Merge pull request #12586 from BerkeleyTrue/feat/real-time-user-count

feat(api): add current active users api

.gitignore

@@ -53,3 +53,4 @@ public/js/frame-runner*
 public/css/main*
 
 server/rev-manifest.json
+google-credentials.json

common/models/challenge.json

@@ -108,22 +108,24 @@
       "default": "{}"
     },
     "required": {
-      "type": [{
-        "type": {
-          "link": {
-            "type": "string",
-            "description": "Used for css files"
-          },
-          "src": {
-            "type": "string",
-            "description": "Used for script files"
-          },
-          "crossDomain": {
-            "type": "boolean",
-            "description": "Files coming from FreeCodeCamp must mark this true"
+      "type": [
+        {
+          "type": {
+            "link": {
+              "type": "string",
+              "description": "Used for css files"
+            },
+            "src": {
+              "type": "string",
+              "description": "Used for script files"
+            },
+            "crossDomain": {
+              "type": "boolean",
+              "description": "Files coming from FreeCodeCamp must mark this true"
+            }
           }
         }
-      }],
+      ],
       "default": []
     }
   },

common/models/flyer.json

@@ -13,9 +13,7 @@
     }
   },
   "validations": [],
-  "relations": {
-
-  },
+  "relations": {},
   "acls": [
     {
       "accessType": "*",
@@ -30,5 +28,5 @@
       "permission": "ALLOW"
     }
   ],
-  "methods": []
+  "methods": {}
 }

common/models/user.json

@@ -122,8 +122,8 @@
     },
     "currentChallengeId": {
       "type": "string",
-      "default": "",
-      "description": "The challenge last visited by the user"
+      "description": "The challenge last visited by the user",
+      "default": ""
     },
     "currentChallenge": {
       "type": {},

package.json

@@ -56,6 +56,7 @@
     "fetchr": "~0.5.12",
     "frameguard": "^3.0.0",
     "gitter-sidecar": "^1.2.3",
+    "googleapis": "16.1.0",
     "helmet": "^3.1.0",
     "helmet-csp": "^2.1.0",
     "history": "^3.2.1",

server/model-config.json

@@ -74,5 +74,9 @@
   "block": {
     "dataSource": "db",
     "public": true
+  },
+  "about": {
+    "dataSource": "db",
+    "public": true
   }
 }

server/models/about.js

@@ -0,0 +1,25 @@
+import { createActiveUsers } from '../utils/about.js';
+
+
+module.exports = function(About) {
+  const activeUsers = createActiveUsers();
+  About.getActiveUsers = function getActiveUsers() {
+    // converting to promise automatically will subscribe to Observable
+    // initiating the sequence above
+    return activeUsers.toPromise();
+  };
+
+  About.remoteMethod(
+    'getActiveUsers',
+    {
+      http: {
+        path: '/get-active-users',
+        verb: 'get'
+      },
+      returns: {
+        type: 'number',
+        arg: 'activeUsers'
+      }
+    }
+  );
+};

server/models/about.json

@@ -0,0 +1,28 @@
+{
+  "name": "about",
+  "plural": "about",
+  "base": "PersistedModel",
+  "idInjection": true,
+  "options": {
+    "validateUpsert": true
+  },
+  "properties": {},
+  "validations": [],
+  "relations": {},
+  "acls": [
+    {
+      "accessType": "*",
+      "principalType": "ROLE",
+      "principalId": "$everyone",
+      "permission": "DENY"
+    },
+    {
+      "accessType": "EXECUTE",
+      "principalType": "ROLE",
+      "principalId": "$everyone",
+      "permission": "ALLOW",
+      "property": "getActiveUsers"
+    }
+  ],
+  "methods": {}
+}

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');
+}
+