<?php

//这个文件里面是处理一些常见的字符串相关的函数
//纯工具类，不包含任何业务逻辑
class LewaimaiString {
	//产生字母或者数字的随机数
	public static function create_noncestr($length = 16) 
	{
		$chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
		$str ="";
		for ( $i = 0; $i < $length; $i++ )  {
			$str.= substr($chars, mt_rand(0, strlen($chars)-1), 1);
		}
		return $str;
	}
	
	//只产生数字的随机数
	public static function create_randnum($length = 6)
	{
		$chars = "0123456789";
		$str ="";
		for ( $i = 0; $i < $length; $i++ )  {
			$str.= substr($chars, mt_rand(0, strlen($chars)-1), 1);
		}
		return $str;
	}
	
	/*
	 * 生成以20160421这样的数字开头的唯一订单号，可能被猜到，不能用于团购券密码等地方
	 */
	public static function GetUniqueTradeNo($length = 16)
	{
		if ($length < 16)
		{
			$length = 16;
		}
		 
		$string = date('Ymd').substr(implode('', array_map('ord', str_split(substr(uniqid(), 7, 13), 1))), 0, 8);
		 
		if ($length > 16)
		{
			$string .= self::create_randnum($length - 16);
		}
		 
		return $string;
	}
	
	//将前缀和数字id串连起来
	//$prefix，前缀，格式如“LWMPT00000000001”
	//$id，要拼接的整数
	//$length 长度
	public static function noToStr($prefix, $id, $length = 16)
	{
		$id = $id . "";
		$idLength = strlen($id);
		return substr($prefix,0,$length-$idLength).$id;
	}
	
	//对姓名做匿名处理
	public static function niming($name)
	{
		$length = mb_strlen($name, 'utf-8');
		if($length == 0 || $length == 1)
		{
			return '***';
		}
		else
		{
			$head = mb_substr($name,0,1,'utf-8');
			$last = mb_substr($name,($length-1),1,'utf-8');
		}
		
		if ($length == 2) 
		{
			return $head . "***";
		}
		else
		{
			return $head . "***" . $last;
		}
	}
	
	public static function _unserialize($string)
	{
	    return unserialize(preg_replace('!s:(\d+):"(.*?)";!se', '"s:".strlen("$2").":\"$2\";"', $string));
	}

	//用于支付的唯一的订单号，长度24位
	public static function GetOutTradeNo()
	{
		$out_trade_no = "LWM" . strtoupper(uniqid()) . strtoupper(self::create_noncestr(8));
	
		return $out_trade_no;
	}

    public static function formatMonth($num , $day=0)
    {
        $year = floor($num/12);
        $month = $num%12;
        $str = $year ? $year . '年' : '';
        $str.= $month ? $month . '个月' : '';
        $day > 0 && $str .= $day.'天';
        return $str;
    }

	// 产生店铺的随机字符串
	public static function getShopNo()
	{
		$str = date('Ymd') . self::create_randnum(8);

		return $str;
	}
}