using LehrerApp.Sync.Models;
using Xunit;

namespace LehrerApp.Sync.Tests;

public sealed class EventQueueTests
{
    [Fact]
    public void MarkReviewed_EntferntKonfliktAusDerUnreviewedListe()
    {
        using var temp = new TempEventQueue();
        var conflict = new ConflictEntry
        {
            LocalEvent = MakeEvent(),
            RemoteEvent = MakeEvent(),
            Resolution = "LocalWon",
        };
        temp.Queue.AddConflict(conflict);

        temp.Queue.MarkReviewed(conflict.Id);

        Assert.Empty(temp.Queue.GetUnreviewed());
        Assert.Equal(0, temp.Queue.ConflictCount());
    }

    [Fact]
    public void MarkReviewed_UnbekannteId_TutNichtsUndWirftNicht()
    {
        using var temp = new TempEventQueue();

        var exception = Record.Exception(() => temp.Queue.MarkReviewed(Guid.NewGuid()));

        Assert.Null(exception);
    }

    [Fact]
    public void ClearConflicts_EntferntAlleKonflikte()
    {
        using var temp = new TempEventQueue();
        temp.Queue.AddConflict(new ConflictEntry
        {
            LocalEvent = MakeEvent(), RemoteEvent = MakeEvent(), Resolution = "LocalWon",
        });
        temp.Queue.AddConflict(new ConflictEntry
        {
            LocalEvent = MakeEvent(), RemoteEvent = MakeEvent(), Resolution = "RemoteWon",
        });

        temp.Queue.ClearConflicts();

        Assert.Empty(temp.Queue.GetUnreviewed());
        Assert.Equal(0, temp.Queue.ConflictCount());
    }

    [Fact]
    public void GetKnownServerSeq_UnbekannteEntitaet_LiefertNull()
    {
        using var temp = new TempEventQueue();

        Assert.Null(temp.Queue.GetKnownServerSeq("Lesson", Guid.NewGuid().ToString()));
    }

    [Fact]
    public void SetKnownServerSeq_GefolgtVonGet_LiefertDenGesetztenWert()
    {
        using var temp = new TempEventQueue();
        var entityId = Guid.NewGuid().ToString();

        temp.Queue.SetKnownServerSeq("Lesson", entityId, 42);

        Assert.Equal(42, temp.Queue.GetKnownServerSeq("Lesson", entityId));
    }

    [Fact]
    public void SetKnownServerSeq_ErneutesSetzen_UeberschreibtDenAltenWert()
    {
        using var temp = new TempEventQueue();
        var entityId = Guid.NewGuid().ToString();
        temp.Queue.SetKnownServerSeq("Lesson", entityId, 42);

        temp.Queue.SetKnownServerSeq("Lesson", entityId, 43);

        Assert.Equal(43, temp.Queue.GetKnownServerSeq("Lesson", entityId));
    }

    [Fact]
    public void SetKnownServerSeq_GleicheEntityIdAndererEntityType_BleibtGetrennt()
    {
        using var temp = new TempEventQueue();
        var entityId = Guid.NewGuid().ToString();
        temp.Queue.SetKnownServerSeq("Lesson", entityId, 42);

        temp.Queue.SetKnownServerSeq("Unit", entityId, 7);

        Assert.Equal(42, temp.Queue.GetKnownServerSeq("Lesson", entityId));
        Assert.Equal(7, temp.Queue.GetKnownServerSeq("Unit", entityId));
    }

    [Fact]
    public void ClearKnownServerSeq_EntferntNurDieAngegebeneEntitaet()
    {
        using var temp = new TempEventQueue();
        var entityId = Guid.NewGuid().ToString();
        temp.Queue.SetKnownServerSeq("Lesson", entityId, 42);
        temp.Queue.SetKnownServerSeq("Unit", entityId, 7);

        temp.Queue.ClearKnownServerSeq("Lesson", entityId);

        Assert.Null(temp.Queue.GetKnownServerSeq("Lesson", entityId));
        Assert.Equal(7, temp.Queue.GetKnownServerSeq("Unit", entityId));
    }

    [Fact]
    public void ClearKnownServerSeq_UnbekannteEntitaet_TutNichtsUndWirftNicht()
    {
        using var temp = new TempEventQueue();

        var exception = Record.Exception(() => temp.Queue.ClearKnownServerSeq("Lesson", "unbekannt"));

        Assert.Null(exception);
    }

    /// Regression: nach einem Kontowechsel (TODO 10.3.5, z.B. Login-Korrektur der Groß-/
    /// Kleinschreibung, siehe TODO 10.2.5) sind alle lokal zwischengespeicherten ServerSeq-Werte
    /// bedeutungslos - sie beziehen sich auf das Event-Log eines ANDEREN Server-Kontos.
    [Fact]
    public void ResetKnownServerSeqs_EntferntAlleEintraege()
    {
        using var temp = new TempEventQueue();
        temp.Queue.SetKnownServerSeq("Lesson", "a", 1);
        temp.Queue.SetKnownServerSeq("Unit", "b", 2);

        temp.Queue.ResetKnownServerSeqs();

        Assert.Null(temp.Queue.GetKnownServerSeq("Lesson", "a"));
        Assert.Null(temp.Queue.GetKnownServerSeq("Unit", "b"));
    }

    private static SyncEvent MakeEvent() => new()
    {
        DeviceId = "desktop-1",
        DeviceType = DeviceType.Desktop,
        EntityType = "Student",
        EntityId = Guid.NewGuid().ToString(),
        Operation = "Save",
        Payload = "{}",
    };

    private sealed class TempEventQueue : IDisposable
    {
        private readonly string _directory = Path.Combine(
            Path.GetTempPath(), $"lehrerapp-sync-tests-eventqueue-{Guid.NewGuid():N}");
        public EventQueue Queue { get; }

        public TempEventQueue()
        {
            Directory.CreateDirectory(_directory);
            Queue = new EventQueue(Path.Combine(_directory, "queue.db"));
        }

        public void Dispose()
        {
            Queue.Dispose();
            if (Directory.Exists(_directory)) Directory.Delete(_directory, recursive: true);
        }
    }
}