using LehrerApp.Core.Models;
using LehrerApp.Desktop.ViewModels.Groups;
using Xunit;

namespace LehrerApp.Desktop.Tests;

public sealed class TeachingModeViewModelTests
{
    private static SeatingPlanTabViewModel BuildSeatingPlan(Guid groupId, FakeSessions? sessions = null,
        List<Student>? students = null, List<GroupMembership>? memberships = null,
        List<SeatingPlan>? plans = null) =>
        new(new FakeSeatingPlans(plans ?? [new SeatingPlan { GroupId = groupId, Name = "Standard", Rows = 1, Columns = 1 }]),
            new FakeStudents(students ?? []), new FakeMemberships(memberships ?? []),
            sessions ?? new FakeSessions([]), new FakeEntries(), new FakeAspects());

    /// Dieselben Fakes wie <see cref="BuildSeatingPlan"/>, aber für ParticipationTabViewModel —
    /// beide brauchen eigene IParticipationSessionRepository/IParticipationRepository-Instanzen
    /// im Produktivcode (siehe TeachingModeWindow-Kommentar zu ReloadSeatBadgesFromRepository),
    /// hier reicht für die Tests aber eine gemeinsame FakeSessions-Instanz, damit beide
    /// ViewModels dieselbe verknüpfte Sitzung sehen.
    private static ParticipationTabViewModel BuildParticipation(LearningGroup group,
        FakeSessions? sessions = null) =>
        new(sessions ?? new FakeSessions([]), new FakeEntries(), new FakeAspects(),
            new FakeStudents([]), new FakeMemberships([]), new FakeGroups([group]),
            new FakeCompetencyDomains());

    [Fact]
    public void Konstruktor_LaedtVerlaufsplanUndInitialisiertSitzplanFuerDieGruppe()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var lesson = new Lesson
        {
            GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox",
            Phases = [new LessonPhaseStep { Name = "Einstieg", DurationMinutes = 10, Activity = "Impuls" }],
        };
        var seatingPlan = BuildSeatingPlan(group.Id);

        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            new FakeLessons(), seatingPlan, BuildParticipation(group));

        Assert.Equal("Q1 Chemie", vm.GroupName);
        Assert.Equal("Redox", vm.LessonInfo.Topic);
        Assert.Single(vm.LessonInfo.PhaseGroups.Single().Phases);
        Assert.True(vm.SeatingPlan.HasSelectedPlan);
    }

    [Fact]
    public void Konstruktor_VerknuepftDieSitzungMitDieserStunde()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var lesson = new Lesson
        { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
        var sessions = new FakeSessions([]);
        var seatingPlan = BuildSeatingPlan(group.Id, sessions);

        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            new FakeLessons(), seatingPlan, BuildParticipation(group, sessions));

        var created = Assert.Single(sessions.GetByGroup(group.Id));
        Assert.Equal(lesson.Id, created.LessonId);
        Assert.Equal(vm.SeatingPlan.SelectedSession?.Id, created.Id);
    }

    /// Nutzer-Feedback: Schnellbewertungs-Dialoge (Mitarbeit, Anwesenheit/Hausaufgabe) sollen sich
    /// im Unterrichtsmodus direkt öffnen lassen — das setzt voraus, dass die dafür verwendete
    /// ParticipationTabViewModel-Instanz von Anfang an auf der zu dieser Stunde gehörenden
    /// Sitzung steht, nicht auf einer beliebigen anderen Sitzung der Gruppe.
    [Fact]
    public void Konstruktor_SelektiertDieselbeSitzungAuchInDerParticipationViewModel()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var lesson = new Lesson
        { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
        var otherSession = new ParticipationSession
        { GroupId = group.Id, Date = lesson.Date.AddDays(-1), Comment = "Andere Stunde" };
        var sessions = new FakeSessions([otherSession]);
        var seatingPlan = BuildSeatingPlan(group.Id, sessions);

        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            new FakeLessons(), seatingPlan, BuildParticipation(group, sessions));

        Assert.NotNull(vm.SeatingPlan.SelectedSession);
        Assert.Equal(vm.SeatingPlan.SelectedSession!.Id, vm.Participation.SelectedSession?.Id);
        Assert.NotEqual(otherSession.Id, vm.Participation.SelectedSession?.Id);
    }

    [Fact]
    public void Konstruktor_BereitsExistierendeVerknuepfteSitzung_WirdWiederverwendet()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var lesson = new Lesson
        { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
        var existing = new ParticipationSession
        { GroupId = group.Id, Date = lesson.Date, LessonId = lesson.Id, Comment = "Redox" };
        var sessions = new FakeSessions([existing]);
        var seatingPlan = BuildSeatingPlan(group.Id, sessions);

        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            new FakeLessons(), seatingPlan, BuildParticipation(group, sessions));

        Assert.Single(sessions.GetByGroup(group.Id));
        Assert.Equal(existing.Id, vm.SeatingPlan.SelectedSession?.Id);
    }

    /// Eine archivierte Gruppe darf im Unterrichtsmodus nicht bearbeitbar sein - genau wie in der
    /// normalen Gruppenansicht (GroupDetailViewModel.IsReadOnly).
    [Fact]
    public void Konstruktor_ArchivierteGruppe_InitialisiertSitzplanSchreibgeschuetzt()
    {
        var group = new LearningGroup { Name = "Q1 Chemie", IsActive = false };
        var lesson = new Lesson
        { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
        var seatingPlan = BuildSeatingPlan(group.Id);

        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            new FakeLessons(), seatingPlan, BuildParticipation(group));

        Assert.False(vm.SeatingPlan.IsEditable);
    }

    // ── Hausaufgabe: letzte Stunde ansehen/abhaken, aktuelle einsehen/ändern ─────

    [Fact]
    public void Konstruktor_FindetHausaufgabeDerVorherigenStunde()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var today = DateOnly.FromDateTime(DateTime.Today);
        var previous = new Lesson
        {
            GroupId = group.Id, Date = today.AddDays(-7), Topic = "Säuren",
            Homework = "S. 42, Aufgabe 3", HomeworkChecked = false,
        };
        var lesson = new Lesson { GroupId = group.Id, Date = today, Topic = "Redox" };
        var lessons = new FakeLessons();
        lessons.Add(previous);
        var seatingPlan = BuildSeatingPlan(group.Id);

        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            lessons, seatingPlan, BuildParticipation(group));

        Assert.True(vm.Homework.HasPreviousHomework);
        Assert.Equal("S. 42, Aufgabe 3", vm.Homework.PreviousHomeworkText);
        Assert.Contains("Säuren", vm.Homework.PreviousLessonLabel);
        Assert.False(vm.Homework.PreviousHomeworkChecked);
    }

    [Fact]
    public void Konstruktor_IgnoriertVorherigeStundeOhneHausaufgabe()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var today = DateOnly.FromDateTime(DateTime.Today);
        var previous = new Lesson { GroupId = group.Id, Date = today.AddDays(-7), Topic = "Säuren" };
        var lesson = new Lesson { GroupId = group.Id, Date = today, Topic = "Redox" };
        var lessons = new FakeLessons();
        lessons.Add(previous);
        var seatingPlan = BuildSeatingPlan(group.Id);

        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            lessons, seatingPlan, BuildParticipation(group));

        Assert.False(vm.Homework.HasPreviousHomework);
    }

    [Fact]
    public void PreviousHomeworkChecked_SpeichertSofortAnDerVorherigenStunde()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var today = DateOnly.FromDateTime(DateTime.Today);
        var previous = new Lesson
        { GroupId = group.Id, Date = today.AddDays(-7), Topic = "Säuren", Homework = "S. 42" };
        var lesson = new Lesson { GroupId = group.Id, Date = today, Topic = "Redox" };
        var lessons = new FakeLessons();
        lessons.Add(previous);
        var seatingPlan = BuildSeatingPlan(group.Id);
        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            lessons, seatingPlan, BuildParticipation(group));

        vm.Homework.PreviousHomeworkChecked = true;

        var saved = Assert.Single(lessons.GetByGroupAndRange(group.Id, today.AddDays(-120), today.AddDays(-1)));
        Assert.True(saved.HomeworkChecked);
    }

    [Fact]
    public void SaveCurrentHomework_SchreibtAufDieAktuelleStunde()
    {
        var group = new LearningGroup { Name = "Q1 Chemie" };
        var lesson = new Lesson
        { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
        var lessons = new FakeLessons();
        lessons.Add(lesson);
        var seatingPlan = BuildSeatingPlan(group.Id);
        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
            lessons, seatingPlan, BuildParticipation(group));

        vm.Homework.CurrentHomework = "AB 7 fertigstellen";
        vm.Homework.SaveCurrentHomeworkCommand.Execute(null);

        var saved = Assert.Single(lessons.GetByGroupAndRange(group.Id, lesson.Date, lesson.Date));
        Assert.Equal("AB 7 fertigstellen", saved.Homework);
        Assert.Equal("Gespeichert.", vm.Homework.SaveStatus);
    }
}