feat: copilot controller (#6272)

fix CLOUD-27

packages/backend/server/src/plugins/copilot/controller.ts

@@ -0,0 +1,151 @@
+import {
+  BadRequestException,
+  Controller,
+  Get,
+  InternalServerErrorException,
+  Param,
+  Query,
+  Req,
+  Sse,
+} from '@nestjs/common';
+import {
+  concatMap,
+  connect,
+  EMPTY,
+  from,
+  map,
+  merge,
+  Observable,
+  switchMap,
+  toArray,
+} from 'rxjs';
+
+import { Public } from '../../core/auth';
+import { CurrentUser } from '../../core/auth/current-user';
+import { CopilotProviderService } from './providers';
+import { ChatSessionService } from './session';
+import { CopilotCapability } from './types';
+
+export interface ChatEvent {
+  data: string;
+  id?: string;
+}
+
+@Controller('/api/copilot')
+export class CopilotController {
+  constructor(
+    private readonly chatSession: ChatSessionService,
+    private readonly provider: CopilotProviderService
+  ) {}
+
+  @Public()
+  @Get('/chat/:sessionId')
+  async chat(
+    @CurrentUser() user: CurrentUser,
+    @Req() req: Request,
+    @Param('sessionId') sessionId: string,
+    @Query('message') content: string,
+    @Query() params: Record<string, string | string[]>
+  ): Promise<string> {
+    const provider = this.provider.getProviderByCapability(
+      CopilotCapability.TextToText
+    );
+    if (!provider) {
+      throw new InternalServerErrorException('No provider available');
+    }
+    const session = await this.chatSession.get(sessionId);
+    if (!session) {
+      throw new BadRequestException('Session not found');
+    }
+    if (!content || !content.trim()) {
+      throw new BadRequestException('Message is empty');
+    }
+    session.push({
+      role: 'user',
+      content: decodeURIComponent(content),
+      createdAt: new Date(),
+    });
+
+    try {
+      delete params.message;
+      const content = await provider.generateText(
+        session.finish(params),
+        session.model,
+        {
+          signal: req.signal,
+          user: user.id,
+        }
+      );
+
+      session.push({
+        role: 'assistant',
+        content,
+        createdAt: new Date(),
+      });
+      await session.save();
+
+      return content;
+    } catch (e: any) {
+      throw new InternalServerErrorException(
+        e.message || "Couldn't generate text"
+      );
+    }
+  }
+
+  @Public()
+  @Sse('/chat/:sessionId/stream')
+  async chatStream(
+    @CurrentUser() user: CurrentUser,
+    @Req() req: Request,
+    @Param('sessionId') sessionId: string,
+    @Query('message') content: string,
+    @Query() params: Record<string, string>
+  ): Promise<Observable<ChatEvent>> {
+    const provider = this.provider.getProviderByCapability(
+      CopilotCapability.TextToText
+    );
+    if (!provider) {
+      throw new InternalServerErrorException('No provider available');
+    }
+    const session = await this.chatSession.get(sessionId);
+    if (!session) {
+      throw new BadRequestException('Session not found');
+    }
+    if (!content || !content.trim()) {
+      throw new BadRequestException('Message is empty');
+    }
+    session.push({
+      role: 'user',
+      content: decodeURIComponent(content),
+      createdAt: new Date(),
+    });
+
+    delete params.message;
+    return from(
+      provider.generateTextStream(session.finish(params), session.model, {
+        signal: req.signal,
+        user: user.id,
+      })
+    ).pipe(
+      connect(shared$ =>
+        merge(
+          // actual chat event stream
+          shared$.pipe(map(data => ({ id: sessionId, data }))),
+          // save the generated text to the session
+          shared$.pipe(
+            toArray(),
+            concatMap(values => {
+              session.push({
+                role: 'assistant',
+                content: values.join(''),
+                createdAt: new Date(),
+              });
+              return from(session.save());
+            }),
+            switchMap(() => EMPTY)
+          )
+        )
+      )
+    );
+  }
+}