package timer

import (
	"errors"
	"testing"
	"time"
)

func TestTracker(t *testing.T) {
	tk := Start()
	time.Sleep(10 * time.Millisecond)
	tk.Record("step1")
	time.Sleep(20 * time.Millisecond)
	tk.Record("step2")

	laps := tk.Summarize()
	if len(laps) != 2 {
		t.Errorf("expected 2 laps, got %d", len(laps))
	}
	if laps[0].Label != "step1" || laps[1].Label != "step2" {
		t.Errorf("invalid lap labels")
	}
	
	desc := tk.Describe()
	if desc == "" {
		t.Error("description should not be empty")
	}
	t.Log(desc)
}

func TestRetry(t *testing.T) {
	count := 0
	err := Retry(func() error {
		count++
		if count < 3 {
			return errors.New("fail")
		}
		return nil
	}, WithMaxRetries(3), WithBackoff(10*time.Millisecond, 2.0))

	if err != nil {
		t.Errorf("expected success, got %v", err)
	}
	if count != 3 {
		t.Errorf("expected 3 attempts, got %d", count)
	}

	count = 0
	err = Retry(func() error {
		count++
		return errors.New("always fail")
	}, WithMaxRetries(2), WithBackoff(5*time.Millisecond, 2.0))

	if err == nil {
		t.Error("expected error, got nil")
	}
	if count != 3 { // 0, 1, 2 = 3 times
		t.Errorf("expected 3 attempts, got %d", count)
	}
}

func TestTimeWheel(t *testing.T) {
	tw := NewTimeWheel(10*time.Millisecond, 10)
	tw.Start()
	defer tw.Stop()

	done := make(chan bool)
	start := time.Now()
	tw.AfterFunc(50*time.Millisecond, func() {
		duration := time.Since(start)
		if duration < 40*time.Millisecond {
			t.Errorf("too early: %v", duration)
		}
		done <- true
	})

	select {
	case <-done:
		// success
	case <-time.After(200 * time.Millisecond):
		t.Fatal("timeout")
	}
}

func TestFlow(t *testing.T) {
	// Debounce test
	count := 0
	d := NewDebouncer(20*time.Millisecond, func() {
		count++
	})
	d.Trigger()
	d.Trigger()
	d.Trigger()
	time.Sleep(50 * time.Millisecond)
	if count != 1 {
		t.Errorf("debounce failed, count: %d", count)
	}

	// Throttle test
	count = 0
	tr := NewThrottler(20*time.Millisecond, func() {
		count++
	})
	tr.Trigger()
	tr.Trigger()
	tr.Trigger()
	time.Sleep(10 * time.Millisecond)
	if count != 1 {
		t.Errorf("throttle initial failed, count: %d", count)
	}
	time.Sleep(30 * time.Millisecond)
	tr.Trigger()
	time.Sleep(10 * time.Millisecond)
	if count != 2 {
		t.Errorf("throttle interval failed, count: %d", count)
	}
}

func TestRunTimeout(t *testing.T) {
	res, err := RunTimeout(50*time.Millisecond, func(tk *Tracker) (string, error) {
		tk.Record("start")
		time.Sleep(10 * time.Millisecond)
		tk.Record("middle")
		return "ok", nil
	})
	if err != nil || res != "ok" {
		t.Errorf("RunTimeout failed: %v, %v", res, err)
	}

	_, err = RunTimeout(20*time.Millisecond, func(tk *Tracker) (string, error) {
		time.Sleep(50 * time.Millisecond)
		return "late", nil
	})
	if err != ErrTimeout {
		t.Errorf("expected ErrTimeout, got %v", err)
	}
}