Several changes about token refreshing.

frontend/src/app/app.config.ts

@@ -1,10 +1,11 @@
-import { ApplicationConfig } from '@angular/core';
+import { APP_INITIALIZER, ApplicationConfig } from '@angular/core';
 import { provideRouter, withRouterConfig } from '@angular/router';
 
 import { HTTP_INTERCEPTORS, provideHttpClient, withInterceptorsFromDi } from '@angular/common/http';
 import { provideAnimationsAsync } from '@angular/platform-browser/animations/async';
 import { routes } from './app.routes';
 import { JwtInterceptor } from './core/interceptor/jwt.interceptor';
+import { AuthenticationService } from './core/service/authentication.service';
 
 export const appConfig: ApplicationConfig = {
   providers: [
@@ -18,5 +19,11 @@ export const appConfig: ApplicationConfig = {
     provideAnimationsAsync(),
     provideHttpClient(withInterceptorsFromDi()),
     { provide: HTTP_INTERCEPTORS, useClass: JwtInterceptor, multi: true },
+    {
+      provide: APP_INITIALIZER,
+      useFactory: (authenticationService: AuthenticationService) => () => authenticationService.startAuthenticationCheckingProcess(),
+      deps: [AuthenticationService],
+      multi: true
+    }
   ]
 };

frontend/src/app/core/guard/authentication.guard.ts

@@ -3,11 +3,13 @@ import { CanActivateFn, Router } from "@angular/router";
 import { AuthenticationService } from "../service/authentication.service";
 import { MatSnackBar } from "@angular/material/snack-bar";
 
-export const authenticationGuard: CanActivateFn = () => {
+export const authenticationGuard: CanActivateFn = async () => {
     const authenticationService = inject(AuthenticationService);
     const router = inject(Router);
     const snackBar = inject(MatSnackBar);
 
+    await authenticationService.checkIsAuthenticated();
+
     if (authenticationService.isAuthenticated()) {
         return true;
     } else {

frontend/src/app/core/interceptor/jwt.interceptor.ts

@@ -41,23 +41,12 @@ export class JwtInterceptor implements HttpInterceptor {
             this.isRefreshingToken = true;
             this.refreshTokenSubject.next(undefined);
 
-            const refreshToken = this.authenticationService.getRefreshToken();
-            if (refreshToken) {
-                const refreshTokenRequest: RefreshTokenRequest = {
-                    refreshTokenValue: refreshToken
-                };
-                this.userRestService.refreshToken(refreshTokenRequest)
+            this.authenticationService.refreshToken()
                 .then(refreshTokenResponse => {
-                        this.authenticationService.authenticate(refreshTokenResponse.accessToken, refreshTokenResponse.refreshToken);
                     this.refreshTokenSubject.next(refreshTokenResponse.accessToken);
                 })
-                    .catch(() => {
-                        return this.handleNoRefreshToken(initialError);
-                    })
+                .catch(() => this.handleNoRefreshToken(initialError))
                 .finally(() => this.isRefreshingToken = false);
-            } else {
-                return this.handleNoRefreshToken(initialError);
-            }
         }
 
         return this.refreshTokenSubject.pipe(

frontend/src/app/core/service/authentication.service.ts

@@ -1,7 +1,9 @@
 import { inject, Injectable } from "@angular/core";
+import { BehaviorSubject, interval } from "rxjs";
 import { User } from "../model/User";
 import { UserRestService } from "../rest-services/user/user.rest-service";
 import { RefreshTokenRequest } from "../rest-services/user/model/refresh-token.model";
+import { LoginResponse } from "../rest-services/user/model/login.model";
 
 const JWT_PARAM = 'jwt';
 const REFRESH_TOKEN_PARAM = 'refresh-token';
@@ -18,18 +20,30 @@ interface UserDetails {
     providedIn: 'root'
 })
 export class AuthenticationService {
+    private readonly AUTHENTICATION_CHECKING_PERIOD = 5 * 60 * 1000;
+    private isAuthenticatedSubject = new BehaviorSubject<boolean>(false);
+    private readonly userRestService = inject(UserRestService);
+
+    startAuthenticationCheckingProcess(): void {
+        this.checkIsAuthenticated();
+        interval(this.AUTHENTICATION_CHECKING_PERIOD)
+            .subscribe(() => this.checkIsAuthenticated());
+    }
 
     authenticate(token: string, refreshToken: string): void {
         localStorage.setItem(JWT_PARAM, token);
         localStorage.setItem(REFRESH_TOKEN_PARAM, refreshToken);
+        this.isAuthenticatedSubject.next(true);
     }
 
     unauthenticate(): void {
         localStorage.removeItem(JWT_PARAM);
+        localStorage.removeItem(REFRESH_TOKEN_PARAM);
+        this.isAuthenticatedSubject.next(false);
     }
     
     isAuthenticated(): boolean {
-        return !!localStorage.getItem(JWT_PARAM);
+        return this.isAuthenticatedSubject.value;
     }
 
     getAuthenticatedUser(): User | undefined {
@@ -45,7 +59,7 @@ export class AuthenticationService {
     }
 
     isTokenExpired(): boolean {
-        let result = false;
+        let result = true;
 
         const userDetails = this.extractUserDetails();
 
@@ -59,8 +73,43 @@ export class AuthenticationService {
         return result;
     }
 
+    refreshToken(): Promise<LoginResponse> {
+        const refreshToken = this.getRefreshToken();
+        if (refreshToken) {
+            const refreshTokenRequest: RefreshTokenRequest = {
+                refreshTokenValue: refreshToken
+            };
+            return this.userRestService.refreshToken(refreshTokenRequest)
+                .then(refreshTokenResponse => {
+                    this.authenticate(refreshTokenResponse.accessToken, refreshTokenResponse.refreshToken);
+                    return refreshTokenResponse;
+                });
+        }
+
+        return Promise.reject('No any refresh token found.');
+    }
+
+    checkIsAuthenticated(): Promise<void> {
+        return new Promise((resolve, reject) => {
+            const isTokenExpired = this.isTokenExpired();
+            if (isTokenExpired) {
+                if (this.getRefreshToken()) {
+                    this.refreshToken()
+                        .then(() => resolve())
+                        .catch(() => reject());
+                } else {
+                    this.isAuthenticatedSubject.next(false);
+                }
+            } else {
+                this.isAuthenticatedSubject.next(true);
+            }
+            resolve();
+        });
+        
+    }
+
     private extractUserFromLocalStorage(): User | undefined {
-        let result: User | undefined = undefined;
+        let result: User | undefined;
 
         const userDetails = this.extractUserDetails();
         if (userDetails) {