AnkiCloze.cs

using System.Globalization;
 
namespace AnkiIO;

public static class AnkiCloze
{
    public static string Wrap(string text, int index = 1, string? hint = null)
    {
        ArgumentException.ThrowIfNullOrEmpty(text);
        ArgumentOutOfRangeException.ThrowIfLessThan(index, 1);
        RejectDelimiter(text, nameof(text));
        if (hint is not null)
        {
            RejectDelimiter(hint, nameof(hint));
        }
 
        var indexText = index.ToString(CultureInfo.InvariantCulture);
        return hint is null
            ? $"{{{{c{indexText}::{text}}}}}"
            : $"{{{{c{indexText}::{text}::{hint}}}}}";
    }
 
    private static void RejectDelimiter(string value, string parameterName)
    {
        if (value.Contains("{{", StringComparison.Ordinal)
            || value.Contains("::", StringComparison.Ordinal)
            || value.Contains("}}", StringComparison.Ordinal))
        {
            throw new ArgumentException("Cloze content cannot contain the structural delimiters '{{', '::', or '}}'.", parameterName);
        }
    }
}