package contentstats

import (
	"regexp"
	"strings"
	"unicode"
)

var latinTokenPattern = regexp.MustCompile(`[A-Za-z0-9]+(?:['’-][A-Za-z0-9]+)?`)

func CountWords(input string) int {
	input = strings.TrimSpace(input)
	if input == "" {
		return 0
	}

	var builder strings.Builder
	hanCount := 0

	for _, r := range input {
		switch {
		case unicode.Is(unicode.Han, r):
			hanCount++
			builder.WriteRune(' ')
		case unicode.IsLetter(r) || unicode.IsDigit(r):
			builder.WriteRune(r)
		case unicode.IsSpace(r):
			builder.WriteRune(' ')
		default:
			builder.WriteRune(' ')
		}
	}

	latinCount := len(latinTokenPattern.FindAllString(builder.String(), -1))
	return hanCount + latinCount
}