/// <summary>
/// Gets whole roman symbol info by symbol.
/// </summary>
/// <param name="symbol">Galaxy symbol.</param>
/// <returns>A Roman symbol object.</returns>
public static RomanSymbol GetRomanSymbol(string symbol)
{
RomanSymbol result = null;
if (Symboles.Any(o => o.Symbol.Equals(symbol)))
{
result = Symboles.Find(o => o.Symbol.Equals(symbol));
}
return(result);
}
/// <summary>
/// Parses the Roman symbol definition
/// </summary>
/// <param name="input">input</param>
/// <returns>The result of whether it is success</returns>
public override bool Parse(string input)
{
string[] words = input.Split(new[] { TranslatorConstant.Is }, StringSplitOptions.RemoveEmptyEntries);
if (words.Count() != 2)
{
return(false);
}
if (words[0].Trim().Contains(TranslatorConstant.Blank))
{
return(false);
}
if (words[1].Length != 1)
{
return(false);
}
RomanSymbol romanSymbol = RomanSymbolUtility.GetRomanSymbol(words[1]);
string key = words[0].Trim();
Context.IrregularSymbolsDefinition[key] = romanSymbol ?? throw new Exception(TranslatorConstant.InvalidRomanSymbol);
return(true);
}
/// <summary>
/// Converts Roman to Arabic.
/// </summary>
/// <returns>Arabic value</returns>
/// <exception cref="Exception">Format error</exception>
private double ConvertToArabic()
{
double total = 0;
double previousValue = 0;
for (int i = 0; i < romanSymbols.Count(); i++)
{
RomanSymbol currentSymbol = romanSymbols[i];
if (i == romanSymbols.Count() - 1)
{
if (i - 1 >= 0)
{
RomanSymbol previousSymbol = romanSymbols[i - 1];
// "D", "L", and "V" can never be repeated.
if (currentSymbol.Symbol.Equals(previousSymbol.Symbol) && !currentSymbol.AllowRepeat)
{
throw new Exception(string.Format(TranslatorConstant.UnRepeatableError, currentSymbol.Symbol));
}
// Symbols must be placed in order of value, starting with the largest values.
if (previousValue != 0 && currentSymbol.ArabicValue > previousValue)
{
throw new Exception(TranslatorConstant.SymbolOrderError);
}
}
total += currentSymbol.ArabicValue;
break;
}
RomanSymbol nextSymbol = romanSymbols[i + 1];
// Only one small value symbol may be subtracted from any large-value symbol.
if (currentSymbol.ArabicValue < nextSymbol.ArabicValue)
{
// "I" can be subtracted from "V" and "X" only. "X" can be subtracted from "L" and "C" only.
// "C" can be subtracted from "D" and "M" only. "V", "L", and "D" can never be subtracted.
if (currentSymbol.AllowSubtracted && currentSymbol.SubtractedFrom.Contains(nextSymbol.Symbol))
{
previousValue = nextSymbol.ArabicValue - currentSymbol.ArabicValue;
total += previousValue;
i++;
}
else
{
if (!currentSymbol.AllowSubtracted)
{
throw new Exception(string.Format(TranslatorConstant.SubtractedError,
currentSymbol.Symbol));
}
if (!currentSymbol.SubtractedFrom.Contains(nextSymbol.Symbol))
{
throw new Exception(string.Format(TranslatorConstant.SubtractedError2,
currentSymbol.Symbol, nextSymbol.Symbol));
}
}
}
else
{
// "D", "L", and "V" can never be repeated.
if (currentSymbol.ArabicValue == nextSymbol.ArabicValue)
{
if (!currentSymbol.AllowRepeat)
{
throw new Exception(string.Format(TranslatorConstant.UnRepeatableError, currentSymbol.Symbol));
}
}
// Symbols must be placed in order of value, starting with the largest values.
if (previousValue != 0 && currentSymbol.ArabicValue > previousValue)
{
throw new Exception(TranslatorConstant.SymbolOrderError);
}
// The symbols "I", "X", "C", and "M" can be repeated three times in succession, but no more.
if (i + 3 < romanSymbols.Count() &&
currentSymbol.Symbol.Equals(nextSymbol.Symbol) &&
currentSymbol.Symbol.Equals(romanSymbols[i + 2].Symbol) &&
currentSymbol.Symbol.Equals(romanSymbols[i + 3].Symbol))
{
throw new Exception(TranslatorConstant.ThreeTimesLimitError);
}
previousValue = currentSymbol.ArabicValue;
total += previousValue;
}
}
return(total);
}
