using LehrerApp.Core.Models;
using LehrerApp.Core.Services;
using LehrerApp.Desktop.ViewModels.Exams;
using Xunit;

namespace LehrerApp.Desktop.Tests;

/// Deckt 1.6 (Klausuren-Hauptseite) ab: Priorisierung end-to-end über die ViewModel-Schicht,
/// Parallelkurs-Umschalter (1.6.4) und Genehmigung/Ankündigung (1.6.5).
public sealed class ExamsOverviewViewModelTests
{
    private static ExamsOverviewViewModel BuildVm(List<LearningGroup> groups, List<Exam> exams,
        FakeMemberships? memberships = null, FakeResults? results = null) =>
        new(new FakeExams(exams), results ?? new FakeResults(), new FakeGroups(groups),
            memberships ?? new FakeMemberships([]), new GradingService(), new SchoolYearService());

    [Fact]
    public void Load_UnbearbeiteteKorrekturStehtVorGeplanterKlausur()
    {
        var group = new LearningGroup { Name = "Q1 Chemie", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
        var today = DateOnly.FromDateTime(DateTime.Today);
        var overdue = new Exam { GroupId = group.Id, Title = "Alte Klausur", Status = ExamStatus.Conducted, Date = today.AddDays(-10) };
        var planned = new Exam { GroupId = group.Id, Title = "Neue Klausur", Status = ExamStatus.Planned, Date = today.AddDays(3) };

        var vm = BuildVm([group], [overdue, planned]);
        vm.LoadCommand.Execute(null);

        Assert.Equal("Alte Klausur", vm.Rows[0].Title);
        Assert.Equal("Neue Klausur", vm.Rows[1].Title);
    }

    [Fact]
    public void Load_ParallelkurseWerdenAlsGeschwisterErkannt()
    {
        var groupA = new LearningGroup { Name = "Chemie GK Q1", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
        var groupB = new LearningGroup { Name = "Chemie GK Q1b", SchoolYear = groupA.SchoolYear };
        var original = new Exam { GroupId = groupA.Id, Title = "Redox", Status = ExamStatus.Planned, Date = DateOnly.FromDateTime(DateTime.Today).AddDays(5) };
        var duplicate = new Exam
        {
            GroupId = groupB.Id, Title = "Redox", Status = ExamStatus.Planned,
            Date = DateOnly.FromDateTime(DateTime.Today).AddDays(6), SharedExamGroupId = original.Id,
        };

        var vm = BuildVm([groupA, groupB], [original, duplicate]);
        vm.LoadCommand.Execute(null);

        vm.SelectedRow = vm.Rows.Single(r => r.Exam.Id == original.Id);
        Assert.True(vm.SelectedRow.HasSibling);
        Assert.Single(vm.Siblings);
        Assert.Equal(duplicate.Id, vm.Siblings[0].Exam.Id);
    }

    [Fact]
    public void ToggleApproval_SetztUndLöschtDatum()
    {
        var group = new LearningGroup { Name = "Q1 Chemie", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
        var exam = new Exam { GroupId = group.Id, Title = "Klausur", Status = ExamStatus.Planned, Date = DateOnly.FromDateTime(DateTime.Today).AddDays(2) };
        var vm = BuildVm([group], [exam]);
        vm.LoadCommand.Execute(null);
        vm.SelectedRow = vm.Rows[0];

        vm.ToggleApprovalCommand.Execute(null);
        Assert.NotNull(exam.ApprovalGrantedAt);
        Assert.StartsWith("Genehmigt am", vm.ApprovalLabel);

        vm.ToggleApprovalCommand.Execute(null);
        Assert.Null(exam.ApprovalGrantedAt);
        Assert.Equal("Genehmigung noch ausstehend", vm.ApprovalLabel);
    }

    [Fact]
    public void Selection_ZeigtKorrekturfortschrittOderNotenspiegelJeNachStatus()
    {
        var group = new LearningGroup { Name = "Q1 Chemie", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
        var today = DateOnly.FromDateTime(DateTime.Today);
        var conducted = new Exam { GroupId = group.Id, Title = "Läuft", Status = ExamStatus.Conducted, Date = today.AddDays(-2) };
        var returned = new Exam { GroupId = group.Id, Title = "Fertig", Status = ExamStatus.Returned, Date = today.AddDays(-20) };
        var vm = BuildVm([group], [conducted, returned]);
        vm.LoadCommand.Execute(null);

        vm.SelectedRow = vm.Rows.Single(r => r.Exam.Id == conducted.Id);
        Assert.True(vm.ShowCorrectionProgress);
        Assert.False(vm.ShowGradeSummary);

        vm.SelectedRow = vm.Rows.Single(r => r.Exam.Id == returned.Id);
        Assert.False(vm.ShowCorrectionProgress);
        Assert.True(vm.ShowGradeSummary);
    }
}