fix: improve session management and prevent duplicate session creation

src/app/components/chat/chat.component.ts

@@ -320,6 +320,7 @@ export class ChatComponent implements OnInit, AfterViewInit, OnDestroy {
   ngOnInit(): void {
     this.syncSelectedAppFromUrl();
     this.updateSelectedAppUrl();
+    this.validateAndFixSessionUrl();
 
     this.webSocketService.onCloseReason().subscribe((closeReason) => {
       const error =
@@ -1458,6 +1459,46 @@ export class ChatComponent implements OnInit, AfterViewInit, OnDestroy {
     });
   }
 
+  private validateAndFixSessionUrl() {
+    // Wait for app and URL query params
+    combineLatest([
+      this.agentService.getApp(),
+      this.router.events.pipe(
+        filter((e) => e instanceof NavigationEnd),
+        map(() => this.activatedRoute.snapshot.queryParams),
+      )
+    ]).pipe(
+      filter(([appName, params]) => !!appName && !!params['session']),
+      take(1),
+      switchMap(([appName, params]) => {
+        const sessionId = params['session'];
+        // Validate current session id in URL
+        return this.sessionService.getSession(this.userId, appName, sessionId)
+          .pipe(
+            catchError((error) => {
+              // If invalid, try to use latest existing session
+              return this.sessionService.listSessions(this.userId, appName)
+                .pipe(
+                  catchError(() => of([])),
+                  switchMap((sessions: any[]) => {
+                    if (sessions && sessions.length > 0) {
+                      const latestSession = sessions.reduce((latest: any, current: any) =>
+                        current.lastUpdateTime > latest.lastUpdateTime ? current : latest
+                      );
+                      this.updateWithSelectedSession(latestSession);
+                      return of(latestSession);
+                    } else {
+                      this.createSessionAndReset();
+                      return of(null);
+                    }
+                  })
+                );
+            })
+          );
+      })
+    ).subscribe();
+  }
+
   private syncSelectedAppFromUrl() {
     combineLatest([
       this.router.events.pipe(
@@ -1682,3 +1723,5 @@ export class ChatComponent implements OnInit, AfterViewInit, OnDestroy {
         this.document.head, style);  // Append to the head of the document
   }
 }
+
+

src/app/components/session-tab/session-tab.component.ts

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import {Component, EventEmitter, Input, OnInit, Output, Inject} from '@angular/core';
+import {Component, EventEmitter, Input, OnInit, Output, Inject, OnChanges, SimpleChanges} from '@angular/core';
 import {MatDialog} from '@angular/material/dialog';
 import {Subject, switchMap} from 'rxjs';
 import {Session} from '../../core/models/Session';
@@ -28,7 +28,7 @@ import { NgClass } from '@angular/common';
     styleUrl: './session-tab.component.scss',
     imports: [NgClass],
 })
-export class SessionTabComponent implements OnInit {
+export class SessionTabComponent implements OnInit, OnChanges {
   @Input() userId: string = '';
   @Input() appName: string = '';
   @Input() sessionId: string = '';
@@ -66,6 +66,13 @@ export class SessionTabComponent implements OnInit {
     }, 500);
   }
 
+  ngOnChanges(changes: SimpleChanges): void {
+    if ((changes['appName'] && !changes['appName'].firstChange) ||
+        (changes['userId'] && !changes['userId'].firstChange)) {
+      this.refreshSessionsSubject.next();
+    }
+  }
+
   getSession(sessionId: string) {
     this.sessionService
       .getSession(this.userId, this.appName, sessionId)

src/assets/config/runtime-config.json

@@ -1,3 +1,3 @@
 {
-  "backendUrl": "http://localhost:8000"
+  "backendUrl": "http://localhost:8080"
 }