using CommunityToolkit.Mvvm.ComponentModel;

namespace LehrerApp.Desktop.ViewModels.Settings;

public partial class CompetencyCatalogCopyTargetViewModel : ObservableObject
{
    [ObservableProperty] private int _targetGradeLevel;
    [ObservableProperty] private string _error = "";

    public string SourceLabel { get; }
    public int SourceGradeLevel { get; }

    public CompetencyCatalogCopyTargetViewModel(string subjectName, int sourceGradeLevel)
    {
        SourceGradeLevel = sourceGradeLevel;
        SourceLabel = $"{subjectName} · Klassenstufe {sourceGradeLevel}";
        _targetGradeLevel = sourceGradeLevel < 13 ? sourceGradeLevel + 1 : sourceGradeLevel - 1;
    }

    public bool Validate()
    {
        Error = TargetGradeLevel == SourceGradeLevel
            ? "Quell- und Zielklassenstufe müssen verschieden sein."
            : TargetGradeLevel is < 1 or > 13
                ? "Die Klassenstufe muss zwischen 1 und 13 liegen."
                : "";
        return Error.Length == 0;
    }
}