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

namespace Omika.Tests.Observability;

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

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

        Assert.Equal(1L, counters.Accepted);
        Assert.Equal(0L, counters.DroppedTotal);
    }

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

        sink.Track(null!);

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

    [Fact]
    public void Disabled_IsDropped()
    {
        var options = new ObservabilityOptions { Enabled = false };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);

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

        Assert.Equal(1L, counters.DroppedDisabled);
        Assert.Equal(0L, counters.Accepted);
    }

    [Fact]
    public void ModeOff_IsDropped()
    {
        var options = new ObservabilityOptions { Mode = TelemetryMode.Off };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);

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

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

    [Fact]
    public void LevelFiltered_IsDropped()
    {
        var options = new ObservabilityOptions { Mode = TelemetryMode.ErrorsOnly };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);

        sink.Track(ObservabilityTestHarness.NewEvent(TelemetryEventCodes.MobileAppStarted, level: TelemetryLevel.Info));

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

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

        sink.Track(new TelemetryEvent { EventCode = default });

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

    [Fact]
    public void MetadataTooLarge_IsDropped()
    {
        var options = new ObservabilityOptions { MaxMetadataProperties = 2 };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);
        var metadata = TelemetryMetadata.Create(("a", 1), ("b", 2), ("c", 3));

        sink.Track(ObservabilityTestHarness.NewEvent(
            TelemetryEventCodes.MobileAppStarted, metadata: metadata));

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

    [Fact]
    public void StringTooLong_IsDropped()
    {
        var options = new ObservabilityOptions { MaxStringLength = 4 };
        var (sink, _, counters) = ObservabilityTestHarness.CreatePipeline(options);
        var metadata = TelemetryMetadata.Create(("k", new string('x', 10)));

        sink.Track(ObservabilityTestHarness.NewEvent(
            TelemetryEventCodes.MobileAppStarted, metadata: metadata));

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

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

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

        Assert.Equal(100L, counters.Accepted + counters.DroppedTotal);
    }
}