using ClawdDotNet.Core.Activity;
using ClawdDotNet.Core.Tests.Infrastructure;
using ClawdDotNet.Core.Tools;
using Shouldly;

namespace ClawdDotNet.Core.Tests.Activity;

/// <summary>
/// #711: Who is working right now and who reached whom — the live side of the team overview.
/// </summary>
public sealed class AgentActivityTests
{
    private readonly FakeTimeProvider _clock = new(new DateTimeOffset(2027, 3, 10, 12, 0, 0, TimeSpan.Zero));

    [Fact]
    public void A_run_is_active_until_its_handle_is_disposed()
    {
        var activity = new AgentActivity(_clock);

        using (var run = activity.Begin("r1", "worker", "task", "t-1", null))
        {
            var active = activity.ActiveRuns().ShouldHaveSingleItem();
            active.AgentId.ShouldBe("worker");
            active.TaskId.ShouldBe("t-1");
            active.CalledBy.ShouldBeNull();
            run.Complete("Completed");
        }

        activity.ActiveRuns().ShouldBeEmpty();
    }

    [Fact]
    public void Start_and_end_are_announced_with_the_status()
    {
        var activity = new AgentActivity(_clock);
        var log = new List<string>();
        activity.RunStarted += r => log.Add($"start {r.AgentId}");
        activity.RunFinished += (r, status) => log.Add($"end {r.AgentId} {status}");

        using (var run = activity.Begin("r1", "worker", "chat", null, null))
            run.Complete("LoopLimitExceeded");
        using (activity.Begin("r2", "worker", "chat", null, null)) { }

        log.ShouldBe(["start worker", "end worker LoopLimitExceeded", "start worker", "end worker Aborted"]);
    }

    [Fact]
    public void A_delegated_run_records_who_called_whom()
    {
        var activity = new AgentActivity(_clock);
        AgentLink? seen = null;
        activity.LinkObserved += l => seen = l;
        var chain = DelegationChain.Root("lead").Append("buyer");

        using (activity.Begin("r1", "buyer", "agent_comm", null, chain)) { }

        seen.ShouldNotBeNull();
        seen.From.ShouldBe("lead");
        seen.To.ShouldBe("buyer");
        seen.Kind.ShouldBe("delegation");
        activity.RecentLinks(TimeSpan.FromMinutes(1)).ShouldHaveSingleItem().From.ShouldBe("lead");
    }

    [Fact]
    public void Old_links_fall_out_of_the_recent_window()
    {
        var activity = new AgentActivity(_clock);
        using (activity.Begin("r1", "buyer", "agent_comm", null, DelegationChain.Root("lead").Append("buyer"))) { }

        _clock.Advance(TimeSpan.FromMinutes(11));

        activity.RecentLinks(TimeSpan.FromMinutes(10)).ShouldBeEmpty();
    }

    [Fact]
    public void The_memory_of_links_is_bounded()
    {
        var activity = new AgentActivity(_clock);
        var chain = DelegationChain.Root("lead").Append("buyer");

        for (var i = 0; i < AgentActivity.RecentLinkCapacity + 50; i++)
            using (activity.Begin($"r{i}", "buyer", "agent_comm", null, chain)) { }

        activity.RecentLinks(TimeSpan.FromDays(1)).Count.ShouldBe(AgentActivity.RecentLinkCapacity);
    }

    [Fact]
    public void A_subscriber_that_throws_does_not_break_the_run()
    {
        var activity = new AgentActivity(_clock);
        activity.RunStarted += _ => throw new InvalidOperationException("broken page");
        activity.RunFinished += (_, _) => throw new InvalidOperationException("broken page");

        Should.NotThrow(() =>
        {
            using var run = activity.Begin("r1", "worker", "chat", null, null);
            run.Complete("Completed");
        });
        activity.ActiveRuns().ShouldBeEmpty();
    }

    // ─── through the engine ───

    [Fact]
    public async Task The_engine_announces_a_delegated_run_with_its_caller()
    {
        var fixture = new EngineFixture();
        fixture.AddAgent("lead");
        fixture.AddAgent("buyer");
        fixture.Client.RespondsWithText("Erledigt.");

        var started = new List<ActiveRun>();
        var finished = new List<string>();
        fixture.Engine.Activity.RunStarted += started.Add;
        fixture.Engine.Activity.RunFinished += (_, status) => finished.Add(status);

        var result = await fixture.Engine.SendMessageAsync("lead", "buyer", "Bitte pruefen", "inst", null, default);

        result.Delivered.ShouldBeTrue(result.Error);
        var run = started.ShouldHaveSingleItem();
        run.AgentId.ShouldBe("buyer");
        run.CalledBy.ShouldBe("lead");
        finished.ShouldBe(["Completed"]);
        fixture.Engine.Activity.ActiveRuns().ShouldBeEmpty();
        fixture.Engine.Activity.RecentLinks(TimeSpan.FromMinutes(1)).ShouldHaveSingleItem().To.ShouldBe("buyer");
    }

    [Fact]
    public async Task A_fresh_run_is_visible_too()
    {
        // Before #711 only runs through ChatAsync counted as "running"; RunAsync (@new) did not.
        var fixture = new EngineFixture();
        var agent = fixture.AddAgent("worker");
        fixture.Client.RespondsWithText("Fertig.");

        var started = new List<ActiveRun>();
        fixture.Engine.Activity.RunStarted += started.Add;

        await fixture.Engine.RunAsync(agent, "Los", "inst", CancellationToken.None);

        started.ShouldHaveSingleItem().AgentId.ShouldBe("worker");
    }
}