LehrerApp/LehrerApp.Desktop.Tests/ClassTeacherViewModelsTests.cs

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

namespace LehrerApp.Desktop.Tests;

public sealed class ClassTeacherViewModelsTests
{
    [Fact]
    public void GroupByStudentAndDay_FasstFehlstundenProSchuelerUndTagZusammen()
    {
        var entries = new[]
        {
            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260824, 1, 45, "HED", "Che", "Absent",
                "Krank", 1, "24.08.26", true, null, 3, "nicht entsch.", false),
            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260824, 1, 45, "PAN", "Kunst", null,
                "Krank", 2, "24.08.26", true, null, 5, "nicht entsch.", true),
            new UntisClassAbsenceEntryDto("Andere Schuelerin", 2, "6a", 20260824, 1, 20, "BEN", "Deu",
                "Verspätung", null, 3, "24.08.26", false, "Zug verpasst", 1, "entsch.", false),
        };

        var rows = ClassAbsenceDaySummaryRow.GroupByStudentAndDay(entries);

        Assert.Equal(2, rows.Count);

        var max = rows[1];
        Assert.Equal("Muster Max", max.StudentName);
        Assert.Equal(2, max.TotalAbsentPeriods);
        Assert.Equal(90, max.TotalAbsentMinutes);
        Assert.Equal(["Che", "Kunst"], max.Subjects);
        Assert.Equal([3, 5], max.PeriodNumbers.Order());
        Assert.Equal(["nicht entsch."], max.Statuses);
        Assert.Equal(["Absent"], max.AbsenceReasons);
        Assert.Equal("Krank", max.Note);
        Assert.Null(max.ExcuseNote);
        Assert.True(max.CountsAsFullDay);

        var andere = rows[0];
        Assert.Equal("Andere Schuelerin", andere.StudentName);
        Assert.Equal(1, andere.TotalAbsentPeriods);
        Assert.Equal(20, andere.TotalAbsentMinutes);
        Assert.Equal(["Deu"], andere.Subjects);
        Assert.Null(andere.Note);
        Assert.Equal("Zug verpasst", andere.ExcuseNote);
        Assert.False(andere.CountsAsFullDay);
    }

    [Fact]
    public void GroupByStudentAndDay_TrenntGleichenNamenAnUnterschiedlichenTagen()
    {
        var entries = new[]
        {
            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260824, 1, 45, "HED", "Che", null,
                null, 1, "24.08.26", true, null, 3, "nicht entsch.", false),
            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260825, 1, 45, "HED", "Che", null,
                null, 2, "25.08.26", true, null, 3, "nicht entsch.", false),
        };

        var rows = ClassAbsenceDaySummaryRow.GroupByStudentAndDay(entries);

        Assert.Equal(2, rows.Count);
        Assert.Equal(new DateOnly(2026, 8, 25), rows[0].Date);
        Assert.Equal(new DateOnly(2026, 8, 24), rows[1].Date);
    }

    [Fact]
    public void RosterBuild_OrdnetFehlzeitPerExternKeyUndKlassenbuchPerNameZu()
    {
        var students = new[]
        {
            Student(1001, "Ada Müller"),
            Student(1002, "Ben Schmidt"),
            Student(1003, "Cem Yilmaz"),
        };
        var todayAbsences = new[]
        {
            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 25), "Ada Müller", 1001, 2, 90,
                ["Che"], [3, 4], ["nicht entsch."], ["Absent"], null, null, false),
        };
        var recentClassRegister = new[]
        {
            new UntisForeignClassRegisterEventDto("6a", 20260824, "Deu", "Ben Schmidt", "mueller",
                "Vergessen", "Organisation", "Buch vergessen"),
        };

        var roster = ClassTeacherRosterRow.Build(students, todayAbsences, recentClassRegister);

        Assert.Equal(3, roster.Count);
        var ada = Assert.Single(roster, r => r.StudentName == "Ada Müller");
        Assert.True(ada.HasAbsenceToday);
        Assert.Contains("nicht entsch.", ada.AbsenceTooltip);
        Assert.False(ada.HasRecentClassRegisterEntry);

        var ben = Assert.Single(roster, r => r.StudentName == "Ben Schmidt");
        Assert.False(ben.HasAbsenceToday);
        Assert.True(ben.HasRecentClassRegisterEntry);

        var cem = Assert.Single(roster, r => r.StudentName == "Cem Yilmaz");
        Assert.False(cem.HasAbsenceToday);
        Assert.False(cem.HasRecentClassRegisterEntry);
    }

    [Fact]
    public void RosterBuild_ErkenntNamenAuchInVertauschterReihenfolge()
    {
        // WebUntis liefert Namen im Schülerreport als "Vorname Nachname", in Fehlzeiten-/
        // Klassenbuchberichten aber typischerweise als "Nachname Vorname" - der Namensabgleich
        // muss das auch ohne ExternKey erkennen (Regressionstest für genau diesen Bug).
        var students = new[] { Student(externKey: null, displayName: "Ben Schmidt") };
        var todayAbsences = new[]
        {
            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 25), "Schmidt Ben", null, 1, 45,
                ["Che"], [3], ["nicht entsch."], ["Absent"], null, null, false),
        };
        var recentClassRegister = new[]
        {
            new UntisForeignClassRegisterEventDto("6a", 20260824, "Deu", "Schmidt Ben", "mueller",
                "Vergessen", "Organisation", "Buch vergessen"),
        };

        var roster = ClassTeacherRosterRow.Build(students, todayAbsences, recentClassRegister);

        var ben = Assert.Single(roster);
        Assert.True(ben.HasAbsenceToday);
        Assert.True(ben.HasRecentClassRegisterEntry);
    }

    [Fact]
    public void RosterBuild_BeschreibtVerspaetungNichtAlsNullFehlstunden()
    {
        var students = new[] { Student(1001, "Ada Müller") };
        var todayAbsences = new[]
        {
            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 26), "Müller Ada", 1001, 0, 20,
                ["Deu"], [1], ["nicht entsch."], ["Verspätung"], null, null, false),
        };

        var row = Assert.Single(ClassTeacherRosterRow.Build(students, todayAbsences, [],
            new DateOnly(2026, 8, 26)));

        Assert.True(row.IsLate);
        Assert.True(row.IsUnexcused);
        Assert.Equal("20 Min. verspätet · Unentschuldigt", row.StatusText);
        Assert.Equal(ClassTeacherStatusKind.Danger, row.StatusKind);
    }

    [Fact]
    public void RosterBuild_PriorisiertHandlungsbedarfVorUnauffaelligenSchuelern()
    {
        var students = new[]
        {
            Student(1001, "Zora Unauffällig"),
            Student(1002, "Ada Fehlzeit"),
            Student(1003, "Ben Klassenbuch"),
        };
        var absences = new[]
        {
            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 26), "Fehlzeit Ada", 1002, 2, 90,
                ["Deu"], [1, 2], ["nicht entsch."], ["Absent"], null, null, false),
        };
        var register = new[]
        {
            new UntisForeignClassRegisterEventDto("10c", 20260825, "Deu", "Klassenbuch Ben", "test",
                "Fehlende HA", "Negativ", "Hausaufgaben fehlen"),
        };

        var rows = ClassTeacherRosterRow.Build(students, absences, register, new DateOnly(2026, 8, 26));

        Assert.Equal(["Ada Fehlzeit", "Ben Klassenbuch", "Zora Unauffällig"],
            rows.Select(r => r.StudentName));
    }

    [Fact]
    public void RosterBuild_BerechnetFehlquoteSeitSchuljahresbeginn()
    {
        var students = new[] { Student(1001, "Ada Müller") };
        var yearAbsences = new[]
        {
            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 10), "Müller Ada", 1001, 2, 90,
                ["Che"], [1, 2], ["entsch."], ["Krank"], null, null, false),
            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 17), "Müller Ada", 1001, 6, 270,
                ["Che"], [1, 2, 3, 4, 5, 6], ["nicht entsch."], ["Absent"], null, null, true),
        };

        var row = Assert.Single(ClassTeacherRosterRow.Build(students, [], [],
            new DateOnly(2026, 8, 26), yearAbsences, schoolDaysElapsed: 20));

        Assert.True(row.HasYearSummary);
        Assert.Equal(2, row.YearAbsenceDayCount);
        Assert.Equal(1, row.YearUnexcusedDayCount);
        Assert.Equal(10, row.YearAbsenceRatePercent);
        Assert.Contains("10 %", row.YearSummaryLabel);
        Assert.Contains("2 von 20", row.YearSummaryTooltip);
        Assert.Contains("1 unentschuldigt", row.YearSummaryTooltip);
    }

    [Fact]
    public void RosterBuild_OhneJahresdatenZeigtKeineFehlquote()
    {
        var students = new[] { Student(1001, "Ada Müller") };

        var row = Assert.Single(ClassTeacherRosterRow.Build(students, [], [], new DateOnly(2026, 8, 26)));

        Assert.False(row.HasYearSummary);
        Assert.Equal("", row.YearSummaryLabel);
        Assert.Null(row.YearSummaryTooltip);
    }

    [Fact]
    public void RosterBuild_OrdnetJahresfehlzeitenAuchOhneExternKeyUeberNamenZu()
    {
        var students = new[] { Student(externKey: null, displayName: "Ben Schmidt") };
        var yearAbsences = new[]
        {
            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 10), "Schmidt Ben", null, 2, 90,
                ["Che"], [1, 2], ["entsch."], ["Krank"], null, null, false),
        };

        var row = Assert.Single(ClassTeacherRosterRow.Build(students, [], [], new DateOnly(2026, 8, 26),
            yearAbsences, schoolDaysElapsed: 10));

        Assert.Equal(1, row.YearAbsenceDayCount);
    }

    [Fact]
    public void TrendDay_BalkenbreitenSummierenSichZurGesamtbreite()
    {
        var day = new ClassTeacherTrendDay("Mo", 5, 2, 1, 2, 40d, 20d, 40d);

        Assert.Equal(100d, day.TotalBarWidth);
    }

    private static UntisStudentRosterCacheEntry Student(int? externKey, string displayName) =>
        new() { ClassName = "6a", ExternKey = externKey, DisplayName = displayName };
}