package hostfile

import "os"

// FileSystem abstracts filesystem operations for testability.
type FileSystem interface {
	ReadFile(path string) ([]byte, error)
	WriteFile(path string, data []byte, perm os.FileMode) error
	Stat(path string) (os.FileInfo, error)
	CreateTemp(dir, pattern string) (*os.File, error)
	Rename(oldpath, newpath string) error
	Remove(path string) error
	Chmod(path string, mode os.FileMode) error
}

// OSFileSystem implements FileSystem using real OS calls.
type OSFileSystem struct{}

func (OSFileSystem) ReadFile(path string) ([]byte, error) { return os.ReadFile(path) }
func (OSFileSystem) WriteFile(path string, data []byte, perm os.FileMode) error {
	return os.WriteFile(path, data, perm)
}
func (OSFileSystem) Stat(path string) (os.FileInfo, error) { return os.Stat(path) }
func (OSFileSystem) CreateTemp(dir, pattern string) (*os.File, error) {
	return os.CreateTemp(dir, pattern)
}
func (OSFileSystem) Rename(oldpath, newpath string) error { return os.Rename(oldpath, newpath) }
func (OSFileSystem) Remove(path string) error             { return os.Remove(path) }
func (OSFileSystem) Chmod(path string, mode os.FileMode) error {
	return os.Chmod(path, mode)
}