Refactoring

app/src/main/java/com/paktalin/vocabularynotebook/utils/ActivityUtil.kt

+package com.paktalin.vocabularynotebook.utils
+
+import android.content.Context
+import android.os.Bundle
+import android.support.v4.app.Fragment
+import android.support.v4.app.FragmentManager
+import android.text.TextUtils
+import android.widget.Toast
+import com.paktalin.vocabularynotebook.ui.activities.MainActivity
+import com.paktalin.vocabularynotebook.ui.fragments.ProgressFragment
+import kotlinx.android.synthetic.main.content_main.*
+
+val progressFragment: Fragment = ProgressFragment()
+
+fun addFragment(fragmentManager: FragmentManager, fragment: Fragment, containerId: Int, arguments: Bundle?) {
+    fragment.arguments = arguments
+    fragmentManager.beginTransaction().add(containerId, fragment).commitAllowingStateLoss()
+}
+
+fun removeFragment(fragmentManager: FragmentManager, fragment: Fragment) {
+    fragmentManager.beginTransaction().remove(fragment).commitAllowingStateLoss()
+}
+
+fun addProgressBar(fragmentManager: FragmentManager, containerId: Int) {
+    addFragment(fragmentManager, progressFragment, containerId, null)
+}
+
+fun removeProgressBar(fragmentManager: FragmentManager) {
+    removeFragment(fragmentManager, progressFragment)
+}
+
+fun fieldsNotEmpty(text1: String, text2: String, toastMessage: String, context: Context): Boolean {
+    if (TextUtils.isEmpty(text1) || TextUtils.isEmpty(text2)) {
+        shortToast(context, toastMessage)
+        return false
+    }
+    return true
+}
+
+fun disableScrolling(mainActivity: MainActivity) {
+    mainActivity.scrollView!!.setScrollingEnabled(false)
+}
+
+fun enableScrolling(mainActivity: MainActivity) {
+    mainActivity.scrollView!!.setScrollingEnabled(true)
+}
+
+fun shortToast(context: Context, text: String) {
+    Toast.makeText(context, text, Toast.LENGTH_SHORT).show()
+}
\ No newline at end of file

app/src/main/java/com/paktalin/vocabularynotebook/utils/UserManager.kt

+package com.paktalin.vocabularynotebook.utils
+
+import android.util.Log
+import com.google.firebase.auth.FirebaseAuth
+import com.google.firebase.auth.FirebaseUser
+import com.paktalin.vocabularynotebook.appsetup.ConfiguredFirestore
+import com.paktalin.vocabularynotebook.ui.activities.LogInActivity
+import com.paktalin.vocabularynotebook.firestoreitems.UserPojo
+import com.paktalin.vocabularynotebook.firestoreitems.Vocabulary
+import com.paktalin.vocabularynotebook.firestoreitems.Vocabulary.Companion.VOCABULARIES
+import java.util.*
+
+private const val TAG = "VN/UserManager"
+
+private fun deleteUser(user: FirebaseUser) {
+    user.delete()
+            .addOnSuccessListener { Log.i(TAG, "UserPojo was successfully deleted") }
+            .addOnFailureListener { Log.i(TAG, "deleteUser:failure", it.cause)}
+}
+
+fun addNewUserToDb(newUser: FirebaseUser, logInActivity: LogInActivity) {
+    //todo add condition to writing to the db in Firebase Console (request.auth.uid)
+    val db = ConfiguredFirestore.instance
+    val user = UserPojo(newUser.email)
+
+    db.collection(VOCABULARIES).add(Vocabulary.Pojo(null))
+            .addOnSuccessListener { firstVocabularyRef ->
+                Log.d(TAG, "VocabularyPojo successfully created: " + firstVocabularyRef.path)
+                user.vocabularies = Collections.singletonList(firstVocabularyRef)
+
+                db.collection("users").document(newUser.uid).set(user)
+                        .addOnCompleteListener { task ->
+                            if (task.isSuccessful) {
+                                Log.i(TAG, "Successfully added user to the collection")
+                                logInActivity.startUserActivity()
+                            } else Log.w(TAG, "addUser:failure", task.exception)
+                        }
+            }
+            .addOnFailureListener {
+                Log.w(TAG, "Couldn't add user to the database", it.cause)
+                deleteUser(newUser)
+            }
+}
+
+fun login(onComplete: () -> Unit, onSuccess: () -> Unit, onFailure: () -> Unit,
+          mAuth: FirebaseAuth?, email: String, password: String) {
+    mAuth!!.signInWithEmailAndPassword(email, password)
+            .addOnCompleteListener { onComplete() }
+            .addOnSuccessListener {
+                Log.d(TAG, "Successfully signed in")
+                onSuccess()
+            }
+            .addOnFailureListener {
+                Log.w(TAG, "signInWithEmail:failure", it)
+                onFailure()
+            }
+}
+
+fun signUp(mAuth: FirebaseAuth?, activity: LogInActivity, email: String, password: String) {
+    mAuth!!.createUserWithEmailAndPassword(email, password)
+            .addOnCompleteListener { removeProgressBar(activity.supportFragmentManager) }
+            .addOnSuccessListener {
+                Log.d(TAG, "Successfully signed up a new user")
+                addNewUserToDb(mAuth.currentUser!!, activity)
+                activity.login()
+            }
+            .addOnFailureListener {
+                Log.d(TAG, "createUserWithEmail:failure", it.fillInStackTrace())
+                shortToast(activity, it.message!!)
+            }
+}