Now it's possible to sign up with either a username or an email

app/src/main/java/com/paktalin/vocabularynotebook/ui/activities/LogInActivity.kt

@@ -8,8 +8,6 @@ import com.paktalin.vocabularynotebook.utils.*
 import kotlinx.android.synthetic.main.activity_log_in.*
 
 class LogInActivity : AppCompatActivity() {
-    private var email: String? = null
-    private var password: String? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -24,25 +22,21 @@ class LogInActivity : AppCompatActivity() {
     }
 
     fun login() {
-        processUser(resources.getString(R.string.toast_incorrect_username_password)) {
+        val (username, password) = getUsernameAndPassword()
+        if (fieldsNotEmpty(username, password, this))
+            addProgressBar()
             mLogIn(
-                    { removeProgressBar() },
+                    { removeProgressBar(supportFragmentManager) },
                     { startUserActivity() },
-                    { showToastFailure() },
-                    email!!, password!!)
-        }
-    }
-
-    private fun signUp() { processUser(resources.getString(R.string.toast_username_characters)) { mSignUp(this, email!!, password!!) }
+                    { shortToast(this@LogInActivity, getString(R.string.toast_auth_failed)) },
+                    username, password)
     }
 
-    private fun processUser(invalidUsername:String, authAction: () -> Unit) {
-        email = etEmail!!.text.toString()
-        password = etPassword!!.text.toString()
-
-        if (validInput(email!!, password!!, this, invalidUsername)) {
+    private fun signUp() {
+        val (username, password) = getUsernameAndPassword()
+        if (fieldsNotEmpty(username, password, this) && validUsername(username, this)) {
             addProgressBar()
-            authAction()
+            mSignUp(this, username, password)
         }
     }
 
@@ -55,11 +49,7 @@ class LogInActivity : AppCompatActivity() {
         com.paktalin.vocabularynotebook.utils.addProgressBar(supportFragmentManager, R.id.container_login)
     }
 
-    private fun removeProgressBar() {
-        com.paktalin.vocabularynotebook.utils.removeProgressBar(supportFragmentManager)
-    }
-
-    private fun showToastFailure() { shortToast(this@LogInActivity, getString(R.string.toast_auth_failed)) }
+    private fun getUsernameAndPassword() = Pair(etEmail!!.text.toString(), etPassword!!.text.toString())
 
     companion object { private val TAG = "VN/" + LogInActivity::class.simpleName }
 }
\ No newline at end of file

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

@@ -5,12 +5,11 @@ import android.content.Intent
 import android.os.Bundle
 import android.support.v4.app.Fragment
 import android.support.v4.app.FragmentManager
-import android.text.TextUtils
 import android.view.View
 import android.widget.Toast
 import com.paktalin.vocabularynotebook.R
 import com.paktalin.vocabularynotebook.ui.fragments.ProgressFragment
-import org.apache.commons.lang3.StringUtils.containsOnly
+import org.apache.commons.lang3.StringUtils
 
 val progressFragment: Fragment = ProgressFragment()
 
@@ -31,20 +30,21 @@ fun removeProgressBar(fragmentManager: FragmentManager) {
     removeFragment(fragmentManager, progressFragment)
 }
 
-fun validInput(username: String, password: String, context: Context, invalidUsername:String): Boolean {
-    if(TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
+fun fieldsNotEmpty(username: String, password: String, context: Context): Boolean {
+    if (username.isEmpty() || password.isEmpty()) {
         shortToast(context, context.resources.getString(R.string.toast_enter_username_password))
         return false
     }
-    else if (!appropriateCharacters(username)) {
-        shortToast(context, invalidUsername)
-        return false
-    }
     return true
 }
 
-private fun appropriateCharacters(username: String): Boolean {
-    return containsOnly(username.toLowerCase(), "abcdefghijklmnopqrstuvwxyz0123456789-_.")
+fun validUsername(username: String, context: Context): Boolean {
+    return if (StringUtils.containsOnly(username.toLowerCase(), "abcdefghijklmnopqrstuvwxyz0123456789-_."))
+        true
+    else {
+        shortToast(context, context.resources.getString(R.string.toast_invalid_username))
+        false
+    }
 }
 
 fun shortToast(context: Context, text: String) {

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

 package com.paktalin.vocabularynotebook.utils
 
+import android.util.Patterns
 import com.google.firebase.auth.FirebaseAuth
 import com.google.firebase.auth.FirebaseUser
 import com.paktalin.vocabularynotebook.R
@@ -28,6 +29,10 @@ fun mLogIn(onComplete: () -> Unit, onSuccess: () -> Unit, onFailure: () -> Unit,
             }
 }
 
+
+
+private fun isEmail(string: String) = Patterns.EMAIL_ADDRESS.matcher(string).matches()
+
 fun mSignUp(activity: LogInActivity, username: String, password: String) {
     mAuth!!.createUserWithEmailAndPassword(email(username), password)
             .addOnCompleteListener { removeProgressBar(activity.supportFragmentManager) }
@@ -52,6 +57,10 @@ fun mLogOut() {
 }
 
 private fun email(username: String): String {
+    return if (isEmail(username))
+        username
+    else {
         val dummyDomain = "@wordbook.com"
-    return username.toLowerCase() + dummyDomain
+        username.toLowerCase() + dummyDomain
+    }
 }
\ No newline at end of file

app/src/main/res/values/strings.xml

@@ -24,6 +24,6 @@
     <string name="toast_update_word_failed">Couldn\'t update the word</string>
     <string name="toast_successful_sign_up">Congratulations! You can now access your vocabulary from any device</string>
     <string name="toast_enter_username_password">Please, enter username and password</string>
-    <string name="toast_username_characters">Please, create a username using letters a–z, numbers 0–9 and characters -_.</string>
+    <string name="toast_invalid_username">Please, create a username using letters a–z, numbers 0–9 and characters -_.</string>
     <string name="toast_incorrect_username_password">Username or password is incorrect</string>
 </resources>