# RedisService

**Kind:** Service

**Source:** [`atloria-monorepo/libs/database/src/lib/redis.service.ts`](https://github.com/sherkety/atloria/blob/main/atloria-monorepo/libs/database/src/lib/redis.service.ts#L7)

`RedisService` is a NestJS service that manages the application’s Redis connection lifecycle and provides a small abstraction for common cache operations. It exposes availability checks, raw string operations, and JSON serialization helpers so consumers can use Redis without handling connection details directly.

## Methods

| Method | Signature | Returns |
|---|---|---|
| `onModuleInit` | `onModuleInit()` | `unknown` |
| `onModuleDestroy` | `onModuleDestroy()` | `unknown` |
| `getClient` | `getClient()` | `Redis | null` |
| `isAvailable` | `isAvailable()` | `boolean` |
| `get` | `get(key: string)` | `Promise<string | null>` |
| `set` | `set(key: string, value: string, ttlSeconds: number)` | `Promise<void>` |
| `del` | `del(key: string)` | `Promise<void>` |
| `exists` | `exists(key: string)` | `Promise<boolean>` |
| `setJson` | `setJson(key: string, value: T, ttlSeconds: number)` | `Promise<void>` |
| `getJson` | `getJson(key: string)` | `Promise<T | null>` |
| `cached` | `cached(key: string, fetchFn: () => Promise<T>, ttlSeconds: unknown)` | `Promise<T>` |
| `invalidatePattern` | `invalidatePattern(pattern: string)` | `Promise<void>` |

## Dependencies

- `ConfigService`

## Where it refuses work

- `RedisService` stops the work with an early return when `!this.isConnected || !this.client`, in 5 places.
- `RedisService` stops the work with an early return when `!this.isConnected`.
- `RedisService` stops the work with an early return when `cached`.

## When something fails

- `RedisService` handles failure in 8 places: it discards it silently in 4, logs it and continues in 2, and turns it into a return value in 2.

## Diagram

```mermaid
sequenceDiagram
    participant App as NestJS Application
    participant Service as RedisService
    participant Redis as Redis Server

    App->>Service: onModuleInit()
    Service->>Redis: Connect client
    Redis-->>Service: Connection ready

    App->>Service: setJson(key, value)
    Service->>Redis: SET key JSON.stringify(value)
    Redis-->>Service: OK

    App->>Service: getJson<T>(key)
    Service->>Redis: GET key
    Redis-->>Service: Serialized value
    Service-->>App: Parsed T | null

    App->>Service: onModuleDestroy()
    Service->>Redis: Disconnect client
```

## Usage

```ts
import { Injectable } from '@nestjs/common';
import { RedisService } from '@atloria/database';

interface CachedUser {
  id: string;
  email: string;
  displayName: string;
}

@Injectable()
export class UserCacheService {
  constructor(private readonly redisService: RedisService) {}

  async cacheUser(user: CachedUser): Promise<void> {
    if (!this.redisService.isAvailable()) {
      return;
    }

    await this.redisService.setJson(`user:${user.id}`, user);
  }

  async getCachedUser(userId: string): Promise<CachedUser | null> {
    return this.redisService.getJson<CachedUser>(`user:${userId}`);
  }

  async invalidateUser(userId: string): Promise<void> {
    await this.redisService.del(`user:${userId}`);
  }

  async hasCachedUser(userId: string): Promise<boolean> {
    return this.redisService.exists(`user:${userId}`);
  }
}
```

## AI Coding Instructions

- Inject `RedisService` through NestJS dependency injection rather than creating Redis clients directly in feature services.
- Check `isAvailable()` when Redis is optional or when cache failures should not block primary application behavior.
- Use `setJson()` and `getJson<T>()` for structured values; use `set()` and `get()` only for plain string payloads.
- Use consistent, namespaced cache keys such as `user:${id}` or `feature:resource:${id}` to avoid collisions.
- Do not manually connect or disconnect the Redis client; lifecycle handling belongs to `onModuleInit()` and `onModuleDestroy()`.

## Relationships

- DEPENDS_ON → `configservice`

## Referenced By

- `AppService` (DEPENDS_ON)
- `AuthService` (DEPENDS_ON)
- `SamlService` (DEPENDS_ON)
- `SsoCodeService` (DEPENDS_ON)
- `CollaborationMetricsService` (DEPENDS_ON)
- `CollaborationService` (DEPENDS_ON)
- `DocsAccessService` (DEPENDS_ON)
- `ReaderMagicLinkService` (DEPENDS_ON)
- `ToursHealingService` (DEPENDS_ON)
- `ToursService` (DEPENDS_ON)
- `BatchScreenshotService` (DEPENDS_ON)
- `FlowReplayService` (DEPENDS_ON)
- `DatabaseModule` (MODULE_PROVIDES)
- `DatabaseModule` (MODULE_EXPORTS)