package organization

import (
	"errors"
	"regexp"
	"strings"
)

const (
	slugMinLength = 1
	slugMaxLength = 63
)

var (
	slugPattern  = regexp.MustCompile(`^[a-z0-9]+(?:-[a-z0-9]+)*$`)
	reservedSlug = "my"
)

var ErrInvalidSlug = errors.New("invalid organization slug")

// NormalizeSlug lowercases and validates an organization slug.
func NormalizeSlug(input string) (string, error) {
	slug := strings.ToLower(strings.TrimSpace(input))
	if len(slug) < slugMinLength || len(slug) > slugMaxLength {
		return "", ErrInvalidSlug
	}
	if slug == reservedSlug {
		return "", ErrInvalidSlug
	}
	if !slugPattern.MatchString(slug) {
		return "", ErrInvalidSlug
	}
	return slug, nil
}