using System.Text;
using System.Text.RegularExpressions;

namespace IceImportDAL.CustomCode.RemoteFileSources;

// Simple glob-style matcher for MICEMAPFTPSOURCE.FILENAMEPATTERN (e.g. "*.csv", "invoice_????.xml")
// — deliberately not a regex (no new dependency, and admins configuring FileNamePattern should
// never need to know regex escaping rules). Supports '*' (any run of characters) and '?' (any
// single character); every other character is matched literally and case-insensitively.
internal static class WildcardPatternMatcher
{
    public static bool IsMatch(string fileName, string pattern)
    {
        if (string.IsNullOrWhiteSpace(pattern))
            return true; // no pattern configured — match everything

        var regexPattern = GlobToRegex(pattern);
        return Regex.IsMatch(fileName, regexPattern, RegexOptions.IgnoreCase);
    }

    private static string GlobToRegex(string glob)
    {
        var sb = new StringBuilder("^");
        foreach (var c in glob)
        {
            switch (c)
            {
                case '*':
                    sb.Append(".*");
                    break;
                case '?':
                    sb.Append('.');
                    break;
                default:
                    sb.Append(Regex.Escape(c.ToString()));
                    break;
            }
        }
        sb.Append('$');
        return sb.ToString();
    }
}