import Redis from 'ioredis';
import type { OnModuleDestroy } from '@nestjs/common';

import type { DependencyHealthDto } from '../../http-contracts/src/health.dto';
import type { RedisRuntimeConfig } from '../../config/src/runtime-config';

interface RedisPingPort {
  status: string;
  connect(): Promise<void>;
  ping(): Promise<string>;
  quit(): Promise<unknown>;
}

export class RedisHealthClient implements OnModuleDestroy {
  constructor(private readonly client: RedisPingPort) {}

  async check(): Promise<DependencyHealthDto> {
    if (
      this.client.status === 'wait' ||
      this.client.status === 'end' ||
      this.client.status === 'close'
    ) {
      await this.client.connect();
    }
    const response = await this.client.ping();
    if (response !== 'PONG') throw new Error('Redis PING 未返回 PONG');
    return { status: 'healthy', detail: 'PONG' };
  }

  async close(): Promise<void> {
    if (
      this.client.status !== 'wait' &&
      this.client.status !== 'end' &&
      this.client.status !== 'close'
    ) {
      await this.client.quit();
    }
  }

  async onModuleDestroy(): Promise<void> {
    await this.close();
  }
}

export function createRedisHealthClient(config: RedisRuntimeConfig): RedisHealthClient {
  const client = new Redis({
    host: config.host,
    port: config.port,
    username: config.username || undefined,
    password: config.password || undefined,
    db: config.database,
    tls: config.tls ? {} : undefined,
    lazyConnect: true,
    enableOfflineQueue: false,
    maxRetriesPerRequest: 0,
  });
  return new RedisHealthClient(client);
}