using Core.Models;

namespace Core.YearTransition;

/// <summary>
/// Resolves the graduating grade from chapter school level configuration.
/// </summary>
public static class GraduatingGradeResolver
{
    /// <summary>
    /// Middle school students graduate after grade 8; high school after grade 12.
    /// Returns null when school level is unset (both / unspecified).
    /// </summary>
    public static int? FromSchoolLevel(SchoolLevel? schoolLevel) => schoolLevel switch
    {
        SchoolLevel.MiddleSchool => 8,
        SchoolLevel.HighSchool => 12,
        _ => null
    };

    /// <summary>
    /// Human-readable label for wizard display.
    /// </summary>
    public static string Describe(SchoolLevel schoolLevel, int graduatingGrade) => schoolLevel switch
    {
        SchoolLevel.MiddleSchool =>
            $"Middle school chapter — students graduate after grade {graduatingGrade}",
        SchoolLevel.HighSchool =>
            $"High school chapter — students graduate after grade {graduatingGrade}",
        _ => $"Students graduate after grade {graduatingGrade}"
    };
}