//go:build !windows

package spool

import (
	"errors"
	"fmt"
	"os"
)

func ensurePrivateFile(path string) error {
	file, err := os.OpenFile(path, os.O_CREATE|os.O_EXCL|os.O_RDWR, 0o600)
	if err == nil {
		return file.Close()
	}
	if !errors.Is(err, os.ErrExist) {
		return err
	}
	info, err := os.Lstat(path)
	if err != nil {
		return err
	}
	if !info.Mode().IsRegular() || info.Mode()&os.ModeSymlink != 0 {
		return fmt.Errorf("%w: %s is not a regular file", ErrUnsafeDataDirectory, path)
	}
	if info.Mode().Perm()&0o077 != 0 {
		return fmt.Errorf("%w: %s permissions %04o expose private state", ErrUnsafeDataDirectory, path, info.Mode().Perm())
	}
	return nil
}

func ensurePrivateDirectory(path string) error {
	info, err := os.Lstat(path)
	if os.IsNotExist(err) {
		if err := os.MkdirAll(path, 0o700); err != nil {
			return err
		}
		info, err = os.Lstat(path)
	}
	if err != nil {
		return err
	}
	if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() {
		return fmt.Errorf("%w: %s is not a real directory", ErrUnsafeDataDirectory, path)
	}
	if info.Mode().Perm()&0o077 != 0 {
		return fmt.Errorf("%w: %s permissions %04o expose private state", ErrUnsafeDataDirectory, path, info.Mode().Perm())
	}
	return nil
}

func securePrivateFile(path string) error { return os.Chmod(path, 0o600) }