feat: add conversation module

src/modules/chatbot/chatbot.controller.ts

@@ -1,6 +1,7 @@
-import { Body, Controller, Post } from '@nestjs/common';
+import { Body, Controller, Post, Res } from '@nestjs/common';
 import { ChatbotService } from './providers/chatbot.service';
 import { Public } from '../auth/decorators/public.decorator';
+import type { Response } from 'express';
 
 @Controller('chatbot')
 export class ChatbotController {
@@ -17,4 +18,52 @@ export class ChatbotController {
   public async chat(@Body('message') message: string) {
     return this.chatbotService.chat(message);
   }
+
+  @Post('stream')
+  // TEMP:
+  @Public()
+  public async streamChat(
+    @Body('message') message: string,
+    @Res() res: Response,
+  ) {
+    res.setHeader('Content-Type', 'text/event-stream');
+    res.setHeader('Cache-Control', 'no-cache');
+    res.setHeader('Connection', 'keep-alive');
+
+    for await (const content of this.chatbotService.streamChat(message)) {
+      res.write(
+        `data: ${JSON.stringify({
+          message: content,
+        })}\n\n`,
+      );
+    }
+
+    res.end();
+  }
+
+  // @Sse('stream')
+  // @Public()
+  // public streamChat(
+  //   @Body('message') message: string,
+  // ): Observable<MessageEvent> {
+  //   return new Observable((subscriber) => {
+  //     const run = async () => {
+  //       try {
+  //         for await (const content of this.chatbotService.streamChat(message)) {
+  //           subscriber.next({
+  //             data: {
+  //               message: content,
+  //             },
+  //           });
+  //         }
+
+  //         subscriber.complete();
+  //       } catch (err) {
+  //         subscriber.error(err);
+  //       }
+  //     };
+
+  //     void run();
+  //   });
+  // }
 }

src/modules/chatbot/constants/index.ts

@@ -0,0 +1,14 @@
+export const CHATBOT_SYSTEM_PROMPT = `
+    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.
+`;

src/modules/chatbot/dtos/chat.dto.ts

@@ -0,0 +1,24 @@
+import { IsNotEmpty, IsOptional, IsString } from 'class-validator';
+import { i18nValidationMessage as t } from 'nestjs-i18n';
+
+export class ChatDTO {
+  @IsString({
+    message: t('validation.wrongFieldFormat', {
+      field: '$t(chatbot.fields.conversationId)',
+    }),
+  })
+  @IsOptional()
+  conversationId?: string;
+
+  @IsString({
+    message: t('validation.wrongFieldFormat', {
+      field: '$t(chatbot.fields.message)',
+    }),
+  })
+  @IsNotEmpty({
+    message: t('validation.requiredField', {
+      field: '$t(chatbot.fields.message)',
+    }),
+  })
+  message!: string;
+}

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

@@ -4,4 +4,7 @@ Content-Type: application/json
 
 {
     "message": "چطوری بفهمم به HPV مبتلا هستم یا خیر؟"
-}
+}
+
+# POST {{baseUrl}}/chatbot/stream/
+# Content-Type: application/json

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

@@ -1,5 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
+import { CHATBOT_SYSTEM_PROMPT } from '../constants';
 
 @Injectable()
 export class ChatbotService {
@@ -14,7 +15,7 @@ export class ChatbotService {
     const { OpenRouter } = await import('@openrouter/sdk');
 
     return new OpenRouter({
-      apiKey: this.configService.get<string>('openRouter.apiKey'),
+      apiKey: this.configService.getOrThrow<string>('openRouter.apiKey'),
     });
   }
 
@@ -23,24 +24,11 @@ export class ChatbotService {
 
     const response = await openRouter.chat.send({
       chatRequest: {
-        model: this.configService.get<string>('openRouter.model'),
+        model: this.configService.getOrThrow<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(),
+            content: CHATBOT_SYSTEM_PROMPT.trim(),
           },
           {
             role: 'user',
@@ -64,4 +52,37 @@ export class ChatbotService {
       message: content,
     };
   }
+
+  public async *streamChat(message: string) {
+    const openRouter = await this.getOpenRouter();
+
+    const response = await openRouter.chat.send({
+      chatRequest: {
+        model: this.configService.getOrThrow<string>('openRouter.model'),
+        messages: [
+          {
+            role: 'system',
+            content: CHATBOT_SYSTEM_PROMPT.trim(),
+          },
+          {
+            role: 'user',
+            content: message,
+          },
+        ],
+        stream: true,
+      },
+    });
+
+    if ('choices' in response) {
+      throw new Error('Expected streaming response');
+    }
+
+    for await (const chunk of response) {
+      const content = chunk.choices[0]?.delta?.content;
+
+      if (content) {
+        yield content;
+      }
+    }
+  }
 }

src/modules/conversation/conversation.module.ts

@@ -0,0 +1,9 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { Conversation } from './entities/conversation.entity';
+import { Message } from './entities/message.entity';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([Conversation, Message])],
+})
+export class ConversationModule {}

src/modules/conversation/entities/conversation.entity.ts

@@ -0,0 +1,32 @@
+import { User } from '@/modules/users/entities/user.entity';
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  ManyToOne,
+  OneToMany,
+  PrimaryGeneratedColumn,
+  UpdateDateColumn,
+} from 'typeorm';
+import { Message } from './message.entity';
+
+@Entity()
+export class Conversation {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column({ type: 'varchar', nullable: true })
+  title!: string | null;
+
+  @ManyToOne(() => User, { onDelete: 'CASCADE' })
+  user!: User;
+
+  @OneToMany(() => Message, (message) => message.conversation)
+  messages!: Message[];
+
+  @CreateDateColumn()
+  createdAt!: Date;
+
+  @UpdateDateColumn()
+  updatedAt!: Date;
+}

src/modules/conversation/entities/message.entity.ts

@@ -0,0 +1,33 @@
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+} from 'typeorm';
+import { Conversation } from './conversation.entity';
+import { MessageRole } from '../enums/message-role.enum';
+
+@Entity()
+export class Message {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @ManyToOne(() => Conversation, (conversation) => conversation.messages, {
+    onDelete: 'CASCADE',
+  })
+  conversation!: Conversation;
+
+  @Column({
+    type: 'enum',
+    enum: MessageRole,
+    nullable: false,
+  })
+  role!: MessageRole;
+
+  @Column({ type: 'text' })
+  content!: string;
+
+  @CreateDateColumn()
+  createdAt!: Date;
+}

src/modules/conversation/enums/conversation-type.enum.ts

@@ -0,0 +1,4 @@
+export enum ConversationType {
+  AI = 'ai',
+  DOCTOR = 'doctor',
+}

src/modules/conversation/enums/message-role.enum.ts

@@ -0,0 +1,5 @@
+export enum MessageRole {
+  USER = 'user',
+  ASSISTANT = 'assistant',
+  DOCTOR = 'doctor',
+}

src/modules/conversation/providers/conversation.service.ts

@@ -0,0 +1,44 @@
+import { Injectable } from '@nestjs/common';
+import { Repository } from 'typeorm';
+import { Conversation } from '../entities/conversation.entity';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Message } from '../entities/message.entity';
+import { User } from '@/modules/users/entities/user.entity';
+import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
+
+@Injectable()
+export class ConversationService {
+  constructor(
+    /**
+     * Inject Conversation Repository
+     */
+    @InjectRepository(Conversation)
+    private readonly conversationRepository: Repository<Conversation>,
+
+    /**
+     * Inject Message Repository
+     */
+    @InjectRepository(Message)
+    private readonly messageRepository: Repository<Message>,
+  ) {}
+
+  public async createConversation(
+    user: User,
+    title?: string,
+  ): Promise<Conversation> {
+    const conversation = this.conversationRepository.create({
+      user,
+      title: title ?? null,
+    });
+
+    try {
+      return await this.conversationRepository.save(conversation);
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+  }
+
+  //   public async findConversationById(id: number, user: User): Promise<Conversation> {
+  //     const
+  //   }
+}