/**
 * @author Martin Karkowski
 * @email m.karkowski@zema.de
 * @create date 2020-08-25 16:18:36
 * @modify date 2020-11-10 09:39:14
 * @desc [description]
 */

import { Logger } from 'winston';
import { exportFunctionToDispatcher } from '../../lib/decorators/dispatcherDecorators';
import { getNopeLogger } from '../../lib/logger/getLogger';

export function now() {
  const _hr = process.hrtime();
  return _hr[0] * 1000 + _hr[1] / 1000 / 1000;
}

/**
 * Function to Generate a Benchmark-Function
 * @param displayQpsAfter 
 * @param textToDisplay 
 */
export const generateBenchmarkFunction = exportFunctionToDispatcher((displayQpsAfter: number, textToDisplay: string, logger?: Logger): () => void => {
  let _counter = 0;
  let _startTime = now();

  const max = displayQpsAfter;
  const _logger = logger !== undefined ? logger : getNopeLogger('algorithmen.benchmark')


  return () => {
    if (_counter === 1) {
      _startTime = now();
    } else if (_counter === max) {

      const _endTime = now();
      const _timeDifference = _endTime - _startTime;
      const _qps = max / (_timeDifference / 1000);
      
      // Show the QPS:
      _logger.info(textToDisplay + ' QPS: ' + (Math.round(_qps * 100) / 100).toString() + ' [Calls/Sec]');

      // Reset the Counter
      _counter = 0;
    }
    _counter++;
  };
}, {
  id: 'generateBenchmarkFunction'
});