package pagination

import (
	"errors"
	"testing"
)

func TestCursorRoundTripAndTamperProtection(t *testing.T) {
	codec, err := NewCodec([]byte("01234567890123456789012345678901"))
	if err != nil {
		t.Fatal(err)
	}
	encoded, err := codec.Encode("2026-08-23T12:00:00Z", "item-1")
	if err != nil {
		t.Fatal(err)
	}
	decoded, err := codec.Decode(encoded)
	if err != nil || decoded.ID != "item-1" {
		t.Fatalf("decoded = %#v, err = %v", decoded, err)
	}
	tampered := encoded[:len(encoded)-1] + "A"
	if _, err := codec.Decode(tampered); !errors.Is(err, ErrInvalidCursor) {
		t.Fatalf("tampered cursor error = %v", err)
	}
}

func TestParseLimit(t *testing.T) {
	if value, err := ParseLimit(""); err != nil || value != DefaultLimit {
		t.Fatalf("default limit = %d, err = %v", value, err)
	}
	for _, invalid := range []string{"0", "101", "abc", "-1"} {
		if _, err := ParseLimit(invalid); err == nil {
			t.Fatalf("expected %q to be rejected", invalid)
		}
	}
}