//go:build linux

package host

import (
	"errors"
	"os"
	"path/filepath"
	"testing"

	"golang.org/x/sys/unix"
)

// On a kernel without openat2 the removal refuses and leaves the tree: there
// is no path-based fallback.
func TestInstallChannelRemovalRefusesWithoutOpenat2(t *testing.T) {
	f := newChannelFixture(t, "v1.2.0")
	entry := filepath.Join(f.a.dataDir, "system", "router", "v1.4.0")
	if err := os.MkdirAll(entry, 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(entry, "carlos"), []byte("x"), 0o755); err != nil {
		t.Fatal(err)
	}
	real := openat2
	defer func() { openat2 = real }()
	for _, refuse := range []error{unix.ENOSYS, unix.EPERM, unix.EXDEV} {
		openat2 = func(int, string, *unix.OpenHow) (int, error) { return -1, refuse }
		if err := removeCacheEntry(f.a.dataDir, "v1.4.0"); !errors.Is(err, refuse) {
			t.Fatalf("removal with openat2 failing %v: %v", refuse, err)
		}
		if _, err := os.Stat(filepath.Join(entry, "carlos")); err != nil {
			t.Fatalf("the tree was removed without openat2: %v", err)
		}
	}
}