package claude

import (
	"os"
	"path/filepath"
	"testing"
	"time"
)

func TestHistoryTailer_EmitsOnAppend(t *testing.T) {
	dir := t.TempDir()
	p := filepath.Join(dir, "history.jsonl")
	if err := os.WriteFile(p, []byte(""), 0o600); err != nil {
		t.Fatalf("write: %v", err)
	}

	hub := NewEventHub(10)
	ch, cancel := hub.Subscribe()
	defer cancel()

	stop := make(chan struct{})
	go TailHistoryFile(stop, hub, p)

	time.Sleep(600 * time.Millisecond)

	if err := os.WriteFile(p, []byte("{\"display\":\"/status\"}\n"), 0o600); err != nil {
		t.Fatalf("append: %v", err)
	}

	select {
	case ev := <-ch:
		if ev.Type != EventTypeHistoryAppend {
			t.Fatalf("type=%s", ev.Type)
		}
	case <-time.After(700 * time.Millisecond):
		t.Fatalf("timed out waiting for event")
	}

	close(stop)
}