/// <summary>
/// The method to convert number words from text to number
/// </summary>
/// <param name="text">The text to be converted.</param>
/// <returns>Zero if the text is not valid; otherwise the converted value;</returns>
public static long DoConvert(string text)
{
long result = 0;
long section = 0;
ParseState parseState = ParseState.FirstWord;
string[] split = text.ToLower().Split(' ');
errorText.Clear();
if (IsValid(text))
{
for (int index = 0; index < split.Length; index++)
{
string item = split[index];
string nextItem = index < split.Length - 1 ? split[index + 1] : string.Empty;
ParseState nextState = GetWordType(nextItem);
switch (parseState)
{
case ParseState.FirstWord:
section = GetValueForFirstDigit(item);
parseState = nextState;
break;
case ParseState.SecondDigit:
section += GetValueForDigit(item);
break;
case ParseState.Multiplier:
section *= multiples[item];
break;
case ParseState.HundredSeparators:
section *= 100;
switch (nextState)
{
case ParseState.Multiplier:
section *= multiples[nextItem];
index++;
parseState = ParseState.Multiplier;
break;
case ParseState.And:
index += 2;
nextItem = split[index];
nextState = GetWordType(nextItem);
switch (nextState)
{
case ParseState.FirstWord:
section += GetValueForFirstDigit(nextItem);
if (index < split.Length - 1)
{
nextItem = split[++index];
nextState = GetWordType(nextItem);
if (nextState.Equals(ParseState.SecondDigit))
{
section += GetValueForDigit(nextItem);
if (index + 1 < split.Length)
{
nextItem = split[index + 1];
parseState = GetWordType(nextItem);
}
else
{
nextState = ParseState.None;
}
}
}
break;
case ParseState.SecondDigit:
section += GetValueForDigit(nextItem);
break;
default:
break;
}
break;
}
break;
}
if (nextState.Equals(ParseState.None) || nextState.Equals(ParseState.And))
{
result += section;
section = 0;
}
}
}
return(errorText.Length > 0 ? 0 : result);
}
/// <summary>
/// The method to determine if the text contains valid text elements.
/// </summary>
/// <param name="text">The text to be processed. Word items such as ten, seventeen, or eighty four.</param>
/// <returns>True if the space separated number words are valid: False if no text, blank items.</returns>
public static bool IsValid(string text)
{
bool seenAnd = false;
ParseState parseState = ParseState.FirstWord;
errorText.Clear();
string[] split = text.ToLower().Split(' ');
if (split.Length == 0)
{
errorText.AppendLine("Blank text is not valid");
}
bool lastWasDigit = false;
bool lastWasAnd = false;
int digitCount = 0;
foreach (string item in split)
{
if (string.IsNullOrEmpty(item))
{
errorText.AppendLine(string.Format("Blank items are not valid"));
}
else
{
lastWasAnd = false;
if (item.Equals(And))
{
if (seenAnd)
{
errorText.AppendLine("Can not repeat and");
}
seenAnd = true;
}
else
{
seenAnd = false;
if (!(digits.ContainsKey(item) ||
teens.ContainsKey(item) ||
tens.ContainsKey(item) ||
multiples.ContainsKey(item) ||
seperators.Contains(item)))
{
errorText.AppendLine(string.Format("The item: {0} is not valid", item));
}
}
ParseState wordsType = GetWordType(item);
switch (parseState)
{
case ParseState.FirstWord:
if (wordsType == ParseState.FirstWord || wordsType == ParseState.SecondDigit)
{
parseState = ParseState.SecondDigit;
lastWasAnd = false;
if (wordsType.Equals(ParseState.SecondDigit))
{
lastWasDigit = true;
digitCount++;
}
else
{
lastWasDigit = false;
digitCount += 2;
}
}
else
{
errorText.AppendLine(string.Format("Expecting a number word rather than : {0}", item));
}
break;
case ParseState.SecondDigit:
if (wordsType == ParseState.SecondDigit)
{
digitCount++;
lastWasAnd = false;
parseState = ParseState.Multiplier;
if (lastWasDigit)
{
errorText.AppendLine(string.Format("Second digit is not valid {0}", item));
}
}
else if (wordsType == ParseState.Multiplier)
{
parseState = ParseState.And;
}
else if (wordsType == ParseState.HundredSeparators)
{
parseState = ParseState.And;
if (!lastWasDigit)
{
errorText.AppendLine("The Hundred can only follow a digit word");
}
}
else
{
string type = wordsType.Equals(ParseState.FirstWord) ? "teens or tens" : wordsType.ToString();
errorText.AppendLine(string.Format("Did not expect the word type of {0} in the position of second digit for {1}", type, item));
}
break;
case ParseState.And:
if (wordsType == ParseState.And)
{
digitCount = 0;
parseState = ParseState.FirstWord;
lastWasAnd = true;
}
else
{
if (wordsType != ParseState.Multiplier)
{
errorText.AppendLine(string.Format("A multiplier must be followed by the word 'And' rather than {0}", item));
}
}
break;
case ParseState.Multiplier:
if (wordsType.Equals(ParseState.HundredSeparators))
{
if (digitCount > 2 || !lastWasDigit)
{
errorText.AppendLine("The Hundred can only follow a digit word");
}
}
if (wordsType.Equals(ParseState.Multiplier))
{
parseState = ParseState.And;
}
else if (wordsType.Equals(ParseState.SecondDigit))
{
parseState = ParseState.SecondDigit;
}
break;
default:
errorText.AppendLine(string.Format("Did not expect the word type of {0}", item));
break;
}
}
}
if (lastWasAnd)
{
errorText.AppendLine("The last word can not be 'and' most be followed by a number word");
}
return(errorText.Length == 0);
}
