// fs implements Storage on filesystem
package fs

import (
	"errors"
	"galaxy/util"
)

type fs struct {
	rootPath string
}

// NewStorage returns on-filesystem implementation of the "galaxy/storage.Storage" with root located at rootPath.
// rootPath must me a directory and has write access to the current user. If initial checks failed, return nil and non-nil error.
func NewFS(rootPath string) (*fs, error) {
	ok, err := util.Writable(rootPath)
	if err != nil {
		return nil, err
	}
	if !ok {
		return nil, errors.New("user does not have write permissions to the storage root")
	}
	s := &fs{
		rootPath: rootPath,
	}
	return s, nil
}