Improved UI and enhanced expense creation

Updated the UI across all screens (Login, Dashboard, Account Selection, Expense Details, and Creation) with a more modern, card-based design and improved layouts.

Expense creation now includes:
- Real-time split validation to ensure shares match the total amount.
- An "Equal Split" shortcut for quick allocation.
- Support for optional descriptions and multiple file attachments.
- Strict save validation.

The `MainActivity` now supports edge-to-edge display, and the `AccountDao` includes a new query to fetch accounts by ID. Added `material-icons-extended` dependency for enhanced iconography.

app/build.gradle.kts

@@ -61,6 +61,7 @@ dependencies {
 
     //Manually added
     implementation("androidx.datastore:datastore-preferences:1.2.0")
+    implementation("androidx.compose.material:material-icons-extended:1.6.0")
 
     val room_version = "2.8.4"
     implementation("androidx.room:room-runtime:$room_version")

app/src/main/java/de/miaurizius/shap_planner/activities/MainActivity.kt

@@ -4,28 +4,50 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.BackHandler
 import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import de.miaurizius.shap_planner.TokenStorage
 import de.miaurizius.shap_planner.UserPreferences
 import de.miaurizius.shap_planner.room.AppDatabase
 import de.miaurizius.shap_planner.ui.AppContent
 import de.miaurizius.shap_planner.ui.theme.ShapPlannerTheme
+import de.miaurizius.shap_planner.viewmodels.ExpenseCreationViewModel
+import de.miaurizius.shap_planner.viewmodels.ExpenseDetailViewModel
 import de.miaurizius.shap_planner.viewmodels.LoginViewModel
 import de.miaurizius.shap_planner.viewmodels.MainViewModel
 
 class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
+        enableEdgeToEdge()
         super.onCreate(savedInstanceState)
 
         val prefs = UserPreferences(this)
         val loginViewModel = LoginViewModel(prefs, applicationContext)
         val database = AppDatabase.getDatabase(applicationContext)
-        val dao = database.accountDao()
+        val accountDao = database.accountDao()
+        val expenseDao = database.expenseDao()
         val tokenStorage = TokenStorage(applicationContext)
-        val mainViewModel = MainViewModel(dao, tokenStorage)
+        val mainViewModel = MainViewModel(
+            accountDao,
+            expenseDao,
+            tokenStorage
+        )
+        val detailViewModel = ExpenseDetailViewModel(
+            database.expenseDao(),
+            database.expenseShareDao(),
+            database.userDao(),
+            tokenStorage
+        )
+        val creationViewModel = ExpenseCreationViewModel(
+            database.userDao(),
+            database.expenseDao(),
+            database.expenseShareDao(),
+            tokenStorage
+        )
 
 
         setContent {
@@ -33,7 +55,6 @@ class MainActivity : ComponentActivity() {
                 val accountList by mainViewModel.accounts.collectAsState()
                 val selectedAccount = mainViewModel.selectedAccount
                 val showLoginForNewAccount = remember { mutableStateOf(false) }
-                val expenses by mainViewModel.expenses.collectAsState()
 
                 BackHandler(enabled = showLoginForNewAccount.value && accountList.isNotEmpty()) {
                     showLoginForNewAccount.value = false
@@ -54,9 +75,10 @@ class MainActivity : ComponentActivity() {
                     sessionState = mainViewModel.sessionState,
                     onValidateSession = { mainViewModel.validateSession(selectedAccount!!) },
                     onSessionInvalid = { mainViewModel.logoutFromAccount() },
-                    expenses = expenses,
                     onExpenseClick = { expense -> println("Clicked: ${expense.title}") },
-                    viewModel = mainViewModel
+                    viewModel = mainViewModel,
+                    detailViewModel = detailViewModel,
+                    creationViewModel = creationViewModel,
                 )
             }
         }

app/src/main/java/de/miaurizius/shap_planner/entities/Account.kt

@@ -25,6 +25,9 @@ interface AccountDao {
     @Query("SELECT * FROM accounts")
     fun getAllAccounts(): Flow<List<Account>>
 
+    @Query("SELECT * FROM accounts WHERE id = :userId")
+    fun getAccountById(userId: UUID): Flow<Account?>
+
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     suspend fun insertAccount(account: Account)
 

app/src/main/java/de/miaurizius/shap_planner/entities/Expense.kt

@@ -5,21 +5,22 @@ import androidx.room.Delete
 import androidx.room.Entity
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
+import androidx.room.PrimaryKey
 import androidx.room.Query
 import kotlinx.coroutines.flow.Flow
 import java.util.UUID
 
 @Entity(tableName = "expenses")
 data class Expense (
-    val id: UUID,
+    @PrimaryKey val id: UUID,
     val payer_id: UUID,
     val amount: Int,
     val title: String,
     val description: String,
-    val attachments: List<String>,
+    val attachments: List<String>?,
     val created_at: Int,
     val last_updated_at: Int
-    )
+)
 
 @Dao
 interface ExpenseDao {

app/src/main/java/de/miaurizius/shap_planner/entities/ExpenseShare.kt

@@ -5,13 +5,14 @@ import androidx.room.Delete
 import androidx.room.Entity
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
+import androidx.room.PrimaryKey
 import androidx.room.Query
 import kotlinx.coroutines.flow.Flow
 import java.util.UUID
 
 @Entity(tableName = "expense_shares")
 data class ExpenseShare(
-    val id: UUID,
+    @PrimaryKey val id: UUID,
     val expense_id: UUID,
     val user_id: UUID,
     val share_cents: Int
@@ -23,7 +24,10 @@ interface ExpenseShareDao {
     fun getAllShares(): Flow<List<ExpenseShare>>
 
     @Query("SELECT * FROM expense_shares WHERE id = :shareId")
-    fun getShareById(shareId: UUID)
+    fun getShareById(shareId: UUID): Flow<ExpenseShare?>
+
+    @Query("SELECT * FROM expense_shares WHERE expense_id = :expense_id")
+    fun getSharesByExpense(expense_id: UUID): Flow<List<ExpenseShare>>
 
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     suspend fun insertShare(share: ExpenseShare)

app/src/main/java/de/miaurizius/shap_planner/entities/User.kt

@@ -5,13 +5,14 @@ import androidx.room.Delete
 import androidx.room.Entity
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
+import androidx.room.PrimaryKey
 import androidx.room.Query
 import kotlinx.coroutines.flow.Flow
 import java.util.UUID
 
 @Entity(tableName = "users")
 data class User (
-    val id: UUID,
+    @PrimaryKey val id: UUID,
     val name: String,
     val avatar_url: String?
 )
@@ -21,6 +22,9 @@ interface UserDao {
     @Query("SELECT * FROM users")
     fun getAllUsers(): Flow<List<User>>
 
+    @Query("SELECT * FROM users WHERE id = :userId")
+    fun getUserById(userId: UUID): Flow<User?>
+
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     suspend fun insertUser(user: User)
 

app/src/main/java/de/miaurizius/shap_planner/network/APIService.kt

@@ -1,5 +1,7 @@
 package de.miaurizius.shap_planner.network
 
+import com.google.gson.annotations.SerializedName
+import de.miaurizius.shap_planner.entities.User
 import retrofit2.Response
 import retrofit2.http.Body
 import retrofit2.http.DELETE
@@ -21,15 +23,32 @@ interface APIService {
 
     // Expenses
     @GET("api/expenses")
-    suspend fun expenseGet(@Header("Authorization") token: String): Response<ExpenseResponse>
+    suspend fun expensesGet(@Header("Authorization") token: String): Response<ExpensesResponse>
     @POST("api/expenses")
-    suspend fun expenseCreate(@Header("Authorization") token: String)
+    suspend fun expenseCreate(@Header("Authorization") token: String, @Body req: ExpenseCreationRequest): Response<ExpenseCreationResponse>
     @PUT("api/expenses")
     suspend fun expenseUpdate(@Header("Authorization") token: String)
     @DELETE("api/expenses")
     suspend fun expenseDelete(@Header("Authorization") token: String)
 
+    // Shares
+    @GET("api/shares")
+    suspend fun sharesGet(@Header("Authorization") token: String): Response<ExpenseSharesResponse>
+    @GET("api/shares")
+    suspend fun shareGet(@Header("Authorization") token: String, @Query("id") shareId: UUID): Response<ExpenseShareResponse>
+    @GET("api/shares")
+    suspend fun shareGet(@Header("Authorization") token: String, @Query("id") expenseId: UUID, @Query("idType") idType: IDType): Response<ExpenseSharesResponse>
+
     // User
     @GET("api/userinfo")
-    suspend fun userinfo(@Header("Authorization") token: String, @Query("id") userId: UUID)
+    suspend fun userinfo(@Header("Authorization") token: String, @Query("id") userId: UUID): Response<User>
+}
+
+enum class IDType {
+    @SerializedName("share")
+    Share,
+    @SerializedName("expense")
+    Expense,
+    @SerializedName("user")
+    User,
 }

app/src/main/java/de/miaurizius/shap_planner/network/ComDataTypes.kt

@@ -1,6 +1,7 @@
 package de.miaurizius.shap_planner.network
 
 import de.miaurizius.shap_planner.entities.Expense
+import de.miaurizius.shap_planner.entities.ExpenseShare
 
 // Login
 data class LoginRequest(val username: String, val password: String)
@@ -12,4 +13,10 @@ data class RefreshRequest(val refresh_token: String)
 data class RefreshResponse(val access_token: String, val refresh_token: String)
 
 // Expenses
-data class ExpenseResponse(val expenses: List<Expense>)
+data class ExpensesResponse(val expenses: List<Expense>)
+data class ExpenseCreationRequest(val expense: Expense, val shares: List<ExpenseShare>)
+data class ExpenseCreationResponse(val expense: Expense, val shares: List<ExpenseShare>)
+
+// ExpenseShares
+data class ExpenseSharesResponse(val shares: List<ExpenseShare>)
+data class ExpenseShareResponse(val share: ExpenseShare)

app/src/main/java/de/miaurizius/shap_planner/repository/ExpenseRepository.kt

@@ -0,0 +1,33 @@
+package de.miaurizius.shap_planner.repository
+
+import de.miaurizius.shap_planner.entities.Expense
+import de.miaurizius.shap_planner.entities.ExpenseDao
+import de.miaurizius.shap_planner.network.APIService
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flow
+
+class ExpenseRepository(
+    private val dao: ExpenseDao,
+    private val api: APIService
+) {
+    fun getExpenses(token: String, forceRefresh: Boolean = false): Flow<Resource<List<Expense>>> = flow {
+        val cachedExpense = dao.getAllExpenses().first()
+        emit(Resource.Loading(cachedExpense))
+
+        if(cachedExpense.isEmpty() || forceRefresh) {
+            try {
+                val response = api.expensesGet("Bearer $token")
+                if(response.isSuccessful) {
+                    val remoteExpense = response.body()?.expenses ?: emptyList()
+                    remoteExpense.forEach {
+                        dao.insertExpense(it)
+                    }
+                }
+            } catch(e: Exception) {
+                emit(Resource.Error("Network Error: ${e.localizedMessage}", cachedExpense))
+            }
+        }
+        dao.getAllExpenses().collect { emit(Resource.Success(it)) }
+    }
+}

app/src/main/java/de/miaurizius/shap_planner/repository/ExpenseShareRepository.kt

@@ -0,0 +1,72 @@
+package de.miaurizius.shap_planner.repository
+
+import de.miaurizius.shap_planner.entities.ExpenseShare
+import de.miaurizius.shap_planner.entities.ExpenseShareDao
+import de.miaurizius.shap_planner.network.APIService
+import de.miaurizius.shap_planner.network.IDType
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flow
+import java.util.UUID
+
+class ExpenseShareRepository(
+    private val dao: ExpenseShareDao,
+    private val api: APIService
+) {
+    fun getShares(token: String, forceRefresh: Boolean = false): Flow<Resource<List<ExpenseShare>>> = flow {
+        val cachedData = dao.getAllShares().first()
+        emit(Resource.Loading(cachedData))
+
+        if(cachedData.isEmpty() || forceRefresh) {
+            try {
+                val response = api.sharesGet("Bearer $token")
+                if(response.isSuccessful) {
+                    val remoteShare = response.body()?.shares ?: emptyList()
+                    remoteShare.forEach {
+                        dao.insertShare(it)
+                    }
+                }
+            } catch(e: Exception) {
+                emit(Resource.Error("Network Error: ${e.localizedMessage}", cachedData))
+            }
+        }
+        dao.getAllShares().collect { emit(Resource.Success(it)) }
+    }
+
+    fun getShareById(token: String, shareId: UUID, forceRefresh: Boolean = false): Flow<Resource<ExpenseShare>> = flow {
+        val cached = dao.getShareById(shareId).first()
+        emit(Resource.Loading(cached))
+        if(cached == null || forceRefresh) {
+            try {
+                val response = api.shareGet("Bearer $token", shareId)
+                if(response.isSuccessful) {
+                    response.body()?.share?.let { remoteShare -> dao.insertShare(remoteShare) }
+                }
+            } catch(e: Exception) {
+                emit(Resource.Error("Network-Error: ${e.localizedMessage}", cached))
+            }
+        }
+        dao.getShareById(shareId).collect { share ->
+            if(share != null) emit(Resource.Success(share))
+            else emit(Resource.Error("Share nicht gefunden", null))
+        }
+    }
+
+    fun getSharesByExpenseId(token: String, expenseId: UUID, forceRefresh: Boolean = false): Flow<Resource<List<ExpenseShare>>> = flow {
+        val cached = dao.getSharesByExpense(expenseId).first()
+        emit(Resource.Loading(cached))
+        if(cached.isEmpty() || forceRefresh) {
+            try {
+                val response = api.shareGet("Bearer $token", expenseId, IDType.Expense)
+                if(response.isSuccessful) {
+                    println("Body: ${response.body()}")
+                    val remoteShare = response.body()?.shares ?: emptyList()
+                    remoteShare.forEach { dao.insertShare(it) }
+                }
+            } catch(e: Exception) {
+                emit(Resource.Error("Network Error: ${e.localizedMessage}", cached))
+            }
+        }
+        dao.getSharesByExpense(expenseId).collect { emit(Resource.Success(it)) }
+    }
+}

app/src/main/java/de/miaurizius/shap_planner/repository/Resource.kt

@@ -0,0 +1,7 @@
+package de.miaurizius.shap_planner.repository
+
+sealed class Resource<T>(val data: T? = null, val message: String? = null) {
+    class Success<T>(data: T): Resource<T>(data)
+    class Loading<T>(data: T? = null): Resource<T>(data)
+    class Error<T>(message: String, data: T? = null): Resource<T>(data, message)
+}

app/src/main/java/de/miaurizius/shap_planner/repository/UserRepository.kt

@@ -0,0 +1,32 @@
+package de.miaurizius.shap_planner.repository
+
+import de.miaurizius.shap_planner.entities.User
+import de.miaurizius.shap_planner.entities.UserDao
+import de.miaurizius.shap_planner.network.APIService
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flow
+import java.util.UUID
+
+class UserRepository(
+    private val dao: UserDao,
+    private val api: APIService
+) {
+    fun getUser(token: String, userId: UUID, forceRefresh: Boolean = false): Flow<Resource<User>> = flow {
+        val cached = dao.getUserById(userId).first()
+        emit(Resource.Loading(cached))
+        if(cached == null || forceRefresh) {
+            try {
+                val response = api.userinfo("Bearer $token", userId)
+                if(response.isSuccessful) {
+                    println("Body: ${response.body()}")
+                    response.body()?.let { remoteUser -> dao.insertUser(remoteUser) }
+                }
+            } catch(e: Exception) {
+                emit(Resource.Error("Network-Error: ${e.localizedMessage}", cached))
+            }
+        }
+        dao.getUserById(userId).collect { user -> if(user != null) emit(Resource.Success(user)) else emit(
+            Resource.Error("User nicht gefunden", null)) }
+    }
+}

app/src/main/java/de/miaurizius/shap_planner/room/AppDatabase.kt

@@ -4,12 +4,31 @@ import android.content.Context
 import androidx.room.Database
 import androidx.room.Room
 import androidx.room.RoomDatabase
+import androidx.room.TypeConverter
+import androidx.room.TypeConverters
 import de.miaurizius.shap_planner.entities.Account
 import de.miaurizius.shap_planner.entities.AccountDao
+import de.miaurizius.shap_planner.entities.Expense
+import de.miaurizius.shap_planner.entities.ExpenseDao
+import de.miaurizius.shap_planner.entities.ExpenseShare
+import de.miaurizius.shap_planner.entities.ExpenseShareDao
+import de.miaurizius.shap_planner.entities.User
+import de.miaurizius.shap_planner.entities.UserDao
 
-@Database(entities = [Account::class], version = 4)
+class Converters {
+    @TypeConverter
+    fun fromList(list: List<String>?): String? = list?.joinToString(",")
+    @TypeConverter
+    fun toList(data: String?): List<String>? = data?.split(",")?.map { it.trim() }
+}
+
+@Database(entities = [Account::class, Expense::class, ExpenseShare::class, User::class], version = 6)
+@TypeConverters(Converters::class)
 abstract class AppDatabase : RoomDatabase() {
     abstract fun accountDao(): AccountDao
+    abstract fun expenseDao(): ExpenseDao
+    abstract fun expenseShareDao(): ExpenseShareDao
+    abstract fun userDao(): UserDao
     companion object {
         @Volatile
         private var INSTANCE: AppDatabase? = null

app/src/main/java/de/miaurizius/shap_planner/ui/AppContent.kt

@@ -1,12 +1,20 @@
 package de.miaurizius.shap_planner.ui
 
 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 de.miaurizius.shap_planner.entities.Account
 import de.miaurizius.shap_planner.entities.Expense
 import de.miaurizius.shap_planner.network.SessionState
 import de.miaurizius.shap_planner.ui.screens.AccountSelectionScreen
 import de.miaurizius.shap_planner.ui.screens.DashboardScreen
+import de.miaurizius.shap_planner.ui.screens.ExpenseCreationScreen
+import de.miaurizius.shap_planner.ui.screens.ExpenseDetailScreen
 import de.miaurizius.shap_planner.ui.screens.LoginScreen
+import de.miaurizius.shap_planner.viewmodels.ExpenseCreationViewModel
+import de.miaurizius.shap_planner.viewmodels.ExpenseDetailViewModel
 import de.miaurizius.shap_planner.viewmodels.MainViewModel
 
 @Composable
@@ -18,7 +26,6 @@ fun AppContent(
     onLogin: (String, String, String) -> Unit,
 
     // Expenses
-    expenses: List<Expense>,
     onExpenseClick: (Expense) -> Unit,
 
     // Account
@@ -33,16 +40,36 @@ fun AppContent(
     onSessionInvalid: () -> Unit,
 
     //Important
-    viewModel: MainViewModel
+    viewModel: MainViewModel,
+    detailViewModel: ExpenseDetailViewModel,
+    creationViewModel: ExpenseCreationViewModel
 ) {
+    var selectedExpense by remember { mutableStateOf<Expense?>(null) }
+    var showAddExpenseScreen by remember { mutableStateOf(false) }
+
     when {
+        showAddExpenseScreen -> {
+            ExpenseCreationScreen(
+                account = selectedAccount!!,
+                viewModel = creationViewModel,
+                onBack = { showAddExpenseScreen = false },
+                onSaved = { showAddExpenseScreen = false },
+            )
+        }
+        selectedExpense != null -> {
+            ExpenseDetailScreen(
+                expense = selectedExpense!!,
+                account = selectedAccount!!,
+                viewModel = detailViewModel,
+                onBack = { selectedExpense = null }
+            )
+        }
         showLoginForNewAccount -> LoginScreen(onLogin)
         accountList.isEmpty() -> LoginScreen(onLogin)
         selectedAccount != null -> DashboardScreen(
             // Data and regarding Methods
             account = selectedAccount,
-            expenses = expenses,
-            onExpenseClick = onExpenseClick,
+            onExpenseClick = { selectedExpense = it },
 
             // Default Methods
             mainViewModel = viewModel,
@@ -50,7 +77,8 @@ fun AppContent(
             onDelete = onDeleteAccount,
             sessionState = sessionState,
             onValidate = onValidateSession,
-            onSessionInvalid = onSessionInvalid
+            onSessionInvalid = onSessionInvalid,
+            onAddExpenseClick = { showAddExpenseScreen = true },
         )
         else -> AccountSelectionScreen(
             accounts = accountList,

app/src/main/java/de/miaurizius/shap_planner/ui/screens/AccountSelectionScreen.kt

@@ -1,10 +1,10 @@
 package de.miaurizius.shap_planner.ui.screens
 
-import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 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.fillMaxSize
@@ -13,57 +13,176 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.statusBarsPadding
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
+import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Home
 import androidx.compose.material3.Button
-import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.CenterAlignedTopAppBar
+import androidx.compose.material3.ElevatedCard
+import androidx.compose.material3.ExperimentalMaterial3Api
+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.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import de.miaurizius.shap_planner.entities.Account
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
-fun AccountSelectionScreen(accounts: List<Account>, onAccountClick: (Account) -> Unit, onAddAccountClick: () -> Unit) {
-    LazyColumn(
+fun AccountSelectionScreen(
+    accounts: List<Account>,
+    onAccountClick: (Account) -> Unit,
+    onAddAccountClick: () -> Unit
+) {
+    Scaffold(
+        topBar = {
+            CenterAlignedTopAppBar(
+                title = { Text("ShAp-Planner", fontWeight = FontWeight.Black) }
+            )
+        },
+        bottomBar = {
+            Surface(
+                modifier = Modifier.fillMaxWidth(),
+                tonalElevation = 2.dp
+            ) {
+                Button(
+                    onClick = onAddAccountClick,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(20.dp)
+                        .navigationBarsPadding()
+                        .height(56.dp),
+                    shape = MaterialTheme.shapes.medium
+                ) {
+                    Icon(Icons.Default.Add, contentDescription = null)
+                    Spacer(modifier = Modifier.width(8.dp))
+                    Text("Add New Account", style = MaterialTheme.typography.titleMedium)
+                }
+            }
+        }
+    ) { padding ->
+        Column(
             modifier = Modifier
                 .fillMaxSize()
-            .padding(16.dp)
-            .statusBarsPadding()
-            .navigationBarsPadding(),
-        verticalArrangement = Arrangement.spacedBy(12.dp)
+                .padding(padding)
+                .padding(horizontal = 20.dp)
         ) {
+            Spacer(modifier = Modifier.height(16.dp))
+
+            Text(
+                text = "Welcome back!",
+                style = MaterialTheme.typography.headlineLarge,
+                fontWeight = FontWeight.Bold
+            )
+            Text(
+                text = "Select an account to continue",
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.secondary,
+                modifier = Modifier.padding(bottom = 16.dp)
+            )
+
+            LazyColumn(
+                modifier = Modifier.fillMaxSize(),
+                verticalArrangement = Arrangement.spacedBy(12.dp),
+                contentPadding = PaddingValues(bottom = 16.dp)
+            ) {
+                if (accounts.isEmpty()) {
                     item {
-            Text("Wähle einen Account", style = MaterialTheme.typography.headlineSmall)
+                        Box(
+                            modifier = Modifier.fillParentMaxHeight(0.6f).fillMaxWidth(),
+                            contentAlignment = Alignment.Center
+                        ) {
+                            Text(
+                                "No accounts yet.\nTap 'Add New Account' to start.",
+                                textAlign = TextAlign.Center,
+                                color = Color.Gray
+                            )
+                        }
+                    }
                 }
 
                 items(accounts) { account ->
-            Card(modifier = Modifier.fillMaxWidth().clickable{ onAccountClick(account) }) {
-                Row(modifier = Modifier.padding(16.dp), verticalAlignment = Alignment.CenterVertically) {
-                    Box(modifier = Modifier.size(40.dp).background(Color.Gray, shape = CircleShape))
-                    Spacer(modifier = Modifier.width(16.dp))
-                    Column {
-                        Text(text = account.name, fontWeight = FontWeight.Bold)
-                        Text(text = account.wgName, style = MaterialTheme.typography.bodyMedium)
+                    AccountItem(account = account, onClick = { onAccountClick(account) })
                 }
             }
         }
     }
-        item {
-            Spacer(modifier = Modifier.height(8.dp))
-            Button(
-                onClick = onAddAccountClick,
-                modifier = Modifier.fillMaxWidth()
-            ) {
-                Text("Anderen Account hinzufügen")
-            }
-        }
-    }
+}
+
+@Composable
+fun AccountItem(account: Account, onClick: () -> Unit) {
+    ElevatedCard(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clickable { onClick() },
+        shape = MaterialTheme.shapes.large,
+        colors = CardDefaults.elevatedCardColors(
+            containerColor = MaterialTheme.colorScheme.surface
+        )
+    ) {
+        Row(
+            modifier = Modifier.padding(16.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            // Stylized Avatar with Initial
+            Surface(
+                modifier = Modifier.size(52.dp),
+                shape = CircleShape,
+                color = MaterialTheme.colorScheme.primaryContainer
+            ) {
+                Box(contentAlignment = Alignment.Center) {
+                    Text(
+                        text = account.name.take(1).uppercase(),
+                        style = MaterialTheme.typography.titleLarge,
+                        fontWeight = FontWeight.Bold,
+                        color = MaterialTheme.colorScheme.onPrimaryContainer
+                    )
+                }
+            }
+
+            Spacer(modifier = Modifier.width(16.dp))
+
+            Column(modifier = Modifier.weight(1f)) {
+                Text(
+                    text = account.name,
+                    style = MaterialTheme.typography.titleMedium,
+                    fontWeight = FontWeight.Bold
+                )
+                Row(verticalAlignment = Alignment.CenterVertically) {
+                    Icon(
+                        Icons.Default.Home,
+                        contentDescription = null,
+                        modifier = Modifier.size(14.dp),
+                        tint = MaterialTheme.colorScheme.secondary
+                    )
+                    Spacer(modifier = Modifier.width(4.dp))
+                    Text(
+                        text = account.wgName,
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.secondary
+                    )
+                }
+            }
+
+            // Trailing Chevron
+            Icon(
+                Icons.AutoMirrored.Filled.KeyboardArrowRight,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.outline
+            )
+        }
+    }
 }

app/src/main/java/de/miaurizius/shap_planner/ui/screens/DashboardScreen.kt

@@ -1,6 +1,6 @@
 package de.miaurizius.shap_planner.ui.screens
 
-import androidx.activity.compose.BackHandler
+import android.annotation.SuppressLint
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
@@ -12,132 +12,206 @@ 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.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.statusBarsPadding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
-import androidx.compose.material3.Button
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Delete
+import androidx.compose.material.icons.filled.Refresh
 import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.ExperimentalMaterial3Api
+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.material3.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import de.miaurizius.shap_planner.entities.Account
 import de.miaurizius.shap_planner.entities.Expense
 import de.miaurizius.shap_planner.network.SessionState
+import de.miaurizius.shap_planner.repository.Resource
 import de.miaurizius.shap_planner.viewmodels.MainViewModel
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun DashboardScreen(
-    // Data and regarding Methods
     account: Account,
-    expenses: List<Expense>,
     onExpenseClick: (Expense) -> Unit,
-
-    // Default Methods
+    onAddExpenseClick: () -> Unit,
     mainViewModel: MainViewModel,
     onBack: () -> Unit,
     onDelete: () -> Unit,
     sessionState: SessionState,
     onValidate: () -> Unit,
-    onSessionInvalid: () -> Unit) {
+    onSessionInvalid: () -> Unit
+) {
+    val expenseResource by mainViewModel.expenseResource.collectAsState()
 
     LaunchedEffect(Unit) { onValidate() }
-    mainViewModel.loadExpenses(account)
-    when (sessionState) {
-        SessionState.Loading -> {
-            Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-                CircularProgressIndicator()
-            }
+    LaunchedEffect(account) { mainViewModel.loadExpenses(account, forceRefresh = false) }
+
+    if (sessionState == SessionState.Invalid) {
+        LaunchedEffect(Unit) { onSessionInvalid() }
+        return
     }
 
-        SessionState.Valid -> {
-            BackHandler {
-                onBack()
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = {
+                    Column {
+                        Text(account.wgName, style = MaterialTheme.typography.titleLarge)
+                        Text("Household", style = MaterialTheme.typography.labelSmall)
                     }
+                },
+                actions = {
+                    IconButton(onClick = onBack) {
+                        Icon(Icons.Default.Refresh, "Switch")
+                    }
+                    IconButton(onClick = onDelete) {
+                        Icon(Icons.Default.Delete, "Delete", tint = MaterialTheme.colorScheme.error)
+                    }
+                }
+            )
+        },
+        floatingActionButton = {
+            androidx.compose.material3.FloatingActionButton(
+                onClick = onAddExpenseClick,
+                containerColor = MaterialTheme.colorScheme.primary,
+                contentColor = MaterialTheme.colorScheme.onPrimary
+            ) {
+                Icon(Icons.Default.Add, "Neu")
+            }
+        }
+    ) { paddingValues ->
         Column(
             modifier = Modifier
                 .fillMaxSize()
-                    .padding(16.dp)
-                    .statusBarsPadding()
-                    .navigationBarsPadding()
+                .padding(paddingValues)
+                .background(MaterialTheme.colorScheme.surface)
         ) {
-                // Header
-                Row(
-                    modifier = Modifier.fillMaxWidth(),
-                    horizontalArrangement = Arrangement.SpaceBetween,
-                    verticalAlignment = Alignment.CenterVertically
-                ) {
-                    Column {
+            Column(modifier = Modifier.padding(16.dp)) {
                 Text(
-                            text = "Hallo, ${account.name}!",
-                            style = MaterialTheme.typography.headlineMedium
+                    text = "Hello, ${account.name}!",
+                    style = MaterialTheme.typography.headlineMedium,
+                    fontWeight = FontWeight.Bold
                 )
+
+                Spacer(modifier = Modifier.height(16.dp))
+
+                SummaryCard(expenses = expenseResource.data ?: emptyList())
+            }
+
             Text(
-                            text = "WG: ${account.wgName}",
-                            style = MaterialTheme.typography.bodyLarge,
-                            color = Color.Gray
+                text = "Latest expenses",
+                style = MaterialTheme.typography.titleMedium,
+                modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+                color = MaterialTheme.colorScheme.secondary
             )
-                    }
-                    Button(onClick = onBack) {
-                        Text("Wechseln")
-                    }
-                }
 
-                Spacer(modifier = Modifier.height(5.dp))
-
-                Button(onClick = onDelete) {
-                    Text("Löschen")
+            Box(modifier = Modifier.fillMaxSize()) {
+                if (expenseResource is Resource.Loading && expenseResource.data?.isEmpty() == true) {
+                    CircularProgressIndicator(modifier = Modifier.align(Alignment.Center))
                 }
 
-                Spacer(modifier = Modifier.height(10.dp))
-
-                Text("WG-Kosten", style = MaterialTheme.typography.titleLarge)
-                Spacer(modifier = Modifier.height(8.dp))
-
                 LazyColumn(
-                    modifier = Modifier
-                        .fillMaxSize()
-                        .background(MaterialTheme.colorScheme.surfaceVariant, shape = MaterialTheme.shapes.medium),
-                    contentPadding = PaddingValues(8.dp),
-                    verticalArrangement = Arrangement.spacedBy(8.dp)
+                    modifier = Modifier.fillMaxSize(),
+                    contentPadding = PaddingValues(16.dp),
+                    verticalArrangement = Arrangement.spacedBy(12.dp)
                 ) {
-                    items(expenses) { expense ->
+                    items(expenseResource.data ?: emptyList()) { expense ->
                         ExpenseItem(expense = expense, onClick = { onExpenseClick(expense) })
                     }
                 }
             }
         }
-
-        SessionState.Invalid -> {
-            LaunchedEffect(Unit) {
-                onSessionInvalid()
-            }
     }
+}
 
-        is SessionState.Error -> {
-            Text("Server error")
+@SuppressLint("DefaultLocale")
+@Composable
+fun SummaryCard(expenses: List<Expense>) {
+    val total = expenses.sumOf { it.amount } / 100.0
+    androidx.compose.material3.Card(
+        modifier = Modifier.fillMaxWidth(),
+        colors = androidx.compose.material3.CardDefaults.cardColors(
+            containerColor = MaterialTheme.colorScheme.primaryContainer
+        )
+    ) {
+        Column(modifier = Modifier.padding(20.dp)) {
+            Text("Total expenditure", style = MaterialTheme.typography.labelMedium)
+            Text(
+                text = String.format("%.2f €", total),
+                style = MaterialTheme.typography.displaySmall,
+                fontWeight = FontWeight.Black
+            )
         }
     }
 }
 
+@SuppressLint("DefaultLocale")
 @Composable
 fun ExpenseItem(expense: Expense, onClick: () -> Unit) {
-    Surface(modifier = Modifier
+    androidx.compose.material3.ElevatedCard(
+        modifier = Modifier
             .fillMaxWidth()
-        .clickable{onClick()},
-        shape = MaterialTheme.shapes.small,
-        color = MaterialTheme.colorScheme.surface) {
-        Row(modifier = Modifier.padding(16.dp), horizontalArrangement = Arrangement.SpaceBetween) {
-            Text(text = expense.title, style = MaterialTheme.typography.bodyLarge)
-            Text(text = expense.amount.toString()+"€", style = MaterialTheme.typography.bodyLarge, fontWeight = FontWeight.Bold)
+            .clickable { onClick() },
+        shape = MaterialTheme.shapes.medium,
+        colors = androidx.compose.material3.CardDefaults.elevatedCardColors(
+            containerColor = MaterialTheme.colorScheme.surface
+        )
+    ) {
+        Row(
+            modifier = Modifier
+                .padding(16.dp)
+                .fillMaxWidth(),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.SpaceBetween
+        ) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Surface(
+                    shape = androidx.compose.foundation.shape.CircleShape,
+                    color = MaterialTheme.colorScheme.primaryContainer,
+                    modifier = Modifier.size(40.dp)
+                ) {
+                    Box(contentAlignment = Alignment.Center) {
+                        Text(
+                            text = expense.title.take(1).uppercase(),
+                            style = MaterialTheme.typography.titleMedium,
+                            color = MaterialTheme.colorScheme.onPrimaryContainer
+                        )
+                    }
+                }
+
+                Spacer(modifier = Modifier.width(16.dp))
+
+                Column {
+                    Text(
+                        text = expense.title,
+                        style = MaterialTheme.typography.titleMedium,
+                        fontWeight = FontWeight.Bold
+                    )
+                }
+            }
+
+            Text(
+                text = String.format("%.2f €", expense.amount / 100.0),
+                style = MaterialTheme.typography.titleLarge,
+                fontWeight = FontWeight.ExtraBold,
+                color = MaterialTheme.colorScheme.primary
+            )
         }
     }
 }

app/src/main/java/de/miaurizius/shap_planner/ui/screens/ExpenseCreationScreen.kt

@@ -0,0 +1,249 @@
+package de.miaurizius.shap_planner.ui.screens
+
+import android.annotation.SuppressLint
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.Delete
+import androidx.compose.material.icons.filled.Description
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+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.unit.dp
+import de.miaurizius.shap_planner.entities.Account
+import de.miaurizius.shap_planner.viewmodels.ExpenseCreationViewModel
+
+@SuppressLint("DefaultLocale")
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ExpenseCreationScreen(
+    account: Account,
+    viewModel: ExpenseCreationViewModel,
+    onSaved: () -> Unit,
+    onBack: () -> Unit
+) {
+    var title by remember { mutableStateOf("") }
+    var description by remember { mutableStateOf("") }
+    var totalAmountStr by remember { mutableStateOf("") }
+    val attachmentUris = remember { mutableStateListOf<android.net.Uri>() }
+    val userShares = remember { mutableStateMapOf<java.util.UUID, String>() }
+    val users by viewModel.users.collectAsState()
+
+    // Real-time calculation logic
+    val totalCents = (totalAmountStr.replace(",", ".").toDoubleOrNull() ?: 0.0) * 100
+    val distributedCents = userShares.values.sumOf {
+        (it.replace(",", ".").toDoubleOrNull() ?: 0.0) * 100
+    }.toLong()
+
+    val diff = totalCents.toLong() - distributedCents
+    val isAmountMatched = totalCents > 0 && diff == 0L
+
+    // File Picker for multiple files (Images & PDFs)
+    val launcher = androidx.activity.compose.rememberLauncherForActivityResult(
+        contract = androidx.activity.result.contract.ActivityResultContracts.GetMultipleContents()
+    ) { uris ->
+        attachmentUris.addAll(uris)
+    }
+
+    LaunchedEffect(Unit) { viewModel.loadUsers() }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("New Expense") },
+                navigationIcon = { IconButton(onClick = onBack) {
+                    Icon(Icons.AutoMirrored.Filled.ArrowBack, "Back")
+                } }
+            )
+        }
+    ) { padding ->
+        LazyColumn(
+            modifier = Modifier.fillMaxSize().padding(padding).padding(horizontal = 16.dp),
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            // Header Info
+            item {
+                Spacer(modifier = Modifier.height(8.dp))
+                ElevatedCard(modifier = Modifier.fillMaxWidth()) {
+                    Column(modifier = Modifier.padding(16.dp)) {
+                        OutlinedTextField(
+                            value = title,
+                            onValueChange = { title = it },
+                            label = { Text("Title *") },
+                            modifier = Modifier.fillMaxWidth()
+                        )
+                        Spacer(modifier = Modifier.height(12.dp))
+                        OutlinedTextField(
+                            value = totalAmountStr,
+                            onValueChange = { totalAmountStr = it },
+                            label = { Text("Total Amount (€) *") },
+                            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                            modifier = Modifier.fillMaxWidth()
+                        )
+                    }
+                }
+            }
+
+            // Optional Description & Multi-File Attachments
+            item {
+                Text("Additional Info", style = MaterialTheme.typography.titleMedium)
+                ElevatedCard(modifier = Modifier.fillMaxWidth()) {
+                    Column(modifier = Modifier.padding(16.dp)) {
+                        OutlinedTextField(
+                            value = description,
+                            onValueChange = { description = it },
+                            label = { Text("Description (Optional)") },
+                            modifier = Modifier.fillMaxWidth(),
+                            minLines = 2
+                        )
+                        Spacer(modifier = Modifier.height(16.dp))
+
+                        Text("Attachments (${attachmentUris.size})", style = MaterialTheme.typography.labelLarge)
+                        attachmentUris.forEach { uri ->
+                            Row(verticalAlignment = Alignment.CenterVertically) {
+                                Icon(Icons.Default.Description, "File", modifier = Modifier.size(20.dp))
+                                Text(" Document attached", modifier = Modifier.weight(1f), style = MaterialTheme.typography.bodySmall)
+                                IconButton(onClick = { attachmentUris.remove(uri) }) {
+                                    Icon(Icons.Default.Delete, "Remove", tint = Color.Red)
+                                }
+                            }
+                        }
+
+                        Button(onClick = { launcher.launch("*/*") }) {
+                            Text("Select Files (Images, PDF)")
+                        }
+                    }
+                }
+            }
+
+            // Split Details & Validation Message
+            item {
+                Column {
+                    Row(modifier = Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.SpaceBetween, verticalAlignment = Alignment.CenterVertically) {
+                        Text("Split Details *", style = MaterialTheme.typography.titleMedium)
+                        TextButton(onClick = {
+                            if (totalCents > 0) {
+                                val share = String.format("%.2f", (totalCents / users.size) / 100.0)
+                                users.forEach { userShares[it.id] = share }
+                            }
+                        }) { Text("Split Equally") }
+                    }
+
+                    // VALIDATION MESSAGE
+                    if (totalCents > 0) {
+                        val statusText = when {
+                            diff > 0 -> "Remaining: ${String.format("%.2f", diff / 100.0)} €"
+                            diff < 0 -> "Over-allocated: ${String.format("%.2f", Math.abs(diff) / 100.0)} €"
+                            else -> "Amount matched! ✓"
+                        }
+                        val statusColor = if (diff == 0L) Color(0xFF2E7D32) else MaterialTheme.colorScheme.error
+
+                        Surface(
+                            color = statusColor.copy(alpha = 0.1f),
+                            shape = MaterialTheme.shapes.small,
+                            modifier = Modifier.fillMaxWidth().padding(vertical = 4.dp)
+                        ) {
+                            Text(
+                                text = statusText,
+                                color = statusColor,
+                                modifier = Modifier.padding(8.dp),
+                                style = MaterialTheme.typography.bodyMedium,
+                                fontWeight = FontWeight.Bold,
+                                textAlign = TextAlign.Center
+                            )
+                        }
+                    }
+                }
+            }
+
+            items(users) { user ->
+                UserShareInputItem(
+                    userName = user.name,
+                    amount = userShares[user.id] ?: "",
+                    onAmountChange = { userShares[user.id] = it }
+                )
+            }
+
+            // Save Actions
+            item {
+                Button(
+                    onClick = {
+                        viewModel.saveExpense(
+                            account = account,
+                            title = title,
+                            description = description,
+                            amountCents = totalCents.toInt(),
+                            shares = userShares.mapValues { (it.value.replace(",",".").toDoubleOrNull() ?: 0.0).toInt() * 100 }.filter { it.value > 0 },
+                            attachments = attachmentUris.map { it.toString() }
+                        )
+                        onSaved()
+                    },
+                    modifier = Modifier.fillMaxWidth().height(56.dp),
+                    enabled = title.isNotBlank() && isAmountMatched // STRICT VALIDATION
+                ) {
+                    Text("Save Expense")
+                }
+
+                if (totalAmountStr.isNotBlank() && !isAmountMatched) {
+                    Text(
+                        "Sum of shares must equal total amount to save.",
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.error,
+                        modifier = Modifier.fillMaxWidth().padding(top = 8.dp),
+                        textAlign = TextAlign.Center
+                    )
+                }
+
+                TextButton(onClick = onBack, modifier = Modifier.fillMaxWidth()) {
+                    Text("Cancel")
+                }
+                Spacer(modifier = Modifier.height(32.dp))
+            }
+        }
+    }
+}
+
+@Composable
+fun UserShareInputItem(userName: String, amount: String, onAmountChange: (String) -> Unit) {
+    Card(
+        modifier = Modifier.fillMaxWidth(),
+        colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.3f))
+    ) {
+        Row(
+            modifier = Modifier.padding(12.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Surface(
+                shape = androidx.compose.foundation.shape.CircleShape,
+                color = MaterialTheme.colorScheme.primaryContainer,
+                modifier = Modifier.size(32.dp)
+            ) {
+                Box(contentAlignment = Alignment.Center) {
+                    Text(userName.take(1).uppercase(), style = MaterialTheme.typography.bodySmall)
+                }
+            }
+            Spacer(modifier = Modifier.width(12.dp))
+            Text(userName, modifier = Modifier.weight(1f), style = MaterialTheme.typography.bodyLarge)
+
+            OutlinedTextField(
+                value = amount,
+                onValueChange = onAmountChange,
+                modifier = Modifier.width(100.dp),
+                placeholder = { Text("0.00") },
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                singleLine = true,
+                textStyle = MaterialTheme.typography.bodyMedium.copy(textAlign = TextAlign.End)
+            )
+            Spacer(modifier = Modifier.width(4.dp))
+            Text("€")
+        }
+    }
+}

app/src/main/java/de/miaurizius/shap_planner/ui/screens/ExpenseDetailScreen.kt

@@ -0,0 +1,189 @@
+package de.miaurizius.shap_planner.ui.screens
+
+import android.annotation.SuppressLint
+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.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material3.ExperimentalMaterial3Api
+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.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import de.miaurizius.shap_planner.entities.Account
+import de.miaurizius.shap_planner.entities.Expense
+import de.miaurizius.shap_planner.viewmodels.ExpenseDetailViewModel
+
+@SuppressLint("DefaultLocale")
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ExpenseDetailScreen(
+    expense: Expense,
+    account: Account,
+    viewModel: ExpenseDetailViewModel,
+    onBack: () -> Unit
+) {
+    val shares by viewModel.sharesWithUser.collectAsState()
+
+    LaunchedEffect(expense) {
+        viewModel.loadExpenseDetail(account, expense)
+    }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Expense Details") },
+                navigationIcon = {
+                    IconButton(onClick = onBack) {
+                        Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = "Back")
+                    }
+                }
+            )
+        }
+    ) { padding ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(padding)
+                .padding(16.dp)
+        ) {
+            // Hero Section: Amount & Title
+            Column(
+                modifier = Modifier.fillMaxWidth().padding(bottom = 24.dp),
+                horizontalAlignment = Alignment.CenterHorizontally
+            ) {
+                Text(
+                    text = "Total Amount",
+                    style = MaterialTheme.typography.labelLarge,
+                    color = MaterialTheme.colorScheme.secondary
+                )
+                Text(
+                    text = String.format("%.2f €", expense.amount / 100.0),
+                    style = MaterialTheme.typography.displayMedium,
+                    fontWeight = FontWeight.Black,
+                    color = MaterialTheme.colorScheme.primary
+                )
+                Text(
+                    text = expense.title,
+                    style = MaterialTheme.typography.headlineSmall,
+                    fontWeight = FontWeight.Bold,
+                    textAlign = TextAlign.Center
+                )
+            }
+
+            // Description Card (only shown if not empty)
+            if (expense.description.isNotBlank()) {
+                androidx.compose.material3.ElevatedCard(
+                    modifier = Modifier.fillMaxWidth().padding(bottom = 24.dp),
+                    colors = androidx.compose.material3.CardDefaults.elevatedCardColors(
+                        containerColor = MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.5f)
+                    )
+                ) {
+                    Column(modifier = Modifier.padding(16.dp)) {
+                        Text(
+                            text = "Description",
+                            style = MaterialTheme.typography.labelMedium,
+                            color = MaterialTheme.colorScheme.primary
+                        )
+                        Spacer(modifier = Modifier.height(4.dp))
+                        Text(text = expense.description, style = MaterialTheme.typography.bodyLarge)
+                    }
+                }
+            }
+
+            Text(
+                text = "Cost Distribution",
+                style = MaterialTheme.typography.titleMedium,
+                fontWeight = FontWeight.Bold,
+                modifier = Modifier.padding(bottom = 12.dp)
+            )
+
+            LazyColumn(
+                verticalArrangement = Arrangement.spacedBy(12.dp),
+                modifier = Modifier.fillMaxSize()
+            ) {
+                items(shares) { item ->
+                    ShareItem(
+                        name = item.user?.name ?: "Unknown User",
+                        amountCents = item.share.share_cents
+                    )
+                }
+            }
+        }
+    }
+}
+
+@SuppressLint("DefaultLocale")
+@Composable
+fun ShareItem(name: String, amountCents: Int) {
+    androidx.compose.material3.OutlinedCard(
+        modifier = Modifier.fillMaxWidth(),
+        shape = MaterialTheme.shapes.medium,
+        colors = androidx.compose.material3.CardDefaults.outlinedCardColors(
+            containerColor = MaterialTheme.colorScheme.surface
+        )
+    ) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(12.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            // User Avatar Circle
+            Surface(
+                shape = androidx.compose.foundation.shape.CircleShape,
+                color = MaterialTheme.colorScheme.secondaryContainer,
+                modifier = Modifier.size(36.dp)
+            ) {
+                Box(contentAlignment = Alignment.Center) {
+                    Text(
+                        text = name.take(1).uppercase(),
+                        style = MaterialTheme.typography.bodyMedium,
+                        fontWeight = FontWeight.Bold,
+                        color = MaterialTheme.colorScheme.onSecondaryContainer
+                    )
+                }
+            }
+
+            Spacer(modifier = Modifier.width(12.dp))
+
+            Text(
+                text = name,
+                style = MaterialTheme.typography.bodyLarge,
+                fontWeight = FontWeight.Medium,
+                modifier = Modifier.weight(1f)
+            )
+
+            Text(
+                text = String.format("%.2f €", amountCents / 100.0),
+                style = MaterialTheme.typography.bodyLarge,
+                fontWeight = FontWeight.Bold,
+                color = if (amountCents > 0) Color(0xFF2E7D32) else Color.Gray
+            )
+        }
+    }
+}

app/src/main/java/de/miaurizius/shap_planner/ui/screens/LoginScreen.kt

@@ -3,68 +3,174 @@ package de.miaurizius.shap_planner.ui.screens
 import androidx.activity.compose.BackHandler
 import androidx.compose.foundation.layout.Column
 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.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.statusBarsPadding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.Cloud
+import androidx.compose.material.icons.filled.Lock
+import androidx.compose.material.icons.filled.Person
+import androidx.compose.material.icons.filled.Visibility
+import androidx.compose.material.icons.filled.VisibilityOff
+import androidx.compose.material.icons.filled.VpnKey
 import androidx.compose.material3.Button
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
-import androidx.compose.material3.TextField
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.TopAppBar
 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.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.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
-fun LoginScreen(onLogin: (String, String, String) -> Unit, onBack: (() -> Unit)? = null) {
-
+fun LoginScreen(
+    onLogin: (String, String, String) -> Unit,
+    onBack: (() -> Unit)? = null
+) {
     if (onBack != null) {
-        BackHandler {
-            onBack()
-        }
+        BackHandler { onBack() }
     }
 
     var serverUrl by remember { mutableStateOf("") }
     var username by remember { mutableStateOf("") }
     var password by remember { mutableStateOf("") }
+    var passwordVisible by remember { mutableStateOf(false) }
 
-    Column(modifier = Modifier.padding(16.dp).statusBarsPadding().navigationBarsPadding()) {
-        Text("Bitte anmelden")
-        Spacer(modifier = Modifier.height(8.dp))
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Add Account", fontWeight = FontWeight.Bold) },
+                navigationIcon = {
+                    if (onBack != null) {
+                        IconButton(onClick = onBack) {
+                            Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = "Back")
+                        }
+                    }
+                }
+            )
+        }
+    ) { padding ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(padding)
+                .padding(24.dp)
+                .verticalScroll(rememberScrollState()), // Scrollbar, falls die Tastatur den Platz wegnimmt
+            horizontalAlignment = Alignment.CenterHorizontally
+        ) {
+            // App Icon or Welcome Text
+            Icon(
+                imageVector = Icons.Default.Lock,
+                contentDescription = null,
+                modifier = Modifier.size(64.dp),
+                tint = MaterialTheme.colorScheme.primary
+            )
 
-        //Home-Server
-        TextField(
+            Text(
+                text = "Connect to Server",
+                style = MaterialTheme.typography.headlineMedium,
+                fontWeight = FontWeight.Bold,
+                modifier = Modifier.padding(top = 16.dp)
+            )
+
+            Text(
+                text = "Enter your credentials to link your account",
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.secondary,
+                textAlign = TextAlign.Center,
+                modifier = Modifier.padding(bottom = 32.dp)
+            )
+
+            // Server URL Field
+            OutlinedTextField(
                 value = serverUrl,
                 onValueChange = { serverUrl = it },
-            label = { Text("Server-Domain") }
+                label = { Text("Server URL") },
+                placeholder = { Text("your-server.com") },
+                modifier = Modifier.fillMaxWidth(),
+                singleLine = true,
+                leadingIcon = { Icon(Icons.Default.Cloud, contentDescription = null) },
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Uri, imeAction = ImeAction.Next)
             )
-        Spacer(modifier = Modifier.height(8.dp))
 
-        //Username
-        TextField(
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // Username Field
+            OutlinedTextField(
                 value = username,
                 onValueChange = { username = it },
-            label = { Text("Nutzername") }
+                label = { Text("Username") },
+                modifier = Modifier.fillMaxWidth(),
+                singleLine = true,
+                leadingIcon = { Icon(Icons.Default.Person, contentDescription = null) },
+                keyboardOptions = KeyboardOptions(imeAction = ImeAction.Next)
             )
-        Spacer(modifier = Modifier.height(8.dp))
 
-        //Password
-        TextField(
+            Spacer(modifier = Modifier.height(16.dp))
+
+            // Password Field
+            OutlinedTextField(
                 value = password,
                 onValueChange = { password = it },
-            label = { Text("Passwort") }
+                label = { Text("Password") },
+                modifier = Modifier.fillMaxWidth(),
+                singleLine = true,
+                leadingIcon = { Icon(Icons.Default.VpnKey, contentDescription = null) },
+                visualTransformation = if (passwordVisible) VisualTransformation.None else PasswordVisualTransformation(),
+                keyboardOptions = KeyboardOptions(
+                    keyboardType = KeyboardType.Password,
+                    imeAction = ImeAction.Done
+                ),
+                trailingIcon = {
+                    val image = if (passwordVisible) Icons.Default.Visibility else Icons.Default.VisibilityOff
+                    IconButton(onClick = { passwordVisible = !passwordVisible }) {
+                        Icon(imageVector = image, contentDescription = "Toggle password visibility")
+                    }
+                }
             )
-        Spacer(modifier = Modifier.height(8.dp))
 
-        Button(onClick = { if(serverUrl.isNotEmpty() && username.isNotEmpty() && password.isNotEmpty()) onLogin(
-            serverUrl,
-            username,
-            password
-        ) }) {
-            Text("Login")
+            Spacer(modifier = Modifier.height(32.dp))
+
+            // Login Button
+            Button(
+                onClick = { onLogin(serverUrl, username, password) },
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .height(56.dp),
+                enabled = serverUrl.isNotBlank() && username.isNotBlank() && password.isNotBlank(),
+                shape = MaterialTheme.shapes.medium
+            ) {
+                Text("Connect Account", style = MaterialTheme.typography.titleMedium)
+            }
+
+            if (onBack != null) {
+                TextButton(onClick = onBack, modifier = Modifier.padding(top = 8.dp)) {
+                    Text("Cancel", color = MaterialTheme.colorScheme.secondary)
+                }
+            }
         }
     }
 }

app/src/main/java/de/miaurizius/shap_planner/viewmodels/ExpenseCreationViewModel.kt

@@ -0,0 +1,66 @@
+package de.miaurizius.shap_planner.viewmodels
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import de.miaurizius.shap_planner.TokenStorage
+import de.miaurizius.shap_planner.entities.Account
+import de.miaurizius.shap_planner.entities.Expense
+import de.miaurizius.shap_planner.entities.ExpenseDao
+import de.miaurizius.shap_planner.entities.ExpenseShare
+import de.miaurizius.shap_planner.entities.ExpenseShareDao
+import de.miaurizius.shap_planner.entities.User
+import de.miaurizius.shap_planner.entities.UserDao
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.launch
+import java.util.UUID
+
+class ExpenseCreationViewModel(
+    private val userDao: UserDao,
+    private val expenseDao: ExpenseDao,
+    private val shareDao: ExpenseShareDao,
+    private val tokenStorage: TokenStorage
+) : ViewModel() {
+    private val _users = MutableStateFlow<List<User>>(emptyList())
+    val users: StateFlow<List<User>> = _users
+
+    fun loadUsers() {
+        viewModelScope.launch {
+            userDao.getAllUsers().collect { _users.value = it }
+        }
+    }
+
+    fun saveExpense(
+        account: Account,
+        title: String,
+        description: String,
+        amountCents: Int,
+        shares: Map<UUID, Int>,
+        attachments: List<String>
+    ) {
+//        viewModelScope.launch {
+//            val expenseId = UUID.randomUUID()
+//            val newExpense = Expense(
+//                id = expenseId,
+//                payer_id = account.id,
+//                amount = amountCents,
+//                title = title,
+//                description = description,
+//                attachments = if (attachments.isEmpty()) null else attachments,
+//                created_at = (System.currentTimeMillis() / 1000).toInt(),
+//                last_updated_at = 0
+//            )
+//
+//            expenseDao.insertExpense(newExpense)
+//
+//            shares.forEach { (userId, shareCents) ->
+//                shareDao.insertShare(
+//                    ExpenseShare(UUID.randomUUID(), expenseId, userId, shareCents)
+//                )
+//            }
+//
+//            // API POST Request
+//
+//        }
+    }
+}

app/src/main/java/de/miaurizius/shap_planner/viewmodels/ExpenseDetailViewModel.kt

@@ -0,0 +1,59 @@
+package de.miaurizius.shap_planner.viewmodels
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import de.miaurizius.shap_planner.TokenStorage
+import de.miaurizius.shap_planner.entities.Account
+import de.miaurizius.shap_planner.entities.Expense
+import de.miaurizius.shap_planner.entities.ExpenseDao
+import de.miaurizius.shap_planner.entities.ExpenseShare
+import de.miaurizius.shap_planner.entities.ExpenseShareDao
+import de.miaurizius.shap_planner.entities.User
+import de.miaurizius.shap_planner.entities.UserDao
+import de.miaurizius.shap_planner.network.RetrofitProvider
+import de.miaurizius.shap_planner.repository.ExpenseShareRepository
+import de.miaurizius.shap_planner.repository.Resource
+import de.miaurizius.shap_planner.repository.UserRepository
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
+
+data class ShareWithUser(
+    val share: ExpenseShare,
+    val user: User?
+)
+
+class ExpenseDetailViewModel(
+    private val expenseDao: ExpenseDao,
+    private val shareDao: ExpenseShareDao,
+    private val userDao: UserDao,
+    private val tokenStorage: TokenStorage
+) : ViewModel() {
+    private val _sharesWithUser = MutableStateFlow<List<ShareWithUser>>(emptyList())
+    val sharesWithUser: StateFlow<List<ShareWithUser>> = _sharesWithUser
+
+    fun loadExpenseDetail(account: Account, expense: Expense) {
+        viewModelScope.launch {
+            val api = RetrofitProvider.create(account.serverUrl)
+            val token = tokenStorage.getAccess(account.id.toString()) ?: ""
+
+            val shareRepo = ExpenseShareRepository(shareDao, api)
+            val userRepo = UserRepository(userDao, api)
+
+            shareRepo.getSharesByExpenseId(token, expense.id).collect { resource ->
+                val shares = resource.data ?: emptyList()
+                val combinedList = shares.map { share ->
+                    val cachedUser = userDao.getUserById(share.user_id).first()
+                    if (cachedUser == null) {
+                        val userResource = userRepo.getUser(token, share.user_id).first { it is Resource.Success || it is Resource.Error }
+                        ShareWithUser(share, userResource.data)
+                    } else {
+                        ShareWithUser(share, cachedUser)
+                    }
+                }
+                _sharesWithUser.value = combinedList
+            }
+        }
+    }
+}

app/src/main/java/de/miaurizius/shap_planner/viewmodels/MainViewModel.kt

@@ -9,9 +9,12 @@ import de.miaurizius.shap_planner.TokenStorage
 import de.miaurizius.shap_planner.entities.Account
 import de.miaurizius.shap_planner.entities.AccountDao
 import de.miaurizius.shap_planner.entities.Expense
+import de.miaurizius.shap_planner.entities.ExpenseDao
 import de.miaurizius.shap_planner.network.RefreshRequest
 import de.miaurizius.shap_planner.network.RetrofitProvider
 import de.miaurizius.shap_planner.network.SessionState
+import de.miaurizius.shap_planner.repository.ExpenseRepository
+import de.miaurizius.shap_planner.repository.Resource
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
@@ -19,7 +22,11 @@ import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import kotlin.collections.emptyList
 
-class MainViewModel(private val accountDao: AccountDao, private val tokenStorage: TokenStorage) : ViewModel() {
+class MainViewModel(
+    private val accountDao: AccountDao,
+    private val expenseDao: ExpenseDao,
+    private val tokenStorage: TokenStorage
+) : ViewModel() {
 
     var selectedAccount by mutableStateOf<Account?>(null)
         private set
@@ -28,22 +35,16 @@ class MainViewModel(private val accountDao: AccountDao, private val tokenStorage
     var sessionState by mutableStateOf<SessionState>(SessionState.Loading)
         private set
 
-    private val _expenses = MutableStateFlow<List<Expense>>(emptyList())
-    val expenses: StateFlow<List<Expense>> = _expenses
+    private val _expenseResource = MutableStateFlow<Resource<List<Expense>>>(Resource.Loading(emptyList()))
+    val expenseResource: StateFlow<Resource<List<Expense>>> = _expenseResource
 
-    fun loadExpenses(account: Account) {
+    fun loadExpenses(account: Account, forceRefresh: Boolean = false) {
         viewModelScope.launch {
-            try {
             val api = RetrofitProvider.create(account.serverUrl)
-                val accessToken = tokenStorage.getAccess(account.id.toString())
+            val repo = ExpenseRepository(expenseDao, api)
+            val accessToken = tokenStorage.getAccess(account.id.toString()) ?: ""
 
-                val response = api.expenseGet("Bearer $accessToken")
-                if (response.isSuccessful) {
-                    _expenses.value = response.body()?.expenses ?: emptyList()
-                }
-            } catch (e: Exception) {
-                _expenses.value = emptyList()
-            }
+            repo.getExpenses(accessToken, forceRefresh).collect { result -> _expenseResource.value = result }
         }
     }
 
@@ -81,10 +82,6 @@ class MainViewModel(private val accountDao: AccountDao, private val tokenStorage
 
                     sessionState = SessionState.Valid
 
-                    // Fetch data
-                    loadExpenses(account)
-                    println("All data fetched")
-
                     return@launch
                 } else {
                     sessionState = SessionState.Invalid