/*
 * @author wuweiru
 * @date 2020/11/05 15:03
 */

import Redis, { KeyType, ValueType } from 'ioredis';

type RedisOptions = {
  databaseIndex: number;
  host: string;
  port: number;
};

export class RedisClient {
  private readonly client: Redis.Redis;

  private readonly options: RedisOptions;

  private static instance?: RedisClient;

  constructor(options: RedisOptions) {
    this.options = options;
    this.client = new Redis({
      port: this.options.port,
      host: this.options.host,
      db: this.options.databaseIndex
    });
  }

  static getInstance() {
    RedisClient.instance ??= new RedisClient({
      port: parseInt(`${process.env.REDIS_PORT}`, 0),
      host: `${process.env.REDIS_HOST}`,
      databaseIndex: parseInt(`${process.env.REDIS_CACHE_DB}`, 0)
    });
    return RedisClient.instance;
  }

  async set(key: KeyType, value: ValueType): Promise<void> {
    await this.client.set(key, value);
  }

  async setExpire(params: {
    key: KeyType;
    value: ValueType;
    time: number;
  }): Promise<void> {
    await this.client.set(params.key, params.value, 'EX', params.time);
  }

  async get(key: KeyType): Promise<string | null> {
    const result = await this.client.get(key);
    return result;
  }

  async delete(key: KeyType): Promise<number> {
    const result = await this.client.del(key);
    return result;
  }

  async getList(keyList: KeyType[]): Promise<Array<string | null>> {
    const result = await this.client.mget(keyList);
    return result;
  }

  async setList(
    keyValueList: { key: string; value: string }[]
  ): Promise<[Error | null, any][]> {
    const setCommands = keyValueList.map(item => ['set', item.key, item.value]);
    const result = await this.client.multi(setCommands).exec();
    return result;
  }

  async setExpireList(
    keyValueList: { key: string; value: string; time: string }[]
  ): Promise<[Error | null, any][]> {
    const setCommands = keyValueList.map(item => [
      'set',
      item.key,
      item.value,
      'EX',
      item.time
    ]);
    const result = await this.client.multi(setCommands).exec();
    return result;
  }

  async deleteList(keyList: string[]): Promise<[Error | null, any][]> {
    const deleteCommands = keyList.map(item => ['del', item]);
    const result = await this.client.multi(deleteCommands).exec();
    return result;
  }
}