feat: infinite scroll in messages, add loader in sidebar

frontend/src/app/chat/chat-service.ts

@@ -20,8 +20,8 @@ export class ChatService {
     });
   }
 
-  public getMessages(id: string) {
-    return this.http.get<MessageCollection>(`${this.apiUrl}/chats/${id}/messages`);
+  public getMessages(id: string, page: number = 1) {
+    return this.http.get<MessageCollection>(`${this.apiUrl}/chats/${id}/messages?page=${page}`);
   }
 
   public getChats() {

frontend/src/app/chat/chat.html

@@ -4,6 +4,13 @@
       class="flex-1 overflow-y-auto p-8 flex flex-col gap-6 scroll-smooth custom-scrollbar"
       #scrollContainer
     >
+      <div appInfiniteScroll (scrolled)="loadMoreChats()">
+        @if(messageStore.isLoadingPaginated()){
+        <div class="w-full max-h-14 flex items-center justify-center">
+          <app-loader class="w-8" />
+        </div>
+        }
+      </div>
       @if(messageStore.isLoading()) {
       <div class="w-full h-full flex items-center justify-center">
         <app-loader class="w-8" />
@@ -15,7 +22,7 @@
       >
         <div
           class="px-5 py-4 rounded-2xl text-sm leading-relaxed shadow-[0_4px_15px_rgba(0,0,0,0.1)] relative whitespace-pre-wrap"
-          [ngClass]="msg.attributes.role === 'user' ? 'bg-linear-to-br from-indigo-500 to-purple-600 text-white rounded-br-sm' : 'bg-white/10 border border-white/5 text-slate-200 rounded-bl-sm backdrop-blur-md'"
+          [ngClass]="msg.attributes.role === 'user' ? 'bg-linear-to-br from-indigo-500 to-blue-600 text-white rounded-br-sm' : 'bg-white/10 border border-white/5 text-slate-200 rounded-bl-sm backdrop-blur-md'"
         >
           {{ msg.attributes.content }}
         </div>

frontend/src/app/chat/chat.store.ts

@@ -6,6 +6,7 @@ import { MessageState, Message, MessageResponse, ChatResponse, ChatState } from
 import { lastValueFrom } from 'rxjs';
 import { Router } from '@angular/router';
 import { JsonApiResource } from '../core/types/api';
+import { environment } from '../../environments/environment.development';
 
 const initialMessageState: MessageState = {
   messages: [
@@ -22,6 +23,9 @@ const initialMessageState: MessageState = {
   ],
   isLoading: true,
   isAgentThinking: false,
+  isLoadingPaginated: false,
+  currentPage: 1,
+  lastPage: 1,
   id: null,
 };
 
@@ -147,7 +151,11 @@ export const MessageStore = signalStore(
         try {
           const chatHistory = await lastValueFrom(chatService.getMessages(<string>store.id()));
           if (chatHistory.data.length !== 0) {
-            patchState(store, { messages: chatHistory.data });
+            patchState(store, {
+              messages: chatHistory.data,
+              currentPage: chatHistory.meta.current_page,
+              lastPage: chatHistory.meta.last_page,
+            });
           } else {
             patchState(store, { messages: initialMessageState.messages });
           }
@@ -173,6 +181,34 @@ export const MessageStore = signalStore(
           patchState(store, { isLoading: false });
         }
       },
+      loadOlderMessages: async () => {
+        if (
+          store.isLoadingPaginated() ||
+          store.isLoading() ||
+          store.currentPage() >= store.lastPage() ||
+          !store.id()
+        ) {
+          return;
+        }
+
+        patchState(store, { isLoadingPaginated: true });
+        const nextPage = store.currentPage() + 1;
+
+        try {
+          const chatHistory = await lastValueFrom(
+            chatService.getMessages(<string>store.id(), nextPage),
+          );
+          patchState(store, (state) => ({
+            messages: [...chatHistory.data, ...state.messages],
+            currentPage: chatHistory.meta.current_page,
+            lastPage: chatHistory.meta.last_page,
+            isLoadingPaginated: false,
+          }));
+        } catch (err) {
+          if (!environment.production) console.error(err);
+          patchState(store, { isLoadingPaginated: false });
+        }
+      },
     };
   }),
 );

frontend/src/app/chat/chat.ts

@@ -3,13 +3,15 @@ import { CommonModule } from '@angular/common';
 import { FormControl, ReactiveFormsModule } from '@angular/forms';
 import { ChatStore, MessageStore } from './chat.store';
 import { ActivatedRoute } from '@angular/router';
-import { Sidebar } from "../core/layout/sidebar/sidebar";
-import { Loader } from "../shared/loader/loader";
+import { Sidebar } from '../core/layout/sidebar/sidebar';
+import { Loader } from '../shared/loader/loader';
+import { InfiniteScroll } from '../core/directives/infinite-scroll';
+import { environment } from '../../environments/environment.development';
 
 @Component({
   selector: 'app-chat',
   standalone: true,
-  imports: [CommonModule, ReactiveFormsModule, Sidebar, Loader],
+  imports: [CommonModule, ReactiveFormsModule, Sidebar, Loader, InfiniteScroll],
   templateUrl: './chat.html',
   styleUrl: './chat.css',
 })
@@ -24,8 +26,6 @@ export class Chat {
   constructor() {
     // Scroll to bottom when messages change
     effect(() => {
-      // Accessing messages will trigger effect on change
-      const msgs = this.messageStore.messages();
       const loading = this.messageStore.isLoading();
 
       setTimeout(() => {
@@ -65,6 +65,12 @@ export class Chat {
     try {
       const el = this.scrollContainer.nativeElement;
       el.scrollTop = el.scrollHeight;
-    } catch (err) {}
+    } catch (err) {
+      if (!environment.production) console.log(err);
+    }
+  }
+
+  protected loadMoreChats() {
+    this.messageStore.loadOlderMessages();
   }
 }

frontend/src/app/chat/chat.types.ts

@@ -24,6 +24,9 @@ export type MessageState = {
   messages: JsonApiResource<Message>[];
   isLoading: boolean;
   isAgentThinking: boolean;
+  isLoadingPaginated: boolean;
+  currentPage: number;
+  lastPage: number;
   id: string | null;
 };
 export type ChatState = {

frontend/src/app/core/directives/infinite-scroll.spec.ts

@@ -0,0 +1,8 @@
+import { InfiniteScroll } from './infinite-scroll';
+
+describe('InfiniteScroll', () => {
+  it('should create an instance', () => {
+    const directive = new InfiniteScroll();
+    expect(directive).toBeTruthy();
+  });
+});

frontend/src/app/core/directives/infinite-scroll.ts

@@ -0,0 +1,26 @@
+import { DestroyRef, Directive, ElementRef, inject, output } from '@angular/core';
+
+@Directive({
+  selector: '[appInfiniteScroll]',
+})
+export class InfiniteScroll {
+  scrolled = output<void>();
+  private elementRef = inject(ElementRef);
+  private destroyRef = inject(DestroyRef);
+  private observer?: IntersectionObserver;
+
+  constructor() {
+    this.observer = new IntersectionObserver(
+      ([entry]) => {
+        if (entry.isIntersecting) {
+          this.scrolled.emit();
+        }
+      },
+      { root: null, rootMargin: '0px', threshold: 0.1 },
+    );
+    this.observer.observe(this.elementRef.nativeElement);
+    this.destroyRef.onDestroy(() => {
+      this.observer?.disconnect();
+    });
+  }
+}

frontend/src/app/core/layout/sidebar/sidebar.html

@@ -150,6 +150,13 @@
     </div>
   </div>
   }
+
+  <!--Loading state-->
+  @if(chatStore.isLoading()){
+  <div class="flex flex-1 h-full flex-col items-center justify-center py-10 px-4">
+    <app-loader class="w-12" />
+  </div>
+  }
   <!-- Empty state -->
   @if (chatStore.chats().length === 0) {
   <div class="flex flex-1 flex-col items-center justify-center py-10 px-4 text-center">

frontend/src/app/core/layout/sidebar/sidebar.ts

@@ -1,17 +1,18 @@
 import { Component, signal, computed, inject, OnInit } from '@angular/core';
 import { CommonModule } from '@angular/common';
-import { RouterModule } from '@angular/router';
+import { ActivatedRoute, RouterModule } from '@angular/router';
 import { ChatStore, MessageStore } from '../../../chat/chat.store';
 import { AuthStore } from '../../../auth/auth.store';
 import { InitialsPipe } from './initials-pipe';
 import { JsonApiResource } from '../../types/api';
 import { Chat } from '../../../chat/chat.types';
 import { Login } from '../../../auth/login/login';
+import { Loader } from "../../../shared/loader/loader";
 
 @Component({
   selector: 'app-sidebar',
   standalone: true,
-  imports: [CommonModule, RouterModule, InitialsPipe],
+  imports: [CommonModule, RouterModule, InitialsPipe, Loader],
   templateUrl: 'sidebar.html',
   styleUrl: 'sidebar.css',
 })
@@ -19,6 +20,7 @@ export class Sidebar implements OnInit {
   protected chatStore = inject(ChatStore);
   protected messageStore = inject(MessageStore);
   protected authStore = inject(AuthStore);
+  private route = inject(ActivatedRoute);
 
   protected isOpen = signal(true);
   protected isCogMenuOpen = signal(false);
@@ -27,6 +29,12 @@ export class Sidebar implements OnInit {
 
   ngOnInit() {
     this.chatStore.fetchChats();
+    this.route.paramMap.subscribe((params) => {
+      const urlId = params.get('id');
+      if (urlId) {
+        this.activeChatId.set(urlId);
+      }
+    });
   }
 
   protected sidebarClasses = computed(() => {
@@ -46,7 +54,7 @@ export class Sidebar implements OnInit {
   }
 
   protected chatIconClasses(chat: any): string {
-    const base = 'w-6 h-6 rounded-md flex items-center justify-center shrink-0 mt-0.5';
+    const base = 'w-6 h-6 rounded-md flex items-center justify-center shrink-0 mt-0.5 pt-0.5';
     return chat.isActive
       ? base + ' bg-[#2d5be3]/20 text-[#5b8af0]'
       : base + ' bg-[#111a2e] text-[#3a5272] group-hover:bg-[#1a2a48] group-hover:text-[#5a80a8]';
@@ -66,7 +74,6 @@ export class Sidebar implements OnInit {
 
   protected selectChat(chatId: string): void {
     this.activeChatId.set(chatId);
-    console.log(chatId);
     this.messageStore.fetchChatHistory(chatId);
   }