using Microsoft.Extensions.DependencyInjection;
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 CancelFlowTests
{
    private readonly InMemoryConnectionRegistry _registry;
    private readonly InMemoryTransportServer _server;
    private readonly InMemoryTransportClient _client;

    public CancelFlowTests()
    {
        var services = new ServiceCollection();
        services.AddLogging();
        services.AddInMemoryTransport();

        var provider = services.BuildServiceProvider();
        _registry = provider.GetRequiredService<InMemoryConnectionRegistry>();
        _server = provider.GetRequiredService<InMemoryTransportServer>();
        _client = provider.GetRequiredService<InMemoryTransportClient>();
    }

    [Fact]
    public async Task SendCancelAsync_SendsCancelFrame()
    {
        // Arrange
        var instance = new InstanceDescriptor
        {
            InstanceId = "inst-1",
            ServiceName = "test-service",
            Version = "1.0.0",
            Region = "eu1"
        };

        await _server.StartAsync(CancellationToken.None);
        await _client.ConnectAsync(instance, [], CancellationToken.None);

        var connectionId = _registry.ConnectionIds.First();
        _server.StartListeningToConnection(connectionId);

        var connections = _registry.GetAllConnections();
        var connection = connections[0];

        var correlationId = Guid.NewGuid();

        // Act
        await _client.SendCancelAsync(connection, correlationId, "Test cancellation");

        // Wait for processing
        await Task.Delay(50);

        // Assert - no exception means cancel was sent successfully
        Assert.Equal(1, _registry.Count);
    }

    [Fact]
    public async Task OnCancelReceived_IsInvoked()
    {
        // Arrange
        var instance = new InstanceDescriptor
        {
            InstanceId = "inst-1",
            ServiceName = "test-service",
            Version = "1.0.0",
            Region = "eu1"
        };

        await _server.StartAsync(CancellationToken.None);
        await _client.ConnectAsync(instance, [], CancellationToken.None);

        var connectionId = _registry.ConnectionIds.First();
        _server.StartListeningToConnection(connectionId);

        Guid? receivedCorrelationId = null;
        _client.OnCancelReceived += (corrId, reason) =>
        {
            receivedCorrelationId = corrId;
            return Task.CompletedTask;
        };

        var correlationId = Guid.NewGuid();

        // Send a cancel frame from server to client
        var cancelFrame = new Frame
        {
            Type = FrameType.Cancel,
            CorrelationId = correlationId.ToString("N"),
            Payload = ReadOnlyMemory<byte>.Empty
        };

        await _server.SendToMicroserviceAsync(connectionId, cancelFrame, CancellationToken.None);

        // Wait for processing
        await Task.Delay(100);

        // Assert
        Assert.Equal(correlationId, receivedCorrelationId);
    }
}