private bool IsValidLogicalConsistency(IEnumerable <string> lines)
{
var firstLine = new LineConversionRequest(lines.First());
var secondLine = new LineExchangeRateCount(lines.Skip(1).First());
var otherLines = lines.Skip(2).Select(l => new LineExchangeRate(l));
var inputFile = new InputFile(firstLine, secondLine, otherLines);
/* Check if declared count of 'exchange rate' lines
* match real count of theses lines */
var declaredCountMatchRealCount = inputFile.ExchangeRateCount.Count == inputFile.ExchangeRates.Count();
/* Check if any exchange rate doesn't contain
* the same value for source and target currency */
var noEchangeRateContainingSameCurrency = !inputFile.ExchangeRates.Any(er => er.SourceCurrency == er.TargetCurrency);
/* check that the 'source currency' of the 'conversion request'
* exists at least once in the exchanges rates */
var existAtLeastOneSourceCurrencyIntoExchangeRates =
inputFile.ExchangeRates.Any(er => er.SourceCurrency == inputFile.ConversionRequest.SourceCurrency) ||
inputFile.ExchangeRates.Any(er => er.TargetCurrency == inputFile.ConversionRequest.SourceCurrency);
/* check that the 'target currency' of the 'conversion request'
* exists at least once in the exchanges rates */
var existAtLeastOneTargetCurrencyIntoExchangeRates =
inputFile.ExchangeRates.Any(er => er.SourceCurrency == inputFile.ConversionRequest.TargetCurrency) ||
inputFile.ExchangeRates.Any(er => er.TargetCurrency == inputFile.ConversionRequest.TargetCurrency);
return(declaredCountMatchRealCount &&
noEchangeRateContainingSameCurrency &&
existAtLeastOneSourceCurrencyIntoExchangeRates &&
existAtLeastOneTargetCurrencyIntoExchangeRates);
}
private ConversionRequest ToConversionRequest(IEnumerable <string> lines)
{
var crl = new LineConversionRequest(lines.First());
return(new ConversionRequest(crl.SourceCurrency, crl.TargetCurrency, crl.Amount));
}
