package playback

import (
	"testing"
	"time"
)

func TestFiniteAttempts(t *testing.T) {
	rp := RetryPolicy{
		MaxAttempts:  3,
		InitialDelay: 500 * time.Millisecond,
		MaxDelay:     10 * time.Second,
	}
	if !rp.canRetry(1) {
		t.Fatal("MaxAttempts=3, failed=1, but can't retry")
	}
	if !rp.canRetry(2) {
		t.Fatal("MaxAttempts=3, failed=2, but can't retry")
	}
	if rp.canRetry(3) {
		t.Fatal("MaxAttempts=3, failed=3, but can retry")
	}
}

func TestOneAllowedAttempt(t *testing.T) {
	rp := RetryPolicy{
		MaxAttempts:  1,
		InitialDelay: 500 * time.Millisecond,
		MaxDelay:     10 * time.Second,
	}
	if rp.canRetry(1) {
		t.Fatal("MaxAttempts=1, failed=1, but can retry")
	}
}

func TestUnlimitedAttempts(t *testing.T) {
	rp := RetryPolicy{
		MaxAttempts:  0,
		InitialDelay: 500 * time.Millisecond,
		MaxDelay:     10 * time.Second,
	}
	for failedAttempts := 1; failedAttempts <= 10; failedAttempts++ {
		if !rp.canRetry(failedAttempts) {
			t.Fatalf(
				"canRetry(%d) = false for unlimited policy",
				failedAttempts,
			)
		}
	}
}

func TestBackoff(t *testing.T) {
	rp := RetryPolicy{
		MaxAttempts:  0,
		InitialDelay: 500 * time.Millisecond,
		MaxDelay:     10 * time.Second,
	}
	want := []time.Duration{
		500 * time.Millisecond,
		1 * time.Second,
		2 * time.Second,
		4 * time.Second,
		8 * time.Second,
		10 * time.Second,
		10 * time.Second,
	}
	for i, wantDelay := range want {
		failedAttempts := i + 1
		got := rp.retryDelay(failedAttempts)
		if got != wantDelay {
			t.Errorf(
				"retryDelay(%d) = %s, want %s",
				failedAttempts,
				got,
				wantDelay,
			)
		}
	}
}

func TestRetryDelayLargeFailureCount(t *testing.T) {
	policy := RetryPolicy{
		MaxAttempts:  0,
		InitialDelay: 500 * time.Millisecond,
		MaxDelay:     10 * time.Second,
	}

	if got := policy.retryDelay(1_000_000); got != policy.MaxDelay {
		t.Fatalf("retryDelay() = %s, want cap %s", got, policy.MaxDelay)
	}
}