using StellaOps.Router.Common.Enums;
using StellaOps.Router.Common.Models;
using StellaOps.Router.Transport.InMemory;
using Xunit;

namespace StellaOps.Router.Transport.InMemory.Tests;

public class InMemoryChannelTests
{
    [Fact]
    public async Task ToMicroservice_WritesAndReads()
    {
        // Arrange
        using var channel = new InMemoryChannel("test-1");
        var frame = new Frame
        {
            Type = FrameType.Request,
            CorrelationId = "corr-1",
            Payload = ReadOnlyMemory<byte>.Empty
        };

        // Act
        await channel.ToMicroservice.Writer.WriteAsync(frame);
        var readFrame = await channel.ToMicroservice.Reader.ReadAsync();

        // Assert
        Assert.Equal(FrameType.Request, readFrame.Type);
        Assert.Equal("corr-1", readFrame.CorrelationId);
    }

    [Fact]
    public async Task ToGateway_WritesAndReads()
    {
        // Arrange
        using var channel = new InMemoryChannel("test-1");
        var frame = new Frame
        {
            Type = FrameType.Response,
            CorrelationId = "corr-1",
            Payload = ReadOnlyMemory<byte>.Empty
        };

        // Act
        await channel.ToGateway.Writer.WriteAsync(frame);
        var readFrame = await channel.ToGateway.Reader.ReadAsync();

        // Assert
        Assert.Equal(FrameType.Response, readFrame.Type);
        Assert.Equal("corr-1", readFrame.CorrelationId);
    }

    [Fact]
    public void Dispose_CancelsLifetimeToken()
    {
        // Arrange
        var channel = new InMemoryChannel("test-1");

        // Act
        channel.Dispose();

        // Assert
        Assert.True(channel.LifetimeToken.IsCancellationRequested);
    }

    [Fact]
    public void Dispose_CompletesChannels()
    {
        // Arrange
        var channel = new InMemoryChannel("test-1");

        // Act
        channel.Dispose();

        // Assert
        Assert.True(channel.ToMicroservice.Reader.Completion.IsCompleted);
        Assert.True(channel.ToGateway.Reader.Completion.IsCompleted);
    }

    [Fact]
    public void BoundedChannel_RespectsBufferSize()
    {
        // Arrange & Act
        using var channel = new InMemoryChannel("test-1", bufferSize: 5);

        // Assert - no exception means it was created successfully
        Assert.NotNull(channel);
    }

    [Fact]
    public void Instance_CanBeSetAndRetrieved()
    {
        // Arrange
        using var channel = new InMemoryChannel("test-1");
        var instance = new InstanceDescriptor
        {
            InstanceId = "inst-1",
            ServiceName = "test-service",
            Version = "1.0.0",
            Region = "eu1"
        };

        // Act
        channel.Instance = instance;

        // Assert
        Assert.Same(instance, channel.Instance);
    }
}