

@Directive({
  selector: '[click-outside-or-esc]'
})

export class ClickOutsideOrEsc implements OnInit, OnDestroy {
  private listening: boolean;
  private subscriptions: any[] = [];
  @Input()
  public targetId = null;
  @Input()
  public escClose = true;
  @Input()
  public clickClose = true;
  @Output('clickOutside') clickOutside: EventEmitter<Object>;

  constructor(private _elRef: ElementRef) {
    this.listening = false;
    this.clickOutside = new EventEmitter();
  }

  ngOnInit() {
    if(typeof document !== 'undefined') {
      this.subscriptions.push(fromEvent(document, 'click').pipe(
        delay(1),
        tap(() => {
          this.listening = true;
        })).subscribe((event: MouseEvent) => {
          this.onGlobalClick(event);
        }));
      this.subscriptions.push(fromEvent(document, 'click').pipe(
        delay(1),
        tap(() => {
          this.listening = true;
        })).subscribe((event: KeyboardEvent) => {
          if (event.keyCode === 27 && this.escClose) {
            this.clickOutside.emit({
              target: (event.target || null),
              value: true
            });
          }
        }));
    }
  }

  ngOnDestroy() {
    if (this.subscriptions) {
      this.subscriptions.forEach((subscription: Subscriber<any>) => {
        subscription.unsubscribe();
      });
    }
    this.subscriptions = [];
  }

  onGlobalClick(event: MouseEvent) {
    if (event instanceof MouseEvent && this.listening === true) {
      let element: HTMLElement = <HTMLElement>event.target;
      while (element) {
        if(element.id === this.targetId) {
          this.clickOutside.emit({
            target: (event.target || null),
            value: false
          });
          return;
        }
        element = element.parentElement;
      }
      if(this.clickClose) {
        this.clickOutside.emit({
          target: (event.target || null),
          value: true
        });
      }
    }
  }
}