feat: Integrate Firebase Cloud Messaging for push notifications; add service to handle token and message reception

app/src/main/java/com/rosetta/messenger/MainActivity.kt

@@ -1,6 +1,7 @@
 package com.rosetta.messenger
 
 import android.os.Bundle
+import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
@@ -27,10 +28,14 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import com.google.firebase.FirebaseApp
+import com.google.firebase.messaging.FirebaseMessaging
+import com.rosetta.messenger.crypto.CryptoManager
 import com.rosetta.messenger.data.AccountManager
 import com.rosetta.messenger.data.DecryptedAccount
 import com.rosetta.messenger.data.PreferencesManager
 import com.rosetta.messenger.data.RecentSearchesManager
+import com.rosetta.messenger.network.PacketPushToken
 import com.rosetta.messenger.network.ProtocolManager
 import com.rosetta.messenger.ui.auth.AccountInfo
 import com.rosetta.messenger.ui.auth.AuthFlow
@@ -49,6 +54,10 @@ class MainActivity : ComponentActivity() {
     private lateinit var preferencesManager: PreferencesManager
     private lateinit var accountManager: AccountManager
     
+    companion object {
+        private const val TAG = "MainActivity"
+    }
+    
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
@@ -60,6 +69,9 @@ class MainActivity : ComponentActivity() {
         // 🔥 Инициализируем ProtocolManager для обработки онлайн статусов
         ProtocolManager.initialize(this)
         
+        // 🔔 Инициализируем Firebase для push-уведомлений
+        initializeFirebase()
+        
         // 🚀 Предзагружаем эмодзи в фоне для мгновенного открытия пикера
         // Используем новый оптимизированный кэш
         OptimizedEmojiCache.preload(this)
@@ -153,7 +165,7 @@ class MainActivity : ComponentActivity() {
                                     }
                                 )
                             }
-                            "auth_new", "auth_new", "auth_unlock" -> {
+                            "auth_new", "auth_unlock" -> {
                                 AuthFlow(
                                     isDarkTheme = isDarkTheme,
                                     hasExistingAccount = screen == "auth_unlock",
@@ -223,6 +235,47 @@ class MainActivity : ComponentActivity() {
             }
         }
     }
+    
+    /**
+     * 🔔 Инициализация Firebase Cloud Messaging
+     */
+    private fun initializeFirebase() {
+        try {
+            // Инициализируем Firebase
+            FirebaseApp.initializeApp(this)
+            
+            // Получаем FCM токен
+            FirebaseMessaging.getInstance().token.addOnCompleteListener { task ->
+                if (!task.isSuccessful) {
+                    Log.e(TAG, "❌ Failed to get FCM token", task.exception)
+                    return@addOnCompleteListener
+                }
+                
+                val token = task.result
+                Log.d(TAG, "🔔 FCM token (short): ${token?.take(20)}...")
+                Log.d(TAG, "🔔 FCM token (FULL): $token")
+                
+                // Сохраняем токен локально
+                token?.let { saveFcmToken(it) }
+                
+                // TODO: Отправляем токен на сервер если аккаунт залогинен
+                // token?.let { sendFcmTokenToServer(it) }
+            }
+            
+            Log.d(TAG, "✅ Firebase initialized successfully")
+        } catch (e: Exception) {
+            Log.e(TAG, "❌ Error initializing Firebase", e)
+        }
+    }
+    
+    /**
+     * Сохранить FCM токен в SharedPreferences
+     */
+    private fun saveFcmToken(token: String) {
+        val prefs = getSharedPreferences("rosetta_prefs", MODE_PRIVATE)
+        prefs.edit().putString("fcm_token", token).apply()
+        Log.d(TAG, "💾 FCM token saved locally")
+    }
 }
 
 @Composable
@@ -333,12 +386,12 @@ fun MainScreen(
             }
         },
         label = "screenNavigation"
-    ) { (user, isSearchOpen, _) ->
+    ) { (currentUser, isSearchOpen, _) ->
         when {
-            user != null -> {
+            currentUser != null -> {
                 // Экран чата
                 ChatDetailScreen(
-                    user = user,
+                    user = currentUser,
                     currentUserPublicKey = accountPublicKey,
                     currentUserPrivateKey = accountPrivateKey,
                     isDarkTheme = isDarkTheme,
@@ -365,9 +418,9 @@ fun MainScreen(
                     isDarkTheme = isDarkTheme,
                     protocolState = protocolState,
                     onBackClick = { showSearchScreen = false },
-                    onUserSelect = { user ->
+                    onUserSelect = { selectedSearchUser ->
                         showSearchScreen = false
-                        selectedUser = user
+                        selectedUser = selectedSearchUser
                     }
                 )
             }
@@ -394,7 +447,14 @@ fun MainScreen(
                         // TODO: Navigate to calls
                     },
                     onSavedMessagesClick = {
-                        // TODO: Navigate to saved messages
+                        // Открываем чат с самим собой (Saved Messages)
+                        selectedUser = SearchUser(
+                            title = "Saved Messages",
+                            username = "",
+                            publicKey = accountPublicKey,
+                            verified = 0,
+                            online = 1
+                        )
                     },
                     onSettingsClick = {
                         // TODO: Navigate to settings
@@ -408,8 +468,8 @@ fun MainScreen(
                     onNewChat = {
                         // TODO: Show new chat screen
                     },
-                    onUserSelect = { user ->
-                        selectedUser = user
+                    onUserSelect = { selectedChatUser ->
+                        selectedUser = selectedChatUser
                     },
                     onLogout = onLogout
                 )
@@ -417,3 +477,4 @@ fun MainScreen(
         }
     }
 }
+