const Transaction = require('../../execution/transaction');

module.exports = class Redshift_Transaction extends Transaction {
  begin(conn) {
    const trxMode = [
      this.isolationLevel ? `ISOLATION LEVEL ${this.isolationLevel}` : '',
      this.readOnly ? 'READ ONLY' : '',
    ]
      .join(' ')
      .trim();

    if (trxMode.length === 0) {
      return this.query(conn, 'BEGIN;');
    }
    return this.query(conn, `BEGIN ${trxMode};`);
  }

  savepoint(conn) {
    this.trxClient.logger('Redshift does not support savepoints.');
    return Promise.resolve();
  }

  release(conn, value) {
    this.trxClient.logger('Redshift does not support savepoints.');
    return Promise.resolve();
  }

  rollbackTo(conn, error) {
    this.trxClient.logger('Redshift does not support savepoints.');
    return Promise.resolve();
  }
};