public void TestMultipleLoanCalculation()
{
MarketRate rate = new MarketRate {
AmountAvailable = 1000, Lender = "Alice", Rate = (float)0.07
};
MarketRate rate1 = new MarketRate {
AmountAvailable = 1000, Lender = "Bob", Rate = (float)0.07
};
MarketRate rate2 = new MarketRate {
AmountAvailable = 1000, Lender = "Charlie", Rate = (float)0.07
};
List <MarketRate> rates = new List <MarketRate>();
rates.Add(rate);
rates.Add(rate1);
rates.Add(rate2);
LoanAggregator agg = new LoanAggregator();
agg.FindLoans(rates, 3000, 36);
Assert.AreEqual(true, agg.IsLoanPossible);
Assert.AreEqual(3000, agg.LoanAmount, "LoanAmount check failed");
Assert.AreEqual("92.63", agg.Monthly, "MonthlyPayments check failed");
Assert.AreEqual("3,334.70", agg.Total, "TotalRepayment check failed");
Assert.AreEqual((float)0.07, agg.Rate, "Rate check failed");
}
public void TestParse()
{
List <MarketRate> rates;
MarketRateCsvParser parser = new MarketRateCsvParser();
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.WriteLine("Lender,Rate,Available");
writer.WriteLine("Alice,0.05,1000");
writer.WriteLine("Bob,0.01,500");
writer.Flush();
stream.Position = 0;
rates = parser.Parse(new StreamReader(stream));
Assert.AreEqual(rates.Count, 2);
MarketRate rate = rates[0];
Assert.AreEqual("Alice", rate.Lender, "Lender check failed");
Assert.AreEqual((float)0.05, rate.Rate, "Rate check failed");
Assert.AreEqual(1000, rate.AmountAvailable, "Amount check failed");
rate = rates[1];
Assert.AreEqual("Bob", rate.Lender, "Lender check failed");
Assert.AreEqual((float)0.01, rate.Rate, "Rate check failed");
Assert.AreEqual(500, rate.AmountAvailable, "Amount check failed");
}
public void TestMixedRateChosen()
{
MarketRate rate = new MarketRate {
AmountAvailable = 100, Lender = "Bob", Rate = (float)0.07
};
List <MarketRate> rates = new List <MarketRate>();
rates.Add(rate);
LoanAggregator agg = new LoanAggregator();
agg.FindLoans(rates, 50, 36);
Assert.AreEqual(true, agg.IsLoanPossible);
}
public void TestInsufficientLoans()
{
MarketRate rate = new MarketRate {
AmountAvailable = 100, Lender = "Bob", Rate = (float)0.07
};
List <MarketRate> rates = new List <MarketRate>();
rates.Add(rate);
LoanAggregator agg = new LoanAggregator();
agg.FindLoans(rates, 1000, 36);
Assert.AreEqual(false, agg.IsLoanPossible);
}
public static async System.Threading.Tasks.Task <MarketRate> GetHistoryRateAsync(DateTime thisDate)
{
string apiUrl = " http://data.fixer.io/api/" + thisDate.ToString("yyyy-MM-dd") + "?access_key=" + ApiController.Key + "&base=EUR";
using (var client = new HttpClient())
{
var uri = new Uri(apiUrl);
var response = client.GetAsync(uri).Result;
string textResult = await response.Content.ReadAsStringAsync();
JavaScriptSerializer j = new JavaScriptSerializer();
MarketRate marketRate = (MarketRate)j.Deserialize(textResult, typeof(MarketRate));
return(marketRate);
}
}
public static async System.Threading.Tasks.Task SetRates()
{
string apiUrl = "http://data.fixer.io/api/latest?access_key=" + Key + "&base=eur";
using (var client = new HttpClient())
{
var uri = new Uri(apiUrl);
var response = await client.GetAsync(uri);
string textResult = await response.Content.ReadAsStringAsync();
JavaScriptSerializer j = new JavaScriptSerializer();
MarketRate a = (MarketRate)j.Deserialize(textResult, typeof(MarketRate));
rates = a.rates;
}
}
public void TestMultipleLoadsPossible()
{
MarketRate rate1 = new MarketRate {
AmountAvailable = 100, Lender = "Bob", Rate = (float)0.07
};
MarketRate rate2 = new MarketRate {
AmountAvailable = 100, Lender = "Alice", Rate = (float)0.06
};
List <MarketRate> rates = new List <MarketRate>();
rates.Add(rate1);
rates.Add(rate2);
LoanAggregator agg = new LoanAggregator();
agg.FindLoans(rates, 50, 36);
Assert.AreEqual(true, agg.IsLoanPossible);
}
public void TestSingleLoanCalculation()
{
MarketRate rate = new MarketRate {
AmountAvailable = 1000, Lender = "Alice", Rate = (float)0.07
};
List <MarketRate> rates = new List <MarketRate>();
rates.Add(rate);
LoanAggregator agg = new LoanAggregator();
agg.FindLoans(rates, 1000, 36);
Assert.AreEqual(true, agg.IsLoanPossible);
Assert.AreEqual(1000, agg.LoanAmount, "LoanAmount check failed");
Assert.AreEqual("30.88", agg.Monthly, "MonthlyPayments check failed");
Assert.AreEqual("1,111.57", agg.Total, "TotalRepayment check failed");
}
public async System.Threading.Tasks.Task <ActionResult> Index()
{
string apiUrl = "http://data.fixer.io/api/latest?access_key=e4e42612bf86976d190d8d29b20fcc32&base=eur";
using (var client = new HttpClient())
{
var uri = new Uri(apiUrl);
var response = await client.GetAsync(uri);
string textResult = await response.Content.ReadAsStringAsync();
JavaScriptSerializer j = new JavaScriptSerializer();
MarketRate a = (MarketRate)j.Deserialize(textResult, typeof(MarketRate));
rates = a.rates;
var currencies = a.rates.Keys.ToList();
return(View(currencies));
}
}
public static async System.Threading.Tasks.Task <Graph> GetGraph(string ExchangeFrom, string ExchangeTo)
{
Graph historicalRates = new Graph();
if (ExchangeFrom != ExchangeTo)
{
int numOfDays = 30;
historicalRates.Title = ExchangeFrom + " To " + ExchangeTo;
historicalRates.ShortDate = new List <string>();
historicalRates.Amount = new List <double>();
historicalRates.RegressionY = new List <double>();
DateTime dateNow = DateTime.Now.AddDays(-1);
DateTime historicalDate = dateNow.AddDays(-numOfDays);
IQueryable <HistoricalRate> storedHistoricalRates;
using (cz2006anythingEntities model = new cz2006anythingEntities())
{
model.HistoricalRates.RemoveRange(model.HistoricalRates.Where(z => z.Date < historicalDate));
var exchangeFromCurrId = model.Currencies.Where(x => x.Name == ExchangeFrom).FirstOrDefault().Id;
var exchangeToCurrId = model.Currencies.Where(x => x.Name == ExchangeTo).FirstOrDefault().Id;
storedHistoricalRates = model.HistoricalRates.Where(z => z.ExchangeFromId == exchangeFromCurrId &&
z.ExchangeToId == exchangeToCurrId);
DateTime latestStoredHistoricalRateDate = new DateTime();
if (storedHistoricalRates != null && storedHistoricalRates.FirstOrDefault() != null)
{
latestStoredHistoricalRateDate = storedHistoricalRates.OrderByDescending(z => z.Date).FirstOrDefault().Date;
}
if (!(storedHistoricalRates.FirstOrDefault() == null ||
latestStoredHistoricalRateDate < dateNow.AddDays(-numOfDays)))
{
TimeSpan dateDiff = dateNow.Subtract(latestStoredHistoricalRateDate);
numOfDays = dateDiff.Days;
historicalDate = dateNow.AddDays(-numOfDays);
}
for (int i = 1; i <= numOfDays; i++)
{
DateTime thisDate = historicalDate.AddDays(i);
MarketRate marketRate = await ApiController.GetHistoryRateAsync(thisDate);
if (marketRate.success == true)
{
double exchangeFrom = marketRate.rates.Where(z => z.Key == ExchangeFrom).FirstOrDefault().Value;
double exchangeTo = marketRate.rates.Where(z => z.Key == ExchangeTo).FirstOrDefault().Value;
HistoricalRate newHistoricalRate = new HistoricalRate();
newHistoricalRate.ExchangeFromId = exchangeFromCurrId;
newHistoricalRate.ExchangeToId = exchangeToCurrId;
newHistoricalRate.Rate = CalculationController.ConvertCurrency(1, exchangeFrom, exchangeTo);
newHistoricalRate.Date = thisDate;
model.HistoricalRates.Add(newHistoricalRate);
}
}
model.SaveChanges();
float exchangeFromToday = ApiController.rates.Where(z => z.Key == ExchangeFrom).FirstOrDefault().Value;
float exchangeToToday = ApiController.rates.Where(z => z.Key == ExchangeTo).FirstOrDefault().Value;
double baseRate = CalculationController.ConvertCurrency(1, exchangeFromToday, exchangeToToday);
List <int> RegressionX = new List <int>();
int n = storedHistoricalRates.Count() + 1;
for (int i = 0; i < n; i++)
{
RegressionX.Add(i);
}
int sumX = RegressionX.Sum();
double sumY = 0;
List <double> xY = new List <double>();
List <double> squareX = new List <double>();
for (int i = 0; i < n - 1; i++)
{
squareX.Add(RegressionX[i] * RegressionX[i]);
double y = storedHistoricalRates.OrderByDescending(z => z.Date).Skip(n - i - 2).FirstOrDefault().Rate;
sumY += y;
xY.Add(RegressionX[i] * y);
}
squareX.Add(RegressionX[n - 1] * RegressionX[n - 1]);
sumY += baseRate;
xY.Add(RegressionX[n - 1] * baseRate);
double b = (n * xY.Sum() - sumX * sumY) / (n * squareX.Sum() - sumX * sumX);
double a = (sumY / n) - b * (sumX / n);
int counter = 0;
foreach (var x in storedHistoricalRates)
{
historicalRates.ShortDate.Add(x.Date.ToString("dd MMM"));
historicalRates.Amount.Add(x.Rate);
historicalRates.RegressionY.Add(a + b * (counter));
counter++;
}
historicalRates.ShortDate.Add(DateTime.Now.ToString("dd MMM"));
historicalRates.Amount.Add(baseRate);
historicalRates.RegressionY.Add(a + b * (counter));
}
}
return(historicalRates);
}
