issue#21 add chat apis

backend/src/chat/chat.model.ts

@@ -1,10 +1,44 @@
-import { Field, InputType, ObjectType } from '@nestjs/graphql';
+import { Field, InputType, ObjectType, ID } from '@nestjs/graphql';
+import { SystemBaseModel } from 'src/system-base-model/system-base.model';
+
+export enum Role {
+  User = 'User',
+  Model = 'Model'
+}
+
+@ObjectType()
+export class Message extends SystemBaseModel {
+  @Field(() => ID)
+  id: string;
+
+  @Field()
+  content: string;
+
+  @Field(() => Role)
+  role: Role;
+
+  @Field({ nullable: true })
+  modelId?: string;
+}
+
+@ObjectType()
+export class Chat extends SystemBaseModel {
+  @Field(() => ID)
+  id: string;
+
+  @Field({ nullable: true })
+  title: string;
+
+  @Field(() => [Message])
+  messages: Message[];
+}
 
 @ObjectType('ChatCompletionDeltaType')
 class ChatCompletionDelta {
   @Field({ nullable: true })
   content?: string;
 }
+
 @ObjectType('ChatCompletionChunkType')
 export class ChatCompletionChunk {
   @Field()

backend/src/chat/chat.module.ts

@@ -3,10 +3,10 @@ import { GraphQLModule } from '@nestjs/graphql';
 import { ApolloDriver, ApolloDriverConfig } from '@nestjs/apollo';
 import { HttpModule } from '@nestjs/axios';
 import { ChatResolver } from './chat.resolver';
-import { ChatProxyService } from './chat.service';
+import { ChatProxyService, ChatService } from './chat.service';
 
 @Module({
   imports: [HttpModule],
-  providers: [ChatResolver, ChatProxyService],
+  providers: [ChatResolver, ChatProxyService, ChatService],
 })
 export class ChatModule {}

backend/src/chat/chat.resolver.ts

@@ -1,10 +1,16 @@
-import { Resolver, Subscription, Args } from '@nestjs/graphql';
+import { Resolver, Subscription, Args, Query, Mutation } from '@nestjs/graphql';
 import { ChatCompletionChunk, ChatInput } from './chat.model';
-import { ChatProxyService } from './chat.service';
+import { ChatProxyService, ChatService } from './chat.service';
+import { title } from 'process';
+import { Chat, Message } from './chat.model';
+import { User } from 'src/user/user.model';
 
 @Resolver('Chat')
 export class ChatResolver {
-  constructor(private chatProxyService: ChatProxyService) {}
+  constructor(
+    private chatProxyService: ChatProxyService,
+    private chatService: ChatService,
+  ) {}
 
   @Subscription(() => ChatCompletionChunk, {
     nullable: true,
@@ -24,4 +30,42 @@ export class ChatResolver {
       throw new Error('Chat stream failed');
     }
   }
+
+  @Query(() => [Message])
+  async getChatHistory(@Args('chatId') chatId: string): Promise<Message[]> {
+    return this.chatService.getChatHistory(chatId);
+  }
+
+  @Query(() => Chat, { nullable: true })
+  async getChatDetails(@Args('chatId') chatId: string): Promise<Chat> {
+    return this.chatService.getChatDetails(chatId);
+  }
+
+  // @Query(() => [Message])
+  // getModelTags(@Args('chatId') chatId: string): Message[] {
+  //   return this.chatService.getChatHistory(chatId);
+  // }
+
+  @Mutation(() => Chat)
+  async createChat(): Promise<Chat> {
+    return this.chatService.createChat();
+  }
+
+  @Mutation(() => Boolean)
+  async deleteChat(@Args('chatId') chatId: string): Promise<boolean> {
+    return this.chatService.deleteChat(chatId);
+  }
+
+  @Mutation(() => Boolean)
+  async clearChatHistory(@Args('chatId') chatId: string): Promise<boolean> {
+    return this.chatService.clearChatHistory(chatId);
+  }
+
+  @Mutation(() => Chat, { nullable: true })
+  async updateChatTitle(
+    @Args('chatId') chatId: string,
+    @Args('title') title: string,
+  ): Promise<Chat> {
+    return this.chatService.updateChatTitle(chatId, title);
+  }
 }

backend/src/chat/chat.service.ts

@@ -1,6 +1,9 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { HttpService } from '@nestjs/axios';
-import { ChatCompletionChunk } from './chat.model';
+import { ChatCompletionChunk, Chat, Message } from './chat.model';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Repository } from 'typeorm';
+import { User } from 'src/user/user.model';
 
 type CustomAsyncIterableIterator<T> = AsyncIterator<T> & {
   [Symbol.asyncIterator](): AsyncIterableIterator<T>;
@@ -132,3 +135,67 @@ export class ChatProxyService {
     );
   }
 }
+
+@Injectable()
+export class ChatService {
+  constructor(
+    @InjectRepository(Chat)
+    private chatRepository: Repository<Chat>,
+    @InjectRepository(User)
+    private userRepository: Repository<User>,
+  ) {}
+
+  async getChatHistory(chatId: string): Promise<Message[]> {
+    const chat = await this.chatRepository.findOne({
+      where: { id: chatId },
+      relations: ['messages'],
+    });
+    return chat ? chat.messages : [];
+  }
+
+  async getChatDetails(chatId: string): Promise<Chat> {
+    return this.chatRepository.findOne({
+      where: { id: chatId },
+      relations: ['messages'],
+    });
+  }
+
+  async createChat(): Promise<Chat> {
+    const newChat = this.chatRepository.create({
+      title: 'New Chat',
+      messages: [],
+      createdAt: new Date(),
+      updatedAt: new Date(),
+    });
+    return await this.chatRepository.save(newChat);
+  }
+
+  async deleteChat(chatId: string): Promise<boolean> {
+    const result = await this.chatRepository.delete(chatId);
+    return result.affected > 0;
+  }
+
+  async clearChatHistory(chatId: string): Promise<boolean> {
+    const chat = await this.chatRepository.findOne({
+      where: { id: chatId },
+      relations: ['messages'],
+    });
+    if (chat) {
+      chat.messages = [];
+      chat.updatedAt = new Date();
+      await this.chatRepository.save(chat);
+      return true;
+    }
+    return false;
+  }
+
+  async updateChatTitle(chatId: string, title: string): Promise<Chat> {
+    const chat = await this.chatRepository.findOne({ where: { id: chatId } });
+    if (chat) {
+      chat.title = title;
+      chat.updatedAt = new Date();
+      return await this.chatRepository.save(chat);
+    }
+    return null;
+  }
+}

backend/src/user/user.model.ts

@@ -2,6 +2,7 @@ import { ObjectType, Field, ID } from '@nestjs/graphql';
 import { IsEmail } from 'class-validator';
 import { Role } from 'src/auth/role/role.model';
 import { SystemBaseModel } from 'src/system-base-model/system-base.model';
+import { Chat } from 'src/chat/chat.model';
 import {
   Entity,
   PrimaryGeneratedColumn,
@@ -29,6 +30,9 @@ export class User extends SystemBaseModel {
   @IsEmail()
   email: string;
 
+  @Field(() => [Chat])
+  chats: Chat[];
+
   @ManyToMany(() => Role)
   @JoinTable({
     name: 'user_roles',