package slug

import (
	"errors"
	"github.com/gosimple/unidecode"
	"regexp"
	"strings"
)

type Slug string

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

	regexpNonAuthorizedChars = regexp.MustCompile("[^a-zA-Z0-9-_]")
	regexpMultipleDashes     = regexp.MustCompile("-+")
)

func New(s string) Slug {
	s = unidecode.Unidecode(s)
	s = strings.ToLower(s)
	s = regexpNonAuthorizedChars.ReplaceAllString(s, "-")
	s = regexpMultipleDashes.ReplaceAllString(s, "-")
	s = strings.Trim(s, "-_")

	return Slug(s)
}

func NewString(s string) string {
	return New(s).String()
}

func Validate(s string) error {
	if s == "" {
		return ErrInvalidSlug
	}

	if s == NewString(s) {
		return nil
	}

	return ErrInvalidSlug
}

func (s Slug) String() string {
	return string(s)
}