using Omika.Core.Configuration;
using Omika.Core.Observability;

namespace Omika.Tests.Observability;

/// <summary>
/// Contrat du chemin chaud <c>Track()</c> : il doit rester synchrone, rapide et
/// sans exception dans tous les états du pipeline (désactivé, file vide, presque
/// pleine, pleine, tempête). Aucun IO réseau/fichier/base n'est réalisé : le
/// chemin est purement en mémoire.
/// </summary>
public class TelemetryHotPathTests
{
    [Fact]
    public void Track_Disabled_ReturnsImmediately()
    {
        var options = new ObservabilityOptions { Enabled = false };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);

        sink.Track(ObservabilityTestHarness.NewEvent(TelemetryEventCodes.MobileAppStarted));

        Assert.Equal(1L, counters.DroppedDisabled);
    }

    [Fact]
    public void Track_EmptyQueue_Accepts()
    {
        var (sink, queue, counters) = ObservabilityTestHarness.CreatePipeline();

        sink.Track(ObservabilityTestHarness.NewEvent(TelemetryEventCodes.MobileAppStarted));

        Assert.Equal(1L, counters.Accepted);
        Assert.Equal(1, queue.Count);
    }

    [Fact]
    public void Track_NearFullQueue_Accepts()
    {
        var options = new ObservabilityOptions
        {
            P0QueueCapacity = 1,
            P1QueueCapacity = 1,
            P2QueueCapacity = 1,
            P3QueueCapacity = 1,
            P4QueueCapacity = 1
        };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);

        sink.Track(ObservabilityTestHarness.NewEvent(TelemetryEventCodes.MobileAppStarted));

        Assert.Equal(1L, counters.Accepted);
    }

    [Fact]
    public void Track_FullQueue_DropsWithoutThrow()
    {
        var options = new ObservabilityOptions
        {
            P0QueueCapacity = 1,
            P1QueueCapacity = 1,
            P2QueueCapacity = 1,
            P3QueueCapacity = 1,
            P4QueueCapacity = 1
        };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);

        sink.Track(ObservabilityTestHarness.NewEvent(TelemetryEventCodes.MobileAppStarted));
        sink.Track(ObservabilityTestHarness.NewEvent(TelemetryEventCodes.MobileAppStarted));

        Assert.Equal(1L, counters.Accepted);
        Assert.Equal(1L, counters.DroppedQueueFull);
    }

    [Fact]
    public void Track_LogStorm_DoesNotThrow()
    {
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline();

        for (int i = 0; i < 100_000; i++)
        {
            sink.Track(ObservabilityTestHarness.NewEvent(TelemetryEventCodes.MobileAppStarted));
        }

        // Aucune exception ; le flux est borné et comptabilisé.
        Assert.Equal(100_000L, counters.Accepted + counters.DroppedTotal);
    }
}