using LehrerApp.Core.Models;
using LehrerApp.Core.Services;
using LehrerApp.Data;
using LehrerApp.Desktop.ViewModels.Settings;
using LehrerApp.Sync;
using LehrerApp.Sync.Models;
using System.Linq;
using Xunit;

namespace LehrerApp.Desktop.Tests;

public sealed class SettingsViewModelTests
{
    private static SettingsViewModel BuildViewModel(FakeSchoolHolidays? holidays = null,
        FakeSupervisionDuties? supervisionDuties = null,
        FakeSubjects? subjects = null, FakeCompetencyDomains? competencyDomains = null,
        EventQueue? eventQueue = null)
    {
        // Bewusst kein "using": SchoolCalendarSettingsService liest den Pfad erst bei SetState,
        // das Verzeichnis muss über die Lebensdauer des ViewModels bestehen bleiben.
        var tempPath = System.IO.Path.Combine(
            System.IO.Path.GetTempPath(), $"lehrerapp-settingsvm-tests-{Guid.NewGuid():N}");
        Directory.CreateDirectory(tempPath);

        return new SettingsViewModel(
            subjects ?? new FakeSubjects([]), competencyDomains ?? new FakeCompetencyDomains(), new FakeGradingKeyTemplates(),
            new FakeSchemes(), new GradingService(), new BackupService(tempPath),
            new DatabaseEncryptionService(), new AppLockService(tempPath),
            new LiteDbContext(new MemoryStream()), new PrivacySettingsService(tempPath),
            new FakeDocumentation(), new FakeStudents([]), new FakeShorthandCodes([]),
            holidays ?? new FakeSchoolHolidays(), new SchoolCalendarSettingsService(tempPath),
            new PeriodScheduleService(tempPath), supervisionDuties ?? new FakeSupervisionDuties(),
            new LetterTemplateService(tempPath), TestSupport.BuildAiSettingsService(), TestSupport.BuildAiPlanningService(),
            TestSupport.BuildSyncSettingsService(), TestSupport.BuildSyncAuthService(),
            eventQueue ?? TestSupport.BuildEventQueue());
    }

    [Fact]
    public void SyncConflicts_ZeigtUnreviewedKonflikteBeimLaden()
    {
        var queue = TestSupport.BuildEventQueue();
        var conflict = new ConflictEntry
        {
            LocalEvent = new SyncEvent { EntityType = "Student", EntityId = Guid.NewGuid().ToString(), Operation = "Save" },
            RemoteEvent = new SyncEvent { EntityType = "Student", EntityId = Guid.NewGuid().ToString(), Operation = "Save" },
            Resolution = "RemoteWon",
        };
        queue.AddConflict(conflict);

        var vm = BuildViewModel(eventQueue: queue);

        var item = Assert.Single(vm.SyncConflicts);
        Assert.Equal(conflict.Id, item.Id);
        Assert.Contains("anderen Gerät", item.ResolutionDisplay);
    }

    [Fact]
    public void MarkConflictReviewed_EntferntKonfliktAusListeUndAusDerQueue()
    {
        var queue = TestSupport.BuildEventQueue();
        var conflict = new ConflictEntry
        {
            LocalEvent = new SyncEvent { EntityType = "Student", EntityId = Guid.NewGuid().ToString(), Operation = "Save" },
            RemoteEvent = new SyncEvent { EntityType = "Student", EntityId = Guid.NewGuid().ToString(), Operation = "Save" },
            Resolution = "LocalWon",
        };
        queue.AddConflict(conflict);
        var vm = BuildViewModel(eventQueue: queue);
        var item = vm.SyncConflicts.Single();

        vm.MarkConflictReviewedCommand.Execute(item);

        Assert.Empty(vm.SyncConflicts);
        Assert.Empty(queue.GetUnreviewed());
    }

    [Fact]
    public void AddSchoolHoliday_GueltigeEingabe_WirdGespeichertUndInListeAngezeigt()
    {
        var holidays = new FakeSchoolHolidays();
        var vm = BuildViewModel(holidays);
        vm.NewHolidayName = "Sommerferien";
        vm.NewHolidayStartText = "01.07.2026";
        vm.NewHolidayEndText = "10.08.2026";

        vm.AddSchoolHolidayCommand.Execute(null);

        Assert.Single(holidays.GetAll());
        Assert.Single(vm.SchoolHolidayEntries);
    }

    [Fact]
    public void AddSchoolHoliday_EndeVorBeginn_SetztFehlerUndSpeichertNicht()
    {
        var holidays = new FakeSchoolHolidays();
        var vm = BuildViewModel(holidays);
        vm.NewHolidayName = "Ungültig";
        vm.NewHolidayStartText = "10.08.2026";
        vm.NewHolidayEndText = "01.07.2026";

        vm.AddSchoolHolidayCommand.Execute(null);

        Assert.Empty(holidays.GetAll());
        Assert.NotEqual("", vm.HolidayDateError);
    }

    [Fact]
    public void AddSchoolHoliday_FehlenderName_SetztFehlerUndSpeichertNicht()
    {
        var holidays = new FakeSchoolHolidays();
        var vm = BuildViewModel(holidays);
        vm.NewHolidayStartText = "01.07.2026";
        vm.NewHolidayEndText = "10.08.2026";

        vm.AddSchoolHolidayCommand.Execute(null);

        Assert.Empty(holidays.GetAll());
        Assert.NotEqual("", vm.HolidayNameError);
    }

    [Fact]
    public void RemoveSchoolHoliday_EntferntEintragAusRepositoryUndListe()
    {
        var holidays = new FakeSchoolHolidays();
        var holiday = new SchoolHoliday { Name = "Herbstferien", StartDate = new DateOnly(2026, 10, 12), EndDate = new DateOnly(2026, 10, 24) };
        holidays.Add(holiday);
        var vm = BuildViewModel(holidays);

        vm.RemoveSchoolHolidayCommand.Execute(vm.SchoolHolidayEntries[0]);

        Assert.Empty(holidays.GetAll());
        Assert.Empty(vm.SchoolHolidayEntries);
    }

    [Fact]
    public void SelectedStateName_Aendern_PersistiertUeberSchoolCalendarSettings()
    {
        var tempPath = System.IO.Path.Combine(
            System.IO.Path.GetTempPath(), $"lehrerapp-settingsvm-state-tests-{Guid.NewGuid():N}");
        Directory.CreateDirectory(tempPath);
        var calendarSettings = new SchoolCalendarSettingsService(tempPath);

        var vm = new SettingsViewModel(
            new FakeSubjects([]), new FakeCompetencyDomains(), new FakeGradingKeyTemplates(),
            new FakeSchemes(), new GradingService(), new BackupService(tempPath),
            new DatabaseEncryptionService(), new AppLockService(tempPath),
            new LiteDbContext(new MemoryStream()), new PrivacySettingsService(tempPath),
            new FakeDocumentation(), new FakeStudents([]), new FakeShorthandCodes([]),
            new FakeSchoolHolidays(), calendarSettings, new PeriodScheduleService(tempPath),
            new FakeSupervisionDuties(), new LetterTemplateService(tempPath), TestSupport.BuildAiSettingsService(), TestSupport.BuildAiPlanningService(),
            TestSupport.BuildSyncSettingsService(), TestSupport.BuildSyncAuthService(), TestSupport.BuildEventQueue());

        vm.SelectedStateName = "Bayern";

        Assert.Equal(GermanState.BY, calendarSettings.State);
    }

    [Fact]
    public void SavePeriodTimes_GueltigeEingabe_WirdPersistiert()
    {
        var tempPath = System.IO.Path.Combine(
            System.IO.Path.GetTempPath(), $"lehrerapp-settingsvm-periods-tests-{Guid.NewGuid():N}");
        Directory.CreateDirectory(tempPath);
        var periodSchedule = new PeriodScheduleService(tempPath);

        var vm = new SettingsViewModel(
            new FakeSubjects([]), new FakeCompetencyDomains(), new FakeGradingKeyTemplates(),
            new FakeSchemes(), new GradingService(), new BackupService(tempPath),
            new DatabaseEncryptionService(), new AppLockService(tempPath),
            new LiteDbContext(new MemoryStream()), new PrivacySettingsService(tempPath),
            new FakeDocumentation(), new FakeStudents([]), new FakeShorthandCodes([]),
            new FakeSchoolHolidays(), new SchoolCalendarSettingsService(tempPath), periodSchedule,
            new FakeSupervisionDuties(), new LetterTemplateService(tempPath), TestSupport.BuildAiSettingsService(), TestSupport.BuildAiPlanningService(),
            TestSupport.BuildSyncSettingsService(), TestSupport.BuildSyncAuthService(), TestSupport.BuildEventQueue());

        vm.PeriodTimes[0].StartText = "08:00";
        vm.PeriodTimes[0].EndText = "08:45";

        vm.SavePeriodTimesCommand.Execute(null);

        Assert.Equal("", vm.PeriodTimesError);
        Assert.Equal(45, periodSchedule.GetDurationMinutes(1));
    }

    [Fact]
    public void SavePeriodTimes_EndeVorBeginn_SetztFehlerUndSpeichertNicht()
    {
        var tempPath = System.IO.Path.Combine(
            System.IO.Path.GetTempPath(), $"lehrerapp-settingsvm-periods-invalid-tests-{Guid.NewGuid():N}");
        Directory.CreateDirectory(tempPath);
        var periodSchedule = new PeriodScheduleService(tempPath);

        var vm = new SettingsViewModel(
            new FakeSubjects([]), new FakeCompetencyDomains(), new FakeGradingKeyTemplates(),
            new FakeSchemes(), new GradingService(), new BackupService(tempPath),
            new DatabaseEncryptionService(), new AppLockService(tempPath),
            new LiteDbContext(new MemoryStream()), new PrivacySettingsService(tempPath),
            new FakeDocumentation(), new FakeStudents([]), new FakeShorthandCodes([]),
            new FakeSchoolHolidays(), new SchoolCalendarSettingsService(tempPath), periodSchedule,
            new FakeSupervisionDuties(), new LetterTemplateService(tempPath), TestSupport.BuildAiSettingsService(), TestSupport.BuildAiPlanningService(),
            TestSupport.BuildSyncSettingsService(), TestSupport.BuildSyncAuthService(), TestSupport.BuildEventQueue());

        vm.PeriodTimes[0].StartText = "08:45";
        vm.PeriodTimes[0].EndText = "08:00";

        vm.SavePeriodTimesCommand.Execute(null);

        Assert.NotEqual("", vm.PeriodTimesError);
        Assert.Equal(0, periodSchedule.GetDurationMinutes(1));
    }

    [Fact]
    public void AddSupervisionDuty_GueltigeEingabe_WirdGespeichertUndInListeAngezeigt()
    {
        var duties = new FakeSupervisionDuties();
        var vm = BuildViewModel(supervisionDuties: duties);
        vm.NewDutyWeekdayName = "Montag";
        vm.NewDutyAfterPeriod = 2;
        vm.NewDutyLocation = "Pausenhof";

        vm.AddSupervisionDutyCommand.Execute(null);

        Assert.Single(duties.GetAll());
        Assert.Single(vm.SupervisionDuties);
        Assert.Equal(DayOfWeek.Monday, duties.GetAll()[0].Weekday);
        Assert.Equal(2, duties.GetAll()[0].AfterPeriod);
    }

    [Fact]
    public void AddSupervisionDuty_FehlenderOrt_SetztFehlerUndSpeichertNicht()
    {
        var duties = new FakeSupervisionDuties();
        var vm = BuildViewModel(supervisionDuties: duties);
        vm.NewDutyWeekdayName = "Montag";
        vm.NewDutyAfterPeriod = 2;

        vm.AddSupervisionDutyCommand.Execute(null);

        Assert.Empty(duties.GetAll());
        Assert.NotEqual("", vm.NewDutyError);
    }

    [Fact]
    public void AddSupervisionDuty_PauseBereitsBelegt_ZeigtFreundlicheFehlermeldung()
    {
        var duties = new FakeSupervisionDuties();
        duties.Add(new SupervisionDuty { Weekday = DayOfWeek.Monday, AfterPeriod = 2, Location = "Pausenhof" });
        var vm = BuildViewModel(supervisionDuties: duties);
        vm.NewDutyWeekdayName = "Montag";
        vm.NewDutyAfterPeriod = 2;
        vm.NewDutyLocation = "Bibliothek";

        vm.AddSupervisionDutyCommand.Execute(null);

        Assert.Single(duties.GetAll());
        Assert.Equal("Für diese Pause ist bereits eine Aufsicht eingetragen.", vm.NewDutyError);
    }

    [Fact]
    public void RemoveSupervisionDuty_EntferntEintragAusRepositoryUndListe()
    {
        var duties = new FakeSupervisionDuties();
        duties.Add(new SupervisionDuty { Weekday = DayOfWeek.Monday, AfterPeriod = 2, Location = "Pausenhof" });
        var vm = BuildViewModel(supervisionDuties: duties);

        vm.RemoveSupervisionDutyCommand.Execute(vm.SupervisionDuties[0]);

        Assert.Empty(duties.GetAll());
        Assert.Empty(vm.SupervisionDuties);
    }

    [Fact]
    public void Kompetenzbereiche_Umsortieren_PersistiertSortOrder()
    {
        var subject = new Subject { Name = "Biologie", ShortName = "Bio" };
        var repository = new FakeCompetencyDomains();
        repository.Add(new CompetencyDomain
        {
            SubjectId = subject.Id, GradeLevel = 10, Name = "Erster Bereich", SortOrder = 0,
        });
        repository.Add(new CompetencyDomain
        {
            SubjectId = subject.Id, GradeLevel = 10, Name = "Zweiter Bereich", SortOrder = 1,
        });
        var vm = BuildViewModel(subjects: new FakeSubjects([subject]), competencyDomains: repository);
        vm.CatalogSubject = vm.Subjects.Single();

        vm.Domains[1].MoveUpCommand.Execute(null);

        Assert.Equal(["Zweiter Bereich", "Erster Bereich"], vm.Domains.Select(x => x.Name));
        var stored = repository.GetBySubjectAndGrade(subject.Id, 10);
        Assert.Equal(["Zweiter Bereich", "Erster Bereich"], stored.Select(x => x.Name));
        Assert.Equal([0, 1], stored.Select(x => x.SortOrder));
    }

    [Fact]
    public void Kompetenzen_Umsortieren_PersistiertSortOrder()
    {
        var repository = new FakeCompetencyDomains();
        var domain = new CompetencyDomain
        {
            Name = "Bereich",
            Items =
            [
                new CompetencyItem { Code = "A", Description = "Erste", SortOrder = 0 },
                new CompetencyItem { Code = "B", Description = "Zweite", SortOrder = 1 },
            ],
        };
        repository.Add(domain);
        var vm = new DomainEditItem(domain, repository);

        vm.Items[1].MoveUpCommand.Execute(null);

        Assert.Equal(["B", "A"], vm.Items.Select(x => x.Code));
        var stored = repository.GetById(domain.Id)!;
        Assert.Equal(["B", "A"], stored.Items.Select(x => x.Code));
        Assert.Equal([0, 1], stored.Items.Select(x => x.SortOrder));
    }

    [Fact]
    public void KatalogKopieren_BereitetSichereVorschauFuerZielstufeVor()
    {
        var subject = new Subject { Name = "Biologie", ShortName = "Bio" };
        var repository = new FakeCompetencyDomains();
        repository.Add(new CompetencyDomain
        {
            SubjectId = subject.Id,
            GradeLevel = 10,
            Name = "Erkenntnisgewinnung",
            Code = "EG",
            Items = [new CompetencyItem { Code = "EG1", Description = "Modelle verwenden" }],
        });
        var vm = BuildViewModel(subjects: new FakeSubjects([subject]), competencyDomains: repository);
        vm.CatalogSubject = vm.Subjects.Single();

        var preview = vm.PrepareCatalogCopy(11);

        Assert.NotNull(preview);
        Assert.Equal(11, preview.GradeLevel);
        Assert.Equal(1, preview.NewDomains);
        Assert.Equal(1, preview.NewCompetencies);

        vm.ApplyCatalogImport(preview, CompetencyCatalogImportMode.Merge, new HashSet<string>());
        var copied = repository.GetBySubjectAndGrade(subject.Id, 11);
        Assert.Single(copied);
        Assert.NotEqual(repository.GetBySubjectAndGrade(subject.Id, 10)[0].Id, copied[0].Id);
        Assert.Equal("EG1", copied[0].Items.Single().Code);
    }
}