/**
 * @file @name KeyValueCache THIS EXPORTS A CLASS, NOT AN INSTANCE
 *
 *
 * @see https://github.com/apollographql/apollo-server/blob/master/packages/apollo-datasource-rest/src/__tests__/RESTDataSource.test.ts
 * @see https://github.com/apollographql/apollo-server/blob/master/packages/apollo-datasource-rest/src/HTTPCache.ts
 *
 * @tutorial https://www.apollographql.com/docs/engine/proxy/guides.html#caching
 */
export interface KeyValueCacheType {
  get(key: string): Promise<string | undefined>;
  set(key: string, value: string, options?: { ttl?: number }): Promise<void>;
}
export class KeyValueCache implements KeyValueCacheType {
  store: Map<string, string> = new Map()

  async get(key: string): Promise<string | undefined> {
    const value = this.store.get(key)

    console.log('[cache] get: ' + key)

    // @todo could get size of this instead
    // console.debug('[cache] get->value: ', value)

    return Promise.resolve(value)
  }
  async set(
    key: string,
    value: string,
    options: { ttl?: number } = {}
  ): Promise<void> {
    console.log('[cache] set: ' + key)
    this.store.set(key, value)
    return Promise.resolve()
  }
}