// 临时密钥服务例子
var bodyParser = require('body-parser');
var STS = require('qcloud-cos-sts');
var express = require('express');
var crypto = require('crypto');
var pathLib = require('path');
var fs = require('fs');

// 配置参数
var config = {
  secretId: process.env.SecretId,
  secretKey: process.env.SecretKey,
  proxy: process.env.Proxy,
  durationSeconds: 1800,
  bucket: process.env.Bucket,
  region: process.env.Region,
  // 允许操作（上传）的对象前缀，可以根据自己网站的用户登录态判断允许上传的目录，例子： user1/* 或者 * 或者a.jpg
  // 请注意当使用 * 时，可能存在安全风险，详情请参阅：https://cloud.tencent.com/document/product/436/40265
  allowPrefix: '_ALLOW_DIR_/*',
  // 密钥的权限列表
  allowActions: [
    // 所有 action 请看文档
    // COS actions: https://cloud.tencent.com/document/product/436/31923
    // CI actions: https://cloud.tencent.com/document/product/460/41741
    // 简单上传
    'name/cos:PutObject',
    'name/cos:PostObject',
    // 分片上传
    'name/cos:InitiateMultipartUpload',
    'name/cos:ListMultipartUploads',
    'name/cos:ListParts',
    'name/cos:UploadPart',
    'name/cos:CompleteMultipartUpload',
    // 下载文件
    'name/cos:GetObject',
    // 文本审核任务
    'ci:CreateAuditingTextJob',
  ],
  // condition条件限定，关于 condition 的详细设置规则和COS支持的condition类型可以参考https://cloud.tencent.com/document/product/436/71306
  // condition:{
  //   // 比如限制该ip才能访问cos
  //   'ip_equal': {
  //       'qcs:ip': '192.168.1.1'
  //   },
  // 比如限制上传文件最大为1MB
  //   'numeric_less_than_equal: {
  //     'cos:content-length': 1038336
  // }
  // }
  // 限制的上传后缀
  extWhiteList: ['jpg', 'jpeg', 'png', 'gif', 'bmp'],
};

function camSafeUrlEncode(str) {
  return encodeURIComponent(str)
    .replace(/!/g, '%21')
    .replace(/'/g, '%27')
    .replace(/\(/g, '%28')
    .replace(/\)/g, '%29')
    .replace(/\*/g, '%2A');
}

var getObjectKeys = function (obj, forKey) {
  var list = [];
  for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
      list.push(forKey ? camSafeUrlEncode(key).toLowerCase() : key);
    }
  }
  return list.sort(function (a, b) {
    a = a.toLowerCase();
    b = b.toLowerCase();
    return a === b ? 0 : a > b ? 1 : -1;
  });
};

/**
 * obj转为string
 * @param  {Object}  obj                需要转的对象，必须
 * @param  {Boolean} lowerCaseKey       key是否转为小写，默认false，非必须
 * @return {String}  data               返回字符串
 */
var obj2str = function (obj, lowerCaseKey) {
  var i, key, val;
  var list = [];
  var keyList = getObjectKeys(obj);
  for (i = 0; i < keyList.length; i++) {
    key = keyList[i];
    val = obj[key] === undefined || obj[key] === null ? '' : '' + obj[key];
    key = lowerCaseKey ? camSafeUrlEncode(key).toLowerCase() : camSafeUrlEncode(key);
    val = camSafeUrlEncode(val) || '';
    list.push(key + '=' + val);
  }
  return list.join('&');
};

// 生成要上传的 COS 文件路径文件名
var generateCosKey = function (ext) {
  var date = new Date();
  var m = date.getMonth() + 1;
  var ymd = `${date.getFullYear()}${m < 10 ? `0${m}` : m}${date.getDate()}`;
  var r = ('000000' + Math.random() * 1000000).slice(-6);
  var cosKey = `file/${ymd}/${ymd}_${r}${ext ? `.${ext}` : ''}`;
  return cosKey;
};
var cosHost = `${config.bucket}.cos.${config.region}.myqcloud.com`;

// 创建临时密钥服务和用于调试的静态服务
var app = express();

var replaceBucketRegion = (filePath) => {
  return (req, res, next) => {
    var content = fs
      .readFileSync(filePath)
      .toString()
      .replace(
        /(var config = {\r?\n *Bucket: ')test-1250000000(',\r?\n *Region: ')ap-guangzhou(')/,
        '$1' + config.bucket + '$2' + config.region + '$3'
      );
    if (process.env.Uin) {
      content = content
        .replace("config.Uin = '10001';", "config.Uin = '" + process.env.Uin + "'")
        .replace("Uin: '10001'", "Uin: '" + process.env.Uin + "'");
    }
    res.header('Content-Type', 'application/javascript');
    res.send(content);
  };
};

app.use(function (req, res, next) {
  res.header('Access-Control-Allow-Origin', '*');
  res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
  next();
});

app.use('/demo/demo.js', replaceBucketRegion(pathLib.resolve(__dirname, '../demo/demo.js')));
app.use('/test/test.js', replaceBucketRegion(pathLib.resolve(__dirname, '../test/test.js')));
app.use('/dist/', express.static(pathLib.resolve(__dirname, '../dist')));
app.use('/demo/', express.static(pathLib.resolve(__dirname, '../demo')));
app.use('/test/', express.static(pathLib.resolve(__dirname, '../test')));
app.all('/', (req, res, next) => res.redirect('/demo/'));
app.use(bodyParser.json());

// 获取临时密钥
function getSts() {
  return new Promise((resolve, reject) => {
    // 获取临时密钥
    var AppId = config.bucket.substr(config.bucket.lastIndexOf('-') + 1);
    // 数据万象DescribeMediaBuckets接口需要resource为*,参考 https://cloud.tencent.com/document/product/460/41741
    var policy = {
      version: '2.0',
      statement: [
        {
          action: config.allowActions,
          effect: 'allow',
          resource: [
            // cos相关授权路径
            'qcs::cos:' + config.region + ':uid/' + AppId + ':' + config.bucket + '/' + config.allowPrefix,
            // ci相关授权路径 按需使用
            'qcs::ci:' + config.region + ':uid/' + AppId + ':bucket/' + config.bucket + '/' + 'job/*',
          ],
        },
      ],
    };
    var startTime = Math.round(Date.now() / 1000);
    STS.getCredential(
      {
        secretId: config.secretId,
        secretKey: config.secretKey,
        proxy: config.proxy,
        region: config.region,
        durationSeconds: config.durationSeconds,
        // endpoint: 'sts.internal.tencentcloudapi.com', // 支持设置sts内网域名
        policy: policy,
      },
      function (err, tempKeys) {
        if (tempKeys) tempKeys.startTime = startTime;
        if (err) {
          reject(err);
        } else {
          resolve(tempKeys);
        }
      }
    );
  });
}

// 返回临时密钥，客户端自行计算签名
app.all('/sts', function (req, res, next) {
  // TODO 这里根据自己业务需要做好放行判断
  if (config.allowPrefix === '_ALLOW_DIR_/*') {
    res.send({ error: '请修改 allowPrefix 配置项，指定允许上传的路径前缀' });
    return;
  }
  getSts()
    .then((data) => {
      res.send(data);
    })
    .catch((err) => {
      res.send(err);
    });
});

// // 格式二：临时密钥接口，支持细粒度权限控制
// // 判断是否允许获取密钥
// var allowScope = function (scope) {
//     var allow = (scope || []).every(function (item) {
//         return config.allowActions.includes(item.action) &&
//             item.bucket === config.bucket &&
//             item.region === config.region &&
//             (item.prefix || '').startsWith(config.allowPrefix);
//     });
//     return allow;
// };
// app.all('/sts-scope', function (req, res, next) {
//     var scope = req.body;
//
//     // TODO 这里根据自己业务需要做好放行判断
//     if (config.allowPrefix === '_ALLOW_DIR_/*') {
//         res.send({error: '请修改 allowPrefix 配置项，指定允许上传的路径前缀'});
//         return;
//     }
//     // TODO 这里可以判断 scope 细粒度控制权限
//     if (!scope || !scope.length || !allowScope(scope)) return res.send({error: 'deny'});
//
//     // 获取临时密钥
//     var policy = STS.getPolicy(scope);
//     var startTime = Math.round(Date.now() / 1000);
//     STS.getCredential({
//         secretId: config.secretId,
//         secretKey: config.secretKey,
//         proxy: config.proxy,
//         durationSeconds: config.durationSeconds,
//         policy: policy,
//     }, function (err, tempKeys) {
//         if (tempKeys) tempKeys.startTime = startTime;
//         res.send(err || tempKeys);
//     });
// });
//

// 生成put上传签名，客户端传递文件后缀，这里生成随机Key
app.all('/put-sign', async function (req, res, next) {
  var ext = req.query.ext;

  // 判断异常情况
  if (!config.secretId || !config.secretKey)
    return res.send({ code: '-1', message: 'secretId or secretKey not ready' });
  if (!config.bucket || !config.region) return res.send({ code: '-1', message: 'bucket or regions not ready' });
  // if (!config.extWhiteList.includes(ext)) return res.send({code: '-1', message: 'ext not allow'});

  var cosKey = generateCosKey(ext);

  let ak = config.secretId;
  let sk = config.secretKey;
  let securityToken = '';

  // 也可以使用临时密钥计算签名，使用临时密钥计算时 前端上传文件时必须上送securityToken字段
  // try {
  //   const tmpData = await getSts();
  //   ak = tmpData.credentials.tmpSecretId;
  //   sk = tmpData.credentials.tmpSecretKey;
  //   securityToken = tmpData.credentials.sessionToken;
  // } catch (e) {
  //   console.log('get sts error', e);
  // }

  // 开始计算签名
  var qSignAlgorithm = 'sha1';
  var method = 'put';
  var pathname = cosKey;
  pathname.indexOf('/') !== 0 && (pathname = '/' + pathname);
  var qAk = ak;
  var now = Math.round(new Date().getTime() / 1000) - 1;
  var exp = now + 900; // 默认900s过期
  var qSignTime = now + ';' + exp;
  var qKeyTime = now + ';' + exp;
  var queryParams = {};
  var headers = {
    host: cosHost,
  };
  var qHeaderList = getObjectKeys(headers, true).join(';').toLowerCase();
  var qUrlParamList = getObjectKeys(queryParams, true).join(';').toLowerCase();

  // 签名算法说明文档：https://www.qcloud.com/document/product/436/7778
  // 步骤一：计算 SignKey
  var signKey = crypto.createHmac('sha1', sk).update(qKeyTime).digest('hex');

  // 步骤二：构成 FormatString
  var formatString = [method, pathname, obj2str(queryParams, true), obj2str(headers, true), ''].join('\n');
  formatString = Buffer.from(formatString, 'utf8');

  // 步骤三：计算 StringToSign
  var r = crypto.createHash('sha1').update(formatString).digest('hex');
  var stringToSign = ['sha1', qSignTime, r, ''].join('\n');

  // 步骤四：计算 Signature
  var qSignature = crypto.createHmac('sha1', signKey).update(stringToSign).digest('hex');

  // 步骤五：构造 Authorization
  var authorization = [
    'q-sign-algorithm=' + qSignAlgorithm,
    'q-ak=' + qAk,
    'q-sign-time=' + qSignTime,
    'q-key-time=' + qKeyTime,
    'q-header-list=' + qHeaderList,
    'q-url-param-list=' + qUrlParamList,
    'q-signature=' + qSignature,
  ].join('&');

  res.send({
    cosHost,
    cosKey,
    authorization,
    securityToken: securityToken, // 如果使用临时密钥，要返回在这个资源 sessionToken 的值
  });
});

// 生成post上传签名，客户端传递文件后缀，这里生成随机Key
app.all('/post-policy', async function (req, res, next) {
  var query = req.query;
  var ext = query.ext;

  // 判断异常情况
  if (!config.secretId || !config.secretKey)
    return res.send({ code: '-1', message: 'secretId or secretKey not ready' });
  if (!config.bucket || !config.region) return res.send({ code: '-1', message: 'bucket or regions not ready' });
  // if (!config.extWhiteList.includes(ext)) return res.send({code: '-1', message: 'ext not allow'});

  // 服务端生成随机Key并计算签名
  var cosKey = generateCosKey(ext);

  let ak = config.secretId;
  let sk = config.secretKey;
  let securityToken = '';

  // 也可以使用临时密钥计算签名，使用临时密钥计算时 前端上传文件时必须上送securityToken字段
  // try {
  //   const tmpData = await getSts();
  //   ak = tmpData.credentials.tmpSecretId;
  //   sk = tmpData.credentials.tmpSecretKey;
  //   securityToken = tmpData.credentials.sessionToken;
  // } catch (e) {
  //   console.log('get sts error', e);
  // }

  var now = Math.round(Date.now() / 1000);
  var exp = now + 900;
  var qKeyTime = now + ';' + exp;
  var qSignAlgorithm = 'sha1';
  var policy = JSON.stringify({
    expiration: new Date(exp * 1000).toISOString(),
    conditions: [
      // {'acl': query.ACL},
      // ['starts-with', '$Content-Type', 'image/'],
      // ['starts-with', '$success_action_redirect', redirectUrl],
      // ['eq', '$x-cos-server-side-encryption', 'AES256'],
      // ['content-length-range', 1, 5242880 ], // 可限制上传文件大小范围比如1 - 5MB
      { 'q-sign-algorithm': qSignAlgorithm },
      { 'q-ak': ak },
      { 'q-sign-time': qKeyTime },
      { bucket: config.bucket },
      { key: cosKey },
    ],
  });

  // 签名算法说明文档：https://www.qcloud.com/document/product/436/7778
  // 步骤一：生成 SignKey
  var signKey = crypto.createHmac('sha1', sk).update(qKeyTime).digest('hex');

  // 步骤二：生成 StringToSign
  var stringToSign = crypto.createHash('sha1').update(policy).digest('hex');

  // 步骤三：生成 Signature
  var qSignature = crypto.createHmac('sha1', signKey).update(stringToSign).digest('hex');

  res.send({
    cosHost,
    cosKey,
    policyObj: JSON.parse(policy),
    policy: Buffer.from(policy).toString('base64'),
    qSignAlgorithm: qSignAlgorithm,
    qAk: ak,
    qKeyTime: qKeyTime,
    qSignature: qSignature,
    securityToken: securityToken, // 如果使用临时密钥，要返回在这个资源 sessionToken 的值
  });
});

//
// // 上传限制 Content-Type 示例，对应示例 demo/mime-limit.html
// var COS = require('cos-nodejs-sdk-v5');
// var cos = new COS({
//     SecretId: config.secretId,
//     SecretKey: config.secretKey,
// });
// app.post('/uploadSign', function (req, res, next) {
//
//     var T = function (x, n) {
//         return ('0000' + x).slice(-(n || 2));
//     }
//     var guid = function () {
//         var S4 = () => (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
//         return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());
//     }
//
//     // 后端来决定文件名，安全性更高
//     var filename = req.query.filename; // 前端传文件原名，后端来决定上传路径
//     var ext = pathLib.extname(filename);
//     var d = new Date();
//     var key = `images/${d.getFullYear()}/${T(d.getMonth() + 1)}/${T(d.getDate())}/${guid()}${ext}`;
//
//     // 计算前端可能会用到的多个签名，x-cos-mime-limit: text/plain;img/jpg;img/*
//     var signMap = {};
//     var expires = 7200;
//     var mimeLimit = 'image/*';
//     var host = `${config.bucket}.cos.${config.region}.myqcloud.com`;
//     // 1. ListMultipartUploads 签名
//     signMap.ListMultipartUploads = cos.getAuth({
//         Method: 'GET',
//         Key: '',
//         Expires: expires,
//         Query: { uploads: '', prefix: key },
//         Headers: { host: host },
//     });
//     // 2. ListParts 签名
//     signMap.ListParts = cos.getAuth({
//         Method: 'GET',
//         Key: key,
//         Expires: expires,
//         Headers: { host: host },
//     });
//     // 3. InitiateMultipartUpload 签名
//     signMap.InitiateMultipartUpload = cos.getAuth({
//         Method: 'POST',
//         Key: key,
//         Expires: expires,
//         Query: { uploads: '' },
//         Headers: { host: host },
//     });
//     // 4. UploadPart 签名
//     signMap.UploadPart = cos.getAuth({
//         Method: 'PUT',
//         Key: key,
//         Expires: expires,
//         Headers: { host: host, 'x-cos-mime-limit': mimeLimit },
//     });
//     // 5. CompleteMultipartUpload 签名
//     signMap.CompleteMultipartUpload = cos.getAuth({
//         Method: 'POST',
//         Key: key,
//         Expires: expires,
//         Headers: { host: host },
//     });
//     // 6. PutObject 签名
//     signMap.PutObject = cos.getAuth({
//         Method: 'PUT',
//         Key: key,
//         Expires: expires,
//         Headers: { host: host, 'x-cos-mime-limit': mimeLimit },
//     });
//     res.send({
//         code: 0,
//         host,
//         signMap,
//         bucket: config.bucket,
//         region: config.region,
//         key,
//         mimeLimit,
//     });
// });

app.all('*', function (req, res, next) {
  res.send({ code: -1, message: '404 Not Found' });
});

// 启动签名服务
app.listen(3000);
console.log('app is listening at http://127.0.0.1:3000');