import { Connection, Driver, getConnection } from 'typeorm';
import { BaseConnectionOptions } from 'typeorm/connection/BaseConnectionOptions';
import { AppLogger } from '../logger/logger';

export class TypeOrmConnectionManagerService {

  private static readonly TAG: string = `${TypeOrmConnectionManagerService.constructor.name}`;
  static reconnectionPromise: Promise<any> = null;
  static isConnection: boolean = false;

  static async reconnectDriverToDb(connectionName: string, username: string, password: string): Promise<void> {
    TypeOrmConnectionManagerService.isConnection = true;
    TypeOrmConnectionManagerService.reconnectionPromise = new Promise(async (resolve, reject) => {
      try {
        AppLogger.debug('Try to reconnected driver to the DB', TypeOrmConnectionManagerService.TAG);
        const connectionPool: Connection = getConnection(connectionName);
        const driver: Driver = connectionPool.driver;
        await driver.disconnect();
        const oldDriverOptions: BaseConnectionOptions = driver.options;
        driver.options = {
          ...oldDriverOptions,
          username,
          password,
        } as BaseConnectionOptions;
        await driver.connect();
        AppLogger.debug('Driver reconnected successfully', TypeOrmConnectionManagerService.TAG);
        resolve(null);
      } catch (e) {
        AppLogger.error(e, TypeOrmConnectionManagerService.TAG);
        reject();
      } finally {
        TypeOrmConnectionManagerService.isConnection = false;
      }
    });
  }

}