wordItem id is generated by default

app/src/main/java/com/paktalin/vocabularynotebook/firestoreitems/WordPojo.kt

 package com.paktalin.vocabularynotebook.firestoreitems
 
 import java.io.Serializable
-import java.util.Date
+import java.util.*
 
 class WordPojo(var word: String,
                var translation: String,
@@ -11,7 +11,7 @@ class WordPojo(var word: String,
     : Serializable {
 
     init {
-        if (time == null)
-            time = Date(System.currentTimeMillis())
+        time = time ?: Date(System.currentTimeMillis())
+        id = id ?: UUID.randomUUID().toString()
     }
 }

app/src/main/java/com/paktalin/vocabularynotebook/ui/recycler_view/VocabularyAdapter.kt

@@ -15,7 +15,6 @@ import com.paktalin.vocabularynotebook.ui.fragments.EditWordFragment
 import com.paktalin.vocabularynotebook.ui.recycler_view.selection_tracker.MySelectionTracker
 import com.paktalin.vocabularynotebook.utils.Log
 import com.paktalin.vocabularynotebook.utils.addFragment
-import com.paktalin.vocabularynotebook.vocabulary.ModifiedVocabulary
 import com.paktalin.vocabularynotebook.vocabulary.Sort
 import com.paktalin.vocabularynotebook.vocabulary.VocabSet
 
@@ -128,7 +127,7 @@ class VocabularyAdapter(private val vocabulary: VocabSet, private val mainActivi
         notifyDataSetChanged()
     }
 
-    fun getModifiedWords(): MutableMap<WordPojo, ModifiedVocabulary.Label> {
+    fun getModifiedWords(): MutableMap<WordPojo, Boolean> {
         return vocabulary.getModified()
     }
 

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

@@ -9,8 +9,6 @@ import com.paktalin.vocabularynotebook.firestoreitems.UserPojo
 import com.paktalin.vocabularynotebook.firestoreitems.VocabularyPojo
 import com.paktalin.vocabularynotebook.firestoreitems.WordPojo
 import com.paktalin.vocabularynotebook.ui.activities.LogInActivity
-import com.paktalin.vocabularynotebook.vocabulary.ModifiedVocabulary
-import com.paktalin.vocabularynotebook.vocabulary.ModifiedVocabulary.Label
 import java.util.*
 
 class FirestoreManager {
@@ -48,20 +46,17 @@ class FirestoreManager {
                 }
     }
 
-    fun saveWords(wordMap: MutableMap<WordPojo, ModifiedVocabulary.Label>) {
+    fun saveWords(wordMap: MutableMap<WordPojo, Boolean>) {
         if (wordMap.isEmpty())
             return
         val batch = db.batch()
 
         wordMap.forEach {
             entry -> run {
-            if (entry.value == Label.DELETED)
-                batch.delete(wordsCollection.document(entry.key.id!!))
-            else if (entry.value == Label.UPDATED && entry.key.id != null)
-                batch.set(wordsCollection.document(entry.key.id!!), entry.key)
-            else
-                batch.set(wordsCollection.document(), entry.key)
+            if (entry.value) batch.delete(wordsCollection.document(entry.key.id!!))
+            else batch.set(wordsCollection.document(entry.key.id!!), entry.key)
         }}
+
         wordMap.clear()
         batch.commit().addOnCompleteListener { Log.d(TAG, "words are successfully pushed to Firestore") }
     }

app/src/main/java/com/paktalin/vocabularynotebook/vocabulary/ModifiedVocabulary.kt

@@ -4,34 +4,30 @@ import com.paktalin.vocabularynotebook.firestoreitems.WordPojo
 import com.paktalin.vocabularynotebook.utils.FirestoreManager
 
 class ModifiedVocabulary : Vocabulary {
-    var wordMap = mutableMapOf<WordPojo, Label>()
+    var wordMap = mutableMapOf<WordPojo, Boolean>()
     private val maxPermitted = 9
 
     override fun addWord(newWord: WordPojo) {
-        add(newWord, Label.ADDED)
+        add(newWord, false)
     }
 
     override fun updateWord(updatedWord: WordPojo) {
-        add(updatedWord, Label.UPDATED)
+        add(updatedWord, false)
     }
 
     override fun deleteWord(wordPojo: WordPojo) {
-        add(wordPojo, Label.DELETED)
+        add(wordPojo, true)
     }
 
     override fun addAll(words: MutableList<WordPojo>) { }
 
-    fun add(wordPojo: WordPojo, label: Label) {
-        wordMap[wordPojo] = label
+    private fun add(wordPojo: WordPojo, deleted: Boolean) {
+        wordMap[wordPojo] = deleted
         if (wordMap.size == maxPermitted)
             FirestoreManager().saveWords(wordMap)
     }
 
-    fun get(): MutableMap<WordPojo, Label> {
+    fun get(): MutableMap<WordPojo, Boolean> {
         return wordMap
     }
-
-    enum class Label {
-        ADDED, UPDATED, DELETED
-    }
 }

app/src/main/java/com/paktalin/vocabularynotebook/vocabulary/VocabSet.kt

@@ -67,5 +67,7 @@ class VocabSet(var wordList: MutableList<WordPojo>) : Vocabulary {
 
     fun clearDisplayed() { displayedVocabulary.clear() }
 
-    fun getModified(): MutableMap<WordPojo, ModifiedVocabulary.Label> { return modifiedVocabulary.get() }
+    fun getModified(): MutableMap<WordPojo, Boolean> {
+        return modifiedVocabulary.get()
+    }
 }
\ No newline at end of file