(function($){
    $.fn.getselfindex=function(type){
        if(typeof(type)=="undefined"){
            //在同辈元素均为同类型的元素时
            return $(this).prevall().length;
        }else {
            //在同辈元素有多种类型时
            return $(this).prevall().filter(type).length;
        }
    };
})(jquery);
$(function () {
    var speed = 1, autotime = 5000;
    var movepx, ind, len, timer;
    window.onresize = function () {
        window.cleartimeout(timer);
        nav_init();
        timer = window.settimeout(function () { automove(); }, autotime);
    }
    function nav_init() {
        movepx = $('.photoshow').width(),
        ind = $('.photoshow .current').getselfindex('.photoshow li'),
        len = $('#photoshow li').length;
        this.navobj = $('#nav');
        this.ul = $('.photoshow ul');
        this.li = $('.photoshow ul li');
        //this.parentwidth = this.navobj.parent().width();
        this.parentwidth = this.navobj.parent().width();
        this.left = (this.parentwidth - this.navobj.width()) / 2;
        //this.navobj.css({'left': this.left});
        this.ul.css({ width: movepx * len + 'px','marginleft': -movepx * ind+'px' });
        this.li.css({ width: movepx  + 'px' });
    }
    function nav_change(next) {
        $('#nav em').removeclass('ehover').eq(next).addclass('ehover');
    }
    function moveto(to) {
        var gotoit;
        ind = $('.photoshow .current').getselfindex('.photoshow li');
        //console.log('当前: ' + ind);
        if ((to == '' || to == null || to == 'undefined') && to != 0) {
        	gotoit = ind < len - 1 ? ind + 1 : 0;
        } else {
            //console.log('选择:' + to);
            gotoit = to < 0 ? len - 1 : to > len - 1 ? 0 : to;
        }
        //console.log('下个: ' + goto);
        //console.log('--------------------');
        $('.photoshow li').removeclass('current').eq(gotoit).addclass('current');
        $('#photoshow').animate({ 'marginleft': -movepx * gotoit }, speed);
        nav_change(gotoit);
    }
    function automove() {
        moveto();
        timer = window.settimeout(function () { automove(); }, autotime);
    }
    nav_init();
    timer = window.settimeout(function () { automove(); }, autotime);


    $('#left').click(function () { ind = $('.photoshow .current').getselfindex('.photoshow li'); moveto(ind - 1); });
    $('#right').click(function () { ind = $('.photoshow .current').getselfindex('.photoshow li'); moveto(ind + 1);  });
    $('#nav em').click(function () { var ind_nav = $(this).getselfindex('#nav em'); moveto(ind_nav);  });
    $('#nav').mouseover(function () {window.cleartimeout(timer);  }).mouseout(function () { timer = window.settimeout(function () { automove(); }, autotime); });
});