ac-node-hipchat/lib/webhooks.js

A common module plugin for building Atlassian Connect add-ons for HipChat

var check = require('check-types');
var verify = check.verify;
var urls = require('url');
var crypto = require('crypto');
var _ = require('lodash');
var param = encodeURIComponent;

var events = [
  'room_enter',
  'room_exit',
  'room_message',
  'room_notification',
  'room_topic_change'
];

var self = exports;

exports.normalize = function (definition, baseUrl, defaultMountPath, token) {
  check.map(definition, {
    event: verify.string,
    name: verify.maybe.string,
    url: verify.maybe.string
  });
  verify.webUrl(baseUrl);
  if (events.indexOf(definition.event) === -1) {
    throw new Error('Unrecognized webhook event: ' + definition.event);
  }
  definition = _.extend({}, definition);
  if (definition.event === 'room_message') {
    verify.defined(definition.pattern)
    if (_.isRegExp(definition.pattern)) {
      definition.pattern = exports.regExpToPattern(definition.pattern);
    } else {
      verify.string(definition.pattern);
    }
  }
  // parse salient path info from the url
  if (definition.url) {
    definition.url = exports.stripNameParam(definition.url);
  }
  var parsed = self.parseUrl(definition.url);
  // re-assemble the webhook url with the base url, as a sanity check
  var fullPath = parsed ? parsed.fullPath : defaultMountPath;
  definition.url = urls.resolve(baseUrl, fullPath);
  if (token) {
    definition.url += '?token=' + param(token);
  }
  if (!definition.name) {
    definition.name = exports.digest(definition);
  }
  definition.url += (definition.url.indexOf('?') > 0 ? '&' : '?') + 'name=' + param(definition.name);
  return definition;
};

exports.parseUrl = function (url) {
  var result;
  if (check.webUrl(url)) {
    // full urls
    parsed = urls.parse(url);
    result = {
      fullPath: parsed.path,
      mountPath: parsed.pathname
    };
  } else if (check.string(url)) {
    // path-only shorthand
    result = {
      fullPath: url,
      mountPath: url.split('?')[0]
    };
  }
  return result;
};

exports.regExpToPattern = function (re) {
  var pattern = re.toString();
  pattern = pattern.replace(/\\u([\da-fA-F]{4,4})/g, function ($0, $1) {
    return '\\x{' + $1 + '}';
  });
  var match = /^\/(.*)\/([gimy]+)?/.exec(pattern);
  if (match) {
    pattern = match[1];
    if (match[2]) {
      pattern = '(?' + match[2] + ')' + pattern;
    }
  }
  return pattern;
};

exports.patternToRegExp = function (pattern) {
  var match = /\(\?([gimy])+\)(.*)/.exec(pattern);
  var flags;
  if (match) {
    flags = match[1];
    pattern = match[2];
  }
  pattern = pattern.replace(/\\x\{([\da-fA-F]{4,4})\}/g, function ($0, $1) {
    return '\\u' + $1 + '';
  });
  return new RegExp(pattern, flags);
};

exports.digest = function (webhook) {
  webhook = _.extend({}, webhook);
  if (webhook.url) {
    webhook.url = exports.stripNameParam(webhook.url);
  }
  // url encode other webhook params to generate a stable hash as the name that
  // will change if any of the fields change
  var fields = ['event', 'url'];
  if (webhook.event === 'room_message') {
    verify.defined(webhook.pattern)
    fields.push('pattern');
  }
  var str = fields.filter(function (key) {
    return !!webhook[key];
  }).map(function (key) {
    return key + '=' + encodeURIComponent(webhook[key].toString());
  }).join('&');
  return crypto.createHash('sha1').update(str).digest('hex');
};

exports.stripNameParam = function (url) {
  return url.replace(/(.*)(\?|&)name=[^&]+&?(.*)/, function ($0, $1, $2, $3) {
    return $1 + ($3 ? $2 : '') + ($3 || '');
  });
};