Centralize Redis Client Usage and Add Caching in LeaderboardService

package.json

@@ -23,7 +23,7 @@
   "dependencies": {
     "@nestjs/axios": "^4.0.0",
     "@nestjs/common": "^11.0.12",
-    "@nestjs/config": "^4.0.1",
+    "@nestjs/config": "^4.0.2",
     "@nestjs/core": "^11.0.12",
     "@nestjs/event-emitter": "^3.0.1",
     "@nestjs/jwt": "^11.0.0",
@@ -39,6 +39,7 @@
     "class-validator": "^0.14.1",
     "fast-csv": "^5.0.2",
     "google-auth-library": "^9.15.1",
+    "ioredis": "^5.6.1",
     "oauth2client": "^1.0.0",
     "passport": "^0.7.0",
     "passport-google-oauth20": "^2.0.0",

src/app.module.ts

@@ -3,7 +3,7 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { ConfigModule, ConfigService } from '@nestjs/config';
 import { EventEmitterModule } from '@nestjs/event-emitter';
-
+import { RedisModule } from './redis/redis.module';
 import { AuthModule } from './auth/auth.module';
 import appConfig from './config/app.config';
 import databaseConfig from './config/database.config';
@@ -18,7 +18,7 @@ import { PuzzleModule } from './puzzle/puzzle.module';
 import { AppService } from './app.service';
 import { AppController } from './app.controller';
 import { GamificationModule } from './gamification/gamification.module';
-import { AchievementModule } from './achievement/achievement.module';
+import { AchievementModule } from './achievement/achievement.module';
 
 // const ENV = process.env.NODE_ENV;
 // console.log('NODE_ENV:', process.env.NODE_ENV);
@@ -50,13 +50,14 @@ import { AchievementModule } from './achievement/achievement.module';
     UsersModule,
     LeaderboardModule,
     CommonModule,
+    RedisModule,
     BlockchainModule,
     BadgeModule,
     TimeFilterModule,
     IQAssessmentModule,
     PuzzleModule,
     GamificationModule,
-    AchievementModule
+    AchievementModule,
   ],
   controllers: [AppController],
   providers: [AppService],

src/leaderboard/leaderboard.service.ts

@@ -1,4 +1,7 @@
-import { Injectable } from '@nestjs/common';
+/* eslint-disable prettier/prettier */
+import { Inject, Injectable } from '@nestjs/common';
+import Redis from 'ioredis';
+import { REDIS_CLIENT } from 'src/redis/redis.constants';
 import {
   LeaderboardQueryDto,
   SortBy,
@@ -15,10 +18,30 @@ export class LeaderboardService {
     private readonly getLeaderboardService: GetLeaderboardProvider,
     private readonly updatePlayerStatsService: UpdatePlayerStatsProvider,
     private readonly getUserRankService: GetUserRankProvider,
+    @Inject(REDIS_CLIENT) private readonly redis: Redis,
   ) {}
 
-  getLeaderboard(query: LeaderboardQueryDto) {
-    return this.getLeaderboardService.execute(query);
+  async getLeaderboard(query: LeaderboardQueryDto): Promise<any[]> {
+    const cacheKey = `leaderboard:${query.sort}:${query.period}:${query.limit}:${query.offset}`;
+
+    try {
+      const cached = await this.redis.get(cacheKey);
+      if (cached) {
+        return JSON.parse(cached) as any[];
+      }
+    } catch (err) {
+      console.warn('Redis read error:', err);
+    }
+
+    const result = await this.getLeaderboardService.execute(query);
+
+    try {
+      await this.redis.set(cacheKey, JSON.stringify(result), 'EX', 60);
+    } catch (err) {
+      console.warn('Redis write error:', err);
+    }
+
+    return result;
   }
 
   updatePlayerStats(userId: string, dto: UpdateLeaderboardDto) {
@@ -37,4 +60,4 @@ export class LeaderboardService {
       offset: 0,
     });
   }
-}
+}

src/redis/redis.constants.ts

@@ -0,0 +1,2 @@
+/* eslint-disable prettier/prettier */
+export const REDIS_CLIENT = 'REDIS_CLIENT';

src/redis/redis.module.ts

@@ -0,0 +1,23 @@
+/* eslint-disable prettier/prettier */
+import { Global, Module, OnModuleDestroy, Inject } from '@nestjs/common';
+import { ConfigModule } from '@nestjs/config';
+import { redisProvider } from './redis.provider';
+import { REDIS_CLIENT } from './redis.constants';
+import Redis from 'ioredis';
+
+@Global()
+@Module({
+  imports: [ConfigModule],
+  providers: [redisProvider],
+  exports: [redisProvider],
+})
+export class RedisModule implements OnModuleDestroy {
+  constructor(@Inject(REDIS_CLIENT) private readonly redis: Redis) {}
+
+  async onModuleDestroy() {
+    if (this.redis) {
+      await this.redis.quit();
+      console.log('🧹 Redis disconnected gracefully');
+    }
+  }
+}

src/redis/redis.provider.ts

@@ -0,0 +1,23 @@
+/* eslint-disable prettier/prettier */
+import { Provider } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+import Redis from 'ioredis';
+import { REDIS_CLIENT } from './redis.constants';
+
+export const redisProvider: Provider = {
+  provide: REDIS_CLIENT,
+  useFactory: (configService: ConfigService) => {
+    const redisUrl = configService.get<string>('REDIS_URL');
+    if (!redisUrl) {
+      throw new Error('REDIS_URL not defined in environment variables');
+    }
+
+    const client = new Redis(redisUrl);
+
+    client.on('connect', () => console.log('Redis connected'));
+    client.on('error', (err) => console.error('Redis error:', err));
+
+    return client;
+  },
+  inject: [ConfigService],
+};