chore(server): Move api-server in to it's own DIR

api-server/server/utils/about.js

@@ -0,0 +1,95 @@
+import _ from 'lodash';
+import debug from 'debug';
+import dedent from 'dedent';
+import fs from 'fs';
+import goog from 'googleapis';
+import { Observable } from 'rx';
+
+import { timeCache, observeMethod } from './rx';
+
+// one million!
+const upperBound = 1000 * 1000;
+const scope = 'https://www.googleapis.com/auth/analytics.readonly';
+const pathToCred = process.env.GOOGLE_APPLICATION_CREDENTIALS;
+
+const log = debug('fcc:server:utils:about');
+const analytics = goog.analytics('v3');
+const makeRequest = observeMethod(analytics.data.realtime, 'get');
+export const toBoundInt = _.flow(
+  // first convert string to integer
+  _.toInteger,
+  // then we bound the integer to prevent weird things like Infinity
+  // and negative numbers
+  // can't wait to the day we need to update this!
+  _.partialRight(_.clamp, 0, upperBound)
+);
+
+export function createActiveUsers() {
+  const zero = Observable.of(0);
+  let credentials;
+  if (!pathToCred) {
+    // if no path to credentials set to zero;
+    log(dedent`
+      no google applications credentials environmental variable found
+      'GOOGLE_APPLICATION_CREDENTIALS'
+      'activeUser' api will always return 0
+      this can safely be ignored during development
+    `);
+    return zero;
+  }
+  try {
+    credentials = require(fs.realpathSync(pathToCred));
+  } catch (err) {
+    log('google applications credentials file failed to require');
+    console.error(err);
+    // if we can't require credentials set to zero;
+    return zero;
+  }
+  if (
+    !credentials.private_key ||
+    !credentials.client_email ||
+    !credentials.viewId
+  ) {
+    log(dedent`
+      google applications credentials json should have a
+      * private_key
+      * client_email
+      * viewId
+      but none were found
+    `);
+    return zero;
+  }
+
+  const client = new goog.auth.JWT(
+    credentials['client_email'],
+    null,
+    credentials['private_key'],
+    [scope],
+  );
+  const authorize = observeMethod(client, 'authorize');
+  const options = {
+    ids: `ga:${credentials.viewId}`,
+    auth: client,
+    metrics: 'rt:activeUsers'
+  };
+  return Observable.defer(
+    // we wait for authorize to complete before attempting to make request
+    // this ensures our token is initialized and valid
+    // we defer here to make sure the actual request is done per subscription
+    // instead of once at startup
+    () => authorize().flatMap(() => makeRequest(options))
+  )
+    // data: Array[body|Object, request: Request]
+    .map(data => data[0])
+    .map(
+      ({ totalsForAllResults } = {}) => totalsForAllResults['rt:activeUsers']
+    )
+    .map(toBoundInt)
+    // print errors to error log for logging, duh
+    .do(null, err => console.error(err))
+    // always send a number down
+    .catch(() => Observable.of(0))
+    // cache for 2 seconds to prevent hitting our daily request limit
+    ::timeCache(2, 'seconds');
+}
+