var win = $(window),
    nav_on = null;
$(function() {
    // banner 切换
    (function() {
        var banner = $('#banner'),
            pic_c  = banner.find('.pics'),
            pics   = pic_c.children(),
            idx_c  = banner.find('.idxs'),
            idxs   = idx_c.children(),
            btns   = banner.find('.btns a'),
            prev   = btns.filter('.prev'),
            next   = btns.filter('.next'),

            len    = pics.length,
            idx    = 0,
            prev_i = -1,
            max_i  = len - 1,
            curr_p = pics.eq(idx),
            curr_i = idxs.eq(idx),
            delay  = 7000,
            timeout = -1;

        win.on('load', function() {
            idx_recu(0, 1500/len, function() {
                settimeout(function() {
                    curr_i.addclass('on');
                    auto();
                }, 300);
                idxs.hover(hover);
            });
            banner.hover(function() {
                // prev.stop().fadein(300);
                // next.stop().fadein(300);
                btns.addclass('on');
            }, function() {
                btns.removeclass('on');
                // prev.stop().fadeout(300);
                // next.stop().fadeout(300);
            });
            prev.on('click', function() {fade(idx===0? idx=max_i:--idx)});
            next.on('click', function() {fade(idx===max_i? idx=0:++idx)});
        });

        function fade(idx) {
            cleartimeout(timeout);
            prev_i = idx;
            curr_p.stop(false,true).fadeout(300);
            curr_p = pics.eq(idx).stop(false,true).fadein(300);
            curr_i.removeclass('on');
            curr_i = idxs.eq(idx).addclass('on');
            auto();
        }
        function hover(){
            idx = $(this).index();
            if (idx === prev_i) return;
            fade(idx);
        }
        function idx_recu(idx, delay, func) {
            temp = idxs.eq(idx);
            if (temp.length) {
                temp.css('margin-top',0).fadein(500);
                settimeout(function() {
                    idx_recu(idx+1, delay, func);
                }, delay);
            } else {
                func();
                return;
            }
        }
        function auto() {
            timeout = settimeout(function() {
                fade(idx===max_i? idx=0: ++idx);
            }, delay);
        }
    }());


});