package utils

import (
	"regexp"
)

// NormalizeISBN removes hyphens and spaces from ISBN to standardize format
// Handles ISBN-10 and ISBN-13 formats
func NormalizeISBN(isbn string) string {
	if isbn == "" {
		return ""
	}

	// Remove hyphens and spaces, return only digits and X (for ISBN-10)
	return regexp.MustCompile(`[-\s]`).ReplaceAllString(isbn, "")
}