private ExchangeRatingModel CalculateRating(string exchangeName)
{
var callStatistic = _statisticsCollector.GetCallStatistics().Where(es => es.ExchangeName == exchangeName).ToArray();
var exCount = _statisticsCollector.GetExceptionStatistics().Count(es => es.ExchangeName == exchangeName);
var exCoef = ExceptionWeight * callStatistic.Length / (exCount + callStatistic.Length);
var avgResponse = callStatistic.Select(cs => cs.Duration.Milliseconds)
.DefaultIfEmpty(_minResponseTime)
.Average(cs => cs);
var callCoef = SpeedWeight * _minResponseTime / avgResponse;
var rating = (exCoef + callCoef) * 10d;
return(new ExchangeRatingModel
{
ExchangeName = exchangeName,
Rating = rating
});
}