Populate participants/challenges (#412)

* will not work if participants array elem > 10

* overcoming in query limitation

* storing id insted of name

* using fetchUser from users.model for fetching user

* a little bit refactoring of code

* post-challenges/subscribe response updated

* made requested changes

* using 204 for response

* refactoring response code

* getting promise array from a function

* refactoring get method in controllers/challenges

Author: akshay1502

controllers/challenge.js

@@ -12,14 +12,12 @@ const sendChallengeResponse = async (req, res) => {
   try {
     if (req.method === 'GET') {
       const allChallenges = await challengeQuery.fetchChallenges()
-      if (allChallenges.length > 0) {
-        return res.status(200).json({
-          message: 'Challenges returned successfully!',
-          challenges: allChallenges
-        })
-      } else {
-        return res.boom.notFound('No challenges found')
-      }
+      const promiseArray = await getParticipantsofChallenges(allChallenges)
+      const challengesWithParticipants = await Promise.all(promiseArray)
+      return res.json({
+        message: challengesWithParticipants.length ? 'Challenges returned successfully!' : 'No Challenges found',
+        challenges: challengesWithParticipants
+      })
     } else {
       if (req.method === 'POST') {
         const challengeAdded = await challengeQuery.postChallenge(req.body)
@@ -40,6 +38,20 @@ const sendChallengeResponse = async (req, res) => {
   }
 }
 
+/**
+ * @param {Array} allChallenges
+ * @returns {Promise<participants|Array>}
+ */
+const getParticipantsofChallenges = async (allChallenges) => {
+  return allChallenges.map(async (challenge) => {
+    const participants = await challengeQuery.fetchParticipantsData(challenge.participants)
+    return {
+      ...challenge,
+      participants
+    }
+  })
+}
+
 /**
  * Suscribe user to a challenge
  * @param {Object} req - Express request object
@@ -52,7 +64,8 @@ const subscribeToChallenge = async (req, res) => {
     const subscribeUser = await challengeQuery.subscribeUserToChallenge(userId, challengeId)
     if (subscribeUser) {
       return res.status(200).json({
-        message: 'User has subscribed to challenge'
+        challenge_id: challengeId,
+        is_user_subscribed: 1
       })
     } else {
       return res.boom.notFound('User cannot be subscribed to challenge')

models/challenges.js

@@ -5,6 +5,7 @@
 
 const Firestore = require('@google-cloud/firestore')
 const firestore = require('../utils/firestore')
+const { fetchUser } = require('./users')
 
 const challengesModel = firestore.collection('challenges')
 const userModel = firestore.collection('users')
@@ -35,6 +36,29 @@ const fetchChallenges = async () => {
   }
 }
 
+/**
+ * Fetch the <user object> from participants array
+ * @param {Array} participants
+ * @returns {Promise<challengesModel|Array>}
+ */
+const fetchParticipantsData = async (participants) => {
+  try {
+    const promises = participants.map(async (userId) => {
+      const { user } = await fetchUser({ userId })
+      return {
+        ...user,
+        phone: undefined,
+        email: undefined
+      }
+    })
+    const fetchedparticipants = await Promise.all(promises)
+    return fetchedparticipants
+  } catch (err) {
+    logger.error('Failed to get participated users', err)
+    throw err
+  }
+}
+
 /**
  * Post the challenge
  *  @return {Promise<challengesModel|Array>}
@@ -66,10 +90,10 @@ const postChallenge = async (challengeData) => {
 const subscribeUserToChallenge = async (userId, challengeId) => {
   try {
     const getUser = await userModel.doc(userId).get()
-    const user = getUser.data().github_display_name
+    const user = getUser.data()
     if (user) {
       const challengeRef = await challengesModel.doc(challengeId)
-      await challengeRef.update({ participants: Firestore.FieldValue.arrayUnion({ name: user }) })
+      await challengeRef.update({ participants: Firestore.FieldValue.arrayUnion(userId) })
       return challengeRef.get()
     } else {
       throw new Error(USER_DOES_NOT_EXIST_ERROR)
@@ -83,5 +107,6 @@ const subscribeUserToChallenge = async (userId, challengeId) => {
 module.exports = {
   fetchChallenges,
   postChallenge,
-  subscribeUserToChallenge
+  subscribeUserToChallenge,
+  fetchParticipantsData
 }