import {Injectable} from "@angular/core";
import {BehaviorSubject, Observable, Subscriber} from "rxjs";
import {ActivationStart, Router} from "@angular/router";

@Injectable({
  providedIn: 'root'
})
export class LayoutService {
  
  /**
   * Set this to true when sidebar items are ready.
   */
  private openSubject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false);
  
  /**
   *  Add hasSidebar: false on data of route config, if sidebar is not needed.
   */
  private hasSidebarSubject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false);
  
  /**
   *  Add hasHeader: false on data of route config, if header is not needed.
   */
  private hasHeaderSubject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false);
  
  /**
   *  Add hasAdminMenu: true on data of route config, if global sidebar should be used.
   */
  private hasAdminMenuSubject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false);
  /**
   *  Add isFrontPage: true on data of route config, if current route is for front page.
   */
  private isFrontPageSubject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false);
  /**
   *  Add isSmallScreen: true on data of route config, if screen is small.
   */
  private isSmallScreenSubject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false);
  
  /**
   *  Add isDashboard: false on data of route config, if page is for a stakeholder but not for dashboard.
   */
  private isDashboardSubject: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(true);
  
  sub: any;
  
  ngOnDestroy() {
    this.clearSubscriptions();
  }
  
  clearSubscriptions() {
    if (this.sub instanceof Subscriber) {
      this.sub.unsubscribe();
    }
  }
  
  constructor(private router: Router) {
    this.sub = this.router.events.subscribe(event => {
      if (event instanceof ActivationStart) {
        let data = event.snapshot.data;
        if (data['hasSidebar'] !== undefined &&
          data['hasSidebar'] === false) {
          this.setHasSidebar(false);
        } else {
          this.setHasSidebar(true);
        }
        if (data['hasHeader'] !== undefined &&
          data['hasHeader'] === false) {
          this.setHasHeader(false);
        } else {
          this.setHasHeader(true);
        }
        if (data['hasAdminMenu'] !== undefined &&
          data['hasAdminMenu'] === true) {
          this.setHasAdminMenu(true);
        } else {
          this.setHasAdminMenu(false);
        }
        if (data['isFrontPage'] !== undefined &&
          data['isFrontPage'] === true) {
          this.setFrontPage(true);
        } else {
          this.setFrontPage(false);
        }
        if (data['isSmallScreen'] !== undefined &&
          data['isSmallScreen'] === true) {
          this.setSmallScreen(true);
        } else {
          this.setSmallScreen(false);
        }
        if (data['isDashboard'] !== undefined &&
          data['isDashboard'] === false) {
          this.setDashboard(false);
        } else {
          this.setDashboard(true);
        }
      }
    });
  }
  
  get open(): boolean {
    return this.openSubject.getValue();
  }
  
  setOpen(value: boolean) {
    this.openSubject.next(value);
  }
  
  get hasSidebar(): Observable<boolean> {
    return this.hasSidebarSubject.asObservable();
  }
  
  setHasSidebar(value: boolean) {
    this.hasSidebarSubject.next(value);
  }
  
  get hasHeader(): Observable<boolean> {
    return this.hasHeaderSubject.asObservable();
  }
  
  setHasHeader(value: boolean) {
    this.hasHeaderSubject.next(value);
  }
  
  
  get hasAdminMenu(): Observable<boolean> {
    return this.hasAdminMenuSubject.asObservable();
  }
  
  setHasAdminMenu(value: boolean) {
    this.hasAdminMenuSubject.next(value);
  }
  
  get isFrontPage(): Observable<boolean> {
    return this.isFrontPageSubject.asObservable();
  }
  
  setFrontPage(value: boolean) {
    this.isFrontPageSubject.next(value);
  }
  
  get isDashboard(): Observable<boolean> {
    return this.isDashboardSubject.asObservable();
  }
  
  setDashboard(value: boolean) {
    this.isDashboardSubject.next(value);
  }
  
  get isSmallScreen(): boolean {
    return this.isSmallScreenSubject.getValue();
  }
  
  setSmallScreen(value: boolean) {
    this.isSmallScreenSubject.next(value);
  }
}