var app = getApp();
var MD5Encode = require("MD5Encode.js");

/**
 * 对字符串判空
 */
function isStringEmpty(data) {
 if (null == data || "" == data) {
 return true;
 }
 return false;
}

/**
 * 封装网络请求
 */
function sentHttpRequestToServer(uri, data, method, successCallback, failCallback, completeCallback) {
 wx.request({
 url: app.d.hostUrl + uri,
 data: data,
 method: method,
 header: {
 'Content-Type': 'application/x-www-form-urlencoded'
 },
 success: successCallback,
 fail: failCallback,
 complete: completeCallback
 })
}

/**
 * 将map对象转换为json字符串
 */
function mapToJson(map) {
 if (null == map) {
 return null;
 }
 var jsonString = "{";
 for (var key in map) {
 jsonString = jsonString + key + ":" + map[key] + ",";
 }
 if ("," == jsonString.charAt(jsonString.length - 1)) {
 jsonString = jsonString.substring(0, jsonString.length - 1);
 }
 jsonString += "}";
 return jsonString;
}

/**
 * 弹窗提示成功
 */
function toastSuccess() {
 wx.showToast({
 title: '成功',
 icon: 'success',
 duration: 2000
 })
}

/**
 * 调用微信支付
 */
function doWechatPay(prepayId, successCallback, failCallback, completeCallback) {
 var nonceString = getRandomString();
 var currentTimeStamp = getCurrentTimeStamp();
 var packageName = "prepay_id=" + prepayId;
 var dataMap = {
 timeStamp: currentTimeStamp,
 nonceStr: nonceString,
 package: packageName,
 signType: "MD5",
 paySign: getWechatPaySign(nonceString, packageName, currentTimeStamp),
 success: successCallback,
 fail: failCallback,
 complete: completeCallback
 }
 console.log(dataMap);
 wx.requestPayment(dataMap);
}

/**
 * 获取微信支付签名字符串
 */
function getWechatPaySign(nonceStr, packageName, timeStamp) {
 var beforMD5 = "appid=" + app.d.appId + "&nonceStr=" + nonceStr + "&package=" + packageName + "&signType=MD5" + "&timeStamp=" + timeStamp + "&key=" + app.d.appKey;
 return doMD5Encode(beforMD5).toUpperCase();
}

/**
 * 获取当前时间戳
 */
function getCurrentTimeStamp() {
 var timestamp = Date.parse(new Date());
 return timestamp + "";
}

/**
 * 获取随机字符串,32位以下
 */
function getRandomString() {
 return Math.random().toString(36).substring(3, 8);
}

/**
 * MD5加密
 */
function doMD5Encode(toEncode) {
 return MD5Encode.hexMD5(toEncode);
}

module.exports = {
 isStringEmpty: isStringEmpty,
 sentHttpRequestToServer: sentHttpRequestToServer,
 mapToJson: mapToJson,
 toastSuccess: toastSuccess,
 doWechatPay: doWechatPay
}