package com.nq.utils;



import org.apache.commons.lang3.StringUtils;



import java.util.regex.Pattern;



public final class PhoneUtil {



    /**

     * 严格大陆手机号（11位）：有效运营商号段

     * 13x | 14[5-9] | 15[0-35-9] | 16[2567] | 17[0-8] | 18x | 19[0-35-9]

     */

    private static final Pattern STRICT_MOBILE = Pattern.compile(

            "^1(3\\d|4[5-9]|5[0-35-9]|6[2567]|7[0-8]|8\\d|9[0-35-9])\\d{8}$");



    private PhoneUtil() {

    }



    /** 规范为 11 位大陆手机号，非法返回 null */

    public static String normalizeChinaMobile(String phone) {

        if (StringUtils.isBlank(phone)) {

            return null;

        }

        String digits = phone.trim().replaceAll("[^0-9]", "");

        if (digits.startsWith("86") && digits.length() == 13) {

            digits = digits.substring(2);

        }

        if (digits.length() != 11 || !digits.startsWith("1")) {

            return null;

        }

        return digits;

    }



    public static boolean isValidChinaMobile(String phone) {

        String normalized = normalizeChinaMobile(phone);

        return normalized != null && STRICT_MOBILE.matcher(normalized).matches();

    }

}