using System.IO.Pipes;
using System.Text;
using RioJoy.Core.Feedback;
using RioJoy.Core.Mapping;
using RioJoy.Core.Plasma;
using RioJoy.Core.Tests.Mapping;
using RioJoy.Core.Tests.Serial;
using Xunit;

namespace RioJoy.Core.Tests.Feedback;

/// <summary>
/// End-to-end: pipe client → line assembly → parse → router → lamp scheduler /
/// plasma, the exact path a sim export script exercises.
/// </summary>
public class FeedbackServiceTests
{
    private static string UniqueName() => $"riojoy-fb-svc-{Guid.NewGuid():N}";

    private static NamedPipeClientStream Connect(string name, int timeoutMs = 5000)
    {
        var deadline = DateTime.UtcNow.AddMilliseconds(timeoutMs);
        while (true)
        {
            var client = new NamedPipeClientStream(".", name, PipeDirection.Out);
            try
            {
                client.Connect(200);
                return client;
            }
            catch (Exception ex) when (ex is IOException or TimeoutException)
            {
                client.Dispose();
                Assert.True(DateTime.UtcNow < deadline, $"could not connect: {ex.Message}");
                Thread.Sleep(20);
            }
        }
    }

    private static void Send(NamedPipeClientStream client, string text)
    {
        byte[] data = Encoding.GetEncoding(28591).GetBytes(text);
        client.Write(data, 0, data.Length);
        client.Flush();
    }

    [Fact]
    public async Task PipeClient_DrivesLampsAndPlasma_MalformedLinesSurvive()
    {
        string name = UniqueName();
        var lamps = new RecordingSink();
        var plasmaTransport = new FakeTransport();
        using var service = new FeedbackService(new FeedbackEndpointConfig { PipeName = name });
        service.Start();
        service.Attach(lamps, new RioInputMap(), new PlasmaDisplay(plasmaTransport),
            new ProfileFeedbackConfig());

        using NamedPipeClientStream client = Connect(name);
        Send(client, "# cockpit warmup\nlamp 0x11 fast bright\nbogus nonsense\nplasma clear\n");

        await FeedbackWait.For(() => lamps.Snapshot().Length >= 1);
        Assert.Equal("Lamp(0x11,0x3F)", Assert.Single(lamps.Snapshot()));
        Assert.Equal(PlasmaCommands.Clear(), await plasmaTransport.NextWriteAsync());
        Assert.Equal(1, service.MalformedLines); // the bogus line, not the comment

        Send(client, "lamp 0x11 off\n"); // the connection survived the bad line
        await FeedbackWait.For(() => lamps.Snapshot().Length >= 2);
        Assert.Equal("Lamp(0x11,0x00)", lamps.Snapshot()[1]);
    }

    [Fact]
    public async Task Detach_DropsCommands_ReattachAppliesAgain()
    {
        string name = UniqueName();
        var lamps = new RecordingSink();
        using var service = new FeedbackService(new FeedbackEndpointConfig { PipeName = name });
        service.Start();
        using NamedPipeClientStream client = Connect(name);

        // Dormant (never attached): commands drop, the client stays connected.
        Send(client, "lamp 0x01 bright\n");
        await FeedbackWait.For(() => service.DroppedCommands >= 1);
        Assert.Empty(lamps.Snapshot());

        // Profile activates: the same client now drives lamps.
        service.Attach(lamps, new RioInputMap(), null, new ProfileFeedbackConfig());
        Send(client, "lamp 0x01 bright\n");
        await FeedbackWait.For(() => lamps.Snapshot().Length >= 1);

        // Yield to a native game: back to dropping, still connected.
        service.Detach();
        Send(client, "lamp 0x01 off\n");
        await FeedbackWait.For(() => service.DroppedCommands >= 2);
        Assert.Single(lamps.Snapshot());
    }
}