NumberPattern FindPattern(decimal value, NumberLength?nl = null)
{
if (!nl.HasValue)
{
nl = Options.Length;
}
value = Math.Abs(value);
// Determine the format length type.
var flt = nl == NumberLength.Default
? "[not(@type)]"
: $"[@type='{nl.ToString().ToLowerInvariant()}']";
// Determine the path in the ldml to the pattern(s)
var path = String.Empty;
if (Options.Style == NumberStyle.Decimal)
{
path = $"ldml/numbers/decimalFormats[@numberSystem='{NumberingSystem.Id}']/decimalFormatLength{flt}/decimalFormat";
}
else if (Options.Style == NumberStyle.Percent)
{
path = $"ldml/numbers/percentFormats[@numberSystem='{NumberingSystem.Id}']/percentFormatLength{flt}/percentFormat";
}
else if (Options.Style == NumberStyle.Scientific)
{
path = $"ldml/numbers/scientificFormats[@numberSystem='{NumberingSystem.Id}']/scientificFormatLength{flt}/scientificFormat";
}
else if (Options.Style == NumberStyle.CurrencyStandard)
{
path = $"ldml/numbers/currencyFormats[@numberSystem='{NumberingSystem.Id}']/currencyFormatLength{flt}/currencyFormat[@type='standard']";
}
else if (Options.Style == NumberStyle.CurrencyAccounting)
{
path = $"ldml/numbers/currencyFormats[@numberSystem='{NumberingSystem.Id}']/currencyFormatLength{flt}/currencyFormat[@type='accounting']";
}
else
{
throw new NotImplementedException($"Unknown NumberStyle '{Options.Style}'.");
}
var xml = Locale.FindOrDefault(path);
// Fall back to default number length;
if (xml == null && nl != NumberLength.Default)
{
return(FindPattern(value, NumberLength.Default));
}
// Should not happen.
if (xml == null)
{
throw new KeyNotFoundException($"Cannot find CLDR '{path}'.");
}
// Get the best pattern.
var category = Plural.Create(Locale).Category(value);
NumberPattern best = null;
NumberPattern previous = null;
var pattern = xml.SelectChildren("pattern", "");
while (pattern.MoveNext())
{
var p = NumberPattern.Parse(pattern.Current);
// If not a value range, then this is the best pattern.
if (!p.MinValue.HasValue)
{
best = p;
break;
}
// Only consider a pattern with the correct count.
if (p.Count != category)
{
continue;
}
// Get closest value in the range.
if (p.MinValue.Value > value)
{
best = previous;
break;
}
previous = p;
}
best = best ?? previous ?? new NumberPattern {
FormatString = "0"
};
return(best);
}