package wsutil

import (
	"testing"
	"time"
)

func TestBackoffSequence(t *testing.T) {
	t.Parallel()
	b := NewBackoff(2*time.Second, 60*time.Second)
	want := []time.Duration{2, 4, 8, 16, 32, 60, 60, 60}
	for i, exp := range want {
		if got := b.Next(); got != exp*time.Second {
			t.Fatalf("Next[%d] = %v, want %v", i, got, exp*time.Second)
		}
	}
}

func TestBackoffReset(t *testing.T) {
	t.Parallel()
	b := NewBackoff(time.Second, time.Minute)
	_ = b.Next()
	_ = b.Next()
	b.Reset()
	if got := b.Next(); got != time.Second {
		t.Errorf("after Reset, Next = %v, want 1s", got)
	}
}

func TestBackoffDefaults(t *testing.T) {
	t.Parallel()
	b := NewBackoff(0, 0)
	if got := b.Next(); got != time.Second {
		t.Errorf("default base Next = %v, want 1s", got)
	}
	if got := b.Next(); got != 2*time.Second {
		t.Errorf("default Next2 = %v, want 2s", got)
	}
	// cap of 60s by default: 1,2,4,8,16,32,60...
	for i := 0; i < 7; i++ {
		_ = b.Next()
	}
	if got := b.Next(); got != 60*time.Second {
		t.Errorf("default cap Next = %v, want 60s", got)
	}
}

func TestBackoffNoOverflow(t *testing.T) {
	t.Parallel()
	b := NewBackoff(time.Second, time.Second)
	for i := 0; i < 200; i++ {
		if got := b.Next(); got != time.Second {
			t.Fatalf("Next[%d] = %v, want 1s (cap)", i, got)
		}
	}
}