package slug

import (
	"regexp"
	"strings"
)

const (
	DefaultLimit = 80
)

var invalidChars = regexp.MustCompile(`[^a-z0-9]+`)

func Normalize(s string) string {
	return NormalizeWithLimit(s, DefaultLimit)
}

func NormalizeWithLimit(s string, limit int) string {
	s = strings.ToLower(strings.TrimSpace(s))
	s = invalidChars.ReplaceAllString(s, "-")
	s = strings.Trim(s, "-")
	if limit > 0 && len(s) > limit {
		s = strings.Trim(s[:limit], "-")
	}
	return s
}