using ClaudeDo.Worker.Runner;
using ClaudeDo.Worker.Runner.Interfaces;

namespace ClaudeDo.Worker.Tests.Runner;

public sealed class LiveSessionRegistryTests
{
    private sealed class FakeLiveSession : ILiveSession
    {
        public bool StopCalled { get; private set; }
        public bool IsTurnInFlight => false;

        public Task SendUserMessageAsync(string text, CancellationToken ct) => Task.CompletedTask;
        public Task RemoveQueuedAsync(string text, CancellationToken ct) => Task.CompletedTask;
        public Task InterruptAsync(CancellationToken ct) => Task.CompletedTask;

        public Task StopAsync()
        {
            StopCalled = true;
            return Task.CompletedTask;
        }

        public ValueTask DisposeAsync() => ValueTask.CompletedTask;
    }

    [Fact]
    public void Register_ThenTryGet_ReturnsSession()
    {
        var registry = new LiveSessionRegistry();
        var session = new FakeLiveSession();

        registry.Register("task-1", session);

        Assert.True(registry.TryGet("task-1", out var retrieved));
        Assert.Same(session, retrieved);
    }

    [Fact]
    public void TryGet_Missing_ReturnsFalse()
    {
        var registry = new LiveSessionRegistry();

        Assert.False(registry.TryGet("no-such-task", out _));
    }

    [Fact]
    public void Unregister_RemovesSession()
    {
        var registry = new LiveSessionRegistry();
        registry.Register("task-1", new FakeLiveSession());
        registry.Unregister("task-1");

        Assert.False(registry.TryGet("task-1", out _));
    }

    [Fact]
    public async Task Register_WhenSessionAlreadyExists_StopsPreviousSession()
    {
        var registry = new LiveSessionRegistry();
        var first = new FakeLiveSession();
        var second = new FakeLiveSession();

        registry.Register("task-1", first);
        registry.Register("task-1", second);

        // Give the fire-and-forget stop a tick to run.
        await Task.Delay(50);

        Assert.True(first.StopCalled);
        Assert.True(registry.TryGet("task-1", out var retrieved));
        Assert.Same(second, retrieved);
    }

    [Fact]
    public async Task StopAsync_StopsAndRemovesSession()
    {
        var registry = new LiveSessionRegistry();
        var session = new FakeLiveSession();
        registry.Register("task-1", session);

        await registry.StopAsync("task-1");

        Assert.True(session.StopCalled);
        Assert.False(registry.TryGet("task-1", out _));
    }

    [Fact]
    public async Task StopAsync_MissingTask_DoesNotThrow()
    {
        var registry = new LiveSessionRegistry();
        await registry.StopAsync("no-such-task"); // should not throw
    }
}