/**
 * WX_SHARE v1.0.3
 * Desc: 使用微信JS-SDK（手浪接口提供动态token）实现自定义微信分享（仅在微信内,非微信浏览器do nothing）
 * Modified: 2017/8/14
 * Email: minhua@staff.sina.com.cn
 */

var WX_SHARE = (function () {
    var isInited = false;
    //工具函数
    function _getScript(src, onLoad) {
        var s = document.createElement('script');
        s.charset = 'utf-8';
        s.type = 'text/javascript';
        s.src = src;
        document.getElementsByTagName('body')[0].appendChild(s);
        if ('onreadystatechange' in s) {
            s.onreadystatechange = function () {
                if (s.readyState.toLowerCase() === 'loaded') {
                    onLoad && onLoad();
                }
            };
        } else {
            s.onload = function () {
                onLoad && onLoad();
            }
        }
    }

    function _merge(tar, src) {
        var val;
        for (var key in src) {
            if (src.hasOwnProperty(key)) {
                //''或null或undefined使用默认,不覆盖
                val = src[key];
                if (val == null || val === '') continue;
                tar[key] = val;
            }
        }
        return tar;
    }

    function init(shareCfg) {
        if (isInited) return;
        if (!navigator.userAgent.match(/MicroMessenger/gi)) return;
        isInited = true;
        _getScript(document.location.protocol+'//res.wx.qq.com/open/js/jweixin-1.0.0.js', function () {
            var _desc = document.querySelector('meta[name=description]');
            var _poster = document.querySelector('img[name=weixin_poster]');
            var _shareCfg = {
                title: document.title,
                desc: (_desc && _desc.content) || document.title,
                imgUrl: (_poster && _poster.src) || document.location.protocol+'//n.sinaimg.cn/finance/6adc145b/20170719/wx_poster_finance.png',
                type: '',
                dataUrl: '',
                success: function () {
                },
                cancel: function () {
                }
            };
            shareCfg && _merge(_shareCfg, shareCfg);
            _shareCfg.link = location.href.split('#')[0];

            window.setWxCfg = function (res) {
                if (Number(res.status) === 0) {
                    var data = res.data;
                    wx.config({
                        debug: false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。
                        appId: data.appid, // 必填，公众号的唯一标识
                        timestamp: data.time, // 必填，生成签名的时间戳
                        nonceStr: data.nonceStr,// 必填，生成签名的随机串
                        signature: data.signature,// 必填，签名
                        jsApiList: ['onMenuShareAppMessage', 'onMenuShareTimeline'] // 必填，需要使用的JS接口列表
                    });
                    wx.ready(function () {
                        wx.onMenuShareAppMessage(_shareCfg);
                        wx.onMenuShareTimeline(_shareCfg);
                        WX_SHARE.update = function (cfg) {
                            _merge(_shareCfg, cfg);
                            wx.onMenuShareAppMessage(_shareCfg);
                            wx.onMenuShareTimeline(_shareCfg);
                        }
                    });
                    wx.error(function (res) {
                        console.log('wx error: ', res);
                    });
                }
            };
            _getScript(document.location.protocol + '//mp.sina.cn/aj/wechat/gettoken?url=' + encodeURIComponent(location.href.split('#')[0]) + '&callback=setWxCfg');
        });
    }


    if (typeof window._wxShareConfig === 'object') {
        init(window._wxShareConfig);
    }
    //export
    return {
        update: null,
        init: init
    };
})();