using Luna.Channels.Abstractions;
using Luna.Channels.Tests.Stubs;
using Luna.Core.Abstractions;
using Luna.Shared;
using Moq;

namespace Luna.Channels.Tests;

[TestFixture]
[Category("Unit")]
public class IntegrationTests
{
    private Mock<ISessionManager> sessionManagerMock = null!;
    private Mock<IChannel> channelMock = null!;
    private ChannelManagerStub manager = null!;

    [SetUp]
    public void SetUp()
    {
        sessionManagerMock = new Mock<ISessionManager>();
        channelMock = new Mock<IChannel>();
        channelMock.Setup(c => c.ChannelId).Returns("test-ch-1");
        channelMock.Setup(c => c.ChannelType).Returns("test");
        channelMock.Setup(c => c.SendStreamingMessageAsync(
            It.IsAny<IAsyncEnumerable<ChatStreamUpdate>>(),
            It.IsAny<CancellationToken>())).Returns(Task.CompletedTask);
        manager = new ChannelManagerStub(sessionManagerMock.Object);
    }

    private static async IAsyncEnumerable<ChatStreamUpdate> BuildStream(params ChatStreamUpdate[] updates)
    {
        foreach (var u in updates)
        {
            yield return u;
            await Task.Yield();
        }
    }

    [Test]
    public async Task MessageReceived_RoutesToSessionManager_WithCorrectContent()
    {
        var message = new ChannelMessage(
            Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "user-1", "User One", "Hello Luna!", DateTimeOffset.UtcNow);

        sessionManagerMock
            .Setup(s => s.RouteMessagesAsync(
                message.Content,
                message.ConversationId,
                It.IsAny<string>(),
                It.IsAny<CancellationToken>()))
            .Returns(BuildStream(new ChatStreamUpdate(ChatStreamUpdateType.Text, "Hi!", null, false)));

        manager.RegisterChannel(new CliChannelStub { ChannelId = "test-1" });

        var args = new ChannelMessageReceivedEventArgs { Message = message, Channel = channelMock.Object };
        channelMock.Raise(c => c.MessageReceived += null, channelMock.Object, args);

        await Task.Delay(50);

        sessionManagerMock.Verify(s => s.RouteMessagesAsync(
            message.Content,
            message.ConversationId,
            It.IsAny<string>(),
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Test]
    public async Task MessageReceived_PipesSessionResponseToChannel_SendStreamingMessageAsync()
    {
        var message = new ChannelMessage(
            Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "user-2", "User Two", "What time is it?", DateTimeOffset.UtcNow);

        var responseStream = BuildStream(
            new ChatStreamUpdate(ChatStreamUpdateType.Text, "It's ", null, false),
            new ChatStreamUpdate(ChatStreamUpdateType.Text, "noon.", null, false),
            new ChatStreamUpdate(ChatStreamUpdateType.Complete, null, null, true));

        sessionManagerMock
            .Setup(s => s.RouteMessagesAsync(
                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .Returns(responseStream);

        manager.RegisterChannel(new CliChannelStub { ChannelId = "test-1" });

        var args = new ChannelMessageReceivedEventArgs { Message = message, Channel = channelMock.Object };
        channelMock.Raise(c => c.MessageReceived += null, channelMock.Object, args);

        await Task.Delay(50);

        channelMock.Verify(c => c.SendStreamingMessageAsync(
            It.IsAny<IAsyncEnumerable<ChatStreamUpdate>>(),
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Test]
    public async Task MessageReceived_WhenIsHandled_True_DoesNotRouteToSessionManager()
    {
        var message = new ChannelMessage(
            Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "user-3", "User Three", "/start", DateTimeOffset.UtcNow);

        manager.RegisterChannel(new CliChannelStub { ChannelId = "test-1" });

        var args = new ChannelMessageReceivedEventArgs { Message = message, Channel = channelMock.Object, IsHandled = true };
        channelMock.Raise(c => c.MessageReceived += null, channelMock.Object, args);

        await Task.Delay(50);

        sessionManagerMock.Verify(s => s.RouteMessagesAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()),
            Times.Never);
    }

    [Test]
    public async Task TwoChannels_ReceiveMessagesIndependently_BothRoutedToSessionManager()
    {
        var channel2Mock = new Mock<IChannel>();
        channel2Mock.Setup(c => c.ChannelId).Returns("test-ch-2");
        channel2Mock.Setup(c => c.ChannelType).Returns("test");
        channel2Mock.Setup(c => c.SendStreamingMessageAsync(
            It.IsAny<IAsyncEnumerable<ChatStreamUpdate>>(), It.IsAny<CancellationToken>()))
            .Returns(Task.CompletedTask);

        sessionManagerMock
            .Setup(s => s.RouteMessagesAsync(
                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .Returns(BuildStream(new ChatStreamUpdate(ChatStreamUpdateType.Text, "ok", null, true)));

        manager.RegisterChannel(new CliChannelStub { ChannelId = "test-1" });
        manager.RegisterChannel(channel2Mock.Object);

        var msg1 = new ChannelMessage(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "u1", "U1", "Msg1", DateTimeOffset.UtcNow);
        var msg2 = new ChannelMessage(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "u2", "U2", "Msg2", DateTimeOffset.UtcNow);

        channelMock.Raise(c => c.MessageReceived += null, channelMock.Object,
            new ChannelMessageReceivedEventArgs { Message = msg1, Channel = channelMock.Object });
        channel2Mock.Raise(c => c.MessageReceived += null, channel2Mock.Object,
            new ChannelMessageReceivedEventArgs { Message = msg2, Channel = channel2Mock.Object });

        await Task.Delay(100);

        sessionManagerMock.Verify(s => s.RouteMessagesAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()),
            Times.Exactly(2));
    }

    [Test]
    public async Task SessionManager_RouteMessagesAsync_ReceivesCancellationToken()
    {
        using var cts = new CancellationTokenSource();
        var message = new ChannelMessage(
            Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "user-4", "User Four", "Cancel me", DateTimeOffset.UtcNow);

        sessionManagerMock
            .Setup(s => s.RouteMessagesAsync(
                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), cts.Token))
            .Returns(BuildStream(new ChatStreamUpdate(ChatStreamUpdateType.Text, "x", null, true)));

        manager.RegisterChannel(new CliChannelStub { ChannelId = "test-1" });

        var args = new ChannelMessageReceivedEventArgs { Message = message, Channel = channelMock.Object };
        await channelMock.RaiseAsync(c => c.MessageReceived += null, channelMock.Object, args);

        await Task.Delay(50, cts.Token);

        sessionManagerMock.Verify(s => s.RouteMessagesAsync(
            message.Content,
            message.ConversationId,
            It.IsAny<string>(),
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Test]
    public async Task SessionManager_Throws_ChannelRemainsActive_NotDisconnected()
    {
        var message = new ChannelMessage(
            Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), "user-5", "User Five", "Boom", DateTimeOffset.UtcNow);

        sessionManagerMock
            .Setup(s => s.RouteMessagesAsync(
                It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .Throws(new InvalidOperationException("Simulated routing failure"));

        manager.RegisterChannel(new CliChannelStub { ChannelId = "test-1" });

        Assert.DoesNotThrowAsync(async () =>
        {
            var args = new ChannelMessageReceivedEventArgs { Message = message, Channel = channelMock.Object };
            await channelMock.RaiseAsync(c => c.MessageReceived += null, channelMock.Object, args);
            await Task.Delay(50);
        });
    }
}