moves all non‑UI logic

app/build.gradle.kts

@@ -1,8 +1,9 @@
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.android)
-    alias(libs.plugins.kotlin.parcelize)
+    alias(libs.plugins.kotlin.serialization)
     alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.ksp)
 }
 
 android {
@@ -82,13 +83,13 @@ dependencies {
 
     // Cryptography
     implementation(libs.bundles.cryptography)
-
-    // JSON
-    implementation(libs.gson)
-
+
     // Coroutines
     implementation(libs.kotlinx.coroutines.android)
 
+    // Serialization
+    implementation(libs.kotlinx.serialization.json)
+
     // Bluetooth
     implementation(libs.nordic.ble)
 
@@ -112,4 +113,12 @@ dependencies {
     androidTestImplementation(platform(libs.androidx.compose.bom))
     androidTestImplementation(libs.bundles.compose.testing)
     debugImplementation(libs.androidx.compose.ui.tooling)
+
+    // Koin
+    implementation(libs.koin.core)
+    implementation(libs.koin.android)
+    implementation(libs.koin.compose)
+    implementation(libs.koin.annotation)
+    implementation(libs.koin.jsr330)
+    ksp(libs.koin.annotation.compiler)
 }

app/src/main/java/com/bitchat/android/BitchatApplication.kt

@@ -1,9 +1,10 @@
 package com.bitchat.android
 
 import android.app.Application
-import com.bitchat.android.nostr.RelayDirectory
+import com.bitchat.android.di.initKoin
 import com.bitchat.android.ui.theme.ThemePreferenceManager
-import com.bitchat.android.net.TorManager
+import org.koin.android.ext.koin.androidContext
+import org.koin.android.ext.koin.androidLogger
 
 /**
  * Main application class for bitchat Android
@@ -12,20 +13,11 @@ class BitchatApplication : Application() {
 
     override fun onCreate() {
         super.onCreate()
-
-        // Initialize Tor first so any early network goes over Tor
-        try { TorManager.init(this) } catch (_: Exception) { }
 
-        // Initialize relay directory (loads assets/nostr_relays.csv)
-        RelayDirectory.initialize(this)
-
-        // Initialize LocationNotesManager dependencies early so sheet subscriptions can start immediately
-        try { com.bitchat.android.nostr.LocationNotesInitializer.initialize(this) } catch (_: Exception) { }
-
-        // Initialize favorites persistence early so MessageRouter/NostrTransport can use it on startup
-        try {
-            com.bitchat.android.favorites.FavoritesPersistenceService.initialize(this)
-        } catch (_: Exception) { }
+        initKoin{
+            androidContext(this@BitchatApplication)
+            androidLogger()
+        }
 
         // Warm up Nostr identity to ensure npub is available for favorite notifications
         try {
@@ -34,10 +26,5 @@ class BitchatApplication : Application() {
 
         // Initialize theme preference
         ThemePreferenceManager.init(this)
-
-        // Initialize debug preference manager (persists debug toggles)
-        try { com.bitchat.android.ui.debug.DebugPreferenceManager.init(this) } catch (_: Exception) { }
-
-        // TorManager already initialized above
     }
 }

app/src/main/java/com/bitchat/android/MainActivity.kt

@@ -7,6 +7,7 @@ import androidx.activity.OnBackPressedCallback
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.activity.viewModels
+import org.koin.androidx.viewmodel.ext.android.viewModel
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.MaterialTheme
@@ -42,37 +43,29 @@ import com.bitchat.android.ui.theme.BitchatTheme
 import com.bitchat.android.nostr.PoWPreferenceManager
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
+import org.koin.android.ext.android.inject
 
 class MainActivity : OrientationAwareActivity() {
 
-    private lateinit var permissionManager: PermissionManager
+    private val permissionManager: PermissionManager by inject()
     private lateinit var onboardingCoordinator: OnboardingCoordinator
     private lateinit var bluetoothStatusManager: BluetoothStatusManager
     private lateinit var locationStatusManager: LocationStatusManager
     private lateinit var batteryOptimizationManager: BatteryOptimizationManager
 
     // Core mesh service - managed at app level
-    private lateinit var meshService: BluetoothMeshService
+    private val  meshService: BluetoothMeshService by inject()
+
     private val mainViewModel: MainViewModel by viewModels()
-    private val chatViewModel: ChatViewModel by viewModels { 
-        object : ViewModelProvider.Factory {
-            override fun <T : androidx.lifecycle.ViewModel> create(modelClass: Class<T>): T {
-                @Suppress("UNCHECKED_CAST")
-                return ChatViewModel(application, meshService) as T
-            }
-        }
-    }
+    private val chatViewModel: ChatViewModel by viewModel()
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
         // Enable edge-to-edge display for modern Android look
         enableEdgeToEdge()
 
-        // Initialize permission management
-        permissionManager = PermissionManager(this)
-        // Initialize core mesh service first
-        meshService = BluetoothMeshService(this)
+        // Initialize core mesh service first - retrieve from Koin
         bluetoothStatusManager = BluetoothStatusManager(
             activity = this,
             context = this,
@@ -593,13 +586,6 @@ class MainActivity : OrientationAwareActivity() {
 
                 Log.d("MainActivity", "Permissions verified, initializing chat system")
 
-                // Initialize PoW preferences early in the initialization process
-                PoWPreferenceManager.init(this@MainActivity)
-                Log.d("MainActivity", "PoW preferences initialized")
-
-                // Initialize Location Notes Manager (extracted to separate file)
-                com.bitchat.android.nostr.LocationNotesInitializer.initialize(this@MainActivity)
-
                 // Ensure all permissions are still granted (user might have revoked in settings)
                 if (!permissionManager.areAllPermissionsGranted()) {
                     val missing = permissionManager.getMissingPermissions()

app/src/main/java/com/bitchat/android/MainViewModel.kt

@@ -8,7 +8,9 @@ import com.bitchat.android.onboarding.BatteryOptimizationStatus
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import org.koin.android.annotation.KoinViewModel
 
+@KoinViewModel
 class MainViewModel : ViewModel() {
 
     private val _onboardingState = MutableStateFlow(OnboardingState.CHECKING)

app/src/main/java/com/bitchat/android/crypto/EncryptionService.kt

@@ -3,6 +3,9 @@ package com.bitchat.android.crypto
 import android.content.Context
 import android.util.Log
 import com.bitchat.android.noise.NoiseEncryptionService
+import com.bitchat.android.mesh.PeerFingerprintManager
+import jakarta.inject.Inject
+import jakarta.inject.Singleton
 import org.bouncycastle.crypto.AsymmetricCipherKeyPair
 import org.bouncycastle.crypto.generators.Ed25519KeyPairGenerator
 import org.bouncycastle.crypto.params.Ed25519KeyGenerationParameters
@@ -19,16 +22,17 @@ import java.util.concurrent.ConcurrentHashMap
  * This is the main interface for all encryption/decryption operations in bitchat.
  * It now uses the Noise protocol for secure transport encryption with proper session management.
  */
-class EncryptionService(private val context: Context) {
+@Singleton
+class EncryptionService @Inject constructor(
+    private val context: Context,
+    private val noiseService: NoiseEncryptionService,
+) {
 
     companion object {
         private const val TAG = "EncryptionService"
         private const val ED25519_PRIVATE_KEY_PREF = "ed25519_signing_private_key"
     }
 
-    // Core Noise encryption service
-    private val noiseService: NoiseEncryptionService = NoiseEncryptionService(context)
-
     // Session tracking for established connections
     private val establishedSessions = ConcurrentHashMap<String, String>() // peerID -> fingerprint
 

app/src/main/java/com/bitchat/android/di/AppModule.kt

@@ -0,0 +1,8 @@
+package com.bitchat.android.di
+
+import org.koin.core.annotation.ComponentScan
+import org.koin.core.annotation.Module
+
+@Module
+@ComponentScan("com.bitchat.android")
+class AppModule

app/src/main/java/com/bitchat/android/di/InitKoin.kt

@@ -0,0 +1,14 @@
+package com.bitchat.android.di
+
+import org.koin.core.context.startKoin
+import org.koin.dsl.KoinAppDeclaration
+import org.koin.ksp.generated.module
+
+fun initKoin(config: KoinAppDeclaration? = null) {
+    startKoin {
+        modules(
+            AppModule().module
+        )
+        config?.invoke(this)
+    }
+}

app/src/main/java/com/bitchat/android/favorites/FavoritesPersistenceService.kt

@@ -1,10 +1,13 @@
 package com.bitchat.android.favorites
 
-import android.content.Context
 import android.util.Log
 import com.bitchat.android.identity.SecureIdentityStateManager
-import com.google.gson.Gson
-import com.google.gson.reflect.TypeToken
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.builtins.MapSerializer
+import kotlinx.serialization.builtins.serializer
+import com.bitchat.android.util.JsonUtil
+import jakarta.inject.Inject
+import jakarta.inject.Singleton
 import java.util.*
 
 /**
@@ -57,32 +60,18 @@ interface FavoritesChangeListener {
  * Manages favorites with Noise↔Nostr mapping
  * Singleton pattern matching iOS implementation.
  */
-class FavoritesPersistenceService private constructor(private val context: Context) {
+@Singleton
+class FavoritesPersistenceService @Inject constructor(
+    private val stateManager : SecureIdentityStateManager
+) {
 
     companion object {
         private const val TAG = "FavoritesPersistenceService"
         private const val FAVORITES_KEY = "favorite_relationships"            // noiseHex -> relationship
         private const val PEERID_INDEX_KEY = "favorite_peerid_index"         // peerID(16-hex) -> npub
-
-        @Volatile
-        private var INSTANCE: FavoritesPersistenceService? = null
-
-        val shared: FavoritesPersistenceService
-            get() = INSTANCE ?: throw IllegalStateException("FavoritesPersistenceService not initialized")
-
-        fun initialize(context: Context) {
-            if (INSTANCE == null) {
-                synchronized(this) {
-                    if (INSTANCE == null) {
-                        INSTANCE = FavoritesPersistenceService(context.applicationContext)
-                    }
-                }
-            }
-        }
     }
 
-    private val stateManager = SecureIdentityStateManager(context)
-    private val gson = Gson()
+
     private val favorites = mutableMapOf<String, FavoriteRelationship>() // noiseHex -> relationship
     // NEW: Index by current mesh peerID (16-hex) for direct lookup when sending Nostr DMs from mesh context
     private val peerIdIndex = mutableMapOf<String, String>() // peerID (lowercase 16-hex) -> npub
@@ -161,7 +150,7 @@ class FavoritesPersistenceService private constructor(private val context: Conte
     fun findPeerIDForNostrPubkey(nostrPubkey: String): String? {
         // First, try direct match in peerIdIndex (values are stored as npub strings)
         peerIdIndex.entries.firstOrNull { it.value.equals(nostrPubkey, ignoreCase = true) }?.let { return it.key }
-        
+
         // Attempt legacy mapping via favorites Noise key association
         val targetHex = normalizeNostrKeyToHex(nostrPubkey)
         if (targetHex != null) {
@@ -258,14 +247,14 @@ class FavoritesPersistenceService private constructor(private val context: Conte
         try {
             val favoritesJson = stateManager.getSecureValue(FAVORITES_KEY)
             if (favoritesJson != null) {
-                val type = object : TypeToken<Map<String, FavoriteRelationshipData>>() {}.type
-                val data: Map<String, FavoriteRelationshipData> = gson.fromJson(favoritesJson, type)
-
-                favorites.clear()
-                data.forEach { (key, relationshipData) ->
-                    favorites[key] = relationshipData.toFavoriteRelationship()
+                val data = JsonUtil.fromJsonOrNull(MapSerializer(String.serializer(), FavoriteRelationshipData.serializer()), favoritesJson)
+                if (data != null) {
+                    favorites.clear()
+                    data.forEach { (key, relationshipData) ->
+                        favorites[key] = relationshipData.toFavoriteRelationship()
+                    }
+                    Log.d(TAG, "Loaded ${favorites.size} favorite relationships")
                 }
-                Log.d(TAG, "Loaded ${favorites.size} favorite relationships")
             }
         } catch (e: Exception) {
             Log.e(TAG, "Failed to load favorites: ${e.message}")
@@ -277,7 +266,7 @@ class FavoritesPersistenceService private constructor(private val context: Conte
             val data = favorites.mapValues { (_, relationship) ->
                 FavoriteRelationshipData.fromFavoriteRelationship(relationship)
             }
-            val favoritesJson = gson.toJson(data)
+            val favoritesJson = JsonUtil.toJson(MapSerializer(String.serializer(), FavoriteRelationshipData.serializer()), data)
             stateManager.storeSecureValue(FAVORITES_KEY, favoritesJson)
             Log.d(TAG, "Saved ${favorites.size} favorite relationships")
         } catch (e: Exception) {
@@ -289,10 +278,11 @@ class FavoritesPersistenceService private constructor(private val context: Conte
         try {
             val json = stateManager.getSecureValue(PEERID_INDEX_KEY)
             if (json != null) {
-                val type = object : TypeToken<Map<String, String>>() {}.type
-                val data: Map<String, String> = gson.fromJson(json, type)
-                peerIdIndex.clear()
-                peerIdIndex.putAll(data)
+                val data = JsonUtil.fromJsonOrNull(MapSerializer(String.serializer(), String.serializer()), json)
+                if (data != null) {
+                    peerIdIndex.clear()
+                    peerIdIndex.putAll(data)
+                }
                 Log.d(TAG, "Loaded ${peerIdIndex.size} peerID→npub mappings")
             }
         } catch (e: Exception) {
@@ -302,7 +292,7 @@ class FavoritesPersistenceService private constructor(private val context: Conte
 
     private fun savePeerIdIndex() {
         try {
-            val json = gson.toJson(peerIdIndex)
+            val json = JsonUtil.toJson(MapSerializer(String.serializer(), String.serializer()), peerIdIndex)
             stateManager.storeSecureValue(PEERID_INDEX_KEY, json)
             Log.d(TAG, "Saved ${peerIdIndex.size} peerID→npub mappings")
         } catch (e: Exception) {
@@ -336,6 +326,7 @@ class FavoritesPersistenceService private constructor(private val context: Conte
 }
 
 /** Serializable data for JSON storage */
+@Serializable
 private data class FavoriteRelationshipData(
     val peerNoisePublicKeyHex: String,
     val peerNostrPublicKey: String?,