firebaseManager.js

import firebase from 'firebase/app'
import 'firebase/auth'
import 'firebase/firestore'
import 'firebase/storage'
import clientCredentials from '../credentials/client'


export default class firebaseManager {
    static sharedInstance = firebaseManager.sharedInstance == null ? new firebaseManager() : this.sharedInstance

    firebase() {
        if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

        return firebase
    }

    firestore() {
        if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

        var db = firebase.firestore()
        db.settings({timestampsInSnapshots: true})  // Using Timestamps

        return db
    }

    handleLogin = event => {
        return new Promise((resolve, reject) => {
            if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

            firebase.auth().signInWithPopup(new firebase.auth.GoogleAuthProvider())

            var unsubscribe = firebase.auth().onAuthStateChanged(user => {
                if (user) {

                    resolve(user)
                    
                } else {

                    resolve()
                }

                if (!unsubscribe) unsubscribe()
            })

        })
    }
    
    handleEmailLogin = (email,pass) => {
        return new Promise((resolve, reject) => {
            if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

            firebase.auth().signInWithEmailAndPassword(email, pass)
                .then((result) => {
                    // console.log(`handleEmailLogin OK`+JSON.stringify(result))
                    resolve()
                })
                .catch(function(error) {
                    // console.log(`handleEmailLogin Error`+JSON.stringify(error))
                    resolve(error)
                })
                
        })
    }

    isLoggedIn() {
        if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

        let user = firebase.auth().currentUser

        return (user != null)
    }

    getUserDetails() {
        if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

        let user = firebase.auth().currentUser || {}

        let userObj = {
            name: user.displayName || "MoFlo User",
            avatarURL: user.photoURL || "https://fillmurray.com/64/64",
            email: user.email || "demo@moflo.me"
        }

        return userObj
    }

    prepareDocForCreate = doc => {
        if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

        // timestamps
        doc.createdBy = firebase.auth().currentUser ? firebase.auth().currentUser.uid : null
        doc.createdAt = firebase.firestore.Timestamp.now()

        return doc
    }

    prepareDocForUpdate = doc => {
        if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

        // timestamps
        doc.updatedBy = firebase.auth().currentUser ? firebase.auth().currentUser.uid : null
        doc.updatedAt = firebase.firestore.Timestamp.now()

        // don't save the id as part of the document
        delete doc.id

        // don't save values that start with an underscore (these are calculated by the backend)
        Object.keys(doc).forEach( key => {
            if (key.indexOf('_') === 0) {
            delete doc[key]
            }
        })

        return doc
    }


    /*
        file :  JS File reference
        name :  Override existing file name, needs and extension ('test.jpg')
        onProgress:  function to update progress (percent, task)
        onError:  function to respond to upload error (error, task)
    */

    uploadFile = (file,name,onProgress,onError) => {
        return new Promise((resolve, reject) => {
            if (!firebase.apps.length) firebase.initializeApp(clientCredentials)

            var storageRef = firebase.storage().ref('images')

            let filenameToUse = name || file.name || 'upload.png'

            console.log(`uploadfile, filename: ${filenameToUse}`)
            console.log(`uploadfile, file type: ${file instanceof File}`)
            
            // var blob = new Blob([file], { type: "image/jpeg" });

            const task = storageRef.child(filenameToUse).put(file)

            task.on(
                'state_changed',
                snapshot =>
                  onProgress &&
                  onProgress(
                    Math.round(100 * snapshot.bytesTransferred / snapshot.totalBytes),
                    task
                  ),
                error => {
                    onError && onError(error, task)
                    resolve()
                },
                () => {
                    // Return download URL
                    storageRef.child(filenameToUse).getDownloadURL()
                    .then(url => resolve( url) );
                }
              );
      
        })
    }

}