feat: add chatbot module and service

src/app.module.ts

@@ -24,6 +24,8 @@ import { AdminModule } from './modules/admin/admin.module';
 import { AppThrottlerGuard } from './common/guards/app-throttler.guard';
 import { ThrottlerModule } from '@nestjs/throttler';
 import { LoggingModule } from './common/modules/logging/logging.module';
+import { ChatbotModule } from './modules/chatbot/chatbot.module';
+import openRouterConfig from './config/open-router.config';
 
 const ENV = process.env.NODE_ENV;
 
@@ -48,7 +50,13 @@ const ENV = process.env.NODE_ENV;
     ConfigModule.forRoot({
       isGlobal: true,
       envFilePath: !ENV ? '.env' : `.env.${ENV}`,
-      load: [appConfig, databaseConfig, jwtConfig, redisConfig],
+      load: [
+        appConfig,
+        databaseConfig,
+        jwtConfig,
+        redisConfig,
+        openRouterConfig,
+      ],
       validationSchema: environmentValidation,
     }),
 
@@ -97,6 +105,7 @@ const ENV = process.env.NODE_ENV;
     ScoringModule,
     AdminModule,
     LoggingModule,
+    ChatbotModule,
   ],
   providers: [
     {

src/config/environment.validation.ts

@@ -23,4 +23,6 @@ export default Joi.object({
   CORS_SUBDOMAIN: Joi.string().required(),
   SWAGGER_SERVERS: Joi.string().required(),
   LOG_LEVEL: Joi.string().default('info'),
+  OPENROUTER_API_KEY: Joi.string().required(),
+  OPENROUTER_MODEL: Joi.string().required(),
 });

src/config/open-router.config.ts

@@ -0,0 +1,6 @@
+import { registerAs } from '@nestjs/config';
+
+export default registerAs('openRouter', () => ({
+  apiKey: process.env.OPENROUTER_API_KEY,
+  model: process.env.OPENROUTER_MODEL,
+}));

src/modules/chatbot/chatbot.controller.ts

@@ -0,0 +1,20 @@
+import { Body, Controller, Post } from '@nestjs/common';
+import { ChatbotService } from './providers/chatbot.service';
+import { Public } from '../auth/decorators/public.decorator';
+
+@Controller('chatbot')
+export class ChatbotController {
+  constructor(
+    /**
+     * Inject Chatbot Service
+     */
+    private readonly chatbotService: ChatbotService,
+  ) {}
+
+  @Post('chat')
+  //   TEMP:
+  @Public()
+  public async chat(@Body('message') message: string) {
+    return this.chatbotService.chat(message);
+  }
+}

src/modules/chatbot/chatbot.module.ts

@@ -0,0 +1,9 @@
+import { Module } from '@nestjs/common';
+import { ChatbotController } from './chatbot.controller';
+import { ChatbotService } from './providers/chatbot.service';
+
+@Module({
+  controllers: [ChatbotController],
+  providers: [ChatbotService],
+})
+export class ChatbotModule {}

src/modules/chatbot/http/chatbot.post.endpoints.http

@@ -0,0 +1,7 @@
+POST {{baseUrl}}/chatbot/chat
+Content-Type: application/json
+# Authorization: Bearer {{$global.accessToken}}
+
+{
+    "message": "چطوری بفهمم به HPV مبتلا هستم یا خیر؟"
+}

src/modules/chatbot/providers/chatbot.service.ts

@@ -0,0 +1,77 @@
+import { Injectable } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+
+@Injectable()
+export class ChatbotService {
+  private openRouter: any;
+
+  constructor(
+    /**
+     * Inject Config Service
+     */
+    private readonly configService: ConfigService,
+  ) {}
+
+  private async getOpenRouter() {
+    if (!this.openRouter) {
+      const { OpenRouter } = await import('@openrouter/sdk');
+
+      this.openRouter = new OpenRouter({
+        apiKey: this.configService.get<string>('openRouter.apiKey'),
+      });
+    }
+
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+    return this.openRouter;
+  }
+
+  public async chat(message: string) {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+    const openRouter = await this.getOpenRouter();
+
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-member-access
+    const response = await openRouter.chat.send({
+      chatRequest: {
+        model: this.configService.get<string>('openRouter.model'),
+        messages: [
+          {
+            role: 'system',
+            content: `
+                You are a medical AI assistant named Heala (Or in persian: هیلا).
+
+                Your role is to provide general medical information
+                and health education.
+
+                - Do not provide definitive diagnoses.
+                - Do not prescribe medications or dosages.
+                - Do not fabricate medical information.
+                - If symptoms may indicate an emergency, recommend
+                seeking urgent medical care.
+                - Clearly communicate uncertainty when appropriate.
+                - Answer in Persian when the user asks in Persian.
+          `.trim(),
+          },
+          {
+            role: 'user',
+            content: message,
+          },
+        ],
+      },
+    });
+
+    if (response instanceof ReadableStream) {
+      throw new Error('Expected non-streaming response');
+    }
+
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+    const content = response.choices[0]?.message?.content;
+
+    if (typeof content !== 'string') {
+      throw new Error('OpenRouter returned an unexpected response');
+    }
+
+    return {
+      message: content,
+    };
+  }
+}