using AcDream.Core.Chat;
using AcDream.UI.Abstractions;
using AcDream.UI.Abstractions.Panels.Chat;
using Xunit;

namespace AcDream.UI.Abstractions.Tests.Panels.Chat;

public class ChatCommandRouterTests
{
    private sealed class CaptureBus : ICommandBus
    {
        public SendChatCmd? Last;
        public void Publish<T>(T command) where T : notnull
        {
            if (command is SendChatCmd c) Last = c;
        }
    }

    private static (ChatVM vm, ChatLog log, CaptureBus bus) Fixture()
    {
        var log = new ChatLog();
        var vm = new ChatVM(log, displayLimit: 50);
        return (vm, log, new CaptureBus());
    }

    [Fact]
    public void PlainText_PublishesOnDefaultChannel()
    {
        var (vm, _, bus) = Fixture();
        var outcome = ChatCommandRouter.Submit("hello there", vm, bus, ChatChannelKind.Say);
        Assert.Equal(SubmitOutcome.Sent, outcome);
        Assert.NotNull(bus.Last);
        Assert.Equal(ChatChannelKind.Say, bus.Last!.Channel);
        Assert.Equal("hello there", bus.Last.Text);
    }

    [Fact]
    public void DefaultChannel_IsHonored()
    {
        var (vm, _, bus) = Fixture();
        ChatCommandRouter.Submit("hi", vm, bus, ChatChannelKind.Fellowship);
        Assert.Equal(ChatChannelKind.Fellowship, bus.Last!.Channel);
    }

    [Fact]
    public void ClearCommand_DrainsLog_DoesNotPublish()
    {
        var (vm, log, bus) = Fixture();
        log.OnSystemMessage("x", chatType: 0);
        var outcome = ChatCommandRouter.Submit("/clear", vm, bus, ChatChannelKind.Say);
        Assert.Equal(SubmitOutcome.ClientHandled, outcome);
        Assert.Null(bus.Last);
        Assert.Empty(log.Snapshot());
    }

    [Fact]
    public void UnknownSlashVerb_ShowsSystemMessage_DoesNotPublish()
    {
        var (vm, log, bus) = Fixture();
        var outcome = ChatCommandRouter.Submit("/notacommand", vm, bus, ChatChannelKind.Say);
        Assert.Equal(SubmitOutcome.UnknownCommand, outcome);
        Assert.Null(bus.Last);
        Assert.Contains(log.Snapshot(), e => e.Text.Contains("Unknown command"));
    }

    [Fact]
    public void EmptyInput_DoesNothing()
    {
        var (vm, _, bus) = Fixture();
        var outcome = ChatCommandRouter.Submit("   ", vm, bus, ChatChannelKind.Say);
        Assert.Equal(SubmitOutcome.Empty, outcome);
        Assert.Null(bus.Last);
    }
}