/// <summary>
/// Convert a supplied <see cref="ExchangeRateData"/> to a new base currency.
/// </summary>
/// <param name="oldRates">The currency exchange rate to convert.</param>
/// <param name="newBaseCurrency">The new base currency.</param>
/// <param name="rounding">Should the converted exchange rates be rounded (saves space when serializing)</param>
/// <returns>A new <see cref="ExchangeRateData"/> instance using the new base currency.</returns>
public static ExchangeRateData ConvertBase(this ExchangeRateData oldRates, string newBaseCurrency, bool rounding = true)
{
var newRates = new ExchangeRateData
{
Base = newBaseCurrency,
TimeStamp = oldRates.TimeStamp,
Rates = new Dictionary<string, decimal>(oldRates.Rates.Count)
};
decimal x = oldRates.Rates[newBaseCurrency];
foreach (var i in oldRates.Rates)
{
var rate = i.Value / x;
if (rounding) rate = decimal.Round(rate, OpenExchangeRoundingPrecision);
newRates.Rates[i.Key] = rate;
}
return newRates;
}
/// <summary>
/// Convert a supplied <see cref="ExchangeRateData"/> to a new base currency.
/// </summary>
/// <param name="oldRates">The currency exchange rate to convert.</param>
/// <param name="newBaseCurrency">The new base currency.</param>
/// <param name="rounding">Should the converted exchange rates be rounded (saves space when serializing)</param>
/// <returns>A new <see cref="ExchangeRateData"/> instance using the new base currency.</returns>
public static ExchangeRateData ConvertBase(this ExchangeRateData oldRates, string newBaseCurrency, bool rounding = true)
{
var newRates = new ExchangeRateData
{
Base = newBaseCurrency,
TimeStamp = oldRates.TimeStamp,
Rates = new Dictionary <string, decimal>(oldRates.Rates.Count)
};
decimal x = oldRates.Rates[newBaseCurrency];
foreach (var i in oldRates.Rates)
{
var rate = i.Value / x;
if (rounding)
{
rate = decimal.Round(rate, OpenExchangeRoundingPrecision);
}
newRates.Rates[i.Key] = rate;
}
return(newRates);
}
/// <summary>
/// Converts the specified ammount <paramref name="value"/> in currency <paramref name="from"/> to the currency specified in <paramref name="to"/>.
/// </summary>
/// <param name="data">The currency exchange rates to use.</param>
/// <param name="value">The ammount of money.</param>
/// <param name="from">The currency code of the given money value.</param>
/// <param name="to">The currency to convert the given money value to.</param>
/// <returns></returns>
public static decimal Convert(this ExchangeRateData data, decimal value, string from, string to)
{
decimal rate;
if (data.Base != from)
{
if (!data.Rates.TryGetValue(from, out rate))
{
throw new ArgumentException("Currency not available.", "from");
}
value /= rate;
}
if (data.Base != to)
{
if (!data.Rates.TryGetValue(to, out rate))
{
throw new ArgumentException("Currency not available.", "to");
}
value *= rate;
}
return(value);
}