import { RedisCache } from './redis-cache';
import type { CacheOptions, CacheProvider } from './types';

// Cache instances registry to prevent multiple instances with same prefix
const cacheInstances = new Map<string, CacheProvider>();

/**
 * Create a Redis cache instance
 */
export function createCache(options: CacheOptions): CacheProvider {
  const defaultOptions: CacheOptions = {
    keyPrefix: 'cache:',
    ttl: 3600, // 1 hour default
    enableMetrics: true,
    shared: true, // Default to shared connections
    ...options,
  };

  // For shared connections, reuse cache instances with the same key prefix
  if (defaultOptions.shared) {
    const cacheKey = `${defaultOptions.keyPrefix}-${defaultOptions.ttl}`;

    if (cacheInstances.has(cacheKey)) {
      const cachedInstance = cacheInstances.get(cacheKey);
      if (!cachedInstance) {
        throw new Error(`Expected cache instance ${cacheKey} to exist`);
      }
      return cachedInstance;
    }

    const cache = new RedisCache(defaultOptions);
    cacheInstances.set(cacheKey, cache);
    return cache;
  }

  // For non-shared connections, always create new instances
  return new RedisCache(defaultOptions);
}

// Export only what's actually used
export type { CacheProvider, CacheStats } from './types';
export { NamespacedCache } from './namespaced-cache';
export { createNamespacedCache } from './cache-factory';