package storage

import (
	"fmt"
	"regexp"
	"strings"
)

// mountNameRe validates mount names: only alphanumeric + underscore.
var mountNameRe = regexp.MustCompile(`^[a-zA-Z0-9_]+$`)

// FstabPath is the path to the host fstab inside the container.
// The compose file mounts /etc/fstab → /host-fstab.
const FstabPath = "/host-fstab"

// HostDevPath is where the host's /dev is mounted inside the container.
// Docker always creates its own tmpfs at /dev (overriding any bind mount),
// so the host's block devices are mounted at a different path instead.
const HostDevPath = "/host-dev"

// HostDevicePath converts a standard /dev/ device path to the container-accessible path.
// "/dev/sdb" → "/host-dev/sdb", "/dev/sdb1" → "/host-dev/sdb1"
// Paths that don't start with /dev/ are returned unchanged.
func HostDevicePath(devPath string) string {
	if strings.HasPrefix(devPath, "/dev/") {
		return HostDevPath + "/" + strings.TrimPrefix(devPath, "/dev/")
	}
	return devPath
}

// ValidateMountName returns an error if the mount name is invalid.
func ValidateMountName(name string) error {
	if name == "" {
		return fmt.Errorf("a csatlakoztatási névnek nem szabad üresnek lennie")
	}
	if !mountNameRe.MatchString(name) {
		return fmt.Errorf("a csatlakoztatási néven csak betűk, számok és alávonás megengedett")
	}
	if len(name) > 32 {
		return fmt.Errorf("a csatlakoztatási néven legfeljebb 32 karakter megengedett")
	}
	return nil
}