import * as NodeCache from 'node-cache';
import { Cache, ExpirationStrategy, MemoryStorage } from '@hokify/node-ts-cache';
import { IAuthentication } from './types/Authentication';
import PackageInterface from './interface';

const cacheStrategy = new ExpirationStrategy(new MemoryStorage());
const packageInterface = PackageInterface.get();

/**
 * this is just a simple abstraction to provide
 * an application layer for caching credentials
 */
export class Authentication implements IAuthentication {
	cache = new NodeCache();

	constructor(private authenticator: IAuthentication) {}

	@Cache(cacheStrategy, { ttl: packageInterface.cacheTTL })
	async authenticate(username: string, password: string): Promise<boolean> {
		const cacheKey = `usr:${username}|pwd:${password}`;
		const fromCache = this.cache.get(cacheKey) as undefined | boolean;
		if (fromCache !== undefined) {
			packageInterface.log(
				`Cached Auth Result for user ${username}`,
				fromCache ? 'SUCCESS' : 'Failure'
			);
			return fromCache;
		}

		const authResult = await this.authenticator.authenticate(username, password);
		packageInterface.log(`Auth Result for user ${username}`, authResult ? 'SUCCESS' : 'Failure');
		this.cache.set(
			cacheKey,
			authResult,
			authResult ? packageInterface.cacheSuccessTTL : packageInterface.cacheFailTTL
		); // cache for one day on success, otherwise just for 60 seconds

		return authResult;
	}
}