package events

import (
	"sync/atomic"
	"testing"
	"time"

	"github.com/kamelion/ratatoskr-go/internal/model"
)

func TestHubDeliversTypedEvent(t *testing.T) {
	bus := New(16)
	h := NewHub(bus)

	var got atomic.Value
	On[TaskStatusChanged](h, func(e TaskStatusChanged) {
		got.CompareAndSwap(nil, e)
	})

	h.Start()
	defer h.Close()

	want := TaskStatusChanged{ID: 7, From: model.StatusReady, To: model.StatusRunning}
	bus.Publish(want)

	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if raw := got.Load(); raw != nil {
			ev := raw.(TaskStatusChanged)
			if ev.ID != 7 || ev.From != model.StatusReady || ev.To != model.StatusRunning {
				t.Fatalf("unexpected event: %+v", ev)
			}
			return
		}
		time.Sleep(10 * time.Millisecond)
	}
	t.Fatal("handler was not called")
}

func TestHubIgnoresUnrelatedTypes(t *testing.T) {
	bus := New(16)
	h := NewHub(bus)

	var calls atomic.Int32
	On[TaskStatusChanged](h, func(TaskStatusChanged) { calls.Add(1) })

	h.Start()
	defer h.Close()

	// другие типы событий не должны дойти до этого обработчика
	bus.Publish(AgentActivity{TaskID: 1, Agent: "dev", Stage: "run"})
	bus.Publish(LogLine{Level: "log", Text: "x"})

	time.Sleep(200 * time.Millisecond)
	if n := calls.Load(); n != 0 {
		t.Fatalf("handler called %d times for unrelated events", n)
	}
}

func TestHubMultipleHandlersSameType(t *testing.T) {
	bus := New(16)
	h := NewHub(bus)

	var a, b atomic.Int32
	On[HistoryAppended](h, func(HistoryAppended) { a.Add(1) })
	On[HistoryAppended](h, func(HistoryAppended) { b.Add(1) })

	h.Start()
	defer h.Close()

	bus.Publish(HistoryAppended{TaskID: 1, Role: "user", Content: "hi"})

	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		if a.Load() == 1 && b.Load() == 1 {
			return
		}
		time.Sleep(10 * time.Millisecond)
	}
	t.Fatal("not all handlers called")
}

func TestHubCloseStopsDelivery(t *testing.T) {
	bus := New(16)
	h := NewHub(bus)

	var calls atomic.Int32
	On[TaskCreated](h, func(TaskCreated) { calls.Add(1) })

	h.Start()
	bus.Publish(TaskCreated{ID: 1})

	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) && calls.Load() == 0 {
		time.Sleep(10 * time.Millisecond)
	}
	if calls.Load() == 0 {
		t.Fatal("initial delivery failed")
	}

	h.Close()
	// после Close Hub отписан — события не доходят
	bus.Publish(TaskCreated{ID: 2})
	time.Sleep(150 * time.Millisecond)
	if n := calls.Load(); n > 1 {
		t.Fatalf("handler called %d times after Close", n)
	}
}

func TestHubStartIdempotent(t *testing.T) {
	bus := New(16)
	h := NewHub(bus)
	h.Start()
	h.Start() // повторный Start не должен создавать вторую горутину
	h.Close()
	// если бы было две горутины — Publish блокировался бы на буфере, но закрытие сняло бы блок;
	// просто проверяем, что Close и повторный Start не падают
	bus.Publish(TaskCreated{ID: 1})
}