-เพิ่ม pkg jose ไว้ encrypt secret key

-jwt services/jwt.service.ts
-เพิ่ม  เวลา expire jwt token

ng-ttc-frontend/src/app/services/jwt.service.ts

@@ -0,0 +1,96 @@
+import { Injectable } from '@angular/core';
+import { environment } from '../../environments/environment';
+import * as jose from 'jose';
+import { BehaviorSubject, Observable, timer, Subscription } from 'rxjs';
+import { map, takeWhile, finalize } from 'rxjs/operators';
+import { Router } from '@angular/router';
+import { ToastrService } from 'ngx-toastr';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class JwtService {
+  private secret = new TextEncoder().encode(environment.jwt_secret);
+  private countdownSub = new BehaviorSubject<string | null>(null);
+  public countdown$: Observable<string | null> = this.countdownSub.asObservable();
+  private timerSubscription: Subscription | null = null;
+
+  constructor(
+    private router: Router,
+    private toastr: ToastrService
+  ) {
+    this.startTokenCountdown();
+  }
+
+  async decodeToken(token: string): Promise<any> {
+    try {
+      const { payload } = await jose.jwtVerify(token, this.secret);
+      return payload;
+    } catch (error) {
+      // console.error('Invalid token:', error);
+      return null;
+    }
+  }
+
+  private startTokenCountdown(): void {
+    if (this.timerSubscription) {
+      this.timerSubscription.unsubscribe();
+    }
+
+    const token = localStorage.getItem('access_token');
+    if (!token) {
+      this.countdownSub.next(null);
+      return;
+    }
+
+    this.decodeToken(token).then(payload => {
+      if (payload && payload.exp) {
+        const expirationTime = payload.exp * 1000;
+        this.timerSubscription = timer(0, 1000).pipe(
+          map(() => {
+            const now = new Date().getTime();
+            const distance = expirationTime - now;
+
+            if (distance < 0) {
+              this.logout();
+              return 'Expired';
+            }
+
+            const hours = Math.floor((distance % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
+            const minutes = Math.floor((distance % (1000 * 60 * 60)) / (1000 * 60));
+            const seconds = Math.floor((distance % (1000 * 60)) / 1000);
+
+            return `${this.pad(hours)}:${this.pad(minutes)}:${this.pad(seconds)}`;
+          }),
+          takeWhile(val => val !== 'Expired', true),
+          finalize(() => {
+            if (this.countdownSub.value !== 'Expired') {
+                this.logout();
+            }
+            this.countdownSub.next('Expired');
+          })
+        ).subscribe(val => this.countdownSub.next(val));
+      } else {
+        this.countdownSub.next(null);
+      }
+    });
+  }
+
+  private pad(num: number): string {
+    return num < 10 ? '0' + num : num.toString();
+  }
+
+  public logout(): void {
+    localStorage.removeItem('access_token');
+    this.countdownSub.next(null);
+    if (this.timerSubscription) {
+      this.timerSubscription.unsubscribe();
+    }
+    // this.toastr.info('Your session has expired. Please log in again.', 'Session Expired');
+    this.router.navigate(['/login']); // Assuming '/login' is your login route
+  }
+
+  public restartCountdown(): void {
+    this.startTokenCountdown();
+  }
+}