Implemented expense tracking and data fetching

The `Expense` entity and its associated API endpoints have been updated, and a new `ExpenseShare` entity with a corresponding DAO has been added.

The `MainViewModel` now includes logic to fetch expenses from the server upon successful session validation. The `DashboardScreen` has been updated to display a list of expenses using a `LazyColumn` and a new `ExpenseItem` component. Additionally, the `APIService` has been expanded to include CRUD operations for expenses and user information.

app/src/main/java/de/miaurizius/shap_planner/TokenStorage.kt

@@ -19,6 +19,7 @@ class TokenStorage(context: Context) {
     )
 
     fun saveTokens(accountId: String, accessToken: String, refreshToken: String) {
+//        println("Account ID: ${accountId}\nAToken: ${accessToken}\nRToken: ${refreshToken}")
         prefs.edit()
             .putString("access_$accountId", accessToken)
             .putString("refresh_$accountId", refreshToken)

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

@@ -27,19 +27,19 @@ class MainActivity : ComponentActivity() {
         val tokenStorage = TokenStorage(applicationContext)
         val mainViewModel = MainViewModel(dao, tokenStorage)
 
+
         setContent {
             ShapPlannerTheme {
-                val isLoggedIn by loginViewModel.isLoggedIn.collectAsState()
                 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
                 }
 
                 AppContent(
-                    isLoggedIn = isLoggedIn,
                     accountList = accountList,
                     selectedAccount = selectedAccount,
                     showLoginForNewAccount = showLoginForNewAccount.value,
@@ -53,7 +53,10 @@ class MainActivity : ComponentActivity() {
                     onDeleteAccount = { mainViewModel.deleteAccount(selectedAccount!!) },
                     sessionState = mainViewModel.sessionState,
                     onValidateSession = { mainViewModel.validateSession(selectedAccount!!) },
-                    onSessionInvalid = { mainViewModel.logoutFromAccount() }
+                    onSessionInvalid = { mainViewModel.logoutFromAccount() },
+                    expenses = expenses,
+                    onExpenseClick = { expense -> println("Clicked: ${expense.title}") },
+                    viewModel = mainViewModel
                 )
             }
         }

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

@@ -12,12 +12,14 @@ import java.util.UUID
 @Entity(tableName = "expenses")
 data class Expense (
     val id: UUID,
-    val amt: Double,
-    val desc: String,
-
-    val payerId: UUID,
-    val debtors: List<User>
-)
+    val payer_id: UUID,
+    val amount: Int,
+    val title: String,
+    val description: 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

@@ -0,0 +1,33 @@
+package de.miaurizius.shap_planner.entities
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Entity
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import kotlinx.coroutines.flow.Flow
+import java.util.UUID
+
+@Entity(tableName = "expense_shares")
+data class ExpenseShare(
+    val id: UUID,
+    val expense_id: UUID,
+    val user_id: UUID,
+    val share_cents: Int
+)
+
+@Dao
+interface ExpenseShareDao {
+    @Query("SELECT * FROM expense_shares")
+    fun getAllShares(): Flow<List<ExpenseShare>>
+
+    @Query("SELECT * FROM expense_shares WHERE id = :shareId")
+    fun getShareById(shareId: UUID)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertShare(share: ExpenseShare)
+
+    @Delete
+    suspend fun deleteShare(share: ExpenseShare)
+}

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

@@ -13,6 +13,7 @@ import java.util.UUID
 data class User (
     val id: UUID,
     val name: String,
+    val avatar_url: String?
 )
 
 @Dao

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

@@ -2,24 +2,34 @@ package de.miaurizius.shap_planner.network
 
 import retrofit2.Response
 import retrofit2.http.Body
+import retrofit2.http.DELETE
 import retrofit2.http.GET
 import retrofit2.http.Header
 import retrofit2.http.POST
-
-data class LoginRequest(val username: String, val password: String)
-data class LoginUser(val id: String, val username: String, val role: String, val avatarUrl: String?)
-data class LoginResponse(val access_token: String, val refresh_token: String, val user: LoginUser, val wgName: String)
-
-data class RefreshRequest(val refresh_token: String)
-data class RefreshResponse(val access_token: String, val refresh_token: String)
+import retrofit2.http.PUT
+import retrofit2.http.Query
+import java.util.UUID
 
 interface APIService {
+    // Account
     @POST("api/login")
     suspend fun login(@Body req: LoginRequest): Response<LoginResponse>
-
     @POST("api/refresh")
     suspend fun refresh(@Body req: RefreshRequest): Response<RefreshResponse>
-
     @GET("api/ping")
     suspend fun ping(@Header("Authorization") token: String): Response<Map<String, String>>
+
+    // Expenses
+    @GET("api/expenses")
+    suspend fun expenseGet(@Header("Authorization") token: String): Response<ExpenseResponse>
+    @POST("api/expenses")
+    suspend fun expenseCreate(@Header("Authorization") token: String)
+    @PUT("api/expenses")
+    suspend fun expenseUpdate(@Header("Authorization") token: String)
+    @DELETE("api/expenses")
+    suspend fun expenseDelete(@Header("Authorization") token: String)
+
+    // User
+    @GET("api/userinfo")
+    suspend fun userinfo(@Header("Authorization") token: String, @Query("id") userId: UUID)
 }

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

@@ -0,0 +1,15 @@
+package de.miaurizius.shap_planner.network
+
+import de.miaurizius.shap_planner.entities.Expense
+
+// Login
+data class LoginRequest(val username: String, val password: String)
+data class LoginUser(val id: String, val username: String, val role: String, val avatarUrl: String?)
+data class LoginResponse(val access_token: String, val refresh_token: String, val user: LoginUser, val wgName: String)
+
+// Refresh-Tokens
+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>)

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

@@ -2,31 +2,50 @@ package de.miaurizius.shap_planner.ui
 
 import androidx.compose.runtime.Composable
 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.LoginScreen
+import de.miaurizius.shap_planner.viewmodels.MainViewModel
 
 @Composable
 fun AppContent(
-    isLoggedIn: Boolean,
+    // Login
     accountList: List<Account>,
     selectedAccount: Account?,
     showLoginForNewAccount: Boolean,
     onLogin: (String, String, String) -> Unit,
+
+    // Expenses
+    expenses: List<Expense>,
+    onExpenseClick: (Expense) -> Unit,
+
+    // Account
     onSelectAccount: (Account) -> Unit,
     onLogoutAccount: () -> Unit,
     onAddAccountClick: () -> Unit,
     onDeleteAccount: () -> Unit,
+
+    // Session
     sessionState: SessionState,
     onValidateSession: () -> Unit,
-    onSessionInvalid: () -> Unit
+    onSessionInvalid: () -> Unit,
+
+    //Important
+    viewModel: MainViewModel
 ) {
     when {
         showLoginForNewAccount -> LoginScreen(onLogin)
         accountList.isEmpty() -> LoginScreen(onLogin)
         selectedAccount != null -> DashboardScreen(
+            // Data and regarding Methods
             account = selectedAccount,
+            expenses = expenses,
+            onExpenseClick = onExpenseClick,
+
+            // Default Methods
+            mainViewModel = viewModel,
             onBack = onLogoutAccount,
             onDelete = onDeleteAccount,
             sessionState = sessionState,

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

@@ -2,9 +2,11 @@ package de.miaurizius.shap_planner.ui.screens
 
 import androidx.activity.compose.BackHandler
 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
@@ -13,22 +15,34 @@ 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.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
 import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.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.viewmodels.MainViewModel
 
 @Composable
 fun DashboardScreen(
+    // Data and regarding Methods
     account: Account,
+    expenses: List<Expense>,
+    onExpenseClick: (Expense) -> Unit,
+
+    // Default Methods
+    mainViewModel: MainViewModel,
     onBack: () -> Unit,
     onDelete: () -> Unit,
     sessionState: SessionState,
@@ -36,7 +50,7 @@ fun DashboardScreen(
     onSessionInvalid: () -> Unit) {
 
     LaunchedEffect(Unit) { onValidate() }
-
+    mainViewModel.loadExpenses(account)
     when (sessionState) {
         SessionState.Loading -> {
             Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
@@ -55,6 +69,7 @@ fun DashboardScreen(
                     .statusBarsPadding()
                     .navigationBarsPadding()
             ) {
+                // Header
                 Row(
                     modifier = Modifier.fillMaxWidth(),
                     horizontalArrangement = Arrangement.SpaceBetween,
@@ -84,16 +99,19 @@ fun DashboardScreen(
 
                 Spacer(modifier = Modifier.height(10.dp))
 
-                Box(
+                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
-                        ),
-                    contentAlignment = Alignment.Center
+                        .background(MaterialTheme.colorScheme.surfaceVariant, shape = MaterialTheme.shapes.medium),
+                    contentPadding = PaddingValues(8.dp),
+                    verticalArrangement = Arrangement.spacedBy(8.dp)
                 ) {
-                    Text("Hier kommen bald deine WG-Kosten hin 🚀")
+                    items(expenses) { expense ->
+                        ExpenseItem(expense = expense, onClick = { onExpenseClick(expense) })
+                    }
                 }
             }
         }
@@ -108,4 +126,18 @@ fun DashboardScreen(
             Text("Server error")
         }
     }
+}
+
+@Composable
+fun ExpenseItem(expense: Expense, onClick: () -> Unit) {
+    Surface(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)
+        }
+    }
 }

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

@@ -8,9 +8,11 @@ import androidx.lifecycle.viewModelScope
 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.network.RefreshRequest
 import de.miaurizius.shap_planner.network.RetrofitProvider
 import de.miaurizius.shap_planner.network.SessionState
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.stateIn
@@ -19,12 +21,32 @@ import kotlin.collections.emptyList
 
 class MainViewModel(private val accountDao: AccountDao, private val tokenStorage: TokenStorage) : ViewModel() {
 
+    var selectedAccount by mutableStateOf<Account?>(null)
+        private set
     val accounts: StateFlow<List<Account>> = accountDao.getAllAccounts()
         .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), emptyList())
-
     var sessionState by mutableStateOf<SessionState>(SessionState.Loading)
         private set
 
+    private val _expenses = MutableStateFlow<List<Expense>>(emptyList())
+    val expenses: StateFlow<List<Expense>> = _expenses
+
+    fun loadExpenses(account: Account) {
+        viewModelScope.launch {
+            try {
+                val api = RetrofitProvider.create(account.serverUrl)
+                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()
+            }
+        }
+    }
+
     fun validateSession(account: Account) {
         viewModelScope.launch {
             sessionState = SessionState.Loading
@@ -54,10 +76,15 @@ class MainViewModel(private val accountDao: AccountDao, private val tokenStorage
                     tokenStorage.saveTokens(
                         account.id.toString(),
                         newTokens.access_token,
-                        newTokens.access_token
+                        newTokens.refresh_token
                     )
 
                     sessionState = SessionState.Valid
+
+                    // Fetch data
+                    loadExpenses(account)
+                    println("All data fetched")
+
                     return@launch
                 } else {
                     sessionState = SessionState.Invalid
@@ -73,7 +100,6 @@ class MainViewModel(private val accountDao: AccountDao, private val tokenStorage
             accountDao.insertAccount(account)
         }
     }
-
     fun deleteAccount(account: Account) {
         viewModelScope.launch {
             accountDao.deleteAccount(account)
@@ -81,14 +107,9 @@ class MainViewModel(private val accountDao: AccountDao, private val tokenStorage
             selectedAccount = null
         }
     }
-
-    var selectedAccount by mutableStateOf<Account?>(null)
-        private set
-
     fun selectAccount(account: Account) {
         selectedAccount = account
     }
-
     fun logoutFromAccount() {
         selectedAccount = null
     }