Feature: Paperless AI (#10319)

src-ui/src/app/services/chat.service.spec.ts

@@ -0,0 +1,58 @@
+import {
+  HttpEventType,
+  provideHttpClient,
+  withInterceptorsFromDi,
+} from '@angular/common/http'
+import {
+  HttpTestingController,
+  provideHttpClientTesting,
+} from '@angular/common/http/testing'
+import { TestBed } from '@angular/core/testing'
+import { environment } from 'src/environments/environment'
+import { ChatService } from './chat.service'
+
+describe('ChatService', () => {
+  let service: ChatService
+  let httpMock: HttpTestingController
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({
+      imports: [],
+      providers: [
+        ChatService,
+        provideHttpClient(withInterceptorsFromDi()),
+        provideHttpClientTesting(),
+      ],
+    })
+    service = TestBed.inject(ChatService)
+    httpMock = TestBed.inject(HttpTestingController)
+  })
+
+  afterEach(() => {
+    httpMock.verify()
+  })
+
+  it('should stream chat messages', (done) => {
+    const documentId = 1
+    const prompt = 'Hello, world!'
+    const mockResponse = 'Partial response text'
+    const apiUrl = `${environment.apiBaseUrl}documents/chat/`
+
+    service.streamChat(documentId, prompt).subscribe((chunk) => {
+      expect(chunk).toBe(mockResponse)
+      done()
+    })
+
+    const req = httpMock.expectOne(apiUrl)
+    expect(req.request.method).toBe('POST')
+    expect(req.request.body).toEqual({
+      document_id: documentId,
+      q: prompt,
+    })
+
+    req.event({
+      type: HttpEventType.DownloadProgress,
+      partialText: mockResponse,
+    } as any)
+  })
+})

src-ui/src/app/services/chat.service.ts

@@ -0,0 +1,46 @@
+import {
+  HttpClient,
+  HttpDownloadProgressEvent,
+  HttpEventType,
+} from '@angular/common/http'
+import { inject, Injectable } from '@angular/core'
+import { filter, map, Observable } from 'rxjs'
+import { environment } from 'src/environments/environment'
+
+export interface ChatMessage {
+  role: 'user' | 'assistant'
+  content: string
+  isStreaming?: boolean
+}
+
+@Injectable({
+  providedIn: 'root',
+})
+export class ChatService {
+  private http: HttpClient = inject(HttpClient)
+
+  streamChat(documentId: number, prompt: string): Observable<string> {
+    return this.http
+      .post(
+        `${environment.apiBaseUrl}documents/chat/`,
+        {
+          document_id: documentId,
+          q: prompt,
+        },
+        {
+          observe: 'events',
+          reportProgress: true,
+          responseType: 'text',
+          withCredentials: true,
+        }
+      )
+      .pipe(
+        map((event) => {
+          if (event.type === HttpEventType.DownloadProgress) {
+            return (event as HttpDownloadProgressEvent).partialText!
+          }
+        }),
+        filter((chunk) => !!chunk)
+      )
+  }
+}