using AcDream.App.Streaming;

namespace AcDream.App.Tests.Streaming;

public sealed class WorldRevealLifecycleTelemetryTests
{
    private static WorldRevealReadinessSnapshot Ready(uint cell = 0x11340021u) => new(
        cell,
        IsIndoor: false,
        IsUnhydratable: false,
        RequiredRenderRadius: 1,
        IsRenderNeighborhoodReady: true,
        AreCompositeTexturesReady: true,
        IsCollisionReady: true);

    [Fact]
    public void Login_RecordsReadyThenFirstVisibleFrameExactlyOnce()
    {
        var logs = new List<string>();
        var telemetry = new WorldRevealLifecycleTelemetry(logs.Add);

        long generation = telemetry.Begin(WorldRevealKind.Login);
        telemetry.ObserveReadiness(Ready());
        telemetry.ObserveWorldViewportVisible();
        telemetry.ObserveWorldViewportVisible();
        telemetry.Complete();

        Assert.Equal(generation, telemetry.Snapshot.Generation);
        Assert.True(telemetry.Snapshot.IsReady);
        Assert.True(telemetry.Snapshot.WorldViewportObserved);
        Assert.True(telemetry.Snapshot.Completed);
        Assert.Equal(0, telemetry.Snapshot.InvariantFailureCount);
        Assert.Single(logs, line => line.Contains("event=world-visible", StringComparison.Ordinal));
    }

    [Fact]
    public void EarlyWorldViewport_IsARecordedHardInvariantFailure()
    {
        var logs = new List<string>();
        var telemetry = new WorldRevealLifecycleTelemetry(logs.Add);

        telemetry.Begin(WorldRevealKind.Login);
        telemetry.ObserveReadiness(Ready() with { AreCompositeTexturesReady = false });
        telemetry.ObserveWorldViewportVisible();

        Assert.Equal(1, telemetry.Snapshot.InvariantFailureCount);
        Assert.Contains(logs, line => line.Contains("reason=viewport-before-ready", StringComparison.Ordinal));
    }

    [Fact]
    public void NewGeneration_SupersedesOldStateAndRejectsDestinationMutation()
    {
        var logs = new List<string>();
        var telemetry = new WorldRevealLifecycleTelemetry(logs.Add);

        long first = telemetry.Begin(WorldRevealKind.Login);
        telemetry.ObserveReadiness(Ready(0x11340021u));
        long second = telemetry.Begin(WorldRevealKind.Portal);
        telemetry.ObserveReadiness(Ready(0x3032001Cu));
        telemetry.ObserveReadiness(Ready(0xC95B0001u));

        Assert.True(second > first);
        Assert.Equal(WorldRevealKind.Portal, telemetry.Snapshot.Kind);
        Assert.Equal(0xC95B0001u, telemetry.Snapshot.Readiness.DestinationCell);
        Assert.Equal(1, telemetry.Snapshot.InvariantFailureCount);
        Assert.Contains(logs, line => line.Contains("event=superseded", StringComparison.Ordinal));
        Assert.Contains(logs, line => line.Contains("reason=destination-changed", StringComparison.Ordinal));
    }

    [Fact]
    public void PortalMaterialization_IsCountedOncePerGeneration()
    {
        var telemetry = new WorldRevealLifecycleTelemetry();

        telemetry.Begin(WorldRevealKind.Portal);
        telemetry.ObserveReadiness(Ready());
        telemetry.ObserveMaterialized();
        telemetry.ObserveMaterialized();
        telemetry.Begin(WorldRevealKind.Portal);
        telemetry.ObserveReadiness(Ready(0x3032001Cu));
        telemetry.ObserveMaterialized();

        Assert.Equal(2, telemetry.PortalMaterializationCount);
    }

    [Fact]
    public void CancelledGeneration_IgnoresLateAsyncObservations()
    {
        var telemetry = new WorldRevealLifecycleTelemetry();

        telemetry.Begin(WorldRevealKind.Portal);
        telemetry.Cancel();
        telemetry.ObserveReadiness(Ready());
        telemetry.ObserveMaterialized();
        telemetry.ObserveWorldViewportVisible();
        telemetry.Complete();

        Assert.True(telemetry.Snapshot.Cancelled);
        Assert.False(telemetry.Snapshot.IsReady);
        Assert.False(telemetry.Snapshot.Materialized);
        Assert.False(telemetry.Snapshot.WorldViewportObserved);
        Assert.False(telemetry.Snapshot.Completed);
        Assert.Equal(0, telemetry.PortalMaterializationCount);
    }
}