WIP

.idea/planningMode.xml

@@ -3,6 +3,7 @@
   <component name="PlanningModeManager">
     <option name="approvalStates">
       <map>
+        <entry key="a82de12b-d0aa-44d8-b9e8-e753cde67ff4" value="false" />
         <entry key="b3cb996b-7f1f-4810-999d-5be96c526f74" value="false" />
       </map>
     </option>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

app/build.gradle.kts

@@ -1,6 +1,7 @@
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.kotlin.serialization)
 }
 
 android {
@@ -46,7 +47,11 @@ dependencies {
     implementation(libs.androidx.compose.ui.graphics)
     implementation(libs.androidx.compose.ui.tooling.preview)
     implementation(libs.androidx.core.ktx)
+    implementation(libs.androidx.core.splashscreen)
+    implementation(libs.androidx.biometric)
+    implementation(libs.androidx.lifecycle.process)
     implementation(libs.androidx.lifecycle.runtime.ktx)
+    implementation(libs.kotlinx.serialization.json)
     testImplementation(libs.junit)
     androidTestImplementation(platform(libs.androidx.compose.bom))
     androidTestImplementation(libs.androidx.compose.ui.test.junit4)

app/src/androidTest/java/swiss/qpq/gajumobile/ExampleInstrumentedTest.kt

@@ -6,7 +6,7 @@ import androidx.test.ext.junit.runners.AndroidJUnit4
 import org.junit.Test
 import org.junit.runner.RunWith
 
-import org.junit.Assert.*
+import org.junit.Assert.assertEquals
 
 /**
  * Instrumented test, which will execute on an Android device.

app/src/androidTest/java/swiss/qpq/gajumobile/WalletSecurityTest.kt

@@ -0,0 +1,47 @@
+package swiss.qpq.gajumobile
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Test
+import org.junit.runner.RunWith
+import swiss.qpq.gajumobile.data.WalletRepository
+import swiss.qpq.gajumobile.data.models.Account
+import swiss.qpq.gajumobile.data.models.Wallet
+
+@RunWith(AndroidJUnit4::class)
+class WalletSecurityTest {
+
+    @Test
+    fun testWalletEncryptionAndPersistence() {
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        val repository = WalletRepository(appContext)
+        
+        val testAccount = Account(
+            id = "test_acc_1",
+            label = "My Test Account",
+            publicKey = "pub_key_base64",
+            encryptedPrivateKey = "enc_priv_key_base64"
+        )
+        
+        val testWallet = Wallet(
+            id = "test_wallet_1",
+            name = "Test Wallet",
+            accounts = listOf(testAccount)
+        )
+
+        // 1. Save the wallet
+        repository.saveWallet(testWallet)
+
+        // 2. Load the wallet
+        val loadedWallet = repository.loadWallet("test_wallet_1")
+
+        // 3. Verify
+        assertNotNull(loadedWallet)
+        assertEquals(testWallet.id, loadedWallet?.id)
+        assertEquals(testWallet.name, loadedWallet?.name)
+        assertEquals(1, loadedWallet?.accounts?.size)
+        assertEquals("My Test Account", loadedWallet?.accounts?.first()?.label)
+    }
+}

app/src/main/AndroidManifest.xml

@@ -15,7 +15,7 @@
             android:name=".MainActivity"
             android:exported="true"
             android:label="@string/app_name"
-            android:theme="@style/Theme.GajuMobile"
+            android:theme="@style/Theme.App.Starting"
             android:windowSoftInputMode="adjustResize">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

app/src/main/java/swiss/qpq/gajumobile/MainActivity.kt

@@ -1,31 +1,88 @@
 package swiss.qpq.gajumobile
 
 import android.os.Bundle
-import androidx.activity.ComponentActivity
+import android.view.WindowManager
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
-import androidx.compose.runtime.*
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
-import swiss.qpq.gajumobile.ui.screens.*
+import androidx.compose.runtime.setValue
+import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
+import androidx.fragment.app.FragmentActivity
+import androidx.lifecycle.ProcessLifecycleOwner
+import swiss.qpq.gajumobile.security.AppLifecycleObserver
+import swiss.qpq.gajumobile.security.BiometricHelper
+import swiss.qpq.gajumobile.security.SecurityManager
+import swiss.qpq.gajumobile.ui.screens.CreateAccountMnemonicScreen
+import swiss.qpq.gajumobile.ui.screens.DashboardScreen
+import swiss.qpq.gajumobile.ui.screens.DeleteConfirmationScreen
+import swiss.qpq.gajumobile.ui.screens.ExplorerScreen
+import swiss.qpq.gajumobile.ui.screens.LockScreen
+import swiss.qpq.gajumobile.ui.screens.ManageAccountScreen
+import swiss.qpq.gajumobile.ui.screens.ManageOverviewScreen
+import swiss.qpq.gajumobile.ui.screens.ManageWalletScreen
+import swiss.qpq.gajumobile.ui.screens.MnemonicGridScreen
+import swiss.qpq.gajumobile.ui.screens.MnemonicVerifyScreen
+import swiss.qpq.gajumobile.ui.screens.QRReceiveScreen
+import swiss.qpq.gajumobile.ui.screens.QRScannerScreen
+import swiss.qpq.gajumobile.ui.screens.RecoverMnemonicScreen
+import swiss.qpq.gajumobile.ui.screens.SendFormScreen
+import swiss.qpq.gajumobile.ui.screens.SendReviewScreen
+import swiss.qpq.gajumobile.ui.screens.SetupChoiceScreen
+import swiss.qpq.gajumobile.ui.screens.SetupSuccessScreen
+import swiss.qpq.gajumobile.ui.screens.TransactionSuccessScreen
+import swiss.qpq.gajumobile.ui.screens.SettingsScreen
 import swiss.qpq.gajumobile.ui.theme.MyApplicationTheme
 
-class MainActivity : ComponentActivity() {
+class MainActivity : FragmentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
+        installSplashScreen()
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
         window.isNavigationBarContrastEnforced = false
+        
+        // Prevent screenshots and obscure recents preview
+        window.addFlags(WindowManager.LayoutParams.FLAG_SECURE)
+
+        // Initialize App Lifecycle Security Observer
+        ProcessLifecycleOwner.get().lifecycle.addObserver(AppLifecycleObserver(this))
+
         setContent {
+            val isLocked by SecurityManager.isLocked.collectAsState()
+            var lockErrorMessage by remember { mutableStateOf<String?>(null) }
+
             MyApplicationTheme {
-                GajuRouter()
+                if (isLocked) {
+                    LockScreen(
+                        errorMessage = lockErrorMessage,
+                        onUnlockRequest = {
+                            BiometricHelper.showBiometricPrompt(
+                                activity = this,
+                                onSuccess = { 
+                                    android.util.Log.d("GajuSecurity", "Unlock success")
+                                    lockErrorMessage = null
+                                    SecurityManager.unlock() 
+                                },
+                                onError = { err -> 
+                                    android.util.Log.e("GajuSecurity", "Unlock error: $err")
+                                    lockErrorMessage = err
+                                }
+                            )
+                        }
+                    )
+                } else {
+                    GajuRouter()
+                }
             }
         }
     }
 }
 
 enum class Screen {
-    SPLASH,
-    ONBOARDING_CONTINUE,
-    BIOMETRICS_PROMPT,
     SETUP_CHOICE,
     CREATE_MNEMONIC,
     MNEMONIC_GRID,
@@ -48,7 +105,7 @@ enum class Screen {
 
 @Composable
 fun GajuRouter() {
-    var currentScreen by rememberSaveable { mutableStateOf(value = Screen.SPLASH) }
+    var currentScreen by rememberSaveable { mutableStateOf(value = Screen.SETUP_CHOICE) }
     var setupRecovered by rememberSaveable { mutableStateOf(value = false) }
     var selectedWallet by rememberSaveable { mutableStateOf(value = "Primary") }
     var selectedAccount by rememberSaveable { mutableStateOf(value = "Daily") }
@@ -56,17 +113,6 @@ fun GajuRouter() {
     var deleteName by rememberSaveable { mutableStateOf(value = "") }
 
     when (currentScreen) {
-        Screen.SPLASH -> {
-            SplashScreen { currentScreen = Screen.ONBOARDING_CONTINUE }
-        }
-        Screen.ONBOARDING_CONTINUE -> {
-            WelcomeContinueScreen { currentScreen = Screen.BIOMETRICS_PROMPT }
-        }
-        Screen.BIOMETRICS_PROMPT -> {
-            BiometricsPromptScreen(
-                onYes = { currentScreen = Screen.SETUP_CHOICE },
-            ) { currentScreen = Screen.SETUP_CHOICE }
-        }
         Screen.SETUP_CHOICE -> {
             SetupChoiceScreen(
                 onCreate = { 

app/src/main/java/swiss/qpq/gajumobile/data/WalletRepository.kt

@@ -0,0 +1,43 @@
+package swiss.qpq.gajumobile.data
+
+import android.content.Context
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import swiss.qpq.gajumobile.data.models.Wallet
+import swiss.qpq.gajumobile.security.EncryptionService
+import java.io.File
+
+class WalletRepository(private val context: Context) {
+
+    private val json = Json { prettyPrint = true }
+
+    fun saveWallet(wallet: Wallet) {
+        val walletJson = json.encodeToString(wallet)
+        val envelope = EncryptionService.encrypt(context, walletJson)
+        val envelopeJson = json.encodeToString(envelope)
+        
+        val file = getWalletFile(wallet.id)
+        file.writeText(envelopeJson)
+    }
+
+    fun loadWallet(walletId: String): Wallet? {
+        val file = getWalletFile(walletId)
+        if (!file.exists()) return null
+        
+        return try {
+            val envelopeJson = file.readText()
+            val envelope = json.decodeFromString<swiss.qpq.gajumobile.security.EncryptedEnvelope>(envelopeJson)
+            val walletJson = EncryptionService.decrypt(context, envelope)
+            json.decodeFromString<Wallet>(walletJson)
+        } catch (e: Exception) {
+            android.util.Log.e("WalletRepository", "Failed to load wallet", e)
+            null
+        }
+    }
+
+    private fun getWalletFile(walletId: String): File {
+        val dir = File(context.filesDir, "wallets")
+        if (!dir.exists()) dir.mkdirs()
+        return File(dir, "wallet_$walletId.gaju")
+    }
+}

app/src/main/java/swiss/qpq/gajumobile/data/models/Account.kt

@@ -0,0 +1,20 @@
+package swiss.qpq.gajumobile.data.models
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Account(
+    val id: String, // Unique identifier (e.g., UUID or derived from pubkey)
+    val label: String,
+    val publicKey: String, // Base64 encoded public key
+    val encryptedPrivateKey: String, // Base64 encoded private key (encrypted by DEK)
+    val cachedBalance: CachedBalance? = null
+)
+
+@Serializable
+data class CachedBalance(
+    val amount: String,
+    val pucks: String, // Fractional part
+    val chainId: String,
+    val timestamp: Long
+)

app/src/main/java/swiss/qpq/gajumobile/data/models/Wallet.kt

@@ -0,0 +1,11 @@
+package swiss.qpq.gajumobile.data.models
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Wallet(
+    val id: String,
+    val name: String,
+    val accounts: List<Account> = emptyList(),
+    val createdAt: Long = System.currentTimeMillis()
+)

app/src/main/java/swiss/qpq/gajumobile/security/AppLifecycleObserver.kt

@@ -0,0 +1,31 @@
+package swiss.qpq.gajumobile.security
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import androidx.lifecycle.DefaultLifecycleObserver
+import androidx.lifecycle.LifecycleOwner
+
+class AppLifecycleObserver(private val context: Context) : DefaultLifecycleObserver {
+
+    private val screenOffReceiver = object : BroadcastReceiver() {
+        override fun onReceive(context: Context?, intent: Intent?) {
+            if (intent?.action == Intent.ACTION_SCREEN_OFF) {
+                SecurityManager.lock()
+            }
+        }
+    }
+
+    override fun onStart(owner: LifecycleOwner) {
+        super.onStart(owner)
+        SecurityManager.onAppForegrounded()
+        context.registerReceiver(screenOffReceiver, IntentFilter(Intent.ACTION_SCREEN_OFF))
+    }
+
+    override fun onStop(owner: LifecycleOwner) {
+        super.onStop(owner)
+        SecurityManager.onAppBackgrounded()
+        context.unregisterReceiver(screenOffReceiver)
+    }
+}

app/src/main/java/swiss/qpq/gajumobile/security/BiometricHelper.kt

@@ -0,0 +1,63 @@
+package swiss.qpq.gajumobile.security
+
+import androidx.biometric.BiometricManager
+import androidx.biometric.BiometricPrompt
+import androidx.core.content.ContextCompat
+import androidx.fragment.app.FragmentActivity
+
+object BiometricHelper {
+
+    fun showBiometricPrompt(
+        activity: FragmentActivity,
+        onSuccess: () -> Unit,
+        onError: (String) -> Unit
+    ) {
+        val biometricManager = BiometricManager.from(activity)
+        val authenticators = BiometricManager.Authenticators.BIOMETRIC_STRONG or BiometricManager.Authenticators.DEVICE_CREDENTIAL
+        
+        when (biometricManager.canAuthenticate(authenticators)) {
+            BiometricManager.BIOMETRIC_ERROR_NONE_ENROLLED -> {
+                onError("No biometrics or PIN enrolled on this device. Please set up security in system settings.")
+                return
+            }
+            BiometricManager.BIOMETRIC_ERROR_NO_HARDWARE -> {
+                // If no hardware, we might still be able to use DEVICE_CREDENTIAL
+                if (biometricManager.canAuthenticate(BiometricManager.Authenticators.DEVICE_CREDENTIAL) != BiometricManager.BIOMETRIC_SUCCESS) {
+                    onError("Device security is not available or not set up.")
+                    return
+                }
+            }
+            BiometricManager.BIOMETRIC_SUCCESS -> { /* Proceed */ }
+            else -> {
+                // Other errors, let the prompt try anyway or handle specifically
+            }
+        }
+
+        val executor = ContextCompat.getMainExecutor(activity)
+        val biometricPrompt = BiometricPrompt(activity, executor,
+            object : BiometricPrompt.AuthenticationCallback() {
+                override fun onAuthenticationError(errorCode: Int, errString: CharSequence) {
+                    super.onAuthenticationError(errorCode, errString)
+                    onError(errString.toString())
+                }
+
+                override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult) {
+                    super.onAuthenticationSucceeded(result)
+                    onSuccess()
+                }
+
+                override fun onAuthenticationFailed() {
+                    super.onAuthenticationFailed()
+                    onError("Authentication failed")
+                }
+            })
+
+        val promptInfo = BiometricPrompt.PromptInfo.Builder()
+            .setTitle("Unlock GajuMobile")
+            .setSubtitle("Authenticate to continue")
+            .setAllowedAuthenticators(BiometricManager.Authenticators.BIOMETRIC_STRONG or BiometricManager.Authenticators.DEVICE_CREDENTIAL)
+            .build()
+
+        biometricPrompt.authenticate(promptInfo)
+    }
+}

app/src/main/java/swiss/qpq/gajumobile/security/EncryptionService.kt

@@ -0,0 +1,77 @@
+package swiss.qpq.gajumobile.security
+
+import android.content.Context
+import android.util.Base64
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import java.security.SecureRandom
+import javax.crypto.Cipher
+import javax.crypto.KeyGenerator
+import javax.crypto.SecretKey
+import javax.crypto.spec.GCMParameterSpec
+import javax.crypto.spec.SecretKeySpec
+
+@Serializable
+data class EncryptedEnvelope(
+    val encryptedData: String, // Base64
+    val encryptedDek: String,  // Base64
+    val dataIv: String,        // Base64
+    val dekIv: String          // Base64
+)
+
+object EncryptionService {
+    private const val AES_GCM = "AES/GCM/NoPadding"
+    private const val GCM_TAG_LENGTH = 128
+    private const val IV_LENGTH = 12
+
+    fun encrypt(context: Context, data: String): EncryptedEnvelope {
+        // 1. Generate a random Data Encryption Key (DEK) in software
+        val dek = generateDek()
+
+        // 2. Encrypt the data with the DEK
+        val dataCipher = Cipher.getInstance(AES_GCM)
+        val dataIv = ByteArray(IV_LENGTH).apply { SecureRandom().nextBytes(this) }
+        dataCipher.init(Cipher.ENCRYPT_MODE, dek, GCMParameterSpec(GCM_TAG_LENGTH, dataIv))
+        val encryptedData = dataCipher.doFinal(data.toByteArray())
+
+        // 3. Encrypt the DEK with the Master Key (Hardware-backed)
+        val masterKey = KeyManager.getMasterKey(context)
+        val dekCipher = Cipher.getInstance(AES_GCM)
+        // Let Keystore generate the IV for the Master Key encryption
+        dekCipher.init(Cipher.ENCRYPT_MODE, masterKey)
+        val encryptedDek = dekCipher.doFinal(dek.encoded)
+        val dekIv = dekCipher.iv
+
+        return EncryptedEnvelope(
+            encryptedData = Base64.encodeToString(encryptedData, Base64.NO_WRAP),
+            encryptedDek = Base64.encodeToString(encryptedDek, Base64.NO_WRAP),
+            dataIv = Base64.encodeToString(dataIv, Base64.NO_WRAP),
+            dekIv = Base64.encodeToString(dekIv, Base64.NO_WRAP)
+        )
+    }
+
+    fun decrypt(context: Context, envelope: EncryptedEnvelope): String {
+        // 1. Decrypt the DEK using the Master Key
+        val masterKey = KeyManager.getMasterKey(context)
+        val dekCipher = Cipher.getInstance(AES_GCM)
+        val dekIv = Base64.decode(envelope.dekIv, Base64.NO_WRAP)
+        dekCipher.init(Cipher.DECRYPT_MODE, masterKey, GCMParameterSpec(GCM_TAG_LENGTH, dekIv))
+        val decryptedDekBytes = dekCipher.doFinal(Base64.decode(envelope.encryptedDek, Base64.NO_WRAP))
+        val dek = SecretKeySpec(decryptedDekBytes, "AES")
+
+        // 2. Decrypt the data using the DEK
+        val dataCipher = Cipher.getInstance(AES_GCM)
+        val dataIv = Base64.decode(envelope.dataIv, Base64.NO_WRAP)
+        dataCipher.init(Cipher.DECRYPT_MODE, dek, GCMParameterSpec(GCM_TAG_LENGTH, dataIv))
+        val decryptedData = dataCipher.doFinal(Base64.decode(envelope.encryptedData, Base64.NO_WRAP))
+
+        return String(decryptedData)
+    }
+
+    private fun generateDek(): SecretKey {
+        val keyGen = KeyGenerator.getInstance("AES")
+        keyGen.init(256)
+        return keyGen.generateKey()
+    }
+}

app/src/main/java/swiss/qpq/gajumobile/security/KeyManager.kt

@@ -0,0 +1,51 @@
+package swiss.qpq.gajumobile.security
+
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build
+import android.security.keystore.KeyGenParameterSpec
+import android.security.keystore.KeyProperties
+import java.security.KeyStore
+import javax.crypto.KeyGenerator
+import javax.crypto.SecretKey
+
+object KeyManager {
+    private const val ANDROID_KEYSTORE = "AndroidKeyStore"
+    private const val MASTER_KEY_ALIAS = "GajuMasterKey"
+
+    fun getMasterKey(context: Context): SecretKey {
+        val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE).apply { load(null) }
+        
+        return if (keyStore.containsAlias(MASTER_KEY_ALIAS)) {
+            keyStore.getKey(MASTER_KEY_ALIAS, null) as SecretKey
+        } else {
+            generateMasterKey(context)
+        }
+    }
+
+    private fun generateMasterKey(context: Context): SecretKey {
+        val keyGenerator = KeyGenerator.getInstance(
+            KeyProperties.KEY_ALGORITHM_AES,
+            ANDROID_KEYSTORE
+        )
+
+        val builder = KeyGenParameterSpec.Builder(
+            MASTER_KEY_ALIAS,
+            KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
+        )
+            .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
+            .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
+            .setKeySize(256)
+
+        // Target StrongBox if available (Android 9+)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+            val hasStrongBox = context.packageManager.hasSystemFeature(PackageManager.FEATURE_STRONGBOX_KEYSTORE)
+            if (hasStrongBox) {
+                builder.setIsStrongBoxBacked(true)
+            }
+        }
+
+        keyGenerator.init(builder.build())
+        return keyGenerator.generateKey()
+    }
+}

app/src/main/java/swiss/qpq/gajumobile/security/SecurityManager.kt

@@ -0,0 +1,32 @@
+package swiss.qpq.gajumobile.security
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+object SecurityManager {
+    private val _isLocked = MutableStateFlow(true)
+    val isLocked = _isLocked.asStateFlow()
+
+    private var lastBackgroundTime: Long = 0
+    private const val LOCK_TIMEOUT_MS = 2 * 60 * 1000L // 2 minutes
+
+    fun lock() {
+        _isLocked.value = true
+    }
+
+    fun unlock() {
+        _isLocked.value = false
+    }
+
+    fun onAppBackgrounded() {
+        lastBackgroundTime = System.currentTimeMillis()
+    }
+
+    fun onAppForegrounded() {
+        if (lastBackgroundTime != 0L && System.currentTimeMillis() - lastBackgroundTime > LOCK_TIMEOUT_MS) {
+            lock()
+        }
+        // Reset background time after checking
+        lastBackgroundTime = 0
+    }
+}

app/src/main/java/swiss/qpq/gajumobile/ui/components/GajuComponents.kt

@@ -2,11 +2,39 @@ package swiss.qpq.gajumobile.ui.components
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.navigationBars
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.layout.windowInsetsPadding
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.*
-import androidx.compose.runtime.*
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.CheckboxDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.OutlinedTextFieldDefaults
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip

app/src/main/java/swiss/qpq/gajumobile/ui/screens/DashboardScreen.kt

@@ -1,10 +1,30 @@
 package swiss.qpq.gajumobile.ui.screens
 
 import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.*
-import androidx.compose.runtime.*
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SecondaryTabRow
+import androidx.compose.material3.Tab
+import androidx.compose.material3.TabRowDefaults
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color

app/src/main/java/swiss/qpq/gajumobile/ui/screens/LockScreen.kt

@@ -0,0 +1,76 @@
+package swiss.qpq.gajumobile.ui.screens
+
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.safeDrawingPadding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.Button
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import swiss.qpq.gajumobile.R
+
+@Composable
+fun LockScreen(
+    errorMessage: String? = null,
+    onUnlockRequest: () -> Unit
+) {
+    Box(
+        modifier = Modifier
+            .fillMaxSize()
+            .background(MaterialTheme.colorScheme.background),
+        contentAlignment = Alignment.Center,
+    ) {
+        Column(
+            modifier = Modifier.safeDrawingPadding(),
+            horizontalAlignment = Alignment.CenterHorizontally
+        ) {
+            Image(
+                painter = painterResource(id = R.drawable.gajumobile_logo_colored),
+                contentDescription = null,
+                modifier = Modifier.size(150.dp),
+            )
+            Spacer(modifier = Modifier.height(48.dp))
+            Text(
+                text = "App Locked",
+                color = MaterialTheme.colorScheme.onBackground,
+                fontSize = 24.sp,
+                fontWeight = FontWeight.Bold,
+            )
+            Spacer(modifier = Modifier.height(16.dp))
+            Text(
+                text = "Please authenticate to continue.",
+                color = MaterialTheme.colorScheme.onBackground.copy(alpha = 0.7f),
+                fontSize = 16.sp,
+            )
+            
+            if (errorMessage != null) {
+                Spacer(modifier = Modifier.height(16.dp))
+                Text(
+                    text = errorMessage,
+                    color = MaterialTheme.colorScheme.error,
+                    fontSize = 14.sp,
+                    fontWeight = FontWeight.Medium,
+                    modifier = Modifier.padding(horizontal = 32.dp)
+                )
+            }
+
+            Spacer(modifier = Modifier.height(48.dp))
+            Button(onClick = onUnlockRequest) {
+                Text("Unlock")
+            }
+        }
+    }
+}

app/src/main/java/swiss/qpq/gajumobile/ui/screens/ManagementScreens.kt

@@ -2,13 +2,39 @@ package swiss.qpq.gajumobile.ui.screens
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.navigationBars
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.layout.windowInsetsPadding
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
-import androidx.compose.material3.*
-import androidx.compose.runtime.*
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Switch
+import androidx.compose.material3.SwitchDefaults
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
@@ -18,7 +44,9 @@ import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import swiss.qpq.gajumobile.R
-import swiss.qpq.gajumobile.ui.components.*
+import swiss.qpq.gajumobile.ui.components.GajuBottomNavigation
+import swiss.qpq.gajumobile.ui.components.GajuButton
+import swiss.qpq.gajumobile.ui.components.GajuHeader
 
 @Composable
 fun SettingsScreen(

app/src/main/java/swiss/qpq/gajumobile/ui/screens/OnboardingFlow.kt

@@ -1,116 +0,0 @@
-package swiss.qpq.gajumobile.ui.screens
-
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.*
-import androidx.compose.material3.*
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.res.painterResource
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-import swiss.qpq.gajumobile.R
-import swiss.qpq.gajumobile.ui.components.GajuButton
-
-@Composable
-fun WelcomeContinueScreen(onContinue: () -> Unit) {
-    Box(
-        modifier = Modifier
-            .fillMaxSize()
-            .background(MaterialTheme.colorScheme.background)
-            .safeDrawingPadding(),
-        contentAlignment = Alignment.Center,
-    ) {
-        Column(horizontalAlignment = Alignment.CenterHorizontally) {
-            Surface(
-                modifier = Modifier.size(180.dp),
-                shape = androidx.compose.foundation.shape.RoundedCornerShape(40.dp),
-                color = Color.Transparent,
-                border = androidx.compose.foundation.BorderStroke(1.dp, Color.Gray),
-            ) {
-                Box(contentAlignment = Alignment.Center) {
-                    Icon(
-                        painter = painterResource(id = R.drawable.ic_account_box), // Replace with actual alien icon if available
-                        contentDescription = null,
-                        modifier = Modifier.size(120.dp),
-                        tint = MaterialTheme.colorScheme.onSurface,
-                    )
-                }
-            }
-            
-            Spacer(modifier = Modifier.height(64.dp))
-            
-            GajuButton(
-                text = "CONTINUE",
-                onClick = onContinue,
-                modifier = Modifier.width(200.dp),
-            )
-        }
-    }
-}
-
-@Composable
-fun BiometricsPromptScreen(
-    onYes: () -> Unit,
-    onNo: () -> Unit,
-) {
-    Box(
-        modifier = Modifier
-            .fillMaxSize()
-            .background(MaterialTheme.colorScheme.background)
-            .safeDrawingPadding(),
-        contentAlignment = Alignment.Center,
-    ) {
-        Column(
-            horizontalAlignment = Alignment.CenterHorizontally,
-            modifier = Modifier.padding(32.dp),
-        ) {
-            Image(
-                painter = painterResource(id = R.drawable.gajumobile_icon_colored),
-                contentDescription = null,
-                modifier = Modifier.size(100.dp),
-            )
-            
-            Spacer(modifier = Modifier.height(48.dp))
-            
-            Text(
-                text = "Would you like to use your phone biometrics for logging in to this app?",
-                color = MaterialTheme.colorScheme.onBackground,
-                fontSize = 20.sp,
-                fontWeight = FontWeight.Bold,
-                textAlign = TextAlign.Center,
-            )
-            
-            Spacer(modifier = Modifier.height(16.dp))
-            
-            Text(
-                text = "Don't worry. You can still change this in your settings later.",
-                color = MaterialTheme.colorScheme.onSurfaceVariant,
-                fontSize = 14.sp,
-                textAlign = TextAlign.Center,
-            )
-            
-            Spacer(modifier = Modifier.height(64.dp))
-            
-            Row(modifier = Modifier.fillMaxWidth()) {
-                GajuButton(
-                    text = "NO",
-                    onClick = onNo,
-                    modifier = Modifier.weight(1f),
-                    containerColor = MaterialTheme.colorScheme.secondary,
-                    contentColor = MaterialTheme.colorScheme.onSecondary,
-                )
-                Spacer(modifier = Modifier.width(16.dp))
-                GajuButton(
-                    text = "YES",
-                    onClick = onYes,
-                    modifier = Modifier.weight(1f),
-                )
-            }
-        }
-    }
-}

app/src/main/java/swiss/qpq/gajumobile/ui/screens/SplashScreen.kt

@@ -1,50 +0,0 @@
-package swiss.qpq.gajumobile.ui.screens
-
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.*
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.painterResource
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-import kotlinx.coroutines.delay
-import swiss.qpq.gajumobile.R
-
-import kotlin.time.Duration.Companion.seconds
-
-@Composable
-fun SplashScreen(onTimeout: () -> Unit) {
-    LaunchedEffect(Unit) {
-        delay(2.seconds)
-        onTimeout()
-    }
-
-    Box(
-        modifier = Modifier
-            .fillMaxSize()
-            .background(MaterialTheme.colorScheme.background)
-            .safeDrawingPadding(),
-        contentAlignment = Alignment.Center,
-    ) {
-        Column(horizontalAlignment = Alignment.CenterHorizontally) {
-            Image(
-                painter = painterResource(id = R.drawable.gajumobile_logo_colored),
-                contentDescription = null,
-                modifier = Modifier.size(200.dp),
-            )
-            Spacer(modifier = Modifier.height(24.dp))
-            Text(
-                text = "Welcome to smarter, safer finance.",
-                color = MaterialTheme.colorScheme.onBackground,
-                fontSize = 16.sp,
-                fontWeight = FontWeight.Medium,
-            )
-        }
-    }
-}

app/src/main/java/swiss/qpq/gajumobile/ui/screens/TransactionScreens.kt

@@ -3,12 +3,36 @@ package swiss.qpq.gajumobile.ui.screens
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
 import androidx.compose.foundation.clickable
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.navigationBars
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.safeDrawingPadding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.layout.windowInsetsPadding
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
-import androidx.compose.material3.*
-import androidx.compose.runtime.*
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
@@ -18,7 +42,10 @@ import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import swiss.qpq.gajumobile.R
-import swiss.qpq.gajumobile.ui.components.*
+import swiss.qpq.gajumobile.ui.components.GajuButton
+import swiss.qpq.gajumobile.ui.components.GajuHeader
+import swiss.qpq.gajumobile.ui.components.GajuTextField
+import swiss.qpq.gajumobile.ui.components.SuccessLayout
 
 @Composable
 fun QRScannerScreen(

app/src/main/java/swiss/qpq/gajumobile/ui/screens/WalletSetupScreens.kt

@@ -3,15 +3,39 @@ package swiss.qpq.gajumobile.ui.screens
 import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.navigationBars
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.safeDrawingPadding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.layout.windowInsetsPadding
 import androidx.compose.foundation.lazy.grid.GridCells
 import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
 import androidx.compose.foundation.lazy.grid.itemsIndexed
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
-import androidx.compose.material3.*
-import androidx.compose.runtime.*
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.painterResource

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

@@ -2,4 +2,10 @@
 <resources>
 
     <style name="Theme.GajuMobile" parent="android:Theme.Material.Light.NoActionBar" />
+
+    <style name="Theme.App.Starting" parent="Theme.SplashScreen">
+        <item name="windowSplashScreenAnimatedIcon">@drawable/gajumobile_logo_colored</item>
+        <item name="windowSplashScreenBackground">@android:color/white</item>
+        <item name="postSplashScreenTheme">@style/Theme.GajuMobile</item>
+    </style>
 </resources>

app/src/test/java/swiss/qpq/gajumobile/ExampleUnitTest.kt

@@ -2,7 +2,7 @@ package swiss.qpq.gajumobile
 
 import org.junit.Test
 
-import org.junit.Assert.*
+import org.junit.Assert.assertEquals
 
 /**
  * Example local unit test, which will execute on the development machine (host).

gradle/libs.versions.toml

@@ -8,6 +8,10 @@ lifecycleRuntimeKtx = "2.6.1"
 activityCompose = "1.8.0"
 kotlin = "2.2.10"
 composeBom = "2025.12.00"
+coreSplashScreen = "1.2.0"
+biometric = "1.1.0"
+lifecycleProcess = "2.6.1"
+kotlinxSerialization = "1.8.0"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -25,8 +29,13 @@ androidx-compose-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-
 androidx-compose-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
 androidx-compose-material3 = { group = "androidx.compose.material3", name = "material3" }
 androidx-compose-material3-adaptive-navigation-suite = { group = "androidx.compose.material3", name = "material3-adaptive-navigation-suite" }
+androidx-core-splashscreen = { group = "androidx.core", name = "core-splashscreen", version.ref = "coreSplashScreen" }
+androidx-biometric = { group = "androidx.biometric", name = "biometric", version.ref = "biometric" }
+androidx-lifecycle-process = { group = "androidx.lifecycle", name = "lifecycle-process", version.ref = "lifecycleProcess" }
+kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerialization" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
 kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
+kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }