//go:build !linux

package apply

// Where there is no openat with O_NOFOLLOW to rely on, the check before use is all: a link below a home is
// refused, and the call is made by path. The node-engine runs on Linux; this keeps the package building.

import (
	"os"
	"path/filepath"

	"github.com/novox/mesh-host/internal/declaration"
)

func chmodUnder(home, path string, mode os.FileMode) error {
	if err := refuseLinksUnderHome(path); err != nil {
		return err
	}
	return os.Chmod(path, mode)
}

func chmodUnderAs(home, path string, mode os.FileMode, _ int) error {
	return chmodUnder(home, path, mode)
}

const kindDir = 1

func chownUnder(home, path string, uid, gid int) error {
	if err := refuseLinksUnderHome(path); err != nil {
		return err
	}
	return os.Lchown(path, uid, gid)
}

func readUnder(home, path string) ([]byte, error) {
	if err := refuseLinksUnderHome(path); err != nil {
		return nil, err
	}
	return os.ReadFile(path)
}

func mkdirAllUnder(home, dir string, mode os.FileMode) ([]string, error) {
	if err := refuseLinksUnderHome(dir); err != nil {
		return nil, err
	}
	var made []string
	for d := filepath.Clean(dir); d != home; d = filepath.Dir(d) {
		if _, err := os.Lstat(d); err == nil {
			break
		}
		made = append(made, d)
	}
	return made, os.MkdirAll(dir, mode)
}

func writeUnder(home, path string, content []byte, mode os.FileMode) error {
	if err := refuseLinksUnderHome(path); err != nil {
		return err
	}
	return writeAtomicallyByPath(path, content, mode)
}

// giveHandedOver is refused where there is no openat with O_NOFOLLOW: a handed-over directory is never changed by
// path (novox/hq issue 356). The node-engine runs on Linux.
func giveHandedOver(path string, _ os.FileMode, _, _ int, _ bool) (os.FileMode, int, int, error) {
	return 0, 0, 0, &PlacementRefusedError{Path: path, Why: "a handed-over directory is changed only through a " +
		"descriptor that followed no link, which this system cannot open"}
}

// judgeMeshDir refuses where there is no openat with O_NOFOLLOW (novox/hq issue 358). The node-engine runs on
// Linux.
func judgeMeshDir(path string) error {
	return &PlacementRefusedError{Path: path, Why: "a mesh directory is judged only by a walk that follows no link " +
		"another account could make, which this system cannot do"}
}

// meshDirsByDescriptor is false where there is no openat with O_NOFOLLOW: a mesh directory is changed by path, as
// before novox/hq issue 358. The node-engine runs on Linux.
const meshDirsByDescriptor = false

func applyMeshDirectory(r *declaration.Directory, out Outcome, _ os.FileMode, _ bool) (Outcome, error) {
	return out, &PlacementRefusedError{Path: r.Path, Why: "a mesh directory is changed only through a descriptor " +
		"that followed no link another account could make, which this system cannot open"}
}