<?php


namespace common\helpers;

/**
 * StringHelper
 *
 */
class StringHelper extends \yii\helpers\StringHelper{

    /**
     * 字符串截取，支持中文和其他编码
     * @param string $str 需要转换的字符串
     * @param string $start 开始位置
     * @param string $length 截取长度
     * @param string $charset 编码格式
     * @param string $suffix 截断显示字符
     * @return string
     */
    public static function substr($str, $start=0, $length, $charset="utf-8", $suffix=false) {
        if(function_exists("mb_substr"))
            $slice = mb_substr($str, $start, $length, $charset);
        elseif(function_exists('iconv_substr')) {
            $slice = iconv_substr($str,$start,$length,$charset);
            if(false === $slice) {
                $slice = '';
            }
        }else{
            $re['utf-8']   = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";
            $re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";
            $re['gbk']    = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";
            $re['big5']   = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";
            preg_match_all($re[$charset], $str, $match);
            $slice = join("",array_slice($match[0], $start, $length));
        }
        return $suffix ? $slice.'...' : $slice;
    }

    /**
     * 获取随机字符串
     *
     * @param $length
     * @param bool $numeric
     * @return string
     */
    public static function random($length, $numeric = false)
    {
        $seed = base_convert(md5(microtime() . $_SERVER['DOCUMENT_ROOT']), 16, $numeric ? 10 : 35);
        $seed = $numeric ? (str_replace('0', '', $seed) . '012340567890') : ($seed . 'zZ' . strtoupper($seed));

        $hash = '';
        if (!$numeric) {
            $hash = chr(rand(1, 26) + rand(0, 1) * 32 + 64);
            $length--;
        }

        $max = strlen($seed) - 1;
        $seed = str_split($seed);
        for ($i = 0; $i < $length; $i++) {
            $hash .= $seed[mt_rand(0, $max)];
        }

        return $hash;
    }

    /**
     * 和谐显示
     * 如：手机号13812345678变成138****5678
     *
     * @param $string
     * @return string
     */
    public static function string_hide_cut($string): string
    {
        $length = mb_strlen($string, 'utf-8');
        if ($length == 0) {
            return '';
        }
        if ($length == 11) {
            $firstStr = mb_substr($string, 0, 3, 'utf-8');
            $lastStr1 = mb_substr($string, -4, 1, 'utf-8');
            $lastStr2 = mb_substr($string, -1, 1, 'utf-8');
            return $firstStr . '****' . $lastStr1 . '**' . $lastStr2;
        } elseif ($length < 11 && $length >= 3) {
            $firstStr = mb_substr($string, 0, 1, 'utf-8');
            $lastStr = mb_substr($string, -1, 1, 'utf-8');
            return $firstStr . str_repeat('*', $length - 2) . $lastStr;
        } elseif ($length == 2) {
            $firstStr = mb_substr($string, 0, 1, 'utf-8');
            return $firstStr . '*';
        } elseif ($length == 1) {
            return $string . '*';
        } else {
            $firstStr = mb_substr($string, 0, 3, 'utf-8');
            $lastStr = mb_substr($string, -4, 2, 'utf-8');
            return $firstStr . str_repeat('*', mb_strlen($string, 'utf-8') - 5) . $lastStr . '**';
        }
    }
}