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

namespace LehrerApp.Desktop.Tests;

public sealed class UntisMappingReviewDialogViewModelTests
{
    private static string BuildTempPath()
    {
        var path = Path.Combine(Path.GetTempPath(), $"lehrerapp-untisreview-tests-{Guid.NewGuid():N}");
        Directory.CreateDirectory(path);
        return path;
    }

    private static UntisSyncService BuildUntisSyncService(FakeUntisSlotMappings mappings) => new(
        new HttpClient(), new WebUntisSettingsService(BuildTempPath()),
        new FakeUntisSnapshots(), mappings, new FakeSubstitutionEntries(), new FakeGroups([]),
        new FakeTimetableSlots(), new FakeSupervisionDuties(), new FakeSchoolHolidays(),
        new PublicHolidayService(), new SchoolCalendarSettingsService(BuildTempPath()),
        new PeriodScheduleService(BuildTempPath()), new UntisMatchingService(), new UntisDiffService());

    private static UntisMappingReviewDialogViewModel BuildDialogVm(FakeUntisSlotMappings mappings,
        List<LearningGroup>? groups = null) =>
        new(BuildUntisSyncService(mappings), mappings, groups ?? [], new FakeSubjects([]));

    private static List<UntisGroupOption> Options(params LearningGroup[] groups) =>
        groups.Select(g => new UntisGroupOption(g, null)).ToList();

    private static UntisSlotMatch BuildLessonMatch(Guid? groupId, string classToken = "10c") => new()
    {
        Pattern = new UntisWeeklyPattern
        {
            Weekday = DayOfWeek.Monday, StartTime = new TimeOnly(7, 50), EndTime = new TimeOnly(9, 20),
            Summary = "SOL", ClassTokens = [classToken], OccurrenceCount = 40,
        },
        PeriodNumber = 1, SuggestedGroupId = groupId, IsConfident = groupId is not null,
    };

    private static UntisSlotMatch BuildSupervisionMatch() => new()
    {
        Pattern = new UntisWeeklyPattern
        {
            Weekday = DayOfWeek.Tuesday, StartTime = new TimeOnly(9, 20), EndTime = new TimeOnly(9, 40),
            Summary = null, ClassTokens = [], OccurrenceCount = 40,
        },
        AfterPeriod = 2,
    };

    [Fact]
    public void UntisMappingRow_VorschlagWirdVorausgewaehlt()
    {
        var group = new LearningGroup { Name = "10c" };
        var row = new UntisMappingRow(BuildLessonMatch(group.Id), Options(group), existing: null);

        Assert.Equal(group.Id, row.SelectedGroup?.Group.Id);
        Assert.True(row.IsConfident);
        Assert.False(row.IsSupervisionCandidate);
    }

    [Fact]
    public void UntisMappingRow_OhneVorschlag_BleibtLeer()
    {
        var row = new UntisMappingRow(BuildLessonMatch(null), [], existing: null);

        Assert.Null(row.SelectedGroup);
        Assert.False(row.IsConfident);
    }

    [Fact]
    public void UntisGroupOption_GleicherNameVerschiedeneFaecher_ZeigtFachImDisplayLabel()
    {
        // Nutzer-Feedback: "Meine Klasse habe ich 3-mal. Ohne das Fach dabei, kann ich nicht
        // sicher die richtige Lerngruppe hier auswählen."
        var option = new UntisGroupOption(new LearningGroup { Name = "10c" }, "Chemie");

        Assert.Equal("10c (Chemie)", option.DisplayLabel);
    }

    [Fact]
    public void UntisGroupOption_OhneFach_ZeigtNurDenNamen()
    {
        var option = new UntisGroupOption(new LearningGroup { Name = "10c" }, null);

        Assert.Equal("10c", option.DisplayLabel);
    }

    [Fact]
    public void UntisMappingRow_AufsichtsMuster_WirdAlsSupervisionCandidateErkanntUndKannAufgeloestWerden()
    {
        // Nutzer-Feedback: "Zwei Termine sind meine Aufsichten [...] vom Zeitraster und von der
        // Dauer her könnten die erfasst werden" - kein Klassenbezug, aber AfterPeriod auflösbar.
        var row = new UntisMappingRow(BuildSupervisionMatch(), [], existing: null);

        Assert.True(row.IsSupervisionCandidate);
        Assert.True(row.CanResolve);
        Assert.False(row.ConfirmAsSupervision);
    }

    [Fact]
    public void Save_SchreibtNurZeilenMitAusgewaehlterGruppeAlsBestaetigt()
    {
        var groupA = new LearningGroup { Name = "10c" };
        var groupB = new LearningGroup { Name = "10d" };
        var mappings = new FakeUntisSlotMappings();
        var vm = BuildDialogVm(mappings, [groupA, groupB]);
        vm.Rows.Add(new UntisMappingRow(BuildLessonMatch(groupA.Id), Options(groupA, groupB), existing: null));
        vm.Rows.Add(new UntisMappingRow(BuildLessonMatch(null, "9z"), Options(groupA, groupB), existing: null)); // ignoriert

        vm.SaveCommand.Execute(null);

        var saved = Assert.Single(mappings.GetAll());
        Assert.True(saved.Confirmed);
        Assert.Equal(SubstitutionKind.Lesson, saved.Kind);
        Assert.Equal(groupA.Id, saved.GroupId);
        Assert.Equal(1, saved.PeriodNumber);
    }

    [Fact]
    public void Save_AufsichtBestaetigt_SchreibtSupervisionMapping()
    {
        var mappings = new FakeUntisSlotMappings();
        var vm = BuildDialogVm(mappings);
        var row = new UntisMappingRow(BuildSupervisionMatch(), [], existing: null) { ConfirmAsSupervision = true };
        vm.Rows.Add(row);

        vm.SaveCommand.Execute(null);

        var saved = Assert.Single(mappings.GetAll());
        Assert.Equal(SubstitutionKind.Supervision, saved.Kind);
        Assert.Null(saved.GroupId);
        Assert.Equal(2, saved.AfterPeriod);
        Assert.True(saved.Confirmed);
    }

    [Fact]
    public void Save_ErneutesSpeichernDerselbenZeile_AktualisiertStattDupliziert()
    {
        // Regression für "Kann es sein, dass er meine Verbesserungen gar nicht einspeichert" -
        // wiederholtes Bestätigen desselben Slots darf keine zweite Zeile anlegen (sonst
        // ArgumentException in UntisDiffService.Diff beim nächsten Poll, siehe dortigen Test).
        var groupA = new LearningGroup { Name = "10c" };
        var groupB = new LearningGroup { Name = "10d" };
        var mappings = new FakeUntisSlotMappings();
        var vm1 = BuildDialogVm(mappings, [groupA, groupB]);
        vm1.Rows.Add(new UntisMappingRow(BuildLessonMatch(groupA.Id), Options(groupA, groupB), existing: null));
        vm1.SaveCommand.Execute(null);

        var firstSaved = Assert.Single(mappings.GetAll());

        // Dialog erneut geöffnet - die bereits bestätigte Gruppe muss vorbefüllt sein.
        var existing = mappings.GetAll().Single();
        var row2 = new UntisMappingRow(BuildLessonMatch(groupA.Id), Options(groupA, groupB), existing);
        Assert.Equal(groupA.Id, row2.SelectedGroup?.Group.Id);

        row2.SelectedGroup = Options(groupB).Single(); // Nutzer korrigiert
        var vm2 = BuildDialogVm(mappings, [groupA, groupB]);
        vm2.Rows.Add(row2);
        vm2.SaveCommand.Execute(null);

        var saved = Assert.Single(mappings.GetAll());
        Assert.Equal(firstSaved.Id, saved.Id);
        Assert.Equal(groupB.Id, saved.GroupId);
    }

    [Fact]
    public void Save_NutzerAendertVorschlag_UebernimmtNeueAuswahl()
    {
        var groupA = new LearningGroup { Name = "10c" };
        var groupB = new LearningGroup { Name = "10d" };
        var mappings = new FakeUntisSlotMappings();
        var vm = BuildDialogVm(mappings, [groupA, groupB]);
        var row = new UntisMappingRow(BuildLessonMatch(groupA.Id), Options(groupA, groupB), existing: null);
        row.SelectedGroup = Options(groupB).Single();
        vm.Rows.Add(row);

        vm.SaveCommand.Execute(null);

        Assert.Equal(groupB.Id, Assert.Single(mappings.GetAll()).GroupId);
    }
}