var env = getApp().globalData.env;

const base64 = require('base64.js');//Base64,hmac,sha1,crypto相关算法
require('hmac.js');
require('sha1.js');
const Crypto = require('crypto.js');

/*
 *上传文件到阿里云oss
 *@param - filePath :图片的本地资源路径
 *@param - dir:表示要传到哪个目录下
 *@param - successc:成功回调
 *@param - failc:失败回调
 */ 
const uploadFile = function (filePath, dir, successc, failc) {
  if (!filePath || filePath.length < 9) {
    wx.showModal({
      title: '图片错误',
      content: '请重试',
      showCancel: false,
    })
    return;
  }
  var scale = null;
  wx.getImageInfo({
    src: filePath,
    success (res) {
      scale = (res.width/res.height).toFixed(2);
    }
  })

  console.log('上传图片.....');

  // console.log(dir)
  //图片名字 可以自行定义，     这里是采用当前的时间戳 + 150内的随机数来给图片命名的
  const aliyunFileKey = dir + new Date().getTime() + Math.floor(Math.random() * 150);

  // console.log(env)
  const aliyunServerURL = env.uploadImageUrl;//OSS地址，需要https
  const accessid = env.OSSAccessKeyId;
  const securityToken = env.securityToken;
  const policyBase64 = getPolicyBase64();
  const signature = getSignature(policyBase64);//获取签名

  wx.uploadFile({
    url: aliyunServerURL,//开发者服务器 url
    filePath: filePath,//要上传文件资源的路径
    name: 'file',//必须填file
    formData: {
      'key': aliyunFileKey,
      'policy': policyBase64,
      'OSSAccessKeyId': accessid,
      'signature': signature,
      'success_action_status': '200',//自定义成功状态200
      'x-oss-security-token': securityToken
    },
    success: function (res) {
      // console.log(res) 
      if (res.statusCode != 200) {
        failc(new Error('上传错误:' + JSON.stringify(res)))
        return;
      }
      successc('https://cdn.toktok.beer/' + aliyunFileKey + '?scale=' + scale);
    },
    fail: function (err) {
      err.wxaddinfo = aliyunServerURL;
      failc(err);
    },
  })
}

const getPolicyBase64 = function () {
  let dateobj = new Date();
  dateobj.setHours(dateobj.getHours() + env.timeout);
  let srcT = dateobj.toISOString();
  const policyText = {
    "expiration": srcT, //设置该Policy的失效时间，超过这个失效时间之后，就没有办法通过这个policy上传文件了 
    "conditions": [
      ["content-length-range", 0, 5 * 1024 * 1024] // 设置上传文件的大小限制,5mb
    ]
  };

  const policyBase64 = base64.encode(JSON.stringify(policyText));
  return policyBase64;
}

const getSignature = function (policyBase64) {
  const accesskey = env.AccessKeySecret;

  const bytes = Crypto.HMAC(Crypto.SHA1, policyBase64, accesskey, {
    asBytes: true
  });
  const signature = Crypto.util.bytesToBase64(bytes);

  return signature;
}

module.exports = uploadFile;