.gitignore

@@ -7,8 +7,13 @@
 /.idea/workspace.xml
 /.idea/navEditor.xml
 /.idea/assetWizardSettings.xml
+/.idea/deploymentTargetSelector.xml
+/.idea/deviceManager.xml
+/.idea/appInsightsSettings.xml
+/.idea/koin-grouping-settings.xml
 .DS_Store
 /build
+.claude/settings.local.json
 /captures
 .externalNativeBuild
 .cxx

app/build.gradle.kts

@@ -4,6 +4,11 @@ plugins {
     alias(libs.plugins.devtool.ksp)
     alias(libs.plugins.serialization)
     alias(libs.plugins.koin.compiler)
+    alias(libs.plugins.room)
+}
+
+room {
+    schemaDirectory("$projectDir/schemas")
 }
 
 android {
@@ -51,6 +56,7 @@ 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.lifecycle.runtime.ktx)
     implementation(libs.androidx.lifecycle.viewmodel.compose)
     testImplementation(libs.junit)
@@ -76,4 +82,11 @@ dependencies {
     implementation(libs.androidx.room)
     ksp(libs.androidx.room.compiler)
     implementation(libs.androidx.room.ktx)
+
+    // Retrofit
+    implementation(libs.squareup.retrofit2)
+    implementation(libs.squareup.retrofit2.kotlinx.serialization)
+
+    // Kotlinx
+    implementation(libs.kotlinx.serialization.json)
 }

app/schemas/com.longnh15.heimdall.data.source.local.HeimdallDatabase/1.json

@@ -0,0 +1,54 @@
+{
+  "formatVersion": 1,
+  "database": {
+    "version": 1,
+    "identityHash": "e09aa1c4dfa12dfb105b0ea16d4584ff",
+    "entities": [
+      {
+        "tableName": "credential",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `name` TEXT NOT NULL, `url` TEXT, `username` TEXT NOT NULL, `password` TEXT NOT NULL)",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "url",
+            "columnName": "url",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "username",
+            "columnName": "username",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "password",
+            "columnName": "password",
+            "affinity": "TEXT",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": true,
+          "columnNames": [
+            "id"
+          ]
+        }
+      }
+    ],
+    "setupQueries": [
+      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
+      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, 'e09aa1c4dfa12dfb105b0ea16d4584ff')"
+    ]
+  }
+}

app/src/main/AndroidManifest.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
-    xmlns:tools="http://schemas.android.com/tools">
+
+    <uses-permission android:name="android.permission.INTERNET" />
 
     <application
         android:name=".HeimdallApplication"
@@ -28,7 +29,7 @@
         <activity
             android:name=".MainActivity"
             android:exported="true"
-            android:theme="@style/Theme.Heimdall">
+            android:theme="@style/Theme.Heimdall.Starting">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

app/src/main/java/com/longnh15/heimdall/HeimdallApplication.kt

@@ -9,8 +9,6 @@ import com.longnh15.heimdall.domain.vault.VaultSessionManager
 import org.koin.android.ext.android.inject
 import org.koin.android.ext.koin.androidContext
 import org.koin.android.ext.koin.androidLogger
-import org.koin.core.annotation.ComponentScan
-import org.koin.core.annotation.KoinApplication
 import org.koin.plugin.module.dsl.startKoin
 
 //@KoinApplication(modules = [DatabaseModule::class])

app/src/main/java/com/longnh15/heimdall/MainActivity.kt

@@ -8,6 +8,7 @@ import androidx.activity.enableEdgeToEdge
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
+import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.longnh15.heimdall.navigation.HeimdallNavGraph
 import com.longnh15.heimdall.navigation.Screen
@@ -18,20 +19,31 @@ class MainActivity : ComponentActivity() {
     private val viewModel: MainViewModel by viewModel()
 
     override fun onCreate(savedInstanceState: Bundle?) {
+        val splashScreen = installSplashScreen()
         super.onCreate(savedInstanceState)
+        // Keep the splash screen until the first-launch flag is resolved so the nav graph
+        // is built once with the correct start destination (no Onboarding -> Login flicker).
+        splashScreen.setKeepOnScreenCondition { viewModel.isFirstLaunch.value == null && viewModel.token.value == null }
         enableEdgeToEdge()
         setContent {
             HeimdallTheme {
                 val isFirstLaunch by viewModel.isFirstLaunch.collectAsStateWithLifecycle()
+                val token by viewModel.token.collectAsStateWithLifecycle()
+                if (isFirstLaunch != null && token != null) {
                     HeimdallNavGraph(
                         modifier = Modifier.fillMaxSize(),
-                    startDestination = if (isFirstLaunch != false) Screen.Onboarding else Screen.Vault,
+                        startDestination = when {
+                            isFirstLaunch!! -> Screen.Onboarding
+                            token!!.isEmpty() -> Screen.Login
+                            else -> Screen.Vault
+                        },
                         isAutofillServiceEnabled = ::isAutofillServiceEnabled,
                         onCompleteOnboarding = viewModel::onCompleteOnboarding,
                     )
                 }
             }
         }
+    }
 
     fun isAutofillServiceEnabled(): Boolean {
         val afm = getSystemService(AutofillManager::class.java)

app/src/main/java/com/longnh15/heimdall/MainViewModel.kt

@@ -3,6 +3,7 @@ package com.longnh15.heimdall
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.longnh15.heimdall.data.preferences.PreferenceDataSource
+import com.longnh15.heimdall.data.source.local.LocalDataSource
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.map
@@ -12,7 +13,8 @@ import org.koin.core.annotation.KoinViewModel
 
 @KoinViewModel
 class MainViewModel (
-    private val preferenceDataSource: PreferenceDataSource
+    private val preferenceDataSource: PreferenceDataSource,
+    private val localDataSource: LocalDataSource
 ) : ViewModel() {
     val isFirstLaunch: StateFlow<Boolean?> = preferenceDataSource.preferences
         .map { it.isFirstLaunch }
@@ -22,6 +24,14 @@ class MainViewModel (
             initialValue = null
         )
 
+    val token: StateFlow<String?> = localDataSource.token
+        .map { it.orEmpty() }
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5000),
+            initialValue = null
+        )
+
     fun onCompleteOnboarding() {
         viewModelScope.launch {
             preferenceDataSource.setFirstLaunchDone()

app/src/main/java/com/longnh15/heimdall/common/GlobalConfig.kt

@@ -0,0 +1,10 @@
+package com.longnh15.heimdall.common
+
+import kotlinx.serialization.json.Json
+
+object GlobalConfig {
+    val json = Json {
+        ignoreUnknownKeys = true
+        isLenient
+    }
+}

app/src/main/java/com/longnh15/heimdall/common/TokenCrypto.kt

@@ -0,0 +1,55 @@
+package com.longnh15.heimdall.common
+
+import android.security.keystore.KeyGenParameterSpec
+import android.security.keystore.KeyProperties
+import java.security.KeyStore
+import javax.crypto.Cipher
+import javax.crypto.KeyGenerator
+import javax.crypto.SecretKey
+import javax.crypto.spec.GCMParameterSpec
+import kotlin.io.encoding.Base64
+
+object TokenCrypto {
+    private const val PROVIDER = "AndroidKeyStore"
+    private const val ALIAS = "auth_token_key"
+    private const val TRANSFORMATION = "AES/GCM/NoPadding"
+    private const val IV_SIZE = 12
+    private const val TAG_BITS = 128
+
+    private val keystore = KeyStore.getInstance(PROVIDER).apply { load(null) }
+
+    private fun getOrCreateKey(): SecretKey {
+        (keystore.getEntry(ALIAS, null) as? KeyStore.SecretKeyEntry)?.let {
+            return it.secretKey
+        }
+        val keyGen = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, PROVIDER)
+        keyGen.init(
+            KeyGenParameterSpec.Builder(
+                ALIAS,
+                KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
+            )
+                .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
+                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
+                .setKeySize(256)
+                .build()
+        )
+        return keyGen.generateKey()
+    }
+
+    fun encrypt(plainText: String): String {
+        val cipher = Cipher.getInstance(TRANSFORMATION)
+        cipher.init(Cipher.ENCRYPT_MODE, getOrCreateKey())
+        val iv = cipher.iv                                  // 12-byte IV, generated by Keystore
+        val cipherText = cipher.doFinal(plainText.toByteArray(Charsets.UTF_8))
+        return Base64.encode(iv + cipherText)  // prepend IV
+    }
+
+    fun decrypt(encoded: String): String {
+        val combined = Base64.decode(encoded)
+        val iv = combined.copyOfRange(0, IV_SIZE)
+        val cipherText = combined.copyOfRange(IV_SIZE, combined.size)
+        val cipher = Cipher.getInstance(TRANSFORMATION)
+        cipher.init(Cipher.DECRYPT_MODE, getOrCreateKey(), GCMParameterSpec(TAG_BITS, iv))
+        return cipher.doFinal(cipherText).toString(Charsets.UTF_8)
+    }
+}

app/src/main/java/com/longnh15/heimdall/common/ValidationHelper.kt

@@ -0,0 +1,9 @@
+package com.longnh15.heimdall.common
+
+import android.util.Patterns.EMAIL_ADDRESS
+
+object ValidationHelper {
+    fun isEmail(input: String): Boolean {
+        return EMAIL_ADDRESS.matcher(input).matches()
+    }
+}

app/src/main/java/com/longnh15/heimdall/data/repository/AuthRepositoryImpl.kt

@@ -0,0 +1,45 @@
+package com.longnh15.heimdall.data.repository
+
+import com.longnh15.heimdall.data.source.local.LocalDataSource
+import com.longnh15.heimdall.data.source.remote.ApiService
+import com.longnh15.heimdall.data.source.remote.dto.LoginRequest
+import com.longnh15.heimdall.data.source.remote.dto.RegisterRequest
+import com.longnh15.heimdall.domain.model.ApiResult
+import com.longnh15.heimdall.domain.model.AuthInfo
+import com.longnh15.heimdall.domain.repository.AuthRepository
+import kotlin.time.Instant
+
+class AuthRepositoryImpl(
+    private val api: ApiService,
+    private val localDataSource: LocalDataSource
+) : BaseRepository(), AuthRepository {
+    override suspend fun register(
+        email: String,
+        password: String,
+        name: String
+    ): ApiResult<String> {
+        val registerInfo = RegisterRequest(email, password, name)
+        return safeApiCall(
+            block = { api.register(registerInfo) },
+            transform = { it.userId }
+        )
+    }
+
+    override suspend fun login(
+        email: String,
+        password: String
+    ): ApiResult<AuthInfo> {
+        val loginInfo = LoginRequest(email, password)
+        return safeApiCall(
+            block = { api.login(loginInfo) },
+            transform = {
+                localDataSource.saveToken(it.token)
+                AuthInfo(
+                    it.userId,
+                    it.token,
+                    Instant.parse(it.expiresAt)
+                )
+            }
+        )
+    }
+}

app/src/main/java/com/longnh15/heimdall/data/repository/BaseRepository.kt

@@ -0,0 +1,36 @@
+package com.longnh15.heimdall.data.repository
+
+import com.longnh15.heimdall.data.source.remote.toApiError
+import com.longnh15.heimdall.domain.model.ApiResult
+import retrofit2.Response
+
+abstract class BaseRepository {
+    suspend fun <RemoteResponse> safeApiCall(
+        block: suspend () -> Response<RemoteResponse>
+    ): ApiResult<RemoteResponse> {
+        val response = block()
+
+        return if (response.isSuccessful) {
+            response.body()?.let {
+                ApiResult.Success(it)
+            } ?: ApiResult.Error(-999, "Empty response body")
+        } else {
+            response.errorBody().toApiError()
+        }
+    }
+
+    suspend fun <RemoteResponse, Expected> safeApiCall(
+        block: suspend () -> Response<RemoteResponse>,
+        transform: suspend (RemoteResponse) -> Expected
+    ): ApiResult<Expected> {
+        val response = block()
+
+        return if (response.isSuccessful) {
+            response.body()?.let {
+                ApiResult.Success(transform(it))
+            } ?: ApiResult.Error(-999, "Empty response body")
+        } else {
+            response.errorBody().toApiError()
+        }
+    }
+}

app/src/main/java/com/longnh15/heimdall/data/source/local/LocalDataSource.kt

@@ -1,14 +1,30 @@
 package com.longnh15.heimdall.data.source.local
 
+import android.content.Context
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import com.longnh15.heimdall.common.TokenCrypto
 import com.longnh15.heimdall.data.source.local.entity.toDomain
 import com.longnh15.heimdall.data.source.local.entity.toEntity
 import com.longnh15.heimdall.domain.model.Credential
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.map
 
+private val Context.dataStore by preferencesDataStore("terces")
+
 class LocalDataSource(
-    private val credentialDao: CredentialDao
+    private val credentialDao: CredentialDao,
+    private val appContext: Context
 ) {
+    private object Keys {
+        val TOKEN = stringPreferencesKey("token")
+    }
+
+    @Volatile
+    private var cachedToken: String? = null
+
     fun getAllCredentials(): Flow<List<Credential>> {
         return credentialDao.getAll().map { entities -> entities.map { it.toDomain() } }
     }
@@ -16,4 +32,22 @@ class LocalDataSource(
     suspend fun save(credential: Credential) {
         credentialDao.insert(credential.toEntity())
     }
+
+    suspend fun saveToken(token: String) {
+        cachedToken = token
+        appContext.dataStore.edit { it[Keys.TOKEN] = TokenCrypto.encrypt(token) }  // encrypt with a Keystore key
+    }
+
+    val token: Flow<String?> = appContext.dataStore.data
+        .map { it[Keys.TOKEN]?.let(TokenCrypto::decrypt) }
+
+    suspend fun getToken(): String? {
+        cachedToken?.let { return it }
+        return token.first().also { cachedToken = it }
+    }
+
+    suspend fun clearToken() {
+        cachedToken = null
+        appContext.dataStore.edit { it.remove(Keys.TOKEN) }
+    }
 }

app/src/main/java/com/longnh15/heimdall/data/source/remote/ApiService.kt

@@ -0,0 +1,17 @@
+package com.longnh15.heimdall.data.source.remote
+
+import com.longnh15.heimdall.data.source.remote.dto.LoginRequest
+import com.longnh15.heimdall.data.source.remote.dto.LoginResponse
+import com.longnh15.heimdall.data.source.remote.dto.RegisterRequest
+import com.longnh15.heimdall.data.source.remote.dto.RegisterResponse
+import retrofit2.Response
+import retrofit2.http.Body
+import retrofit2.http.POST
+
+interface ApiService {
+    @POST("/api/auth/register")
+    suspend fun register(@Body registerInfo: RegisterRequest): Response<RegisterResponse>
+
+    @POST("/api/app/login")
+    suspend fun login(@Body loginInfo: LoginRequest): Response<LoginResponse>
+}

app/src/main/java/com/longnh15/heimdall/data/source/remote/ErrorBodyParser.kt

@@ -0,0 +1,18 @@
+package com.longnh15.heimdall.data.source.remote
+
+import com.longnh15.heimdall.common.GlobalConfig.json
+import com.longnh15.heimdall.data.source.remote.dto.ErrorResponse
+import com.longnh15.heimdall.domain.model.ApiResult
+import okhttp3.ResponseBody
+
+fun  ResponseBody?.toApiError(): ApiResult.Error {
+    if (this == null) {
+        return ApiResult.Error(-999, "Unknown error")
+    }
+    return try {
+        val error = json.decodeFromString<ErrorResponse>(string())
+        ApiResult.Error(error.error, error.message)
+    } catch (_: Exception) {
+        ApiResult.Error(-999, "Unknown error")
+    }
+}

app/src/main/java/com/longnh15/heimdall/data/source/remote/dto/ErrorResponse.kt

@@ -0,0 +1,9 @@
+package com.longnh15.heimdall.data.source.remote.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class ErrorResponse(
+    val error: Int,
+    val message: String
+)

app/src/main/java/com/longnh15/heimdall/data/source/remote/dto/LoginRequest.kt

@@ -0,0 +1,9 @@
+package com.longnh15.heimdall.data.source.remote.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class LoginRequest(
+    val email: String,
+    val password: String
+)

app/src/main/java/com/longnh15/heimdall/data/source/remote/dto/LoginResponse.kt

@@ -0,0 +1,10 @@
+package com.longnh15.heimdall.data.source.remote.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class LoginResponse(
+    val token: String,
+    val userId: String,
+    val expiresAt: String,
+)

app/src/main/java/com/longnh15/heimdall/data/source/remote/dto/RegisterRequest.kt

@@ -0,0 +1,10 @@
+package com.longnh15.heimdall.data.source.remote.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class RegisterRequest(
+    val email: String,
+    val password: String,
+    val name: String
+)

app/src/main/java/com/longnh15/heimdall/data/source/remote/dto/RegisterResponse.kt

@@ -0,0 +1,9 @@
+package com.longnh15.heimdall.data.source.remote.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class RegisterResponse(
+    val ok: Boolean,
+    val userId: String
+)

app/src/main/java/com/longnh15/heimdall/di/AppModule.kt

@@ -2,16 +2,17 @@ package com.longnh15.heimdall.di
 
 import com.longnh15.heimdall.MainViewModel
 import com.longnh15.heimdall.data.preferences.PreferenceDataSource
+import com.longnh15.heimdall.data.repository.AuthRepositoryImpl
 import com.longnh15.heimdall.data.repository.CredentialRepositoryImpl
-import com.longnh15.heimdall.data.source.local.LocalDataSource
 import com.longnh15.heimdall.data.vault.VaultSessionManagerImpl
+import com.longnh15.heimdall.domain.repository.AuthRepository
 import com.longnh15.heimdall.domain.repository.CredentialRepository
 import com.longnh15.heimdall.domain.vault.VaultSessionManager
+import com.longnh15.heimdall.ui.auth.login.LoginViewModel
 import com.longnh15.heimdall.ui.onboarding.OnboardingViewModel
+import com.longnh15.heimdall.ui.auth.register.RegisterViewModel
 import com.longnh15.heimdall.ui.vault.VaultViewModel
 import com.longnh15.heimdall.ui.vault.edit.AddEditVaultViewModel
-import org.koin.core.annotation.Module
-import org.koin.core.annotation.Single
 import org.koin.dsl.bind
 import org.koin.dsl.module
 import org.koin.plugin.module.dsl.single
@@ -31,10 +32,13 @@ import org.koin.plugin.module.dsl.viewModel
 val appModule = module {
     single<VaultSessionManagerImpl>() bind VaultSessionManager::class
     single<CredentialRepositoryImpl>() bind CredentialRepository::class
+    single<AuthRepositoryImpl>() bind AuthRepository::class
     single<PreferenceDataSource>()
 
     viewModel<MainViewModel>()
     viewModel<OnboardingViewModel>()
     viewModel<VaultViewModel>()
     viewModel<AddEditVaultViewModel>()
+    viewModel<LoginViewModel>()
+    viewModel<RegisterViewModel>()
 }

app/src/main/java/com/longnh15/heimdall/di/DatabaseModule.kt

@@ -24,7 +24,7 @@ class DatabaseModule {
     }
 
     @Single
-    fun provideLocalDataSource(credentialDao: CredentialDao): LocalDataSource {
+    fun provideLocalDataSource(credentialDao: CredentialDao, context: Context): LocalDataSource {
-        return LocalDataSource(credentialDao)
+        return LocalDataSource(credentialDao, context)
     }
 }

app/src/main/java/com/longnh15/heimdall/di/NetworkModule.kt

@@ -0,0 +1,27 @@
+package com.longnh15.heimdall.di
+
+import com.longnh15.heimdall.common.GlobalConfig.json
+import com.longnh15.heimdall.data.source.remote.ApiService
+import okhttp3.MediaType.Companion.toMediaType
+import org.koin.core.annotation.Module
+import org.koin.core.annotation.Single
+import retrofit2.Retrofit
+import retrofit2.converter.kotlinx.serialization.asConverterFactory
+import retrofit2.create
+
+@Module
+class NetworkModule {
+    private companion object {
+        const val BASE_URL = "https://heimdall.lol"
+    }
+    @Single
+    fun provideRetrofit() = Retrofit.Builder()
+        .addConverterFactory(
+            json.asConverterFactory("application/json".toMediaType())
+        )
+        .baseUrl(BASE_URL)
+        .build()
+
+    @Single
+    fun provideApiService(retrofit: Retrofit): ApiService = retrofit.create<ApiService>()
+}

app/src/main/java/com/longnh15/heimdall/domain/model/ApiResult.kt

@@ -0,0 +1,6 @@
+package com.longnh15.heimdall.domain.model
+
+sealed class ApiResult<out T> {
+    data class Success<T>(val data: T): ApiResult<T>()
+    data class Error(val code: Int, val message: String): ApiResult<Nothing>()
+}

app/src/main/java/com/longnh15/heimdall/domain/model/AuthInfo.kt

@@ -0,0 +1,9 @@
+package com.longnh15.heimdall.domain.model
+
+import kotlin.time.Instant
+
+data class AuthInfo(
+    val token: String,
+    val userId: String,
+    val expiresAt: Instant
+)

app/src/main/java/com/longnh15/heimdall/domain/repository/AuthRepository.kt

@@ -0,0 +1,9 @@
+package com.longnh15.heimdall.domain.repository
+
+import com.longnh15.heimdall.domain.model.ApiResult
+import com.longnh15.heimdall.domain.model.AuthInfo
+
+interface AuthRepository {
+    suspend fun register(email: String, password: String, name: String): ApiResult<String>
+    suspend fun login(email: String, password: String): ApiResult<AuthInfo>
+}

app/src/main/java/com/longnh15/heimdall/domain/vault/VaultSessionManager.kt

@@ -1,7 +1,6 @@
 package com.longnh15.heimdall.domain.vault
 
 import kotlinx.coroutines.flow.StateFlow
-import org.koin.core.annotation.Singleton
 
 interface VaultSessionManager {
     val sessionState: StateFlow<VaultSessionState>

app/src/main/java/com/longnh15/heimdall/navigation/HeimdallNavGraph.kt

@@ -6,8 +6,12 @@ import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
+import com.longnh15.heimdall.ui.auth.login.LoginScreen
+import com.longnh15.heimdall.ui.auth.login.LoginViewModel
 import com.longnh15.heimdall.ui.onboarding.OnboardingPage
 import com.longnh15.heimdall.ui.onboarding.OnboardingViewModel
+import com.longnh15.heimdall.ui.auth.register.RegisterScreen
+import com.longnh15.heimdall.ui.auth.register.RegisterViewModel
 import com.longnh15.heimdall.ui.vault.VaultScreen
 import com.longnh15.heimdall.ui.vault.VaultViewModel
 import com.longnh15.heimdall.ui.vault.edit.AddEditVaultItemScreen
@@ -18,7 +22,7 @@ import org.koin.compose.viewmodel.koinViewModel
 fun HeimdallNavGraph(
     modifier: Modifier = Modifier,
     navController: NavHostController = rememberNavController(),
-    startDestination: Screen = Screen.Onboarding,
+    startDestination: Screen = Screen.Login,
     isAutofillServiceEnabled: () -> Boolean,
     onCompleteOnboarding: () -> Unit,
 ) {
@@ -27,6 +31,27 @@ fun HeimdallNavGraph(
         startDestination = startDestination,
         modifier = modifier
     ) {
+        composable<Screen.Login> {
+            LoginScreen(
+                viewModel = koinViewModel<LoginViewModel>(),
+                navigateToVault = {
+                    navController.navigate(Screen.Vault) {
+                        popUpTo(Screen.Login) { inclusive = true }
+                    }
+                },
+                navigateToRegister = {
+                    navController.navigate(Screen.Register)
+                }
+            )
+        }
+        composable<Screen.Register> {
+            RegisterScreen(
+                viewModel = koinViewModel<RegisterViewModel>(),
+                navigateToLogin = {
+                    navController.popBackStack()
+                }
+            )
+        }
         composable<Screen.Onboarding> {
             OnboardingPage(
                 viewModel = koinViewModel<OnboardingViewModel>(),

app/src/main/java/com/longnh15/heimdall/navigation/Screen.kt

@@ -4,6 +4,10 @@ import kotlinx.serialization.Serializable
 
 @Serializable
 sealed class Screen {
+    @Serializable
+    data object Login: Screen()
+    @Serializable
+    data object Register: Screen()
     @Serializable
     data object Onboarding: Screen()
     @Serializable

app/src/main/java/com/longnh15/heimdall/ui/auth/login/AuthForm.kt

@@ -0,0 +1,210 @@
+package com.longnh15.heimdall.ui.auth.login
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.RowScope
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.BasicTextField
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Visibility
+import androidx.compose.material.icons.outlined.VisibilityOff
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.LocalContentColor
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.focus.focusProperties
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.PasswordVisualTransformation
+import androidx.compose.ui.text.input.VisualTransformation
+import androidx.compose.ui.tooling.preview.AndroidUiModes.UI_MODE_NIGHT_NO
+import androidx.compose.ui.tooling.preview.AndroidUiModes.UI_MODE_NIGHT_YES
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import com.longnh15.heimdall.ui.theme.HeimdallTheme
+
+@Composable
+fun AuthForm(
+    modifier: Modifier = Modifier,
+    content: @Composable ColumnScope.() -> Unit
+) {
+    Column(
+        modifier = modifier
+            .fillMaxWidth()
+            .clip(RoundedCornerShape(12.dp))
+            .background(MaterialTheme.colorScheme.onPrimary)
+            .border(0.5.dp, MaterialTheme.colorScheme.outline, RoundedCornerShape(12.dp)),
+        content = content
+    )
+}
+
+@Composable
+fun AuthFormTextField(
+    value: String,
+    onValueChange: (String) -> Unit,
+    label: String,
+    placeholder: String,
+    error: String? = null,
+    isHideContent: Boolean = false,
+    isLastField: Boolean = false,
+    autoCorrectEnabled: Boolean = true,
+    keyboardType: KeyboardType = KeyboardType.Unspecified,
+    actions: @Composable RowScope.() -> Unit = {},
+) {
+    Column {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 12.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Text(
+                text = label.uppercase(),
+                modifier = Modifier.width(100.dp).padding(vertical = 12.dp),
+                color = MaterialTheme.colorScheme.primary,
+                fontSize = 13.sp,
+                fontWeight = FontWeight.Bold
+            )
+            BasicTextField(
+                value = value,
+                onValueChange = onValueChange,
+                modifier = Modifier.weight(1f),
+                textStyle = TextStyle(
+                    color = MaterialTheme.colorScheme.onSurface,
+                    fontSize = 16.sp
+                ),
+                keyboardOptions = if (isLastField)
+                    KeyboardOptions.Default.copy(
+                        autoCorrectEnabled = autoCorrectEnabled,
+                        keyboardType = keyboardType,
+                        imeAction = ImeAction.Done
+                    )
+                else
+                    KeyboardOptions.Default.copy(
+                        autoCorrectEnabled = autoCorrectEnabled,
+                        keyboardType = keyboardType,
+                        imeAction = ImeAction.Next
+                    ),
+                singleLine = true,
+                visualTransformation = if (isHideContent) PasswordVisualTransformation() else VisualTransformation.None,
+                decorationBox = { innerTextField ->
+                    if (value.isEmpty()) {
+                        Text(
+                            text = placeholder,
+                            fontSize = 16.sp,
+                            color = MaterialTheme.colorScheme.surfaceVariant
+                        )
+                    }
+                    innerTextField()
+                }
+            )
+            CompositionLocalProvider(LocalContentColor provides MaterialTheme.colorScheme.primary) {
+                actions()
+            }
+        }
+        if (error != null) {
+            Text(
+                text = error,
+                modifier = Modifier.padding(horizontal = 12.dp, vertical = 4.dp),
+                color = MaterialTheme.colorScheme.error,
+                fontSize = 12.sp
+            )
+        }
+    }
+}
+
+@Composable
+fun AuthDivider() {
+    HorizontalDivider(
+        modifier = Modifier.padding(horizontal = 12.dp),
+        thickness = 0.5.dp,
+        color = MaterialTheme.colorScheme.outline
+    )
+}
+
+@Preview(uiMode = UI_MODE_NIGHT_NO)
+@Composable
+fun AuthFormPreviewLight() {
+    HeimdallTheme {
+        AuthForm {
+            AuthFormTextField(
+                value = "",
+                onValueChange = {},
+                label = "Name",
+                placeholder = "e.g. Google"
+            )
+            AuthDivider()
+            AuthFormTextField(
+                value = "abc",
+                onValueChange = {},
+                label = "Password",
+                placeholder = "••••••••",
+                isHideContent = true,
+                autoCorrectEnabled = false,
+                actions = {
+                    IconButton(
+                        onClick = {},
+                        modifier = Modifier.focusProperties { canFocus = false }
+                    ) {
+                        Icon(
+                            imageVector = Icons.Outlined.Visibility,
+                            null
+                        )
+                    }
+                }
+            )
+        }
+    }
+}
+
+@Preview(uiMode = UI_MODE_NIGHT_YES)
+@Composable
+fun AuthFormPreviewDark() {
+    HeimdallTheme {
+        AuthForm {
+            AuthFormTextField(
+                value = "",
+                onValueChange = {},
+                label = "Name",
+                placeholder = "e.g. Google"
+            )
+            AuthDivider()
+            AuthFormTextField(
+                value = "abc",
+                onValueChange = {},
+                label = "Password",
+                placeholder = "••••••••",
+                isHideContent = true,
+                autoCorrectEnabled = false,
+                actions = {
+                    IconButton(
+                        onClick = {},
+                        modifier = Modifier.focusProperties { canFocus = false }
+                    ) {
+                        Icon(
+                            imageVector = Icons.Outlined.VisibilityOff,
+                            null
+                        )
+                    }
+                }
+            )
+        }
+    }
+}

app/src/main/java/com/longnh15/heimdall/ui/auth/login/LoginEvent.kt

@@ -0,0 +1,6 @@
+package com.longnh15.heimdall.ui.auth.login
+
+sealed class LoginEvent {
+    data object LoginSuccess: LoginEvent()
+    data class LoginError(val message: String): LoginEvent()
+}

app/src/main/java/com/longnh15/heimdall/ui/auth/login/LoginScreen.kt

@@ -0,0 +1,226 @@
+package com.longnh15.heimdall.ui.auth.login
+
+import android.content.res.Configuration.UI_MODE_NIGHT_YES
+import androidx.compose.foundation.background
+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.imePadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.widthIn
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Lock
+import androidx.compose.material.icons.outlined.Visibility
+import androidx.compose.material.icons.outlined.VisibilityOff
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.focus.focusProperties
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.viewmodel.compose.viewModel
+import com.longnh15.heimdall.ui.theme.HeimdallTheme
+
+@Composable
+fun LoginScreen(
+    modifier: Modifier = Modifier,
+    viewModel: LoginViewModel = viewModel(),
+    navigateToVault: () -> Unit,
+    navigateToRegister: () -> Unit,
+) {
+    val snackbarHostState = remember { SnackbarHostState() }
+    val state = viewModel.state
+
+    LaunchedEffect(Unit) {
+        viewModel.uiEvent.collect { event ->
+            when (event) {
+                is LoginEvent.LoginSuccess -> navigateToVault()
+                is LoginEvent.LoginError -> snackbarHostState.showSnackbar(event.message)
+            }
+        }
+    }
+
+    HeimdallTheme {
+        Scaffold(
+            modifier = Modifier.fillMaxSize(),
+            containerColor = MaterialTheme.colorScheme.background,
+            snackbarHost = {
+                SnackbarHost(snackbarHostState)
+            }
+        ) { paddingValues ->
+            Column(
+                modifier = modifier
+                    .padding(paddingValues)
+                    .fillMaxSize()
+                    .verticalScroll(rememberScrollState())
+                    .imePadding()
+                    .padding(horizontal = 24.dp, vertical = 40.dp),
+                horizontalAlignment = Alignment.CenterHorizontally
+            ) {
+                BrandBadge()
+
+                Spacer(Modifier.height(24.dp))
+
+                Text(
+                    text = "Welcome back",
+                    style = MaterialTheme.typography.headlineLarge,
+                    color = MaterialTheme.colorScheme.onBackground
+                )
+
+                Spacer(Modifier.height(8.dp))
+
+                Text(
+                    text = "Access your secure vault credentials",
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    textAlign = TextAlign.Center
+                )
+
+                Spacer(Modifier.height(36.dp))
+
+                AuthForm(modifier = Modifier.widthIn(max = 480.dp)) {
+                    AuthFormTextField(
+                        value = state.email,
+                        onValueChange = viewModel::onEmailChanged,
+                        label = "Email",
+                        placeholder = "you@email.com",
+                        error = state.emailError,
+                        keyboardType = KeyboardType.Email
+                    )
+                    AuthDivider()
+                    AuthFormTextField(
+                        value = state.password,
+                        onValueChange = viewModel::onPasswordChanged,
+                        label = "Password",
+                        placeholder = "••••••••",
+                        error = state.passwordError,
+                        isHideContent = !state.isShowPassword,
+                        autoCorrectEnabled = false,
+                        isLastField = true,
+                        keyboardType = KeyboardType.Password,
+                        actions = {
+                            IconButton(
+                                onClick = viewModel::toggleShowPassword,
+                                modifier = Modifier.focusProperties { canFocus = false }
+                            ) {
+                                Icon(
+                                    imageVector = if (state.isShowPassword) Icons.Outlined.VisibilityOff else Icons.Outlined.Visibility,
+                                    null
+                                )
+                            }
+                        }
+                    )
+                }
+
+                TextButton(
+                    onClick = {},
+                    modifier = Modifier
+                        .align(Alignment.End)
+                        .widthIn(max = 480.dp)
+                ) {
+                    Text("Forgot password?")
+                }
+
+                Spacer(Modifier.height(8.dp))
+
+                Button(
+                    onClick = viewModel::onLoginPressed,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .widthIn(max = 480.dp)
+                        .height(52.dp),
+                    shape = RoundedCornerShape(14.dp),
+                    colors = ButtonDefaults.buttonColors(
+                        containerColor = MaterialTheme.colorScheme.primary,
+                        contentColor = MaterialTheme.colorScheme.onPrimary
+                    )
+                ) {
+                    Text(
+                        text = "Login",
+                        style = MaterialTheme.typography.titleMedium
+                    )
+                }
+
+                Spacer(Modifier.height(28.dp))
+
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.Center
+                ) {
+                    Text(
+                        text = "Don't have an account?",
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                    TextButton(onClick = navigateToRegister) {
+                        Text(
+                            text = "Create one",
+                            fontWeight = FontWeight.SemiBold
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun BrandBadge() {
+    Box(
+        modifier = Modifier
+            .size(72.dp)
+            .clip(RoundedCornerShape(22.dp))
+            .background(MaterialTheme.colorScheme.primaryContainer),
+        contentAlignment = Alignment.Center
+    ) {
+        Icon(
+            imageVector = Icons.Outlined.Lock,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.primary,
+            modifier = Modifier.size(36.dp)
+        )
+    }
+}
+
+@Preview
+@Composable
+fun LoginScreenPreviewLight() {
+    LoginScreen(
+        navigateToVault = {},
+        navigateToRegister = {}
+    )
+}
+
+@Preview(uiMode = UI_MODE_NIGHT_YES)
+@Composable
+fun LoginScreenPreviewDark() {
+    LoginScreen(
+        navigateToVault = {},
+        navigateToRegister = {}
+    )
+}

app/src/main/java/com/longnh15/heimdall/ui/auth/login/LoginState.kt

@@ -0,0 +1,11 @@
+package com.longnh15.heimdall.ui.auth.login
+
+data class LoginState(
+    val email: String = "",
+    val password: String = "",
+
+    val emailError: String? = null,
+    val passwordError: String? = null,
+
+    val isShowPassword: Boolean = false,
+)

app/src/main/java/com/longnh15/heimdall/ui/auth/login/LoginViewModel.kt

@@ -0,0 +1,57 @@
+package com.longnh15.heimdall.ui.auth.login
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.longnh15.heimdall.common.ValidationHelper
+import com.longnh15.heimdall.domain.model.ApiResult
+import com.longnh15.heimdall.domain.repository.AuthRepository
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.launch
+
+class LoginViewModel(
+    private val authRepository: AuthRepository
+) : ViewModel() {
+    var state by mutableStateOf(LoginState())
+        private set
+    private val _uiEvent = Channel<LoginEvent>()
+    val uiEvent = _uiEvent.receiveAsFlow()
+
+    fun onEmailChanged(value: String) {
+        state = state.copy(email = value, emailError = null)
+    }
+
+    fun onPasswordChanged(value: String) {
+        state = state.copy(password = value, passwordError = null)
+    }
+
+    fun toggleShowPassword() {
+        state = state.copy(isShowPassword = !state.isShowPassword)
+    }
+
+    fun onLoginPressed() {
+        if (!validate()) return
+
+        viewModelScope.launch {
+            when (val result = authRepository.login(state.email, state.password)) {
+                is ApiResult.Success -> _uiEvent.send(LoginEvent.LoginSuccess)
+                is ApiResult.Error -> _uiEvent.send(LoginEvent.LoginError(result.message))
+            }
+        }
+    }
+
+    private fun validate(): Boolean {
+        val emailError = when {
+            state.email.isBlank() -> "Email is required"
+            !ValidationHelper.isEmail(state.email) -> "Enter a valid email address"
+            else -> null
+        }
+        val passwordError = if (state.password.isBlank()) "Password is required" else null
+
+        state = state.copy(emailError = emailError, passwordError = passwordError)
+        return emailError == null && passwordError == null
+    }
+}

app/src/main/java/com/longnh15/heimdall/ui/auth/register/RegisterEvent.kt

@@ -0,0 +1,6 @@
+package com.longnh15.heimdall.ui.auth.register
+
+sealed class RegisterEvent {
+    data object RegisterSuccess: RegisterEvent()
+    data class RegisterError(val message: String): RegisterEvent()
+}

app/src/main/java/com/longnh15/heimdall/ui/auth/register/RegisterScreen.kt

@@ -0,0 +1,212 @@
+package com.longnh15.heimdall.ui.auth.register
+
+import android.content.res.Configuration.UI_MODE_NIGHT_YES
+import androidx.compose.foundation.background
+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.imePadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.widthIn
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.PersonAddAlt1
+import androidx.compose.material.icons.outlined.Visibility
+import androidx.compose.material.icons.outlined.VisibilityOff
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.focus.focusProperties
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.viewmodel.compose.viewModel
+import com.longnh15.heimdall.ui.auth.login.AuthDivider
+import com.longnh15.heimdall.ui.auth.login.AuthForm
+import com.longnh15.heimdall.ui.auth.login.AuthFormTextField
+import com.longnh15.heimdall.ui.theme.HeimdallTheme
+
+@Composable
+fun RegisterScreen(
+    modifier: Modifier = Modifier,
+    viewModel: RegisterViewModel = viewModel(),
+    navigateToLogin: () -> Unit = {},
+) {
+    val state = viewModel.state
+
+    HeimdallTheme {
+        Scaffold(
+            modifier = Modifier.fillMaxSize(),
+            containerColor = MaterialTheme.colorScheme.background
+        ) { paddingValues ->
+            Column(
+                modifier = modifier
+                    .padding(paddingValues)
+                    .fillMaxSize()
+                    .verticalScroll(rememberScrollState())
+                    .imePadding()
+                    .padding(horizontal = 24.dp, vertical = 40.dp),
+                horizontalAlignment = Alignment.CenterHorizontally
+            ) {
+                BrandBadge()
+
+                Spacer(Modifier.height(24.dp))
+
+                Text(
+                    text = "Create account",
+                    style = MaterialTheme.typography.headlineLarge,
+                    color = MaterialTheme.colorScheme.onBackground
+                )
+
+                Spacer(Modifier.height(8.dp))
+
+                Text(
+                    text = "Secure your digital life with enterprise-grade encryption.",
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    textAlign = TextAlign.Center
+                )
+
+                Spacer(Modifier.height(36.dp))
+
+                AuthForm(modifier = Modifier.widthIn(max = 480.dp)) {
+                    AuthFormTextField(
+                        value = state.name,
+                        onValueChange = viewModel::onNameChanged,
+                        label = "Full name",
+                        placeholder = "John Doe",
+                        keyboardType = KeyboardType.Text
+                    )
+                    AuthDivider()
+                    AuthFormTextField(
+                        value = state.email,
+                        onValueChange = viewModel::onEmailChanged,
+                        label = "Email",
+                        placeholder = "name@vault.com",
+                        keyboardType = KeyboardType.Email,
+                    )
+                    AuthDivider()
+                    AuthFormTextField(
+                        value = state.password,
+                        onValueChange = viewModel::onPasswordChanged,
+                        label = "Password",
+                        placeholder = "••••••••",
+                        isHideContent = !state.isShowPassword,
+                        autoCorrectEnabled = false,
+                        isLastField = true,
+                        keyboardType = KeyboardType.Password,
+                        actions = {
+                            IconButton(
+                                onClick = viewModel::toggleShowPassword,
+                                modifier = Modifier.focusProperties { canFocus = false }
+                            ) {
+                                Icon(
+                                    imageVector = if (state.isShowPassword) Icons.Outlined.VisibilityOff else Icons.Outlined.Visibility,
+                                    null
+                                )
+                            }
+                        }
+                    )
+                }
+
+                Spacer(Modifier.height(24.dp))
+
+                Button(
+                    onClick = viewModel::onRegisterPressed,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .widthIn(max = 480.dp)
+                        .height(52.dp),
+                    shape = RoundedCornerShape(14.dp),
+                    colors = ButtonDefaults.buttonColors(
+                        containerColor = MaterialTheme.colorScheme.primary,
+                        contentColor = MaterialTheme.colorScheme.onPrimary
+                    )
+                ) {
+                    Text(
+                        text = "Create account",
+                        style = MaterialTheme.typography.titleMedium
+                    )
+                }
+
+                Spacer(Modifier.height(16.dp))
+
+                Text(
+                    text = "By creating an account you agree to our Terms of Service and Privacy Policy.",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    textAlign = TextAlign.Center,
+                    modifier = Modifier.widthIn(max = 480.dp)
+                )
+
+                Spacer(Modifier.height(28.dp))
+
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.Center
+                ) {
+                    Text(
+                        text = "Already have an account?",
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                    TextButton(onClick = navigateToLogin) {
+                        Text(
+                            text = "Sign in",
+                            fontWeight = FontWeight.SemiBold
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun BrandBadge() {
+    Box(
+        modifier = Modifier
+            .size(72.dp)
+            .clip(RoundedCornerShape(22.dp))
+            .background(MaterialTheme.colorScheme.primaryContainer),
+        contentAlignment = Alignment.Center
+    ) {
+        Icon(
+            imageVector = Icons.Outlined.PersonAddAlt1,
+            contentDescription = null,
+            tint = MaterialTheme.colorScheme.primary,
+            modifier = Modifier.size(36.dp)
+        )
+    }
+}
+
+@Preview
+@Composable
+fun RegisterScreenLightPreview() {
+    RegisterScreen()
+}
+
+@Preview(uiMode = UI_MODE_NIGHT_YES)
+@Composable
+fun RegisterScreenDarkPreview() {
+    RegisterScreen()
+}

app/src/main/java/com/longnh15/heimdall/ui/auth/register/RegisterState.kt

@@ -0,0 +1,12 @@
+package com.longnh15.heimdall.ui.auth.register
+
+data class RegisterState(
+    val name: String = "",
+    val email: String = "",
+    val password: String = "",
+
+    val emailError: String? = null,
+    val passwordError: String? = null,
+
+    val isShowPassword: Boolean = false
+)

app/src/main/java/com/longnh15/heimdall/ui/auth/register/RegisterViewModel.kt

@@ -0,0 +1,66 @@
+package com.longnh15.heimdall.ui.auth.register
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.longnh15.heimdall.common.ValidationHelper
+import com.longnh15.heimdall.domain.model.ApiResult
+import com.longnh15.heimdall.domain.repository.AuthRepository
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.launch
+
+class RegisterViewModel(
+    private val authRepository: AuthRepository
+) : ViewModel() {
+    var state by mutableStateOf(RegisterState())
+        private set
+    private val _uiEvent = Channel<RegisterEvent>()
+    val uiEvent = _uiEvent.receiveAsFlow()
+
+    fun onNameChanged(value: String) {
+        state = state.copy(name = value)
+    }
+
+    fun onEmailChanged(value: String) {
+        state = state.copy(email = value)
+    }
+
+    fun onPasswordChanged(value: String) {
+        state = state.copy(password = value)
+    }
+
+    fun toggleShowPassword() {
+        state = state.copy(isShowPassword = !state.isShowPassword)
+    }
+
+    fun onRegisterPressed() {
+        if (!validate()) return
+
+        viewModelScope.launch {
+            when (val result = authRepository.register(state.email, state.password, state.name)) {
+                is ApiResult.Success -> _uiEvent.send(RegisterEvent.RegisterSuccess)
+                is ApiResult.Error -> _uiEvent.send(RegisterEvent.RegisterError(result.message))
+            }
+        }
+    }
+
+    private fun validate(): Boolean {
+        val emailError = when {
+            state.email.isBlank() -> "Email is required"
+            !ValidationHelper.isEmail(state.email) -> "Enter a valid email address"
+            else -> null
+        }
+        val passwordError = when {
+            state.password.isBlank() -> "Password is required"
+            state.password.length < 12 -> "Password must be at least 12 characters"
+            else -> null
+        }
+
+        state = state.copy(emailError = emailError, passwordError = passwordError)
+        return emailError == null && passwordError == null
+    }
+
+}

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

@@ -2,4 +2,12 @@
 <resources>
 
     <style name="Theme.Heimdall" parent="android:Theme.Material.Light.NoActionBar" />
+
+    <!-- Splash screen shown during cold start, kept on screen until the first-launch
+         flag is resolved so the nav graph builds with the correct start destination. -->
+    <style name="Theme.Heimdall.Starting" parent="Theme.SplashScreen">
+        <item name="windowSplashScreenBackground">@color/white</item>
+        <item name="windowSplashScreenAnimatedIcon">@mipmap/ic_launcher</item>
+        <item name="postSplashScreenTheme">@style/Theme.Heimdall</item>
+    </style>
 </resources>

gradle/libs.versions.toml

@@ -14,9 +14,12 @@ koinKsp = "4.2.1"
 koinPlugin = "1.0.0"
 navigation = "2.9.8"
 serialization = "2.4.0"
+serializationJson = "1.11.0"
 datastore = "1.2.1"
 biometric = "1.4.0-alpha07"
 room = "2.8.4"
+retrofit = "3.0.0"
+splashscreen = "1.2.0"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -43,10 +46,14 @@ koin-compose-viewmodel-navigation = { group = "io.insert-koin", name = "koin-com
 koin-compose-viewmodel = { group = "io.insert-koin", name = "koin-compose-viewmodel", version.ref = "koin" }
 koin-annotations = { group = "io.insert-koin", name = "koin-annotations", version.ref = "koinKsp"}
 navigation-compose = { group = "androidx.navigation" , name = "navigation-compose", version.ref = "navigation" }
+androidx-core-splashscreen = { group = "androidx.core", name = "core-splashscreen", version.ref = "splashscreen" }
 biometric-compose = { group = "androidx.biometric", name = "biometric-compose", version.ref = "biometric" }
 androidx-room = { group = "androidx.room", name = "room-runtime", version.ref = "room" }
 androidx-room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }
 androidx-room-ktx = { group = "androidx.room", name = "room-ktx", version.ref = "room" }
+kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "serializationJson" }
+squareup-retrofit2 = { group = "com.squareup.retrofit2", name = "retrofit", version.ref = "retrofit" }
+squareup-retrofit2-kotlinx-serialization = { group = "com.squareup.retrofit2", name = "converter-kotlinx-serialization", version.ref = "retrofit" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
@@ -54,4 +61,5 @@ devtool-ksp = { id = "com.google.devtools.ksp", version.ref = "kspVersion" }
 kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
 serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "serialization" }
 koin-compiler = { id = "io.insert-koin.compiler.plugin", version.ref = "koinPlugin" }
+room = { id = "androidx.room", version.ref = "room" }