feat: Implement setup screen and login logic

- Add SetupScreen with UI for server URL, username, and password input.
- Make SetupScreen the initial screen in the navigation graph.
- Implement secure credential storage using EncryptedSharedPreferences.
- Create CredentialsRepository and AuthRepository to manage credentials and auth tokens.
- Add LoginUseCase to handle the business logic for logging in.
- Implement a temporary Retrofit client in ItemRepository to handle login against a user-provided URL.
- Integrate login logic into SetupViewModel.
- Update all relevant project documentation and DI modules.

app/build.gradle.kts

@@ -82,6 +82,9 @@ dependencies {
     // [DEPENDENCY] Logging
     implementation(Libs.timber)
 
+    // [DEPENDENCY] Security
+    implementation(Libs.securityCrypto)
+
     // [DEPENDENCY] Testing
     testImplementation(Libs.junit)
     androidTestImplementation(Libs.extJunit)

app/src/main/java/com/homebox/lens/navigation/NavGraph.kt

@@ -8,6 +8,13 @@ import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
 import com.homebox.lens.ui.screen.dashboard.DashboardScreen
+import com.homebox.lens.ui.screen.inventorylist.InventoryListScreen
+import com.homebox.lens.ui.screen.itemdetails.ItemDetailsScreen
+import com.homebox.lens.ui.screen.itemedit.ItemEditScreen
+import com.homebox.lens.ui.screen.labelslist.LabelsListScreen
+import com.homebox.lens.ui.screen.locationslist.LocationsListScreen
+import com.homebox.lens.ui.screen.search.SearchScreen
+import com.homebox.lens.ui.screen.setup.SetupScreen
 
 // [CORE-LOGIC]
 /**
@@ -19,12 +26,36 @@ fun NavGraph() {
     val navController = rememberNavController()
     NavHost(
         navController = navController,
-        startDestination = Screen.Dashboard.route
+        startDestination = Screen.Setup.route
     ) {
+        composable(route = Screen.Setup.route) {
+            SetupScreen(onSetupComplete = {
+                navController.navigate(Screen.Dashboard.route) {
+                    popUpTo(Screen.Setup.route) { inclusive = true }
+                }
+            })
+        }
         composable(route = Screen.Dashboard.route) {
             DashboardScreen()
         }
-        // TODO: Добавить остальные экраны в граф навигации
+        composable(route = Screen.InventoryList.route) {
+            InventoryListScreen()
+        }
+        composable(route = Screen.ItemDetails.route) {
+            ItemDetailsScreen()
+        }
+        composable(route = Screen.ItemEdit.route) {
+            ItemEditScreen()
+        }
+        composable(route = Screen.LabelsList.route) {
+            LabelsListScreen()
+        }
+        composable(route = Screen.LocationsList.route) {
+            LocationsListScreen()
+        }
+        composable(route = Screen.Search.route) {
+            SearchScreen()
+        }
     }
 }
 // [END_FILE_NavGraph.kt]

app/src/main/java/com/homebox/lens/navigation/Screen.kt

@@ -11,14 +11,17 @@ package com.homebox.lens.navigation
  * @property route Строковый идентификатор маршрута.
  */
 sealed class Screen(val route: String) {
-    /**
+    data object Setup : Screen("setup_screen")
-     * [CONTRACT]
-     * Представляет экран "Дэшборд".
-     */
     data object Dashboard : Screen("dashboard_screen")
-
+    data object InventoryList : Screen("inventory_list_screen")
-    // TODO: Добавить объекты для остальных экранов:
+    data object ItemDetails : Screen("item_details_screen/{itemId}") {
-    // data object ItemDetails : Screen("item_details_screen")
+        fun createRoute(itemId: String) = "item_details_screen/$itemId"
-    // data object Search : Screen("search_screen")
+    }
+    data object ItemEdit : Screen("item_edit_screen/{itemId}") {
+        fun createRoute(itemId: String) = "item_edit_screen/$itemId"
+    }
+    data object LabelsList : Screen("labels_list_screen")
+    data object LocationsList : Screen("locations_list_screen")
+    data object Search : Screen("search_screen")
 }
 // [END_FILE_Screen.kt]

app/src/main/java/com/homebox/lens/ui/screen/setup/SetupScreen.kt

@@ -0,0 +1,113 @@
+// [PACKAGE] com.homebox.lens.ui.screen.setup
+// [FILE] SetupScreen.kt
+
+package com.homebox.lens.ui.screen.setup
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.PasswordVisualTransformation
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+
+// [ENTRYPOINT]
+@Composable
+fun SetupScreen(
+    viewModel: SetupViewModel = hiltViewModel(),
+    onSetupComplete: () -> Unit
+) {
+    val uiState by viewModel.uiState.collectAsState()
+
+    if (uiState.isSetupComplete) {
+        onSetupComplete()
+    }
+
+    SetupScreenContent(
+        uiState = uiState,
+        onServerUrlChange = viewModel::onServerUrlChange,
+        onUsernameChange = viewModel::onUsernameChange,
+        onPasswordChange = viewModel::onPasswordChange,
+        onConnectClick = viewModel::connect
+    )
+}
+
+// [CONTENT]
+@Composable
+private fun SetupScreenContent(
+    uiState: SetupUiState,
+    onServerUrlChange: (String) -> Unit,
+    onUsernameChange: (String) -> Unit,
+    onPasswordChange: (String) -> Unit,
+    onConnectClick: () -> Unit
+) {
+    Scaffold(
+        topBar = {
+            TopAppBar(title = { Text("Server Setup") })
+        }
+    ) { paddingValues ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(paddingValues)
+                .padding(16.dp),
+            verticalArrangement = Arrangement.Center,
+            horizontalAlignment = Alignment.CenterHorizontally
+        ) {
+            OutlinedTextField(
+                value = uiState.serverUrl,
+                onValueChange = onServerUrlChange,
+                label = { Text("Server URL") },
+                modifier = Modifier.fillMaxWidth()
+            )
+            Spacer(modifier = Modifier.height(8.dp))
+            OutlinedTextField(
+                value = uiState.username,
+                onValueChange = onUsernameChange,
+                label = { Text("Username") },
+                modifier = Modifier.fillMaxWidth()
+            )
+            Spacer(modifier = Modifier.height(8.dp))
+            OutlinedTextField(
+                value = uiState.password,
+                onValueChange = onPasswordChange,
+                label = { Text("Password") },
+                visualTransformation = PasswordVisualTransformation(),
+                modifier = Modifier.fillMaxWidth()
+            )
+            Spacer(modifier = Modifier.height(16.dp))
+            Button(
+                onClick = onConnectClick,
+                enabled = !uiState.isLoading,
+                modifier = Modifier.fillMaxWidth()
+            ) {
+                if (uiState.isLoading) {
+                    CircularProgressIndicator(modifier = Modifier.size(24.dp))
+                } else {
+                    Text("Connect")
+                }
+            }
+            uiState.error?.let {
+                Spacer(modifier = Modifier.height(8.dp))
+                Text(text = it, color = MaterialTheme.colorScheme.error)
+            }
+        }
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+fun SetupScreenPreview() {
+    SetupScreenContent(
+        uiState = SetupUiState(error = "Failed to connect"),
+        onServerUrlChange = {},
+        onUsernameChange = {},
+        onPasswordChange = {},
+        onConnectClick = {}
+    )
+}
+// [END_FILE_SetupScreen.kt]

app/src/main/java/com/homebox/lens/ui/screen/setup/SetupUiState.kt

@@ -0,0 +1,15 @@
+// [PACKAGE] com.homebox.lens.ui.screen.setup
+// [FILE] SetupUiState.kt
+
+package com.homebox.lens.ui.screen.setup
+
+// [STATE]
+data class SetupUiState(
+    val serverUrl: String = "",
+    val username: String = "",
+    val password: String = "",
+    val isLoading: Boolean = false,
+    val error: String? = null,
+    val isSetupComplete: Boolean = false
+)
+// [END_FILE_SetupUiState.kt]

app/src/main/java/com/homebox/lens/ui/screen/setup/SetupViewModel.kt

@@ -0,0 +1,88 @@
+// [PACKAGE] com.homebox.lens.ui.screen.setup
+// [FILE] SetupViewModel.kt
+
+package com.homebox.lens.ui.screen.setup
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.homebox.lens.domain.model.Credentials
+import com.homebox.lens.domain.model.Result
+import com.homebox.lens.domain.repository.CredentialsRepository
+import com.homebox.lens.domain.usecase.LoginUseCase
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+// [VIEWMODEL]
+@HiltViewModel
+class SetupViewModel @Inject constructor(
+    private val credentialsRepository: CredentialsRepository,
+    private val loginUseCase: LoginUseCase
+) : ViewModel() {
+
+    // [STATE]
+    private val _uiState = MutableStateFlow(SetupUiState())
+    val uiState = _uiState.asStateFlow()
+
+    init {
+        loadCredentials()
+    }
+
+    private fun loadCredentials() {
+        viewModelScope.launch {
+            credentialsRepository.getCredentials().collect { credentials ->
+                if (credentials != null) {
+                    _uiState.update {
+                        it.copy(
+                            serverUrl = credentials.serverUrl,
+                            username = credentials.username,
+                            password = credentials.password
+                        )
+                    }
+                }
+            }
+        }
+    }
+
+    // [ACTION]
+    fun onServerUrlChange(newUrl: String) {
+        _uiState.update { it.copy(serverUrl = newUrl) }
+    }
+
+    // [ACTION]
+    fun onUsernameChange(newUsername: String) {
+        _uiState.update { it.copy(username = newUsername) }
+    }
+
+    // [ACTION]
+    fun onPasswordChange(newPassword: String) {
+        _uiState.update { it.copy(password = newPassword) }
+    }
+
+    // [ACTION]
+    fun connect() {
+        viewModelScope.launch {
+            _uiState.update { it.copy(isLoading = true, error = null) }
+            val credentials = Credentials(
+                serverUrl = _uiState.value.serverUrl.trim(),
+                username = _uiState.value.username.trim(),
+                password = _uiState.value.password
+            )
+            
+            credentialsRepository.saveCredentials(credentials)
+            
+            when (val result = loginUseCase(credentials)) {
+                is Result.Success -> {
+                    _uiState.update { it.copy(isLoading = false, isSetupComplete = true) }
+                }
+                is Result.Error -> {
+                    _uiState.update { it.copy(isLoading = false, error = result.exception.message ?: "Login failed") }
+                }
+            }
+        }
+    }
+}
+// [END_FILE_SetupViewModel.kt]

buildSrc/src/main/java/Dependencies.kt

@@ -94,6 +94,9 @@ object Libs {
     const val composeUiTestJunit4 = "androidx.compose.ui:ui-test-junit4"
     const val composeUiTooling = "androidx.compose.ui:ui-tooling"
     const val composeUiTestManifest = "androidx.compose.ui:ui-test-manifest"
+
+    // Security
+    const val securityCrypto = "androidx.security:security-crypto:${Versions.securityCrypto}"
 }
 
 // [END_FILE_Dependencies.kt]

data/src/main/java/com/homebox/lens/data/api/HomeboxApiService.kt

@@ -10,7 +10,9 @@ import com.homebox.lens.data.api.dto.ItemSummaryDto
 import com.homebox.lens.data.api.dto.ItemUpdateDto
 import com.homebox.lens.data.api.dto.LabelOutDto
 import com.homebox.lens.data.api.dto.LocationOutCountDto
+import com.homebox.lens.data.api.dto.LoginFormDto
 import com.homebox.lens.data.api.dto.PaginationResultDto
+import com.homebox.lens.data.api.dto.TokenResponseDto
 import retrofit2.Response
 import retrofit2.http.Body
 import retrofit2.http.DELETE
@@ -27,6 +29,10 @@ import retrofit2.http.Query
  */
 interface HomeboxApiService {
 
+    // [ENDPOINT] Auth
+    @POST("v1/users/login")
+    suspend fun login(@Body loginForm: LoginFormDto): TokenResponseDto
+
     // [ENDPOINT] Items
     @GET("v1/items")
     suspend fun getItems(

data/src/main/java/com/homebox/lens/data/api/dto/LoginFormDto.kt

@@ -0,0 +1,15 @@
+// [PACKAGE] com.homebox.lens.data.api.dto
+// [FILE] LoginFormDto.kt
+
+package com.homebox.lens.data.api.dto
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class LoginFormDto(
+    @Json(name = "username") val username: String,
+    @Json(name = "password") val password: String,
+    @Json(name = "stayLoggedIn") val stayLoggedIn: Boolean = true
+)
+// [END_FILE_LoginFormDto.kt]

data/src/main/java/com/homebox/lens/data/api/dto/TokenResponseDto.kt

@@ -0,0 +1,15 @@
+// [PACKAGE] com.homebox.lens.data.api.dto
+// [FILE] TokenResponseDto.kt
+
+package com.homebox.lens.data.api.dto
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class TokenResponseDto(
+    @Json(name = "token") val token: String,
+    @Json(name = "attachmentToken") val attachmentToken: String,
+    @Json(name = "expiresAt") val expiresAt: String
+)
+// [END_FILE_TokenResponseDto.kt]

data/src/main/java/com/homebox/lens/data/di/ApiModule.kt

@@ -56,12 +56,19 @@ object ApiModule {
     // [PROVIDER]
     @Provides
     @Singleton
-    fun provideRetrofit(okHttpClient: OkHttpClient, moshi: Moshi): Retrofit {
+    fun provideMoshiConverterFactory(moshi: Moshi): MoshiConverterFactory {
+        return MoshiConverterFactory.create(moshi)
+    }
+
+    // [PROVIDER]
+    @Provides
+    @Singleton
+    fun provideRetrofit(okHttpClient: OkHttpClient, moshiConverterFactory: MoshiConverterFactory): Retrofit {
         // [ACTION] Build Retrofit instance
         return Retrofit.Builder()
             .baseUrl(BASE_URL)
             .client(okHttpClient)
-            .addConverterFactory(MoshiConverterFactory.create(moshi))
+            .addConverterFactory(moshiConverterFactory)
             .build()
     }
 

data/src/main/java/com/homebox/lens/data/di/RepositoryModule.kt

@@ -3,11 +3,13 @@
 
 package com.homebox.lens.data.di
 
-import com.homebox.lens.data.api.HomeboxApiService
+import com.homebox.lens.data.repository.AuthRepositoryImpl
-import com.homebox.lens.data.repository.ItemRepositoryImpl
+import com.homebox.lens.data.repository.CredentialsRepositoryImpl
+import com.homebox.lens.domain.repository.AuthRepository
+import com.homebox.lens.domain.repository.CredentialsRepository
 import com.homebox.lens.domain.repository.ItemRepository
+import dagger.Binds
 import dagger.Module
-import dagger.Provides
 import dagger.hilt.InstallIn
 import dagger.hilt.components.SingletonComponent
 import javax.inject.Singleton
@@ -15,18 +17,23 @@ import javax.inject.Singleton
 // [CONTRACT]
 /**
  * [MODULE: DaggerHilt('RepositoryModule')]
- * [PURPOSE] Предоставляет реализацию для интерфейса ItemRepository.
+ * [PURPOSE] Предоставляет реализации для интерфейсов репозиториев.
  */
 @Module
 @InstallIn(SingletonComponent::class)
-object RepositoryModule {
+abstract class RepositoryModule {
 
-    // [PROVIDER]
+    @Binds
-    @Provides
     @Singleton
-    fun provideItemRepository(apiService: HomeboxApiService): ItemRepository {
+    abstract fun bindItemRepository(itemRepositoryImpl: com.homebox.lens.data.repository.ItemRepositoryImpl): ItemRepository
-        return ItemRepositoryImpl(apiService)
+
-    }
+    @Binds
+    @Singleton
+    abstract fun bindCredentialsRepository(credentialsRepositoryImpl: CredentialsRepositoryImpl): CredentialsRepository
+
+    @Binds
+    @Singleton
+    abstract fun bindAuthRepository(authRepositoryImpl: AuthRepositoryImpl): AuthRepository
 }
 
 // [END_FILE_RepositoryModule.kt]

data/src/main/java/com/homebox/lens/data/di/StorageModule.kt

@@ -0,0 +1,37 @@
+// [PACKAGE] com.homebox.lens.data.di
+// [FILE] StorageModule.kt
+
+package com.homebox.lens.data.di
+
+import android.content.Context
+import android.content.SharedPreferences
+import androidx.security.crypto.EncryptedSharedPreferences
+import androidx.security.crypto.MasterKey
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object StorageModule {
+
+    @Provides
+    @Singleton
+    fun provideEncryptedSharedPreferences(@ApplicationContext context: Context): SharedPreferences {
+        val masterKey = MasterKey.Builder(context)
+            .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
+            .build()
+
+        return EncryptedSharedPreferences.create(
+            context,
+            "secret_shared_prefs",
+            masterKey,
+            EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+            EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+        )
+    }
+}
+// [END_FILE_StorageModule.kt]

data/src/main/java/com/homebox/lens/data/repository/AuthRepositoryImpl.kt

@@ -0,0 +1,30 @@
+// [PACKAGE] com.homebox.lens.data.repository
+// [FILE] AuthRepositoryImpl.kt
+
+package com.homebox.lens.data.repository
+
+import android.content.SharedPreferences
+import com.homebox.lens.domain.repository.AuthRepository
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import javax.inject.Inject
+
+class AuthRepositoryImpl @Inject constructor(
+    private val encryptedPrefs: SharedPreferences
+) : AuthRepository {
+
+    companion object {
+        private const val KEY_AUTH_TOKEN = "key_auth_token"
+    }
+
+    override suspend fun saveToken(token: String) {
+        encryptedPrefs.edit().putString(KEY_AUTH_TOKEN, token).apply()
+    }
+
+    override fun getToken(): Flow<String?> = flow {
+        emit(encryptedPrefs.getString(KEY_AUTH_TOKEN, null))
+    }.flowOn(Dispatchers.IO)
+}
+// [END_FILE_AuthRepositoryImpl.kt]

data/src/main/java/com/homebox/lens/data/repository/CredentialsRepositoryImpl.kt

@@ -0,0 +1,46 @@
+// [PACKAGE] com.homebox.lens.data.repository
+// [FILE] CredentialsRepositoryImpl.kt
+
+package com.homebox.lens.data.repository
+
+import android.content.SharedPreferences
+import com.homebox.lens.domain.model.Credentials
+import com.homebox.lens.domain.repository.CredentialsRepository
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import javax.inject.Inject
+
+// [REPOSITORY_IMPL]
+class CredentialsRepositoryImpl @Inject constructor(
+    private val encryptedPrefs: SharedPreferences
+) : CredentialsRepository {
+
+    companion object {
+        private const val KEY_SERVER_URL = "key_server_url"
+        private const val KEY_USERNAME = "key_username"
+        private const val KEY_PASSWORD = "key_password"
+    }
+
+    override suspend fun saveCredentials(credentials: Credentials) {
+        encryptedPrefs.edit()
+            .putString(KEY_SERVER_URL, credentials.serverUrl)
+            .putString(KEY_USERNAME, credentials.username)
+            .putString(KEY_PASSWORD, credentials.password)
+            .apply()
+    }
+
+    override fun getCredentials(): Flow<Credentials?> = flow {
+        val serverUrl = encryptedPrefs.getString(KEY_SERVER_URL, null)
+        val username = encryptedPrefs.getString(KEY_USERNAME, null)
+        val password = encryptedPrefs.getString(KEY_PASSWORD, null)
+
+        if (serverUrl != null && username != null && password != null) {
+            emit(Credentials(serverUrl, username, password))
+        } else {
+            emit(null)
+        }
+    }.flowOn(Dispatchers.IO)
+}
+// [END_FILE_CredentialsRepositoryImpl.kt]

data/src/main/java/com/homebox/lens/data/repository/ItemRepositoryImpl.kt

@@ -4,10 +4,15 @@
 package com.homebox.lens.data.repository
 // [IMPORTS]
 import com.homebox.lens.data.api.HomeboxApiService
+import com.homebox.lens.data.api.dto.LoginFormDto
 import com.homebox.lens.data.api.dto.toDomain
 import com.homebox.lens.data.api.dto.toDto
 import com.homebox.lens.domain.model.*
+import com.homebox.lens.domain.repository.AuthRepository
 import com.homebox.lens.domain.repository.ItemRepository
+import okhttp3.OkHttpClient
+import retrofit2.Retrofit
+import retrofit2.converter.moshi.MoshiConverterFactory
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -19,9 +24,29 @@ import javax.inject.Singleton
  */
 @Singleton
 class ItemRepositoryImpl @Inject constructor(
-    private val apiService: HomeboxApiService
+    private val apiService: HomeboxApiService,
+    private val authRepository: AuthRepository,
+    private val okHttpClient: OkHttpClient,
+    private val moshiConverterFactory: MoshiConverterFactory
 ) : ItemRepository {
 
+    override suspend fun login(credentials: Credentials): Result<Unit> {
+        return try {
+            val tempApiService = Retrofit.Builder()
+                .baseUrl(credentials.serverUrl)
+                .client(okHttpClient)
+                .addConverterFactory(moshiConverterFactory)
+                .build()
+                .create(HomeboxApiService::class.java)
+
+            val loginForm = LoginFormDto(credentials.username, credentials.password)
+            val tokenResponse = tempApiService.login(loginForm)
+            authRepository.saveToken(tokenResponse.token)
+            Result.Success(Unit)
+        } catch (e: Exception) {
+            Result.Error(e)
+        }
+    }
     /**
      * [CONTRACT] @see ItemRepository.createItem
      */

domain/src/main/java/com/homebox/lens/domain/model/Credentials.kt

@@ -0,0 +1,18 @@
+// [PACKAGE] com.homebox.lens.domain.model
+// [FILE] Credentials.kt
+
+package com.homebox.lens.domain.model
+
+/**
+ * [CONTRACT]
+ * Data class to hold server credentials.
+ * @property serverUrl The URL of the Homebox server.
+ * @property username The username for authentication.
+ * @property password The password for authentication.
+ */
+data class Credentials(
+    val serverUrl: String,
+    val username: String,
+    val password: String
+)
+// [END_FILE_Credentials.kt]

domain/src/main/java/com/homebox/lens/domain/repository/AuthRepository.kt

@@ -0,0 +1,27 @@
+// [PACKAGE] com.homebox.lens.domain.repository
+// [FILE] AuthRepository.kt
+
+package com.homebox.lens.domain.repository
+
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * [CONTRACT]
+ * Repository for managing authentication tokens.
+ */
+interface AuthRepository {
+    /**
+     * [CONTRACT]
+     * Saves the authentication token.
+     * @param token The token to save.
+     */
+    suspend fun saveToken(token: String)
+
+    /**
+     * [CONTRACT]
+     * Retrieves the authentication token.
+     * @return A Flow emitting the token, or null if not found.
+     */
+    fun getToken(): Flow<String?>
+}
+// [END_FILE_AuthRepository.kt]

domain/src/main/java/com/homebox/lens/domain/repository/CredentialsRepository.kt

@@ -0,0 +1,28 @@
+// [PACKAGE] com.homebox.lens.domain.repository
+// [FILE] CredentialsRepository.kt
+
+package com.homebox.lens.domain.repository
+
+import com.homebox.lens.domain.model.Credentials
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * [CONTRACT]
+ * Repository for managing user credentials.
+ */
+interface CredentialsRepository {
+    /**
+     * [CONTRACT]
+     * Saves the user credentials securely.
+     * @param credentials The credentials to save.
+     */
+    suspend fun saveCredentials(credentials: Credentials)
+
+    /**
+     * [CONTRACT]
+     * Retrieves the saved user credentials.
+     * @return A Flow emitting the saved [Credentials], or null if none are saved.
+     */
+    fun getCredentials(): Flow<Credentials?>
+}
+// [END_FILE_CredentialsRepository.kt]

domain/src/main/java/com/homebox/lens/domain/repository/ItemRepository.kt

@@ -12,6 +12,7 @@ import com.homebox.lens.domain.model.*
  * Определяет контракт, которому должен следовать слой данных.
  */
 interface ItemRepository {
+    suspend fun login(credentials: Credentials): Result<Unit>
     suspend fun createItem(newItemData: ItemCreate): ItemSummary
     suspend fun getItemDetails(itemId: String): ItemOut
     suspend fun updateItem(itemId: String, item: ItemUpdate): ItemOut

domain/src/main/java/com/homebox/lens/domain/usecase/LoginUseCase.kt

@@ -0,0 +1,29 @@
+// [PACKAGE] com.homebox.lens.domain.usecase
+// [FILE] LoginUseCase.kt
+
+package com.homebox.lens.domain.usecase
+
+import com.homebox.lens.domain.model.Credentials
+import com.homebox.lens.domain.repository.ItemRepository
+import javax.inject.Inject
+import com.homebox.lens.domain.model.Result
+
+/**
+ * [CONTRACT]
+ * Use case for user login.
+ * @param itemRepository The repository to handle item and auth operations.
+ */
+class LoginUseCase @Inject constructor(
+    private val itemRepository: ItemRepository
+) {
+    /**
+     * [CONTRACT]
+     * Executes the login process.
+     * @param credentials The user's credentials.
+     * @return A [Result] object indicating success or failure.
+     */
+    suspend operator fun invoke(credentials: Credentials): Result<Unit> {
+        return itemRepository.login(credentials)
+    }
+}
+// [END_FILE_LoginUseCase.kt]

tech_spec/project_structure.txt

@@ -59,6 +59,15 @@
         <file name="app/src/main/java/com/homebox/lens/ui/screen/search/SearchViewModel.kt" status="stub" spec_ref_id="screen_search">
             <purpose_summary>ViewModel for the Search screen.</purpose_summary>
         </file>
+        <file name="app/src/main/java/com/homebox/lens/ui/screen/setup/SetupScreen.kt" status="stub" spec_ref_id="screen_setup">
+            <purpose_summary>UI for the Setup screen.</purpose_summary>
+        </file>
+        <file name="app/src/main/java/com/homebox/lens/ui/screen/setup/SetupViewModel.kt" status="stub" spec_ref_id="screen_setup">
+            <purpose_summary>ViewModel for the Setup screen.</purpose_summary>
+        </file>
+        <file name="app/src/main/java/com/homebox/lens/ui/screen/setup/SetupUiState.kt" status="implemented" spec_ref_id="screen_setup">
+            <purpose_summary>UI state for the Setup screen.</purpose_summary>
+        </file>
     </module>
     <module name="data" type="android_library">
         <purpose_summary>Data layer, responsible for data sources (network, local DB) and repository implementations.</purpose_summary>
@@ -80,12 +89,33 @@
         <file name="data/src/main/java/com/homebox/lens/data/di/RepositoryModule.kt" status="implemented" ref_id="di_repo">
             <purpose_summary>Hilt module for binding repository interfaces to their implementations.</purpose_summary>
         </file>
+        <file name="data/src/main/java/com/homebox/lens/data/di/StorageModule.kt" status="implemented" ref_id="di_storage">
+            <purpose_summary>Hilt module for providing storage-related dependencies (EncryptedSharedPreferences).</purpose_summary>
+        </file>
+        <file name="data/src/main/java/com/homebox/lens/data/repository/CredentialsRepositoryImpl.kt" status="implemented" ref_id="repo_credentials_impl">
+            <purpose_summary>Implementation of the CredentialsRepository.</purpose_summary>
+        </file>
+        <file name="data/src/main/java/com/homebox/lens/data/repository/AuthRepositoryImpl.kt" status="implemented" ref_id="repo_auth_impl">
+            <purpose_summary>Implementation of the AuthRepository.</purpose_summary>
+        </file>
     </module>
     <module name="domain" type="kotlin_jvm_library">
         <purpose_summary>Domain layer, contains business logic, use cases, and repository interfaces. Pure Kotlin module.</purpose_summary>
+        <file name="domain/src/main/java/com/homebox/lens/domain/model/Credentials.kt" status="implemented" ref_id="model_credentials">
+            <purpose_summary>Data class for holding user credentials.</purpose_summary>
+        </file>
+        <file name="domain/src/main/java/com/homebox/lens/domain/repository/AuthRepository.kt" status="implemented" ref_id="repo_auth_interface">
+            <purpose_summary>Interface for the auth repository.</purpose_summary>
+        </file>
+        <file name="domain/src/main/java/com/homebox/lens/domain/repository/CredentialsRepository.kt" status="implemented" ref_id="repo_credentials_interface">
+            <purpose_summary>Interface for the credentials repository.</purpose_summary>
+        </file>
         <file name="domain/src/main/java/com/homebox/lens/domain/repository/ItemRepository.kt" status="implemented" ref_id="repo_interface">
             <purpose_summary>Interface defining the contract for data operations related to items.</purpose_summary>
         </file>
+        <file name="domain/src/main/java/com/homebox/lens/domain/usecase/LoginUseCase.kt" status="implemented" spec_ref_id="uc_login">
+            <purpose_summary>Use case for user login.</purpose_summary>
+        </file>
         <file name="domain/src/main/java/com/homebox/lens/domain/usecase/CreateItemUseCase.kt" status="implemented" spec_ref_id="uc_create_item">
             <purpose_summary>Use case for creating a new item.</purpose_summary>
         </file>

tech_spec/tech_spec.txt

@@ -117,6 +117,7 @@
         <USE_CASE id="uc_delete_item" file_ref="domain/src/main/java/com/homebox/lens/domain/usecase/DeleteItemUseCase.kt" />
         <USE_CASE id="uc_get_all_labels" file_ref="domain/src/main/java/com/homebox/lens/domain/usecase/GetAllLabelsUseCase.kt" />
         <USE_CASE id="uc_get_all_locations" file_ref="domain/src/main/java/com/homebox/lens/domain/usecase/GetAllLocationsUseCase.kt" />
+        <USE_CASE id="uc_login" file_ref="domain/src/main/java/com/homebox/lens/domain/usecase/LoginUseCase.kt" />
 
         <!-- UI Screens -->
         <UI_SCREEN id="screen_dashboard" file_ref="app/src/main/java/com/homebox/lens/ui/screen/dashboard/DashboardScreen.kt" />
@@ -126,5 +127,6 @@
         <UI_SCREEN id="screen_labels_list" file_ref="app/src/main/java/com/homebox/lens/ui/screen/labelslist/LabelsListScreen.kt" />
         <UI_SCREEN id="screen_locations_list" file_ref="app/src/main/java/com/homebox/lens/ui/screen/locationslist/LocationsListScreen.kt" />
         <UI_SCREEN id="screen_search" file_ref="app/src/main/java/com/homebox/lens/ui/screen/search/SearchScreen.kt" />
+        <UI_SCREEN id="screen_setup" file_ref="app/src/main/java/com/homebox/lens/ui/screen/setup/SetupScreen.kt" />
     </IMPLEMENTATION_MAP>
 </PROJECT_SPECIFICATION>