using Core.Models;

namespace GoogleSheetsScheduleImport;

/// <summary>
/// Strips leading MS / HS markers from grid titles so titles can be fuzzy-matched to <see cref="Core.Entities.EventDefinition.Name"/>.
/// </summary>
public static class SchoolLevelPrefixParser
{
    /// <returns>Remainder text and school level when unambiguous; <c>null</c> level for MS/HS combined or unknown.</returns>
    public static (string Remainder, SchoolLevel? Level) StripLeadingSchoolPrefix(string raw)
    {
        var s = TextNormalization.ForEmitLine(raw);
        if (string.IsNullOrEmpty(s))
            return (s, null);

        if (s.StartsWith("MS/HS", StringComparison.OrdinalIgnoreCase))
        {
            var rest = s[5..].TrimStart();
            if (rest.StartsWith('/'))
                rest = rest[1..].TrimStart();
            return (rest, null);
        }

        if (s.Length >= 3 && s.StartsWith("MS ", StringComparison.OrdinalIgnoreCase))
            return (s[3..].TrimStart(), SchoolLevel.MiddleSchool);
        if (s.Length >= 3 && s.StartsWith("HS ", StringComparison.OrdinalIgnoreCase))
            return (s[3..].TrimStart(), SchoolLevel.HighSchool);

        if (s.Length >= 3 && s.StartsWith("MS/", StringComparison.OrdinalIgnoreCase))
            return (s[3..].TrimStart(), SchoolLevel.MiddleSchool);
        if (s.Length >= 3 && s.StartsWith("HS/", StringComparison.OrdinalIgnoreCase))
            return (s[3..].TrimStart(), SchoolLevel.HighSchool);

        return (s, null);
    }

    public static string ToSectionSuffix(SchoolLevel level) =>
        level == SchoolLevel.MiddleSchool ? "MS" : "HS";
}