private ExchangeRateResult ConvertToExchangeResult(List <DataAccess.Models.CachedExchangeRate> existingRates)
{
var rates = new ExchangeRateResult();
var firstExistingRate = existingRates.First();
rates.Base = firstExistingRate.CurrencyCodeFrom;
rates.Date = firstExistingRate.RateDate;
rates.Rates = new Dictionary <string, decimal>();
foreach (var rate in existingRates)
{
rates.Rates.Add(rate.CurrencyCodeTo, rate.Rate);
}
return(rates);
}
private void SaveRates(ExchangeRateResult rates)
{
var cachedRates = new List <DataAccess.Models.CachedExchangeRate>();
foreach (var rate in rates.Rates)
{
cachedRates.Add(new DataAccess.Models.CachedExchangeRate
{
RateDate = rates.Date,
CurrencyCodeFrom = rates.Base,
CurrencyCodeTo = rate.Key,
Rate = rate.Value
});
}
_cachedExchangeRateRepository.SaveRates(cachedRates);
}
/// <summary>
/// Get rate to convert the amount to transfer to the account's currency
/// </summary>
/// <param name="rateDate">Date of the rate</param>
/// <param name="fromCurrency">Currency of the destination</param>
/// <param name="toCurrency">Currency of the user's account</param>
/// <returns></returns>
public async Task <CachedExchangeRate> GetExchangeRate(DateTime rateDate, string fromCurrency, string toCurrency)
{
ExchangeRateResult exchangeRateResult = new ExchangeRateResult();
if (fromCurrency.Equals(toCurrency, StringComparison.InvariantCultureIgnoreCase))
{
return(new CachedExchangeRate
{
RateDate = DateTime.Today,
CurrencyCodeFrom = fromCurrency,
CurrencyCodeTo = toCurrency,
Rate = 1
});
}
if (rateDate < DateTime.Today.AddDays(-2))
{
return(null);
}
var existingRates = _cachedExchangeRateRepository.GetRate(rateDate, fromCurrency, toCurrency);
if (existingRates.Count == 0)
{
if (DateTime.Today == rateDate)
{
exchangeRateResult = await _wrapperExchangeRateAPI.GetLatestRates();
if (exchangeRateResult == null)
{
return(await GetExchangeRate(rateDate.AddDays(-1), fromCurrency, toCurrency));
}
SaveRates(exchangeRateResult);
}
else
{
return(await GetExchangeRate(rateDate.AddDays(-1), fromCurrency, toCurrency));
}
}
else
{
exchangeRateResult = ConvertToExchangeResult(existingRates);
}
return(ExtractRate(fromCurrency, toCurrency, exchangeRateResult));
}
public async Task <ExchangeRateResult> GetLatestRates()
{
ExchangeRateResult rateResponse = null;
try
{
var client = _clientFactory.CreateClient("exchangerate");
var response = await client.GetAsync("/latest");
if (response.IsSuccessStatusCode)
{
var responseStream = await response.Content.ReadAsStringAsync();
rateResponse = JsonConvert.DeserializeObject <ExchangeRateResult>(responseStream);
}
}
catch (System.Exception ex)
{
_logger.LogError("Error getting rates from the Exchange Rate API", ex);
}
return(rateResponse);
}
private CachedExchangeRate ExtractRate(string fromCurrency, string toCurrency, ExchangeRateResult rates)
{
fromCurrency = fromCurrency.ToUpper();
toCurrency = toCurrency.ToUpper();
var result = new CachedExchangeRate
{
CurrencyCodeFrom = fromCurrency,
CurrencyCodeTo = toCurrency,
RateDate = rates.Date
};
if (toCurrency == rates.Base)
{
if (rates.Rates.ContainsKey(fromCurrency))
{
result.Rate = rates.Rates[fromCurrency];
result.IsBaseCurrencySameAsTo = true;
}
else
{
return(null);
}
}
else
{
if (rates.Rates.ContainsKey(fromCurrency) && rates.Rates.ContainsKey(toCurrency))
{
var toRate = rates.Rates[toCurrency];
var fromRate = rates.Rates[fromCurrency];
result.Rate = toRate / fromRate;
}
else if (rates.Rates.ContainsKey(toCurrency))
{
result.Rate = rates.Rates[toCurrency];
}
else
{
return(null);
}
}
return(result);
}
