package region

import (
	"regexp"
	"strings"
)

var spaceRE = regexp.MustCompile(`\s+`)
var edgePunctRE = regexp.MustCompile(`^[\s\.,!\?;:"'«»\(\)\[\]\{\}]+|[\s\.,!\?;:"'«»\(\)\[\]\{\}]+$`)

func Normalize(input string) string {
	s := strings.TrimSpace(strings.ToLower(input))
	s = strings.ReplaceAll(s, "ё", "е")
	s = strings.ReplaceAll(s, "-", " ")
	s = strings.ReplaceAll(s, "г.", "город ")
	s = strings.ReplaceAll(s, "обл.", "обл")
	s = edgePunctRE.ReplaceAllString(s, "")
	s = strings.Map(func(r rune) rune {
		switch r {
		case '.', ',', '!', '?', ';', ':', '"', '\'', '«', '»', '(', ')', '[', ']', '{', '}':
			return ' '
		default:
			return r
		}
	}, s)
	return spaceRE.ReplaceAllString(strings.TrimSpace(s), " ")
}