refactor: clean up MVI pattern

Author: thunderbiscuit

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/domain/Wallet.kt

@@ -33,7 +33,7 @@ import org.bitcoindevkit.devkitwallet.data.Timestamp
 import org.bitcoindevkit.devkitwallet.data.TxDetails
 import org.bitcoindevkit.devkitwallet.domain.utils.intoDomain
 import org.bitcoindevkit.devkitwallet.domain.utils.intoProto
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.Recipient
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.Recipient
 import java.util.UUID
 import org.bitcoindevkit.Wallet as BdkWallet
 
@@ -63,7 +63,7 @@ class Wallet private constructor(
         // txBuilder = txBuilder.feeRate(satPerVbyte = fee_rate)
 
         // technique 2 for adding a list of recipients to the TxBuilder
-        var txBuilder =
+        val txBuilder =
             recipientList.fold(TxBuilder()) { builder, recipient ->
                 // val address = Address(recipient.address)
                 val scriptPubKey: Script = Address(recipient.address, Network.TESTNET).scriptPubkey()

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/navigation/HomeNavigation.kt

@@ -8,6 +8,9 @@ package org.bitcoindevkit.devkitwallet.presentation.navigation
 import androidx.compose.animation.AnimatedContentTransitionScope
 import androidx.compose.animation.core.tween
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
@@ -25,7 +28,9 @@ private const val ANIMATION_DURATION: Int = 400
 @Composable
 fun HomeNavigation(activeWallet: Wallet) {
     val navController: NavHostController = rememberNavController()
-    val walletViewModel = WalletViewModel(activeWallet)
+    val walletViewModel = viewModel<WalletViewModel> {
+        WalletViewModel(activeWallet)
+    }
 
     NavHost(
         navController = navController,
@@ -126,8 +131,9 @@ fun HomeNavigation(activeWallet: Wallet) {
                 )
             }
         ) {
+            val state by walletViewModel.state.collectAsState()
             BlockchainClientScreen(
-                state = walletViewModel.state,
+                state = state,
                 navController = navController
             )
         }

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/navigation/WalletNavigation.kt

@@ -9,6 +9,9 @@ import androidx.compose.animation.AnimatedContentTransitionScope
 import androidx.compose.animation.core.tween
 import androidx.compose.material3.DrawerState
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
@@ -30,8 +33,12 @@ private const val ANIMATION_DURATION: Int = 400
 @Composable
 fun WalletNavigation(drawerState: DrawerState, activeWallet: Wallet, walletViewModel: WalletViewModel) {
     val navController: NavHostController = rememberNavController()
-    val addressViewModel = AddressViewModel(activeWallet)
-    val sendViewModel = SendViewModel(activeWallet)
+    val addressViewModel = viewModel<AddressViewModel> {
+        AddressViewModel(activeWallet)
+    }
+    val sendViewModel = viewModel<SendViewModel> {
+        SendViewModel(activeWallet)
+    }
 
     NavHost(
         navController = navController,
@@ -50,7 +57,15 @@ fun WalletNavigation(drawerState: DrawerState, activeWallet: Wallet, walletViewM
                     animationSpec = tween(ANIMATION_DURATION)
                 )
             },
-        ) { WalletHomeScreen(navController, drawerState, walletViewModel) }
+        ) {
+            val walletState by walletViewModel.state.collectAsState()
+            WalletHomeScreen(
+                drawerState = drawerState,
+                state = walletState,
+                onAction = walletViewModel::onAction,
+                navController = navController
+            )
+        }
 
         composable<ReceiveScreen>(
             enterTransition = {
@@ -78,10 +93,11 @@ fun WalletNavigation(drawerState: DrawerState, activeWallet: Wallet, walletViewM
                 )
             }
         ) {
+            val state by addressViewModel.state.collectAsState()
             ReceiveScreen(
-                state = addressViewModel.state,
+                state = state,
                 onAction = addressViewModel::onAction,
-                navController
+                navController = navController
             )
         }
 
@@ -110,7 +126,8 @@ fun WalletNavigation(drawerState: DrawerState, activeWallet: Wallet, walletViewM
                     animationSpec = tween(ANIMATION_DURATION)
                 )
             }
-        ) { SendScreen(navController, sendViewModel) }
+        ) { SendScreen(onAction = sendViewModel::onAction, navController = navController) }
+
 
         composable<RbfScreen>(
             enterTransition = {

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/ui/screens/drawer/BlockchainClientScreen.kt

@@ -24,7 +24,7 @@ import org.bitcoindevkit.devkitwallet.presentation.theme.DevkitWalletColors
 import org.bitcoindevkit.devkitwallet.presentation.theme.quattroBold
 import org.bitcoindevkit.devkitwallet.presentation.theme.standardText
 import org.bitcoindevkit.devkitwallet.presentation.ui.components.SecondaryScreensAppBar
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.WalletScreenState
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.WalletScreenState
 
 @Composable
 internal fun BlockchainClientScreen(state: WalletScreenState, navController: NavController) {

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/ui/screens/wallet/ReceiveScreen.kt

@@ -62,9 +62,9 @@ import org.bitcoindevkit.devkitwallet.presentation.theme.DevkitWalletColors
 import org.bitcoindevkit.devkitwallet.presentation.theme.monoRegular
 import org.bitcoindevkit.devkitwallet.presentation.theme.standardText
 import org.bitcoindevkit.devkitwallet.presentation.ui.components.SecondaryScreensAppBar
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.ReceiveScreenAction
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.ReceiveScreenState
 import androidx.core.graphics.set
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.ReceiveScreenAction
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.ReceiveScreenState
 
 private const val TAG = "ReceiveScreen"
 

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/ui/screens/wallet/SendScreen.kt

@@ -69,19 +69,19 @@ import org.bitcoindevkit.devkitwallet.presentation.theme.DevkitWalletColors
 import org.bitcoindevkit.devkitwallet.presentation.theme.standardText
 import org.bitcoindevkit.devkitwallet.presentation.ui.components.NeutralButton
 import org.bitcoindevkit.devkitwallet.presentation.ui.components.SecondaryScreensAppBar
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.SendViewModel
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.Recipient
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.SendScreenAction
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.TransactionType
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.TxDataBundle
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.Recipient
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.SendScreenAction
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.TransactionType
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.TxDataBundle
 
 private const val TAG = "SendScreen"
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
-internal fun SendScreen(navController: NavController, sendViewModel: SendViewModel) {
-    val onAction = sendViewModel::onAction
-
+internal fun SendScreen(
+    onAction: (SendScreenAction) -> Unit,
+    navController: NavController,
+) {
     val context = LocalContext.current
     val coroutineScope = rememberCoroutineScope()
 

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/ui/screens/wallet/WalletHomeScreen.kt

@@ -59,22 +59,19 @@ import org.bitcoindevkit.devkitwallet.presentation.theme.monoRegular
 import org.bitcoindevkit.devkitwallet.presentation.theme.quattroBold
 import org.bitcoindevkit.devkitwallet.presentation.ui.components.LoadingAnimation
 import org.bitcoindevkit.devkitwallet.presentation.ui.components.NeutralButton
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.WalletViewModel
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.WalletScreenAction
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.WalletScreenState
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.WalletScreenAction
+import org.bitcoindevkit.devkitwallet.presentation.viewmodels.WalletScreenState
 
 private const val TAG = "WalletHomeScreen"
 
 @Composable
 internal fun WalletHomeScreen(
-    navController: NavHostController,
     drawerState: DrawerState,
-    walletViewModel: WalletViewModel,
+    state: WalletScreenState,
+    onAction: (WalletScreenAction) -> Unit,
+    navController: NavHostController,
 ) {
     val networkAvailable: Boolean = isOnline(LocalContext.current)
-    val state: WalletScreenState = walletViewModel.state
-    val onAction = walletViewModel::onAction
-
     val interactionSource = remember { MutableInteractionSource() }
     val scope: CoroutineScope = rememberCoroutineScope()
 

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/viewmodels/AddressViewModel.kt

@@ -5,20 +5,28 @@
 
 package org.bitcoindevkit.devkitwallet.presentation.viewmodels
 
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
 import org.bitcoindevkit.AddressInfo
 import org.bitcoindevkit.devkitwallet.domain.DwLogger
 import org.bitcoindevkit.devkitwallet.domain.DwLogger.LogLevel.INFO
 import org.bitcoindevkit.devkitwallet.domain.Wallet
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.ReceiveScreenAction
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.ReceiveScreenState
+
+data class ReceiveScreenState(
+    val address: String? = null,
+    val addressIndex: UInt? = null,
+)
+
+sealed interface ReceiveScreenAction {
+    data object UpdateAddress : ReceiveScreenAction
+}
 
 internal class AddressViewModel(private val wallet: Wallet) : ViewModel() {
-    var state: ReceiveScreenState by mutableStateOf(ReceiveScreenState())
-        private set
+    private val _state: MutableStateFlow<ReceiveScreenState> = MutableStateFlow(ReceiveScreenState())
+    val state: StateFlow<ReceiveScreenState> = _state.asStateFlow()
 
     fun onAction(action: ReceiveScreenAction) {
         when (action) {
@@ -30,9 +38,11 @@ internal class AddressViewModel(private val wallet: Wallet) : ViewModel() {
         val newAddress: AddressInfo = wallet.getNewAddress()
         DwLogger.log(INFO, "Revealing new address at index ${newAddress.index}")
 
-        state = ReceiveScreenState(
-            address = newAddress.address.toString(),
-            addressIndex = newAddress.index
-        )
+        _state.update {
+            ReceiveScreenState(
+                address = newAddress.address.toString(),
+                addressIndex = newAddress.index
+            )
+        }
     }
 }

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/viewmodels/SendViewModel.kt

@@ -10,12 +10,26 @@ import androidx.lifecycle.ViewModel
 import org.bitcoindevkit.FeeRate
 import org.bitcoindevkit.Psbt
 import org.bitcoindevkit.devkitwallet.domain.Wallet
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.SendScreenAction
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.TransactionType
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.TxDataBundle
 
 private const val TAG = "SendViewModel"
 
+sealed class SendScreenAction {
+    data class Broadcast(val txDataBundle: TxDataBundle) : SendScreenAction()
+}
+
+data class TxDataBundle(
+    val recipients: List<Recipient>,
+    val feeRate: ULong,
+    val transactionType: TransactionType,
+)
+
+data class Recipient(var address: String, var amount: ULong)
+
+enum class TransactionType {
+    STANDARD,
+    SEND_ALL,
+}
+
 internal class SendViewModel(private val wallet: Wallet) : ViewModel() {
     fun onAction(action: SendScreenAction) {
         when (action) {

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/viewmodels/WalletViewModel.kt

@@ -6,26 +6,37 @@
 package org.bitcoindevkit.devkitwallet.presentation.viewmodels
 
 import android.util.Log
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.bitcoindevkit.devkitwallet.domain.CurrencyUnit
 import org.bitcoindevkit.devkitwallet.domain.Wallet
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.WalletScreenAction
-import org.bitcoindevkit.devkitwallet.presentation.viewmodels.mvi.WalletScreenState
 
 private const val TAG = "WalletViewModel"
 
+data class WalletScreenState(
+    val balance: ULong = 0u,
+    val syncing: Boolean = false,
+    val unit: CurrencyUnit = CurrencyUnit.Bitcoin,
+    val esploraEndpoint: String = "",
+)
+
+sealed interface WalletScreenAction {
+    data object UpdateBalance : WalletScreenAction
+    data object SwitchUnit : WalletScreenAction
+}
+
 class WalletViewModel(
     private val wallet: Wallet,
 ) : ViewModel() {
-    var state: WalletScreenState by mutableStateOf(WalletScreenState())
-        private set
+    private val _state: MutableStateFlow<WalletScreenState> = MutableStateFlow(WalletScreenState())
+    val state: StateFlow<WalletScreenState> = _state.asStateFlow()
 
     init {
         updateClientEndpoint()
@@ -39,20 +50,23 @@ class WalletViewModel(
     }
 
     private fun switchUnit() {
-        state = when (state.unit) {
-            CurrencyUnit.Bitcoin -> state.copy(unit = CurrencyUnit.Satoshi)
-            CurrencyUnit.Satoshi -> state.copy(unit = CurrencyUnit.Bitcoin)
+        _state.update { state ->
+            when (state.unit) {
+                CurrencyUnit.Bitcoin -> state.copy(unit = CurrencyUnit.Satoshi)
+                CurrencyUnit.Satoshi -> state.copy(unit = CurrencyUnit.Bitcoin)
+            }
         }
     }
 
     private fun updateBalance() {
-        state = state.copy(syncing = true)
+        _state.update { it.copy(syncing = true) }
+
         viewModelScope.launch(Dispatchers.IO) {
             wallet.sync()
             withContext(Dispatchers.Main) {
                 val newBalance = wallet.getBalance()
                 Log.i(TAG, "New balance: $newBalance")
-                state = state.copy(balance = newBalance, syncing = false)
+                _state.update { it.copy(balance = newBalance, syncing = false) }
             }
         }
     }
@@ -61,7 +75,7 @@ class WalletViewModel(
         viewModelScope.launch(Dispatchers.IO) {
             val endpoint = wallet.getClientEndpoint()
             withContext(Dispatchers.Main) {
-                state = state.copy(esploraEndpoint = endpoint)
+                _state.update { it.copy(esploraEndpoint = endpoint) }
             }
         }
     }