/**
 * 
 * @authors yutent (yutent@doui.cc)
 * @date    2017-02-27 22:01:10
 *
 */

"use strict";


//类似于Array 的splice方法
if(!String.prototype.splice){
    Object.defineProperty(String.prototype,
        'splice',
        {
            value: function(start, len, fill){
                let length = this.length,
                    argLen = arguments.length;

                fill = fill === undefined ? '' : fill

                if(argLen < 1){
                    return this
                }

                //处理负数
                if(start < 0){
                    if(Math.abs(start) >= length)
                        start = 0
                    else
                        start = length + start
                }

                if(argLen === 1){
                    return this.slice(0, start)
                }else{
                    len -= 0;

                    let strl = this.slice(0, start)
                    let strr = this.slice(start + len)

                    return strl + fill + strr
                }
            },
            enumerable: false
        })
}



//同php的htmlspecialchars函数
if(!String.prototype.htmlspecialchars){
    Object.defineProperty(String.prototype,
        'htmlspecialchars',
        {
            value: function(sign){
                let str = this.replace(/&(?!\w+;)/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')

                if(sign === 'ENT_QUOTES')
                    return str.replace(/"/g, '&quot;').replace(/'/g, '&#39;')
                else if(sign === 'ENT_NOQUOTES')
                    return str
                else
                    return str.replace(/"/g, '&quot;')
            },
            enumerable: false
        })
}


//htmlspecialchars的还原
if(!String.prototype.tohtml){
    Object.defineProperty(String.prototype,
        'tohtml',
        {
            value: function(){
                return this.replace(/&lt;/ig, '<')
                        .replace(/&gt;/ig, '>')
                        .replace(/&quot;/ig, '"')
                        .replace(/&#39;/g, '\'')
                        .replace(/&amp;/ig, '&')
            },
            enumerable: false
        })
}


//简单的过滤xss
if(!String.prototype.xss){
    Object.defineProperty(String.prototype,
        'xss',
        {
            value: function(){
                let str = this.htmlspecialchars('ENT_QUOTES')
                    str = str.replace(/(document\.cookie)|(document\.write)|(\.parentNode)|(window\.location)|(\.innerHTML)/g, '')
                        .replace(/(%0[0-8bcef])|(%1[0-9a-f])/g, '')
                    return str
            },
            enumerable: false
        })
}

// js特殊字符的转义
if(!String.prototype.escape){
    Object.defineProperty(String.prototype,
        'escape',
        {
            value: function(){
                return this.replace(/('|"|&|\\|\}|\{|\(|\)|;|=|\,|&)/g, '\\$1')
            },
            enumerable: false
        })
}





// padStart & padEnd
if(!String.prototype.padStart){
    Object.defineProperty(String.prototype,
        'padStart',
        {
            value: function(len, fill){
                let alen = arguments.length,
                    length = this.length,
                    ilen = len - length;

                if(alen < 1 || ilen < 1)
                    return this

                if(alen < 2 || typeof fill !== 'string')
                    fill = ' '

                while(fill.length < ilen){
                    fill += fill
                }

                return fill.slice(0, ilen) + this
            },
            enumerable: false
        })

    Object.defineProperty(String.prototype,
        'padEnd',
        {
            value: function(len, fill){
                let alen = arguments.length,
                    length = this.length,
                    ilen = len - length;

                if(alen < 1 || ilen < 1)
                    return this

                if(alen < 2 || typeof fill !== 'string')
                    fill = ' '

                while(fill.length < ilen){
                    fill += fill
                }

                return this + fill.slice(0, ilen)
            },
            enumerable: false
        })
}