Implement Notification & Alert System Module

libs/common/src/interceptors/transform.interceptor.ts

@@ -18,9 +18,10 @@ export interface ApiResponse<T> {
  * on a stable shape regardless of the controller that produced it.
  */
 @Injectable()
-export class TransformInterceptor<T>
-  implements NestInterceptor<T, ApiResponse<T>>
-{
+export class TransformInterceptor<T> implements NestInterceptor<
+  T,
+  ApiResponse<T>
+> {
   intercept(
     _context: ExecutionContext,
     next: CallHandler,

package.json

@@ -24,6 +24,7 @@
     "@nestjs/common": "^10.4.4",
     "@nestjs/config": "^3.2.3",
     "@nestjs/core": "^10.4.4",
+    "@nestjs/event-emitter": "^3.1.0",
     "@nestjs/jwt": "^10.2.0",
     "@nestjs/passport": "^10.0.3",
     "@nestjs/platform-express": "^10.4.4",

src/app.module.ts

@@ -11,8 +11,10 @@ import { MarketplaceModule } from './modules/marketplace/marketplace.module';
 import { AssetsModule } from './modules/assets/assets.module';
 import { TransactionsModule } from './modules/transactions/transactions.module';
 import { StellarModule } from './modules/stellar/stellar.module';
-import { TradingEngineModule } from './modules/trading-engine/trading-engine.module';
 import { WalletModule } from './modules/wallet/wallet.module';
+import { NotificationsModule } from './modules/notifications/notifications.module';
+import { EventEmitterModule } from '@nestjs/event-emitter';
+import { TradingEngineModule } from './modules/trading-engine/trading-engine.module';
 import { ErrorHandlerModule } from './modules/error-handler/error-handler.module';
 import { ResilienceModule } from './modules/resilience/resilience.module';
 import { QueueModule } from './modules/queue/queue.module';
@@ -21,6 +23,7 @@ import { BlockchainIndexerModule } from './modules/blockchain-indexer/blockchain
 
 @Module({
   imports: [
+    EventEmitterModule.forRoot(),
     ConfigModule,
     TypeOrmModule.forRootAsync({
       useClass: DatabaseConfig,
@@ -34,6 +37,7 @@ import { BlockchainIndexerModule } from './modules/blockchain-indexer/blockchain
     StellarModule,
     TradingEngineModule,
     WalletModule,
+    NotificationsModule,
     ErrorHandlerModule,
     ResilienceModule,
     QueueModule,

src/config/configuration.ts

@@ -46,7 +46,10 @@ export default () => ({
       10,
     ),
     // How long, and how often, we poll RPC for a submitted tx to settle.
-    pollIntervalMs: parseInt(process.env.SOROBAN_POLL_INTERVAL_MS ?? '1000', 10),
+    pollIntervalMs: parseInt(
+      process.env.SOROBAN_POLL_INTERVAL_MS ?? '1000',
+      10,
+    ),
     pollTimeoutMs: parseInt(process.env.SOROBAN_POLL_TIMEOUT_MS ?? '30000', 10),
     // Contract state cache TTL (seconds) in Redis.
     stateCacheTtlSecs: parseInt(

src/config/database.config.ts

@@ -1,9 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
-import {
-  TypeOrmModuleOptions,
-  TypeOrmOptionsFactory,
-} from '@nestjs/typeorm';
+import { TypeOrmModuleOptions, TypeOrmOptionsFactory } from '@nestjs/typeorm';
 
 /**
  * Builds TypeORM connection options from validated configuration. Entities are

src/modules/auth/auth.controller.ts

@@ -1,10 +1,21 @@
-import { Body, Controller, Get, HttpCode, HttpStatus, Post, UseGuards } from '@nestjs/common';
+import {
+  Body,
+  Controller,
+  Get,
+  HttpCode,
+  HttpStatus,
+  Post,
+  UseGuards,
+} from '@nestjs/common';
 import { ApiBearerAuth, ApiOperation, ApiTags } from '@nestjs/swagger';
 import { AuthService } from './auth.service';
 import { RegisterDto } from './dto/register.dto';
 import { LoginDto } from './dto/login.dto';
 import { JwtAuthGuard } from './guards/jwt-auth.guard';
-import { CurrentUser, AuthenticatedUser } from './decorators/current-user.decorator';
+import {
+  CurrentUser,
+  AuthenticatedUser,
+} from './decorators/current-user.decorator';
 
 @ApiTags('auth')
 @Controller('auth')

src/modules/auth/auth.service.ts

@@ -1,7 +1,4 @@
-import {
-  Injectable,
-  UnauthorizedException,
-} from '@nestjs/common';
+import { Injectable, UnauthorizedException } from '@nestjs/common';
 import { JwtService } from '@nestjs/jwt';
 import * as bcrypt from 'bcryptjs';
 import { UsersService } from '../users/users.service';

src/modules/marketplace/marketplace.service.ts

@@ -28,9 +28,7 @@ export class MarketplaceService {
     return this.listingsRepository.save(listing);
   }
 
-  async findAll(
-    query: QueryListingDto,
-  ): Promise<PaginatedResultDto<Listing>> {
+  async findAll(query: QueryListingDto): Promise<PaginatedResultDto<Listing>> {
     const qb = this.listingsRepository
       .createQueryBuilder('listing')
       .leftJoinAndSelect('listing.seller', 'seller')

src/modules/notifications/dto/create-notification-template.dto.ts

@@ -0,0 +1,11 @@
+import { IsNotEmpty, IsString } from 'class-validator';
+
+export class CreateNotificationTemplateDto {
+  @IsString()
+  @IsNotEmpty()
+  name: string;
+
+  @IsString()
+  @IsNotEmpty()
+  template: string;
+}

src/modules/notifications/dto/search-notifications.dto.ts

@@ -0,0 +1,20 @@
+import { IsOptional, IsString, IsEnum, IsDateString } from 'class-validator';
+import { Channel } from '../enums/channel.enum';
+
+export class SearchNotificationsDto {
+  @IsOptional()
+  @IsString()
+  userId?: string;
+
+  @IsOptional()
+  @IsEnum(Channel)
+  channel?: Channel;
+
+  @IsOptional()
+  @IsDateString()
+  startDate?: string;
+
+  @IsOptional()
+  @IsDateString()
+  endDate?: string;
+}

src/modules/notifications/dto/send-from-template.dto.ts

@@ -0,0 +1,18 @@
+import { IsEnum, IsNotEmpty, IsObject, IsString } from 'class-validator';
+import { Channel } from '../enums/channel.enum';
+
+export class SendFromTemplateDto {
+  @IsString()
+  @IsNotEmpty()
+  templateName: string;
+
+  @IsEnum(Channel)
+  channel: Channel;
+
+  @IsString()
+  @IsNotEmpty()
+  recipient: string;
+
+  @IsObject()
+  data: Record<string, any>;
+}

src/modules/notifications/dto/test-notification.dto.ts

@@ -0,0 +1,6 @@
+import { IsString } from 'class-validator';
+
+export class TestNotificationDto {
+  @IsString()
+  message: string;
+}

src/modules/notifications/dto/update-notification-preference.dto.ts

@@ -0,0 +1,10 @@
+import { IsBoolean, IsEnum } from 'class-validator';
+import { Channel } from '../enums/channel.enum';
+
+export class UpdateNotificationPreferenceDto {
+  @IsEnum(Channel)
+  channel: Channel;
+
+  @IsBoolean()
+  isEnabled: boolean;
+}

src/modules/notifications/entities/notification-preference.entity.ts

@@ -0,0 +1,32 @@
+import {
+  Column,
+  Entity,
+  PrimaryGeneratedColumn,
+  CreateDateColumn,
+  UpdateDateColumn,
+} from 'typeorm';
+import { Channel } from '../enums/channel.enum';
+
+@Entity('notification_preferences')
+export class NotificationPreference {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column()
+  userId: string;
+
+  @Column({
+    type: 'enum',
+    enum: Channel,
+  })
+  channel: Channel;
+
+  @Column({ default: true })
+  isEnabled: boolean;
+
+  @CreateDateColumn()
+  createdAt: Date;
+
+  @UpdateDateColumn()
+  updatedAt: Date;
+}

src/modules/notifications/entities/notification-template.entity.ts

@@ -0,0 +1,25 @@
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  PrimaryGeneratedColumn,
+  UpdateDateColumn,
+} from 'typeorm';
+
+@Entity('notification_templates')
+export class NotificationTemplate {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column({ unique: true })
+  name: string;
+
+  @Column('text')
+  template: string;
+
+  @CreateDateColumn()
+  createdAt: Date;
+
+  @UpdateDateColumn()
+  updatedAt: Date;
+}

src/modules/notifications/entities/notification.entity.ts

@@ -0,0 +1,35 @@
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  PrimaryGeneratedColumn,
+  UpdateDateColumn,
+} from 'typeorm';
+import { Channel } from '../enums/channel.enum';
+
+@Entity('notifications')
+export class Notification {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column()
+  recipient: string;
+
+  @Column({
+    type: 'enum',
+    enum: Channel,
+  })
+  channel: Channel;
+
+  @Column('text')
+  message: string;
+
+  @Column({ default: false })
+  isRead: boolean;
+
+  @CreateDateColumn()
+  createdAt: Date;
+
+  @UpdateDateColumn()
+  updatedAt: Date;
+}

src/modules/notifications/enums/channel.enum.ts

@@ -0,0 +1,5 @@
+export enum Channel {
+  WEB_SOCKET = 'web_socket',
+  EMAIL = 'email',
+  SMS = 'sms',
+}

src/modules/notifications/events/notification.events.ts

@@ -0,0 +1,3 @@
+export class NotificationEvents {
+  static readonly SEND_NOTIFICATION = 'notification.send';
+}

src/modules/notifications/listeners/notification.listener.ts

@@ -0,0 +1,15 @@
+import { Injectable } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { NotificationEvents } from '../events/notification.events';
+import { NotificationsService } from '../notifications.service';
+import { Notification } from '../notification.class';
+
+@Injectable()
+export class NotificationListener {
+  constructor(private readonly notificationsService: NotificationsService) {}
+
+  @OnEvent(NotificationEvents.SEND_NOTIFICATION)
+  handleSendNotificationEvent(notification: Notification) {
+    this.notificationsService.send(notification);
+  }
+}

src/modules/notifications/notification.class.ts

@@ -0,0 +1,13 @@
+import { Channel } from './enums/channel.enum';
+
+export class Notification {
+  channel: Channel;
+  recipient: string;
+  message: string;
+
+  constructor(channel: Channel, recipient: string, message: string) {
+    this.channel = channel;
+    this.recipient = recipient;
+    this.message = message;
+  }
+}