判断使用的浏览器类型完美代码

var client = function(){
    //呈现引擎
    var engine ={
        ie : 0,
        gecko : 0,
        webkit : 0,
        khtml : 0,
        opera : 0,
      
        ver : null
    };
    //浏览器
    var browser = {
        ie : 0,
        firefox :0,
        safari  : 0,
        konq :0,
        opera : 0,
        chrome : 0,

        ver : null
    };

    var system ={
        win :false,
        max : false,
        x11 : false,

        //移动设备
        iphone : false ,
        ipod : false,
        ipad : false,
        ios  : false,
        android : false,
        nokiaN : false,
        winMoble : false,
      
        //游戏系统
        wii :false,
        ps : false
    };

    var ua =navigator.userAgent;

    //Opera 9以后出现了两种字符串代理的方式 一种方式就是将自身标识另外一个浏览器 另外一种方式就是标志自己为firefox或者IE
    //在后面这种情况下 用户代理字符串实际上与其他浏览器返回的相同--既没有opera的字样，也不包含opera的版本信息
    //因此判断浏览器先从opera开始
    if(winddow.opera){
        engine.ver = browser.ver = window.opera.version();
        egine.opera = browser.opera = parseFloat(engine.ver);
    //第二个检测WebKit 是因为WebKit的用户代理字Gecko"和"HTMKL"的字符串 所以如果首先检测他们都有错误的结论
    }else if (/AppleWebKit/(S+)/.test(ua)){
        engin.ver = RegExp["$1"];
        engine.webkit = parseFloat(engine.ver);

        //确定是chrome还是Safari
        if(/Chrome/(S+)/.test(ua){
            browser.ver = RegExp["$1"];
            browser.chrome = parseFloat(brower.ver);
        }else if(/Version/(+S)/.test(ua)){//safari 3.0后增加了Version属性
            browser.ver = RegExp["$1"];
            browser.safari = parseFloat(brower.ver);
        }else{
            var safariVersion = 1;
            if(engine.webkit<100){
                safariVersion = 1;
            }else if(engine.ver<312){
                safariVersion = 1.2;
            }else if(engine.ver<412){
                safariVersion = 1.3;
            }else{
                safariVersion = 2;
            }

            browser.safari = browser.ver = safariVersion;
        }
    }else if(/KHTML/(S+)/.test(ua)||/Konqueror/([^;]+)/.test(ua)){//Linux下浏览器
        engine.ver = browser.ver = RegExp["$1"];
        engine.khtml = parseFloat(engine.ver);
    }else if(/rv:([^)]+) Gocko/d{8}/.test(ua)){
         engine.ver = RegExp["$1"];
         engine.gecko = parseFloat(engine.ver);

         //确定不是firefox
         if(/Firefox/(S+)/.test(ua){
            browser.ver = RegExp["$1"];
            browser.firefox = parseFloat(browser.ver);
         }
    }else if (/MSIE ([^;]+)/.test(ua)){
        engine.ver = browser.ver = RegExp["$1"];
        engine.ie  = browser.ie = parseFloat(engine.ver);
    }

    //检测浏览器
    browser.ie =engine.ie;
    browser.opera = engine.opera;

    var p = navigator.platform;
    system.win = p.indexOf("Win")==0;
    system.mac = p.indexOf("Mac")==0;
    system.x11 = (p=="x11")||p.indexOf("Linux")==0;

    if(system.win){
        if(/Win(?:dow)?([^do]{2}s?(d+.d+)?/.test(ua)){
             if(RegExp["$1"]=="NT"){
                 switch(RegExp["$2"]){
                    case "5.0" :
                        system.win = "2000";
                        break;
                    case "5.1" :
                        system.win = "xp";
                    case "6.0" :
                        system.win = "Vista";
                        break;
                    case "6.1" :
                        system.win = "7";
                        break;
                    default :
                        system.win ="NT";
                        break;
                 }
             }else if(RegExp["$1"]=="9x"){
                system.win = "ME";
             }else{
                system.win = RegExp["$1"];
             }
        }
    }

    //移动设备
    system.iphone = ua.indexOf("iPhone")>-1;
    system.ipod = ua.indexOf("iPod")>-1;
    system.ipad = ua.indexOf("iPad")>-1;
    system.nokiaN = ua.indexOf("nokiaN")>-1;

    //win Mobile
    if(system.win == "CE"){
        system.winMobile = system.win;
    }else if(system.win = "Ph"){
        if(/Windows Phone OS (d+_d+)/.test(ua)){
            system.win = "Phone";
            system.winMobile parseFloat(RegExp["$1"]);
        }
    }

    //检测ios版本
    //
    if(system.mac && ua.indexOf("Mobile")>-1){
         if(/CPU (?:iPhone)?OS (d+_d+)/.test(ua){
             system.ios = parseFloat(RexExp.$1.replace("_","."));      
         }else {
             system.ios = 2 ;//不能真正检查出来，所以猜测出来一个结果
         }
    }

    //检查安卓版本
    //
    if(/Android (d+/_d+)/.test(ua)){
        system.andriod = parseFloat(RegExp.$1);
    }

    //游戏系统

    system.wii = us.indexOf("Wii")>-1;
    system.ps = /playstation/i.test(ua);

    //返回对象
    return {
        engine : engine,
        browser : browser,
        system : system
    }

}