using RioJoy.Core.Feedback;
using RioJoy.Core.Mapping;
using RioJoy.Core.Plasma;
using RioJoy.Core.Protocol;
using RioJoy.Core.Tests.Mapping;
using RioJoy.Core.Tests.Serial;
using Xunit;

namespace RioJoy.Core.Tests.Feedback;

public class FeedbackRouterTests : IDisposable
{
    private readonly RecordingSink _sink = new();
    private readonly CoalescingLampScheduler _scheduler;
    private readonly CancellationTokenSource _cts = new();
    private readonly Task _pump;

    public FeedbackRouterTests()
    {
        _scheduler = new CoalescingLampScheduler(_sink, TimeSpan.FromMilliseconds(1));
        _pump = _scheduler.RunAsync(_cts.Token);
    }

    public void Dispose()
    {
        _cts.Cancel();
        _pump.Wait(TimeSpan.FromSeconds(5));
        _cts.Dispose();
    }

    private static FeedbackCommand Lamp(int address, byte state) =>
        new() { Kind = FeedbackCommandKind.Lamp, Address = address, LampState = state };

    private static FeedbackCommand Text(string text) =>
        new() { Kind = FeedbackCommandKind.PlasmaText, Text = text };

    private static FeedbackCommand Row(byte y)
    {
        var data = new byte[16];
        data[0] = y; // distinguishable payload per row
        return new FeedbackCommand { Kind = FeedbackCommandKind.PlasmaRow, Y = y, Data = data };
    }

    [Fact]
    public async Task Lamp_ProfileOwnedAddressDropped_UnownedApplied()
    {
        var map = new RioInputMap();
        map[0x10] = RioMapEntry.Create(RioRouteKind.Keyboard, 0x41, lit: true); // InputRouter owns this lamp
        var router = new FeedbackRouter();
        var logged = new List<string>();
        router.Logged += logged.Add;
        router.Attach(_scheduler, map, plasma: null, new ProfileFeedbackConfig());

        router.Dispatch(Lamp(0x11, RioLampState.SolidBright)); // unowned → applied
        await FeedbackWait.For(() => _sink.Snapshot().Length >= 1);
        Assert.Equal("Lamp(0x11,0x3C)", Assert.Single(_sink.Snapshot()));

        router.Dispatch(Lamp(0x10, RioLampState.SolidBright)); // owned → dropped
        router.Dispatch(Lamp(0x10, RioLampState.SolidOff));
        await Task.Delay(50);
        Assert.Single(_sink.Snapshot());
        Assert.Equal(2, router.DroppedCommands);
        Assert.Single(logged); // logged once per address per attach, not per drop
    }

    [Fact]
    public async Task Detached_CommandsDroppedAndCounted()
    {
        var router = new FeedbackRouter();
        router.Dispatch(Lamp(0x01, RioLampState.SolidBright)); // never attached
        Assert.Equal(1, router.DroppedCommands);

        router.Attach(_scheduler, new RioInputMap(), null, new ProfileFeedbackConfig());
        router.Detach();
        router.Dispatch(Lamp(0x01, RioLampState.SolidBright));
        Assert.Equal(2, router.DroppedCommands);

        await Task.Delay(50);
        Assert.Empty(_sink.Snapshot());
    }

    [Fact]
    public async Task AllowFlags_GateLampAndPlasma()
    {
        var transport = new FakeTransport();
        var router = new FeedbackRouter();
        router.Attach(_scheduler, new RioInputMap(), new PlasmaDisplay(transport),
            new ProfileFeedbackConfig { AllowLampCommands = false, AllowPlasmaText = false });

        router.Dispatch(Lamp(0x01, RioLampState.SolidBright));
        router.Dispatch(Text("NOPE"));
        await Task.Delay(50);

        Assert.Empty(_sink.Snapshot());
        Assert.False(transport.Writes.TryRead(out _));
        Assert.Equal(2, router.DroppedCommands);
    }

    [Fact]
    public async Task LampAll_SkipsProfileOwnedLamps()
    {
        var map = new RioInputMap();
        map[0x00] = RioMapEntry.Create(RioRouteKind.Joystick, 1, lit: true);
        var router = new FeedbackRouter();
        router.Attach(_scheduler, map, null, new ProfileFeedbackConfig());

        router.Dispatch(new FeedbackCommand
        {
            Kind = FeedbackCommandKind.LampAll,
            LampState = RioLampState.SolidDim,
        });

        int expected = Enumerable.Range(0, RioAddress.TableSize).Count(RioAddress.IsValid) - 1;
        await FeedbackWait.For(() => _sink.Snapshot().Length >= expected);
        await Task.Delay(50);

        string[] sent = _sink.Snapshot();
        Assert.Equal(expected, sent.Length);
        Assert.DoesNotContain("Lamp(0x00,0x14)", sent); // the profile-owned lamp is untouched
    }

    [Fact]
    public async Task Plasma_FloodCoalesces_FirstAndLatestOnly()
    {
        // Park the first text mid-write; everything dispatched meanwhile collapses
        // to the single latest pending command.
        var transport = new GatedTransport();
        var router = new FeedbackRouter();
        router.Attach(_scheduler, new RioInputMap(), new PlasmaDisplay(transport),
            new ProfileFeedbackConfig());

        router.Dispatch(Text("FIRST"));  // goes busy, parked on the gate
        router.Dispatch(Text("MID-1"));  // pending
        router.Dispatch(Text("MID-2"));  // supersedes MID-1
        router.Dispatch(Text("LAST"));   // supersedes MID-2
        transport.Open();

        var writes = new List<byte[]>();
        for (int i = 0; i < 10; i++)
            writes.Add(await transport.NextWriteAsync());
        await Task.Delay(50);

        Assert.Equal(PlasmaCommands.Text("FIRST"), writes[4]); // FIRST's text chunk
        Assert.Equal(PlasmaCommands.Text("LAST"), writes[9]);  // then only LAST's
        Assert.True(transport.NoMoreWrites);
        Assert.Equal(2, router.DroppedCommands); // the two superseded middles
    }

    [Fact]
    public async Task PlasmaRows_StreamInFifoOrder_NotCoalesced()
    {
        // A bitmap frame is many rows — unlike text, rows must all land, in order.
        var transport = new GatedTransport();
        var router = new FeedbackRouter();
        router.Attach(_scheduler, new RioInputMap(), new PlasmaDisplay(transport),
            new ProfileFeedbackConfig());

        router.Dispatch(Row(0)); // goes busy, parked on the gate
        router.Dispatch(Row(1));
        router.Dispatch(Row(2));
        transport.Open();

        Assert.Equal(PlasmaCommands.GraphicsRow(0, Row(0).Data!), await transport.NextWriteAsync());
        Assert.Equal(PlasmaCommands.GraphicsRow(1, Row(1).Data!), await transport.NextWriteAsync());
        Assert.Equal(PlasmaCommands.GraphicsRow(2, Row(2).Data!), await transport.NextWriteAsync());
        Assert.Equal(0, router.DroppedCommands);
    }

    [Fact]
    public async Task PlasmaClear_FlushesQueuedRowsAndTexts()
    {
        var transport = new GatedTransport();
        var router = new FeedbackRouter();
        router.Attach(_scheduler, new RioInputMap(), new PlasmaDisplay(transport),
            new ProfileFeedbackConfig());

        router.Dispatch(Row(0));  // in flight, parked
        router.Dispatch(Row(1));  // queued…
        router.Dispatch(Text("STALE"));
        router.Dispatch(new FeedbackCommand { Kind = FeedbackCommandKind.PlasmaClear }); // …flushed
        transport.Open();

        Assert.Equal(PlasmaCommands.GraphicsRow(0, Row(0).Data!), await transport.NextWriteAsync());
        Assert.Equal(PlasmaCommands.Clear(), await transport.NextWriteAsync());
        await Task.Delay(50);
        Assert.True(transport.NoMoreWrites);
        Assert.Equal(2, router.DroppedCommands); // the flushed row + text
    }

    [Fact]
    public async Task PlasmaRowQueue_IsBounded()
    {
        var transport = new GatedTransport();
        var router = new FeedbackRouter();
        router.Attach(_scheduler, new RioInputMap(), new PlasmaDisplay(transport),
            new ProfileFeedbackConfig());

        router.Dispatch(Row(0)); // parked in flight; everything below queues
        for (int i = 0; i < 140; i++)
            router.Dispatch(Row(1));

        Assert.Equal(140 - 128, router.DroppedCommands); // over the 128-entry bound

        transport.Open();
        // Drain: the parked row + the 128 queued ones.
        for (int i = 0; i < 129; i++)
            await transport.NextWriteAsync();
        await Task.Delay(50);
        Assert.True(transport.NoMoreWrites);
    }

    [Fact]
    public async Task PlasmaClear_WritesTheClearCommand()
    {
        var transport = new FakeTransport();
        var router = new FeedbackRouter();
        router.Attach(_scheduler, new RioInputMap(), new PlasmaDisplay(transport),
            new ProfileFeedbackConfig());

        router.Dispatch(new FeedbackCommand { Kind = FeedbackCommandKind.PlasmaClear });

        Assert.Equal(PlasmaCommands.Clear(), await transport.NextWriteAsync());
    }
}