public async Task <IActionResult> Get([FromQuery] ExchangeRatesRequest request, CancellationToken cancellationToken)
{
try
{
if (request.currencyCodes.Values.Where(x => x != "EUR").Count() > 0)
{
return(BadRequest("Denominated currency has to be EUR!"));
}
DateTime endDate = request.endDate.GetValueOrDefault(request.startDate);
if (request.startDate > DateTime.Now || request.endDate > DateTime.Now ||
request.startDate > request.endDate)
{
throw new InvalidDateTime("Startdate has to be earlier or equal to enddate " +
"and earlier or equal to current date!");
}
var response = await _currencyRatesService.GetExchangeRatesAsync(request.currencyCodes,
request.startDate, endDate, cancellationToken);
return(Ok(response));
}
catch (InvalidDateTime ex)
{
return(NotFound(ex.Message));
}
catch (Exception ex)
{
_logger.LogError(ex.Message);
return(BadRequest(ex.Message));
}
}
public ExchangeRatesResponse GetExchangeRatesFor(ExchangeRatesRequest request)
{
var req = CreateRestRequest("/", Method.POST);
req.AddBody(request);
return(RestClient.Execute <ExchangeRatesResponse>(req).Data);
}
public async Task <ExchangeRatesResult> GetExchangeRates(ExchangeRatesRequest request)
{
ValidateCurrencies(request.BaseCurrency, request.TargetCurrency);
ValidateDates(request.Dates);
var tasks = request.Dates.Select(date => _connector.GetExchangeRate(date, request.BaseCurrency, request.TargetCurrency));
var exchangeRatesResponses = await Task.WhenAll(tasks);
var dateRateList = exchangeRatesResponses.Select(x => new { x.Date, Rate = x.Rates.First().Value })
.OrderBy(x => x.Rate)
.ToList();
var minRate = dateRateList.First();
var maxRate = dateRateList.Last();
var average = dateRateList.Average(x => x.Rate);
var minRateDate = new RateOnDate {
Rate = minRate.Rate, Date = minRate.Date
};
var maxRateDate = new RateOnDate {
Rate = maxRate.Rate, Date = maxRate.Date
};
return(new ExchangeRatesResult(minRateDate, maxRateDate, average));
}
public async Task <ExchangeRateResponse> GetExchangeRatesAsync(ExchangeRatesRequest request)
{
ValidateCurrencies(request.BaseCurrency, request.TargetCurrency);
var tasks = new List <Task <ExchangeRatesResult> >();
request.Dates.ForEach(date =>
{
tasks.Add(GetExchangeRatesAsync(date, request.BaseCurrency, request.TargetCurrency));
});
var result = await Task.WhenAll(tasks);
if (result == null || result.Length == 0)
{
throw new NotFoundException("There are no exchange rates for provided dates.");
}
var rateDates = result.Select(res => new DateRate(res.Date, res.Rates.Values.First())).OrderBy(r => r.Rate).ToList();
var minRate = rateDates.FirstOrDefault();
var maxRate = rateDates.LastOrDefault();
var average = rateDates.Average(rd => rd.Rate);
return(new ExchangeRateResponse(minRate, maxRate, average));
}
public async Task <ExchangeRatesResponse> GetRates(ExchangeRatesRequest request)
{
if (request is null)
{
throw new ArgumentNullException(nameof(request));
}
if (request.Date < _MinDate)
{
throw new ArgumentOutOfRangeException($"{nameof(request.Date)} must be greater than {_MinDate} but was {request.Date}");
}
var uriBuilder = new UriBuilder(_EcbBaseUri)
{
Path = $"{request.Date.ToString("yyyy-MM-dd")}",
Query = $"base={request.BaseCurrency}"
};
var apiResponse = await _HttpClient.GetAsync(uriBuilder.Uri).ConfigureAwait(false);
var apiContent = await apiResponse.Content.ReadAsStringAsync();
if (!apiResponse.IsSuccessStatusCode)
{
var error = _ResponseHandler.ParseError(apiContent);
throw new HttpRequestException(
$"{nameof(apiResponse.StatusCode)}: {apiResponse.StatusCode}. {error}");
}
var exchangeRates = _ResponseHandler.ParseResponse(apiContent);
return(exchangeRates);
}
public IEnumerable <ExchangeRate> Fetch(ExchangeRatesRequest request)
{
ConfigurationContainer.EnsureAppSettingExists("OpenExchangeRates.ApiKey");
var exchangeRateData = Client.Get();
return(exchangeRateData.Rates.Select(r => new ExchangeRate(r.Key, r.Value, exchangeRateData.Base, DateTime.UtcNow)));
}
private static HttpWebRequest CreateRequest(ExchangeRatesRequest request)
{
var apiUri = string.Format(ApiUriFormat, request.BaseCurrencyCode, request.CurrencyCode);
var httpRequest = (HttpWebRequest)WebRequest.Create(apiUri);
httpRequest.Method = "GET";
return(httpRequest);
}
public IEnumerable <ExchangeRate> GetLatest(ExchangeRatesRequest request)
{
var dataFetchingStrategy = _configuration.DataFetchingStrategy;
if (_strategies.Keys.All(x => !string.Equals(x, dataFetchingStrategy, StringComparison.InvariantCultureIgnoreCase)))
{
const string errMsgFormat = "Data fetching strategy not found: {0}.";
var errMsg = string.Format(errMsgFormat, dataFetchingStrategy);
throw new ConfigurationMissingException(errMsg);
}
return(_strategies[dataFetchingStrategy].Fetch(request));
}
public static Task <ExchangeRatesResponse> ExchangeRates(bool isshort = false, bool accepted = false)
{
var request = new ExchangeRatesRequest
{
Short = isshort ? 1 : 0,
Accepted = accepted ? 1 : 0
};
var req = new HttpUrlRequest(request);
return(process <ExchangeRatesResponse>(req));
}
public IEnumerable <ExchangeRate> Fetch(ExchangeRatesRequest request)
{
var httpRequest = CreateRequest(request);
var httpResponse = ExecuteHttpRequest(httpRequest);
var rate = ScrapeExchangeRate(httpResponse);
var exchangeRate = new ExchangeRate(request.CurrencyCode, rate, request.BaseCurrencyCode, DateTime.UtcNow);
return(new List <ExchangeRate> {
exchangeRate
});
}
public void WhenDefaultRequestIsRetrieved_ThenItIsTheDefaultOfTheInjectedAccess()
{
var expectedRequest = new ExchangeRatesRequest("BASEBASE", DateTime.UtcNow);
var injectedAccess = new Mock <IExchangeRatesAccess>();
injectedAccess.SetupGet(m => m.DefaultRequest).Returns(expectedRequest);
var cachingAccess = new CachingExchangeRatesAccess(
new MemoryCache("name"),
injectedAccess.Object);
var defaultRequest = cachingAccess.DefaultRequest;
defaultRequest.Should().BeEquivalentTo(expectedRequest);
}
public async Task WhenCacheDoesNotContainItem_ThenAccessIsInvoked()
{
var expectedRequest = new ExchangeRatesRequest("BASE", DateTime.UtcNow);
var accessMock = new Mock <IExchangeRatesAccess>();
ExchangeRatesRequest actualRequest = null;
accessMock.Setup(m => m.GetRates(It.IsAny <ExchangeRatesRequest>()))
.Callback <ExchangeRatesRequest>(request => actualRequest = request)
.ReturnsAsync(new ExchangeRatesResponse(
expectedRequest.BaseCurrency,
expectedRequest.Date,
new Dictionary <string, decimal>()));
var cachingAccess = new CachingExchangeRatesAccess(new MemoryCache("rates"), accessMock.Object);
await cachingAccess.GetRates(expectedRequest);
actualRequest.Should().BeEquivalentTo(expectedRequest);
}
public async Task WhenLatestRatesAreRetrieved_ThenAccessDefaultRequestIsUsed()
{
var expectedRequest = new ExchangeRatesRequest("DEFAULTBase", DateTime.MaxValue);
var accessMock = new Mock <IExchangeRatesAccess>();
accessMock.SetupGet(m => m.DefaultRequest).Returns(expectedRequest);
ExchangeRatesRequest actualRequest = null;
accessMock.Setup(m => m.GetRates(It.IsAny <ExchangeRatesRequest>()))
.Callback <ExchangeRatesRequest>(request => actualRequest = request)
.ReturnsAsync(new ExchangeRatesResponse(
"blah",
DateTime.UtcNow,
new Dictionary <string, decimal>()));
var manager = new ExchangeRatesManager(accessMock.Object, Mock.Of <IExchangeRatesEngine>());
await manager.GetLatestRates();
actualRequest.Should().Be(expectedRequest);
}
public ExchangeRate Get(ExchangeRatesRequest request)
{
var cacheKey = GetCacheKey(request);
return(MemCache.Get(cacheKey) as ExchangeRate);
}
private static string GetCacheKey(ExchangeRatesRequest request)
{
return(GetCacheKey(request.BaseCurrencyCode, request.CurrencyCode));
}
public ExchangeRatesResponse GetExchangeRatesFor(ExchangeRatesRequest request)
{
Contract.Ensures(Contract.Result <ExchangeRatesResponse>() != null);
// Check if there is a valid cached response to this request.
var cached = _cache.Get(request);
if (cached != null)
{
// If yes, return that result
return(new ExchangeRatesResponse(cached));
}
//TODO: We're making the assumption here that our API fetches USD as the default base rate.
// It's kinda bad, but I can't think of a better solution right now.
var cachedBaseRate = _cache.Get(new ExchangeRatesRequest
{
BaseCurrencyCode = "USD",
CurrencyCode = request.BaseCurrencyCode
});
var cachedCurrRate = _cache.Get(new ExchangeRatesRequest
{
BaseCurrencyCode = "USD",
CurrencyCode = request.CurrencyCode
});
if (cachedBaseRate != null && cachedCurrRate != null)
{
var rate = cachedCurrRate.ConversionRate / cachedBaseRate.ConversionRate;
var exRate = new ExchangeRate(request.CurrencyCode, rate, request.BaseCurrencyCode, DateTime.UtcNow);
_cache.Add(exRate);
_historicalStorage.Store(new List <ExchangeRate> {
exRate
});
return(new ExchangeRatesResponse(exRate));
}
// If no, check when we last pulled from the API.
var lastFetch = _cache.GetLastFetch();
var cacheExpiryTime = DateTime.UtcNow.AddMinutes(_config.CacheExpiryTime);
// It isn't in the cache, and we've made a request recently, so no dice.
if (lastFetch.HasValue && lastFetch.Value > cacheExpiryTime)
{
return(new ExchangeRatesResponse(null));
}
// We've not made a request recently, so go get 'em.
var fetchedRates = _fetch.GetLatest(request);
// If there was data, store this data in the historical storage & cache.
var latestRates = fetchedRates as IList <ExchangeRate> ?? fetchedRates.ToList();
_cache.Add(latestRates);
_historicalStorage.Store(latestRates);
// Save when we last did a fetch, so we don't spam an API somewhere.
_cache.AddLastFetch(DateTime.UtcNow);
// If we have the rate we are looking for, return it. If not, we end up with an empty result.
var requestedRate = latestRates.SingleOrDefault(x => x.BaseCurrencyCode == request.BaseCurrencyCode &&
x.CurrencyCode == request.CurrencyCode);
// If it doesn't exist, but we can figure it out, figure it out and cache that too.
if (requestedRate == null &&
latestRates.Any(x => x.CurrencyCode == request.BaseCurrencyCode) &&
latestRates.Any(x => x.CurrencyCode == request.CurrencyCode))
{
var baseRate = latestRates.Single(x => x.CurrencyCode == request.BaseCurrencyCode);
var currRate = latestRates.Single(x => x.CurrencyCode == request.CurrencyCode);
var rate = currRate.ConversionRate / baseRate.ConversionRate;
var exRate = new ExchangeRate(request.CurrencyCode, rate, request.BaseCurrencyCode, DateTime.UtcNow);
_cache.Add(exRate);
_historicalStorage.Store(new List <ExchangeRate> {
exRate
});
requestedRate = exRate;
}
return(new ExchangeRatesResponse(requestedRate));
}
