public static IEnumerable<string> EquationsFromParentheses(string recipe)
{
var equations = new List<string>();
if (string.IsNullOrWhiteSpace(recipe))
{
return equations;
}
recipe = "(" + recipe + ")"; // If this is a duplication of effort, we'll silently ignore it later.
recipe = new Regex(@"\s+").Replace(recipe, string.Empty); // Remove all whitespace.
recipe = LeveledPreparser(recipe);
var multiLetterMatch = invalidLetterFinder.Match(recipe);
if (multiLetterMatch.Success)
{
throw new ArgumentException("The gem \"" + multiLetterMatch.Value + "\" must be a single letter. Gem combinations must be expressed as individual components separated with plus signs and brackets, as needed. For example:\nob → o+b\nob+o → (o+b)+o");
}
var id = 0;
foreach (var c in Gem.GemInitializer)
{
if (recipe.IndexOf(c) > -1)
{
recipe = recipe.Replace(c, id.ToString(CultureInfo.InvariantCulture)[0]);
equations.Add(string.Format(CultureInfo.InvariantCulture, "{0}={1}", id, c));
id++;
}
}
if (equations.Count == 0)
{
throw new ArgumentException("Recipe did not contain any recognizable gems.");
}
// Scan for plus signs within the formula and add gems together appropriately.
int plus = recipe.IndexOf('+');
string newNum = (id - 1).ToString(CultureInfo.InvariantCulture);
while (plus > -1)
{
string thisCombine;
var close = recipe.IndexOf(')', plus);
if (close >= 0)
{
var open = recipe.LastIndexOf('(', close);
if (open < 0)
{
throw new ArgumentException("Bracket mismatch in formula.");
}
thisCombine = recipe.Substring(open + 1, close - open - 1);
string[] combineGems = thisCombine.Split('+');
if (combineGems.Length != 2)
{
throw new ArgumentException("The formula provided contains more than a single plus sign within a pair of brackets or a term that is over-bracketed (e.g., \"((o+o))\"). These are not currently supported.");
}
if (combineGems[0].Length == 0 || combineGems[1].Length == 0)
{
throw new ArgumentException("Invalid formula part: (" + thisCombine + ")");
}
newNum = id.ToString(CultureInfo.InvariantCulture);
recipe = recipe.Replace("(" + thisCombine + ")", newNum);
equations.Add(string.Format(CultureInfo.InvariantCulture, "{0}={1}+{2}", id, combineGems[0], combineGems[1]));
}
else
{
throw new ArgumentException("Bracket mismatch in formula.");
}
plus = recipe.IndexOf('+');
id++;
}
while (recipe.StartsWith("(", StringComparison.Ordinal) && recipe.EndsWith(")", StringComparison.Ordinal))
{
recipe = recipe.Substring(1, recipe.Length - 2);
}
if (recipe != newNum)
{
if (recipe.Contains("("))
{
throw new ArgumentException("Bracket mismatch in formula.");
}
throw new ArgumentException("Invalid recipe.");
}
return equations;
}