doneit-web/src/app/interceptors/token.interceptors.ts

import { Injectable } from "@angular/core";
import {
  HttpRequest,
  HttpHandler,
  HttpEvent,
  HttpInterceptor,
  HttpErrorResponse,
  HTTP_INTERCEPTORS,
  HttpClient,
} from "@angular/common/http";
import { AuthService } from '../services/auth.service';
import { Observable, throwError, BehaviorSubject, of } from "rxjs";
import { catchError, filter, take, switchMap, tap } from "rxjs/operators";
import { SessionStore } from '../store/session.service';
import { environment } from "src/environments/environment";
import { Router } from "@angular/router";

@Injectable()
export class TokenInterceptor implements HttpInterceptor {
  private isRefreshing = false;
  private refreshTokenSubject: BehaviorSubject<any> = new BehaviorSubject<any>(
    null
  );

  constructor(private http: HttpClient, private router: Router,) { }


  intercept(
    request: HttpRequest<any>,
    next: HttpHandler
  ): Observable<HttpEvent<any>> {
    if (SessionStore.user.Authorization) {
      request = this.addToken(request, SessionStore.user.Authorization);
    }

    return next.handle(request).pipe(
      catchError((error) => {
        if (error instanceof HttpErrorResponse && error.status === 401) {
          return this.handle401Error(request, next);
        } else {
          return throwError(error);
        }
      })
    );
  }

  private addToken(request: HttpRequest<any>, token: string) {
    return request.clone({
      setHeaders: {
        Authorization: `Bearer ${token}`,
      },
    });
  }

  private handle401Error(request: HttpRequest<any>, next: HttpHandler) {
    if (!this.isRefreshing) {
      this.isRefreshing = true;
      this.refreshTokenSubject.next(null);

      return this.refreshToken().pipe(
        switchMap((token: any) => {
          this.isRefreshing = false;
          this.refreshTokenSubject.next(token.Authorization);
          return next.handle(this.addToken(request, token.Authorization));
        })
      );
    } else {
      return this.refreshTokenSubject.pipe(
        filter((token) => token != null),
        take(1),
        switchMap((jwt) => {
          return next.handle(this.addToken(request, jwt));
        })
      );
    }
  }


  //this method refresh token is declared here temporary beacouse a circular error
  refreshToken() {

    return this.http
      .put<any>(environment.apiURL + "UserAuthentication/RefreshToken", {
        refreshToken: SessionStore.user.RefreshToken,
      },)
      .pipe(
        tap((tokens) => {
          console.log(tokens)
          SessionStore.user.Authorization = tokens.Authorization;
          SessionStore.user.RefreshToken = tokens.refreshToken;
          SessionStore.save();

        }),
        catchError((error) => {
          console.log(error)
          SessionStore.user.Authorization = "";
          SessionStore.user.RefreshToken = "";
          SessionStore.setInativity(false)
          /*  SessionStore.setUrlBeforeInactivity(this.router.url); */

          if (environment.production) {
            window.location.pathname = '/auth'
          } else {
            /* const pathBeforeGoOut = window.location.pathname */
            this.router.navigateByUrl('/auth', { replaceUrl: true });

          }
          return of(false);
        })
      );
  }

}

export const tokenInterceptor = {
  provide: HTTP_INTERCEPTORS,
  useClass: TokenInterceptor,
  multi: true
};