//check if the ertmp node is fully filled in; if so - update er object
public bool CheckAndPush(ERTMP node)
{
if (node.am == 0 || node.cd == null || node.rt == 0.0F)
{
return(false);
}
if (node.am > 1)
{
node.rt = node.rt / node.am;
node.am = 1;
}
er = new ExchangeRate(new Currency(node.cd), new Currency("CZK"), (decimal)node.rt);
return(true);
}
/// <summary>
/// Should return exchange rates among the specified currencies that are defined by the source. But only those defined
/// by the source, do not return calculated exchange rates. E.g. if the source contains "EUR/USD" but not "USD/EUR",
/// do not return exchange rate "USD/EUR" with value calculated as 1 / "EUR/USD". If the source does not provide
/// some of the currencies, ignore them.
/// </summary>
public IEnumerable <ExchangeRate> GetExchangeRates(IEnumerable <Currency> currencies)
{
List <ExchangeRate> exchangeRates = new List <ExchangeRate>();
IRateProvider rateProvider = RateProviderFactory.Create();
IDictionary <string, decimal> exchangeRatesDictionary = rateProvider.GetExchangeRates();
foreach (Currency currency in currencies)
{
if (exchangeRatesDictionary.ContainsKey(currency.Code))
{
ExchangeRate exchangeRate = ExchangeRateFactory.Create(rateProvider.SourceCurrencyCode, currency, exchangeRatesDictionary[currency.Code]);
exchangeRates.Add(exchangeRate);
}
}
return(exchangeRates);
}
private void ParseData(string data, string baseCurrencyCode, IEnumerable <Currency> currencies, List <ExchangeRate> exchangeRates)
{
var lines = data.Split('\n').Skip(2).Where(x => !String.IsNullOrWhiteSpace(x)); // první dva řádky jsou headery;
var baseCurrency = new Currency(baseCurrencyCode); // všechno děláme v poměru ke koruně
try
{
foreach (var line in lines)
{
var parts = line.Split('|'); // země|měna|množství|kód|kurz
var currencyCode = parts[3];
var definedCurrency = currencies.FirstOrDefault(x => x.Code.ToLower() == currencyCode.ToLower());
if (definedCurrency == null)
{
continue;
}
int amount = 0;
if (!int.TryParse(parts[2], out amount))
{
throw new FormatException($"Nepovedlo se naparsovat amount hodnotu '{parts[2]}' na int.");
}
decimal rate = 0m;
if (!decimal.TryParse(parts[4], out rate))
{
throw new FormatException($"Nepovedlo se naparsovat rate hodnotu '{parts[4]}' na decimal.");
}
var currency = new Currency(currencyCode);
var exchangeRate = new ExchangeRate(baseCurrency, currency, rate / amount); // některé měny nejsou 1:1, ale např. Filipíny|peso|100|PHP|43,861 => za 100 peso dostanu 43 korun.
exchangeRates.Add(exchangeRate);
}
}
catch (Exception ex)
{
throw new Exception($"Došlo k následující chybě během zpracování obsahu, zkontrolujte vstupní data. Chyba: '{ex.ToString()}'. Data: {data}.");
}
}
private void ParseFeed(string txtFeed)
{
// Row follows pattern country|currency name|multiplier|code|value
List <string> lines = txtFeed.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.RemoveEmptyEntries).ToList();
lines.RemoveRange(0, 2);
foreach (string line in lines)
{
string[] splitRow = line.Split('|');
if (splitRow.Count() < 5)
{
throw new Exception("Data source doesn't follow specified pattern");
}
// CNB has only currency/CZK exchange rates available in TXT feed
Currency sourceCurrency = new Currency(splitRow[3]);
Currency targetCurrency = new Currency("CZK");
decimal value = 0;
bool decSuccess = decimal.TryParse(splitRow[4], out value);
if (!decSuccess)
{
throw new Exception("Value in feed is not a number");
}
int multiplier = 1;
bool intSuccess = int.TryParse(splitRow[2], out multiplier);
if (!decSuccess)
{
throw new Exception("Multiplier in feed is not a number");
}
ExchangeRate rate = new ExchangeRate(sourceCurrency, targetCurrency, value / multiplier);
Rates.Add(rate);
}
}
public IEnumerable <ExchangeRate> GetExchangeRates()
{
var xmldoc = new XmlDocument();
xmldoc.Load(@"https://www.cnb.cz/cs/financni_trhy/devizovy_trh/kurzy_devizoveho_trhu/denni_kurz.xml");
XmlNodeList nodes = xmldoc.SelectNodes("//*[@kod]");
if (nodes != null)
{
foreach (XmlNode node in nodes)
{
if (node.Attributes != null)
{
var rate = new ExchangeRate(("CZK"), (node.Attributes["kod"].Value),
Decimal.Parse(node.Attributes["kurz"].Value, NumberStyles.Any,
new CultureInfo("cs-CZ")));
yield return(rate);
}
}
}
}
public IEnumerable <ExchangeRate> GetExchangeRates(IEnumerable <Currency> currencies)
{
// getting html code from the webpage
var client = new WebClient();
var text = client.DownloadString(
"https://www.cnb.cz/en/financial_markets/foreign_exchange_market/exchange_rate_fixing/daily.jsp");
// processing the html code string, using regular expressions
StringReader sr = new StringReader(text);
string s = null;
Regex rgx = new Regex(@"kurzy_tisk");
// I studied the initial html code and after the lines with "kurzy tisk" there are a few lines with
// the codes and rates that we need, so I just made a simple loop which breaks as soon as I find those
// works as follows: finds "kurzy tisk", then for 20 lines (enough to read all rates) processes another
// regular expression to extract the required info and parses to another method
while (true)
{
s = sr.ReadLine();
if (rgx.IsMatch(s))
{
for (int i = 0; i < 20; i++)
{
String k = sr.ReadLine();
MatchCollection mc = Regex.Matches(k, @"(<td>|<td align=.right.>)(.+?)</td>");
int c = 0; // iterator for matches of the regex (because the expression extracts some extra info which we need to dispose of)
int y = 0; // iterator for the insides of ertmp class
ERTMP tmp = new ERTMP();
foreach (Match m in mc)
{
if (c % 5 < 2) // we don't need names of the countries and names of their currencies
{
y = 0;
c++;
continue;
}
else
{
String x = m.Groups[2].Value; //once we reach what we need, we push it to the corresponding values of a node
//pushing info to different fields of the ertmp class
switch (y)
{
case 0:
tmp.am = int.Parse(x);
break;
case 1:
tmp.cd = x;
break;
case 2:
tmp.rt = float.Parse(x);
break;
}
// if our temp class is fully filled with info, we process it, push to the list and renew
if (CheckAndPush(tmp))
{
tmp = new ERTMP();
foreach (Currency cu in currencies)
{
if (cu.Code.Equals(er.SourceCurrency.Code))
{
data.Add(er);
er = new ExchangeRate(new Currency(""), new Currency(""), 0);
break;
}
}
}
c++;
y++;
}
}
}
break;
}
}
return(data);
}
public IEnumerable <ExchangeRate> GetExchangeRates(IEnumerable <Currency> currencies, ExchangeRateType rateType)
{
string[] lines = File.ReadAllText(ExchangeRateFile).Split('\n');
var rates = new List <ExchangeRate>();
var sourceCurrency = new Currency(ExchangeRateSourceCurrency);
foreach (var row in lines.Skip(2))
{
var fields = row.Split(';');
string currency = fields[0].Trim().ToUpper();
if (currencies.Any(x => x.Code == currency))
{
var targetCurency = new Currency(currency);
decimal value = 0;
switch (rateType)
{
case ExchangeRateType.BuyInCash:
{
decimal.TryParse(fields[1].Trim(), out value);
break;
}
case ExchangeRateType.SellInCash:
{
decimal.TryParse(fields[2].Trim(), out value);
break;
}
case ExchangeRateType.MiddleInCash:
{
decimal value1 = 0;
decimal value2 = 0;
decimal.TryParse(fields[1].Trim(), out value1);
decimal.TryParse(fields[2].Trim(), out value2);
value = (value1 + value2) / 2;
break;
}
case ExchangeRateType.BuyTransfer:
{
decimal.TryParse(fields[3].Trim(), out value);
break;
}
case ExchangeRateType.SellTransfer:
{
decimal.TryParse(fields[3].Trim(), out value);
break;
}
case ExchangeRateType.MiddleTransfer:
{
decimal value1 = 0;
decimal value2 = 0;
decimal.TryParse(fields[3].Trim(), out value1);
decimal.TryParse(fields[4].Trim(), out value2);
value = (value1 + value2) / 2;
break;
}
case ExchangeRateType.CentralBank:
{
decimal.TryParse(fields[5].Trim(), out value);
break;
}
default:
{
break;
}
}
var rate = new ExchangeRate(sourceCurrency, targetCurency, rateType, value);
rates.Add(rate);
}
}
return(rates.ToArray());
}
/* Parse rates from CNB into Dictionary */
public void ParseRatesFromCNB(string data)
{
string line;
int lineNo = 0;
string[] fields;
Decimal multipler;
Currency curr;
Decimal rate;
ExchangeRate exRate;
AllExchangeRates = new Dictionary <Currency, ExchangeRate>(new CurrencyComparer());
//AllExchangeRates = new Dictionary<Currency, ExchangeRate>();
using (StringReader reader = new StringReader(data))
{
while ((line = reader.ReadLine()) != null)
{
lineNo += 1;
// System.Console.WriteLine($"Read line {lineNo} [{line}]");
/* Parse file header */
if (lineNo == 1)
{
fields = line.Split(' ');
if (fields.Length != 2)
{
throw new Exception($"Unsupported file format - wrong head [{line}]");
}
try
{
/* Parse datestamp of the file */
LastLoadDate = DateTime.Parse(fields[0]);
/* Parse dayNo of the file */
Match match = Regex.Match(fields[1], @"^\s*#(\d+)\s*$");
if (match.Success)
{
DayNo = Int32.Parse(match.Groups[1].Value);
}
else
{
System.Console.WriteLine($"Cannot parse day number from [{line}]");
}
}
catch (Exception ex)
{
throw new Exception($"Cannot parse file datestamp or date number [{line}]:[{ex.Message}]");
}
// System.Console.WriteLine($"Parsed file header [{LastLoadDate.ToShortDateString()}] [{DayNo}]");
continue;
}
/* Check table header */
if (lineNo == 2)
{
if (line.CompareTo(CNB_EXPECTED_RATE_TABLE_HEADER) != 0)
{
throw new Exception($"Table header is not as expected [{line}] vs [{CNB_EXPECTED_RATE_TABLE_HEADER}]");
}
// System.Console.WriteLine($"Table header accepted");
continue;
}
/* Parse rates */
fields = line.Split('|');
if (fields.Length != EXPECTED_COLUMNS)
{
throw new Exception($"Unsupported number of fields [{fields.Length}] vs [{EXPECTED_COLUMNS}]");
}
try
{
multipler = Decimal.Parse(fields[POS_MUTIPLIER]);
curr = new Currency(fields[POS_CURRENCY]);
rate = Decimal.Parse(fields[POS_RATE]);
exRate = new ExchangeRate(curr, czk_curr, rate / multipler);
AllExchangeRates.Add(curr, exRate);
// System.Console.WriteLine($"Parsed rate {lineNo-2}: {exRate}");
}
catch (Exception ex)
{
throw new Exception($"Cannot parse rate from [{line}]:[{ex.Message}]");
}
}
}
}
