/**
 * Build the TypeORM `cache:` config object from an explicit Redis config.
 *
 * Consumers own the env-var reading (so the wiring is visible in their config
 * tree) and pass us a plain object. We translate it into the TypeORM-native
 * shape, handling the standalone-vs-cluster fork plus the ElastiCache
 * cluster-mode safety defaults (enableOfflineQueue:false, checkServerIdentity
 * bypass for TLS — see project_elasticache_cluster_ioredis_tls).
 */
export type CacheMode = 'standalone' | 'cluster';
/**
 * `host` is `string | undefined` so consumers can populate this directly from
 * env vars without a guarding ternary — when REDIS_HOST is unset in dev/test,
 * `buildCache()` returns undefined and no cache is installed.
 */
export interface RedisConfig {
    host: string | undefined;
    port: number;
    tls: boolean;
    mode: CacheMode;
}
/**
 * Matches the shape of TypeORM's `DataSourceOptions.cache`. Fields are typed
 * loose (`any` / `unknown`) deliberately — TypeORM's own type is loose, and
 * tightening here would force `as any` casts at every consumer's callsite when
 * the result is spread into a `DeepPartial<DataSourceOptions>` config tree.
 */
export interface BuiltCacheConfig {
    type?: 'ioredis';
    options?: any;
    client?: unknown;
    ignoreErrors?: boolean;
}
/**
 * Returns undefined when `config` is missing or has no host. Consumers can write:
 *
 *   redis: {
 *     host: process.env.REDIS_HOST,            // string | undefined
 *     port: Number(process.env.REDIS_PORT ?? '6379'),
 *     tls:  process.env.REDIS_TLS === 'true',
 *     mode: (process.env.REDIS_MODE ?? 'standalone') as Cache.CacheMode,
 *   }
 *   cache: Cache.buildCache(config.redis)
 *
 * No ternary, no cast. In dev/test where REDIS_HOST is unset the cache is
 * simply not installed.
 */
export declare function buildCache(config: RedisConfig | undefined): BuiltCacheConfig | undefined;