LehrerApp/LehrerApp.Tests/PrivacySettingsServiceTests.cs

using LehrerApp.Core.Services;
using Xunit;

namespace LehrerApp.Tests;

public sealed class PrivacySettingsServiceTests
{
    [Fact]
    public void NeueKonfiguration_HatDreiJahreAlsStandard()
    {
        using var temp = new TempAppData();
        var service = new PrivacySettingsService(temp.Path);

        Assert.Equal(3, service.RetentionYears);
    }

    [Fact]
    public void SetRetentionYears_WirdUeberNeueInstanzHinwegPersistiert()
    {
        using var temp = new TempAppData();
        new PrivacySettingsService(temp.Path).SetRetentionYears(5);

        var second = new PrivacySettingsService(temp.Path);

        Assert.Equal(5, second.RetentionYears);
    }

    [Fact]
    public void SetRetentionYears_WertUnterEinsWirdAufEinsBegrenzt()
    {
        using var temp = new TempAppData();
        var service = new PrivacySettingsService(temp.Path);

        service.SetRetentionYears(0);

        Assert.Equal(1, service.RetentionYears);
    }

    [Fact]
    public void RetentionCutoff_LiegtRetentionYearsVorDemStichtag()
    {
        using var temp = new TempAppData();
        var service = new PrivacySettingsService(temp.Path);
        service.SetRetentionYears(3);
        var now = new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc);

        var cutoff = service.RetentionCutoff(now);

        Assert.Equal(new DateTime(2023, 1, 1, 0, 0, 0, DateTimeKind.Utc), cutoff);
    }

    private sealed class TempAppData : IDisposable
    {
        public string Path { get; } = System.IO.Path.Combine(
            System.IO.Path.GetTempPath(), $"lehrerapp-privacy-tests-{Guid.NewGuid():N}");

        public TempAppData() => Directory.CreateDirectory(Path);
        public void Dispose() { if (Directory.Exists(Path)) Directory.Delete(Path, recursive: true); }
    }
}