FireBase Cloud Function

app.js

const functions = require('firebase-functions');
const express = require('express');
const path = require('path');
// The Firebase Admin SDK to access the Firebase Realtime Database.
const admin = require('firebase-admin');
admin.initializeApp()

/* This function may break  now*/
// exports.onUserCreated = functions.firestore.collection("users").onCreate((change, context)=>{
//  return console.log(change);
// });

const app = express();

// Test Start
// app.use(express.static(path.join(__dirname, 'build')));
// app.get('/admin',  (req, res) => {
//   res.sendFile(path.join(__dirname, 'build', 'index.html'));
// });

// Test End

app.get('/timestamp', (request, response) => {
  response.send(`${Date.now()}`);
});

app.get('/updateday', (request, response) => {
  const users = [];
  const question = [];
  var db = admin.firestore();

  var docRefQuestion = db.collection("questions").get().then((snapShot) => {
    snapShot.forEach((doc) => {
      console.log(doc.id, "=>", doc.data());
      question.push(doc.data().id);
    });
    response.send("not working")
    return "";
  }).catch((error) => {
    console.log(error);
  });

  var docRefUser = db.collection("users").get().then((snapShot) => {
    snapShot.forEach((doc) => {
      const currentUser = doc.data();
      var QuidRef = db.collection('users').doc(currentUser.uid);
      const setWithMerge = QuidRef.update({
        questionId: `${question[0]}`,
        isAttempt: false
      });

    });

    // All set Sucess
    response.send(`${question[0]}`);

    return "";
  }).catch((error) => {
    // all failed error
    response.send(error);
  });

});

app.get('/updatedayv2', (request, response) => {
  const users = [];
  const question = [];
  var db = admin.firestore();

  var docRefQuestion = db.collection("questions").get().then((snapShot) => {
    snapShot.forEach((doc) => {
      console.log(doc.id, "=>", doc.data());
      question.push(doc.data().id);
    })

    // eslint-disable-next-line promise/no-nesting
    var docRefUser = db.collection("users").get().then((snapShot) => {
      snapShot.forEach((doc) => {
        const currentUser = doc.data();
        var QuidRef = db.collection('users').doc(currentUser.uid);
        const setWithMerge = QuidRef.update({
          questionId: `${question[0]}`,
          isAttempt: false
        });

      });

      // All set Sucess
      response.send(`${question[0]}`);

      return "";
    }).catch((error) => {
      // all failed error
      response.send(error);
    });

    return "";
  }).catch((error) => {
    console.log(error);
  });


});
// Updatw With Question offset
// Trigger by https://cron-job.org/
 app.get('/updatedayv3', async (request, response) => {
  const users = [];
  const question = [];
  var myoffset = -1;
  var db = admin.firestore();
  var docRef = db.collection("last_question_set_to_user_id").doc("1");
  await   docRef.get().then((doc)=>{
     myoffset = doc.data().offset;
    return null
  }).catch((error)=>{
    console.log(error);
  });



  var docRefQuestion = db.collection("questions").doc(myoffset.toString()).get().then((doc) => {
    // snapShot.forEach((doc) => {
    //   console.log(doc.id, "=>", doc.data());
    //   question.push(doc.data().id);
    // })
    console.log(doc.data());
    question.push(doc.data().id);
    


    // eslint-disable-next-line promise/no-nesting
    var docRefUser = db.collection("users").get().then((snapShot) => {
      snapShot.forEach((doc) => {
        const currentUser = doc.data();
        var QuidRef = db.collection('users').doc(currentUser.uid);
        const setWithMerge = QuidRef.update({
          questionId: `${question[0]}`,
          isAttempt: false
        });

      });

     docRef.update({offset:myoffset+1});

      // All set Sucess
      response.send(`${question[0]}`);

      return "";
    }).catch((error) => {
      // all failed error
      response.send(error);
    });

    return "";
  }).catch((error) => {
    console.log(error);
  });


});



app.get('/updateLeaderBoard', (request, response) => {
  var db = admin.firestore();

  // Read all users and store them to leaderBoard

  var docRefUser = db.collection("users").get().then((snapShot) => {
    snapShot.forEach((doc) => {
      const currentUser = doc.data();
      // eslint-disable-next-line promise/no-nesting
      var QuidRef = db.collection('leaderboard').doc(currentUser.uid).set({

        points: `${currentUser.points}`

      }).then(() => {
        // Avoid Using Nesting Promises  This method may not required. Only .Catch() is enough and each promise must return value
        console.log("Document successfully written!");
        return '';
      })
        .catch((error) => {
          console.error("Error writing document: ", error);
          return '';
        });


    });

    // All set Sucess
    response.send('Ok Leader Board Updated');

    return "";
  }).catch((error) => {
    // all failed error
    response.send(error);
  });


});


// Get qestion from qestion buffer and set to main db
// Trigger by https://cron-job.org/
app.get('/transfer', (request, response) => {
  var myoffset = -1;
  var db = admin.firestore();
  var docRef = db.collection("last_add_question_main").doc("1");

  docRef.get().then((doc) => {
    if (doc.exists) {
      myoffset = doc.data().offset;
      console.log("Document data:", doc.data());
      // Now get the question from question_buffer
      var docRef_2 = db.collection("question_buffer").doc(myoffset.toString());
      docRef_2.get().then((Qdoc) => {

        if (Qdoc.exists) {
          console.log(Qdoc.data());
          // Now Save the Document(Question) to  main DB;
          var docRef_3 = db.collection("questions").doc(Qdoc.data().id.toString());
          docRef_3.set(Qdoc.data());
          myoffset = myoffset + 1;
          docRef.update({ offset: myoffset })


        } else {
          console.log("No Question found! Wiht id = ", myoffset);
        }

        return "";
      }).catch((_error) => {

      });

    } else {
      // doc.data() will be undefined in this case
      console.log("No such document!");

    }

    return ""

  }).catch((error) => {
    console.log("Error getting document:", error);

  });

  response.send('Transfer Complete');

});//end get reques function

exports.app = functions.https.onRequest(app);