apigee-edge-js/lib/common.js

nodejs library for the administration API for Apigee (Edge and X and hybrid).

// common.js
// ------------------------------------------------------------------
// Copyright 2018-2021 Google LLC.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
/* jshint esversion:9, node:true, strict:implied */
/* global Buffer */

const tokenMgmt = require('./tokenMgmt.js'),
      utility   = require('./utility.js'),
      jsonRe    = new RegExp('application/json');

function generateRandomString(L) {
  function c() {
    return (Math.floor(Math.random() * 5)<1) ?
      (Math.floor(Math.random() * 10) + 48) : // number
      String.fromCharCode(65 + Math.floor(Math.random() * 26) + (Math.floor(Math.random() * 2) * 32)); // alpha
  }
  var i, s = '';
  L = L || (Math.floor(Math.random() * 7) + 13);
  for (i=0; i<L; i++) {
    s += c();
  }
  return s;
}

/*
 * convert a simple timespan string, expressed in days, hours, minutes, or
 * seconds, such as 30d, 12d, 8h, 45m, 30s, into a numeric quantity in
 * seconds.
 */
function resolveExpiry(subject) {
  let pattern = new RegExp('^([1-9][0-9]*)([smhdw])$','i'),
      multipliers = {s: 1, m: 60, h : 60*60, d:60*60*24, w: 60*60*24*7, y: 60*60*24*365},
      match = pattern.exec(subject);
  if (match) {
    return match[1] * multipliers[match[2]] * 1000;
  }
  return -1;
}

function safeJsonParse(response, body) {
  if ( ! response || !response.headers) return body;
  let isJson = jsonRe.test(response.headers['content-type']);
  // this simple approach does not work because the
  // Apigee API sometimes claims application/json erroneously.

  //return (isJson) ? (body ? JSON.parse(body): null) : body;

  if ( ! isJson) { return body; } // no parse
  if (body){
    try {
      //console.log('jsonparse ' + body);
      return JSON.parse(body);
    }
    catch (e) {
      response.headers['content-type'] = 'application/octet-stream';
      return body;
    }
  }
  return null;
}

function callback(conn, okstatuses, cb) {
  return function (error, response, body) {
    if (conn.verbosity>0) {
      if (response) {
        utility.logWrite('status: ' + response.statusCode);
      } else {
        utility.logWrite('no response');
      }
    }
    if ( ! response) {
      return cb(error || new Error('no response'), null);
    }
    if (error) {
      return cb(error, safeJsonParse(response, body));
    }
    if ( !okstatuses || (okstatuses.length == 0) || (okstatuses.indexOf(response.statusCode) > -1)) {
      cb(null, safeJsonParse(response, body));
    }
    else {
      let result = safeJsonParse(response, body);
      if (conn.verbosity>0) {
        utility.logWrite('result: ' + JSON.stringify(result) );
      }
      cb(new Error('bad status: ' + response.statusCode), result);
    }
  };
}

// to handle expiry of the oauth token
function insureFreshToken(conn, cb) {
  let rh = conn.requestHeaders;
  if (rh && rh.authorization &&
      conn.user && rh.authorization.indexOf('Bearer ') === 0) {
    var stashedToken = tokenMgmt.currentToken(conn.user, conn.loginBaseUrl, conn.mgmtServer);
    if (tokenMgmt.isInvalidOrExpired(stashedToken)) {
      return conn.refreshToken(stashedToken, function(e, result){
        if (e) {
          throw new Error('error refreshing token: ' + e );
        }
        cb({ headers: {...rh}});
      });
    }
    else {
      cb({ headers: {...rh}});
    }
  }
  else {
    cb({ headers: {...rh}});
  }
}

function base64Encode(s) {
  return new Buffer.from(s).toString('base64');
}

function arrayOfKeyValuePairsToHash(properties) {
  if (Array.isArray(properties)) {
    let hash = {};
    properties.forEach(item => hash[item.name] = item.value);
    return hash;
  }
  return properties;
}

function hashToArrayOfKeyValuePairs(hash) {
  if (Array.isArray(hash)) { return hash; }
  return Object.keys(hash).map(key => ( { name : key, value : hash[key]}) );
}

function maybeReformAttributes(ary1) {
  if (Array.isArray(ary1)) {
    if (typeof ary1[0] == 'string') {
      let ary2 = [];
      ary1.forEach(item => {
        let parts = item.split(':');
        ary2[parts[0]] = parts[1];
      });
      return ary2;
    }
  }
  return ary1;
}

module.exports = {
  insureFreshToken,
  callback,
  resolveExpiry,
  generateRandomString,
  base64Encode,
  arrayOfKeyValuePairsToHash,
  hashToArrayOfKeyValuePairs,
  maybeReformAttributes
};