[wallet] Initial (WIP) implementation of currency conversion

9 files changed, 464 insertions, 216 deletions

diff --git a/wallet/src/main/java/net/taler/wallet/transactions/TransactionWithdrawalFragment.kt b/wallet/src/main/java/net/taler/wallet/transactions/TransactionWithdrawalFragment.kt
index 6dc079f..f19fa4a 100644
--- a/wallet/src/main/java/net/taler/wallet/transactions/TransactionWithdrawalFragment.kt
+++ b/wallet/src/main/java/net/taler/wallet/transactions/TransactionWithdrawalFragment.kt
@@ -80,10 +80,11 @@ class TransactionWithdrawalFragment : TransactionDetailFragment(), ActionListene
                 // TODO what if there's more than one or no URI?
                 if (tx.withdrawalDetails.exchangeCreditAccounts?.isEmpty() != false) return
                 val status = createManualTransferRequired(
-                    amount = tx.amountRaw,
-                    exchangeBaseUrl = tx.exchangeBaseUrl,
-                    uriStr = tx.withdrawalDetails.exchangeCreditAccounts[0].paytoUri,
                     transactionId = tx.transactionId,
+                    exchangeBaseUrl = tx.exchangeBaseUrl,
+                    amountRaw = tx.amountRaw,
+                    amountEffective = tx.amountEffective,
+                    withdrawalAccountList = tx.withdrawalDetails.exchangeCreditAccounts,
                 )
                 withdrawManager.viewManualWithdrawal(status)
                 findNavController().navigate(
diff --git a/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt b/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt
index 6cd5602..3af6aaf 100644
--- a/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt
+++ b/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt
@@ -42,6 +42,7 @@ import net.taler.wallet.TAG
 import net.taler.wallet.backend.TalerErrorCode
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.cleanExchange
+import net.taler.wallet.currency.CurrencySpecification
 import net.taler.wallet.refund.RefundPaymentInfo
 import net.taler.wallet.transactions.TransactionMajorState.None
 import net.taler.wallet.transactions.TransactionMajorState.Pending
@@ -224,6 +225,13 @@ data class WithdrawalExchangeAccountDetails (
     val transferAmount: Amount? = null,
 
     /**
+     * Currency specification for the external currency.
+     *
+     * Only included if this account requires a currency conversion.
+     */
+    val currencySpecification: CurrencySpecification? = null,
+
+    /**
      * Further restrictions for sending money to the
      * exchange.
      */
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/ConversionComposable.kt b/wallet/src/main/java/net/taler/wallet/withdraw/ConversionComposable.kt
new file mode 100644
index 0000000..cbe4a65
--- /dev/null
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/ConversionComposable.kt
@@ -0,0 +1,156 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.wallet.withdraw
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyRow
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+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.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import net.taler.common.Amount
+import net.taler.wallet.R
+import net.taler.wallet.compose.SelectionChip
+import net.taler.wallet.currency.CurrencySpecification
+import net.taler.wallet.transactions.AmountType
+import net.taler.wallet.transactions.TransactionAmountComposable
+import net.taler.wallet.transactions.WithdrawalExchangeAccountDetails
+
+@Composable
+fun ConversionComposable(
+    amountRaw: Amount,
+    amountEffective: Amount,
+    accounts: List<WithdrawalExchangeAccountDetails>?,
+) {
+    val altCurrencies = accounts
+        ?.filter { it.currencySpecification != null }
+        ?.map { it.currencySpecification!!.name } ?: emptyList()
+    var selectedCurrency by remember { mutableStateOf(amountRaw.currency) }
+    val selectedAccount = accounts?.find {
+        it.currencySpecification?.name == selectedCurrency
+    }
+
+    Column(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalAlignment = Alignment.CenterHorizontally,
+    ) {
+        if (altCurrencies.isNotEmpty()) {
+            TransferCurrencyChooser(
+                currencies = listOf(amountRaw.currency) + altCurrencies,
+                selectedCurrency = selectedCurrency,
+                onSelectedCurrency = { selectedCurrency = it }
+            )
+        }
+
+        selectedAccount?.transferAmount?.let { transferAmount ->
+            TransactionAmountComposable(
+                label = "Transfer",
+                amount = transferAmount,
+                amountType = AmountType.Neutral,
+            )
+        }
+
+        TransactionAmountComposable(
+            label = if (selectedCurrency == amountRaw.currency) {
+                stringResource(R.string.amount_chosen)
+            } else {
+                "Conversion"
+            },
+            amount = amountRaw,
+            amountType = AmountType.Neutral,
+        )
+
+        val fee = amountRaw - amountEffective
+        if (!fee.isZero()) {
+            TransactionAmountComposable(
+                label = stringResource(id = R.string.withdraw_fees),
+                amount = fee,
+                amountType = AmountType.Negative,
+            )
+        }
+    }
+}
+
+@Composable
+fun TransferCurrencyChooser(
+    modifier: Modifier = Modifier,
+    currencies: List<String>,
+    selectedCurrency: String,
+    onSelectedCurrency: (currency: String) -> Unit,
+) {
+    if (currencies.isEmpty()) return
+    val currencyOptions: List<String> = currencies.distinct()
+
+    Column(
+        modifier = modifier,
+        horizontalAlignment = Alignment.CenterHorizontally,
+    ) {
+        Text(
+            modifier = Modifier.padding(top = 16.dp, start = 16.dp, end = 16.dp),
+            text = "This exchange allows currency conversion.",
+            style = MaterialTheme.typography.bodyMedium,
+        )
+
+        LazyRow {
+            items(items = currencyOptions) { currency ->
+                SelectionChip(
+                    modifier = Modifier.padding(horizontal = 4.dp),
+                    label = { Text(currency) },
+                    selected = currency == selectedCurrency,
+                    value = currency,
+                    onSelected = onSelectedCurrency,
+                )
+            }
+        }
+    }
+}
+
+@Preview
+@Composable
+fun ConversionComposablePreview() {
+    Surface {
+        ConversionComposable(
+            amountRaw = Amount.fromJSONString("CHF:10"),
+            amountEffective = Amount.fromJSONString("CHF:9.5"),
+            accounts = listOf(
+                WithdrawalExchangeAccountDetails(
+                    paytoUri = "payto://IBAN/1231231231",
+                    transferAmount = Amount.fromJSONString("NETZBON:10"),
+                    currencySpecification = CurrencySpecification(
+                        name = "NETZBON",
+                        numFractionalInputDigits = 2,
+                        numFractionalNormalDigits = 2,
+                        numFractionalTrailingZeroDigits = 2,
+                        altUnitNames = mapOf("0" to "NETZBON"),
+                    ),
+                ),
+            ),
+        )
+    }
+}
\ No newline at end of file
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt b/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt
index aab22d3..3930966 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt
@@ -38,6 +38,7 @@ import net.taler.wallet.R
 import net.taler.wallet.backend.TalerErrorCode
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.cleanExchange
+import net.taler.wallet.currency.CurrencySpecification
 import net.taler.wallet.transactions.ActionButton
 import net.taler.wallet.transactions.ActionListener
 import net.taler.wallet.transactions.AmountType
@@ -54,6 +55,7 @@ import net.taler.wallet.transactions.TransactionState
 import net.taler.wallet.transactions.TransactionWithdrawal
 import net.taler.wallet.transactions.TransitionsComposable
 import net.taler.wallet.transactions.WithdrawalDetails.ManualTransfer
+import net.taler.wallet.transactions.WithdrawalExchangeAccountDetails
 
 @Composable
 fun TransactionWithdrawalComposable(
@@ -75,30 +77,30 @@ fun TransactionWithdrawalComposable(
             text = t.timestamp.ms.toAbsoluteTime(context).toString(),
             style = MaterialTheme.typography.bodyLarge,
         )
+
         TransactionAmountComposable(
             label = stringResource(id = R.string.withdraw_total),
             amount = t.amountEffective,
             amountType = AmountType.Positive,
         )
+
         ActionButton(tx = t, listener = actionListener)
-        TransactionAmountComposable(
-            label = stringResource(id = R.string.amount_chosen),
-            amount = t.amountRaw,
-            amountType = AmountType.Neutral,
-        )
-        val fee = t.amountRaw - t.amountEffective
-        if (!fee.isZero()) {
-            TransactionAmountComposable(
-                label = stringResource(id = R.string.withdraw_fees),
-                amount = fee,
-                amountType = AmountType.Negative,
+
+        if (t.withdrawalDetails is ManualTransfer) {
+            ConversionComposable(
+                amountRaw = t.amountRaw,
+                amountEffective = t.amountEffective,
+                accounts = t.withdrawalDetails.exchangeCreditAccounts,
             )
         }
+
         TransactionInfoComposable(
             label = stringResource(id = R.string.withdraw_exchange),
             info = cleanExchange(t.exchangeBaseUrl),
         )
+        
         TransitionsComposable(t, devMode, onTransition)
+
         if (devMode && t.error != null) {
             ErrorTransactionButton(error = t.error)
         }
@@ -114,15 +116,30 @@ fun TransactionWithdrawalComposablePreview() {
         txState = TransactionState(Pending),
         txActions = listOf(Retry, Suspend, Abort),
         exchangeBaseUrl = "https://exchange.demo.taler.net/",
-        withdrawalDetails = ManualTransfer(exchangeCreditAccounts = emptyList()),
+        withdrawalDetails = ManualTransfer(
+            exchangeCreditAccounts = listOf(
+                WithdrawalExchangeAccountDetails(
+                    paytoUri = "payto://IBAN/1231231231",
+                    transferAmount = Amount.fromJSONString("NETZBON:42.23"),
+                    currencySpecification = CurrencySpecification(
+                        name = "NETZBON",
+                        numFractionalInputDigits = 2,
+                        numFractionalNormalDigits = 2,
+                        numFractionalTrailingZeroDigits = 2,
+                        altUnitNames = mapOf("0" to "NETZBON"),
+                    ),
+                ),
+            ),
+        ),
         amountRaw = Amount.fromString("TESTKUDOS", "42.23"),
         amountEffective = Amount.fromString("TESTKUDOS", "42.1337"),
         error = TalerErrorInfo(code = TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED),
     )
+
     val listener = object : ActionListener {
-        override fun onActionButtonClicked(tx: Transaction, type: ActionListener.Type) {
-        }
+        override fun onActionButtonClicked(tx: Transaction, type: ActionListener.Type) {}
     }
+
     Surface {
         TransactionWithdrawalComposable(t, true, listener) {}
     }
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/WithdrawManager.kt b/wallet/src/main/java/net/taler/wallet/withdraw/WithdrawManager.kt
index e18ab1a..c309a07 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/WithdrawManager.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/WithdrawManager.kt
@@ -38,6 +38,7 @@ import net.taler.wallet.withdraw.WithdrawStatus.ReceivedDetails
 
 sealed class WithdrawStatus {
     data class Loading(val talerWithdrawUri: String? = null) : WithdrawStatus()
+
     data class NeedsExchange(val exchangeSelection: Event<ExchangeSelection>) : WithdrawStatus()
 
     data class TosReviewRequired(
@@ -63,33 +64,43 @@ sealed class WithdrawStatus {
         val ageRestrictionOptions: List<Int>? = null,
     ) : WithdrawStatus()
 
-    object Withdrawing : WithdrawStatus()
+    data object Withdrawing : WithdrawStatus()
+
     data class Success(val currency: String, val transactionId: String) : WithdrawStatus()
-    sealed class ManualTransferRequired : WithdrawStatus() {
-        abstract val uri: Uri
-        abstract val transactionId: String?
-    }
 
-    data class ManualTransferRequiredIBAN(
+    class ManualTransferRequired(
+        val transactionId: String?,
         val exchangeBaseUrl: String,
+        val withdrawalTransfers: List<TransferData>,
+    ) : WithdrawStatus()
+
+    data class Error(val message: String?) : WithdrawStatus()
+}
+
+sealed class TransferData {
+    abstract val uri: Uri
+    abstract val subject: String
+    abstract val amountRaw: Amount
+    abstract val amountEffective: Amount
+
+    val currency get() = amountRaw.currency
+
+    data class IBAN(
         override val uri: Uri,
+        override val subject: String,
+        override val amountRaw: Amount,
+        override val amountEffective: Amount,
         val iban: String,
-        val subject: String,
-        val amountRaw: Amount,
-        override val transactionId: String?,
-    ) : ManualTransferRequired()
+    ): TransferData()
 
-    data class ManualTransferRequiredBitcoin(
-        val exchangeBaseUrl: String,
+    data class Bitcoin(
         override val uri: Uri,
+        override val subject: String,
+        override val amountRaw: Amount,
+        override val amountEffective: Amount,
         val account: String,
-        val segwitAddrs: List<String>,
-        val subject: String,
-        val amountRaw: Amount,
-        override val transactionId: String?,
-    ) : ManualTransferRequired()
-
-    data class Error(val message: String?) : WithdrawStatus()
+        val segwitAddresses: List<String>,
+    ): TransferData()
 }
 
 sealed class WithdrawTestStatus {
@@ -290,10 +301,8 @@ class WithdrawManager(
             handleError("acceptManualWithdrawal", it)
         }.onSuccess { response ->
             withdrawStatus.value = createManualTransferRequired(
-                amount = status.amountRaw,
-                exchangeBaseUrl = status.exchangeBaseUrl,
-                // TODO what if there's more than one or no URI?
-                uriStr = response.withdrawalAccountsList[0].paytoUri,
+                status = status,
+                response = response,
             )
         }
     }
@@ -316,33 +325,46 @@ class WithdrawManager(
 }
 
 fun createManualTransferRequired(
-    amount: Amount,
+    transactionId: String,
     exchangeBaseUrl: String,
-    uriStr: String,
-    transactionId: String? = null,
-): WithdrawStatus.ManualTransferRequired {
-    val uri = Uri.parse(uriStr.replace("receiver-name=", "receiver_name="))
-    if ("bitcoin".equals(uri.authority, true)) {
-        val msg = uri.getQueryParameter("message").orEmpty()
-        val reg = "\\b([A-Z0-9]{52})\\b".toRegex().find(msg)
-        val reserve = reg?.value ?: uri.getQueryParameter("subject")!!
-        val segwitAddrs = Bech32.generateFakeSegwitAddress(reserve, uri.pathSegments.first())
-        return WithdrawStatus.ManualTransferRequiredBitcoin(
-            exchangeBaseUrl = exchangeBaseUrl,
+    amountRaw: Amount,
+    amountEffective: Amount,
+    withdrawalAccountList: List<WithdrawalExchangeAccountDetails>,
+) = WithdrawStatus.ManualTransferRequired(
+    transactionId = transactionId,
+    exchangeBaseUrl = exchangeBaseUrl,
+    withdrawalTransfers = withdrawalAccountList.map {
+        val uri = Uri.parse(it.paytoUri.replace("receiver-name=", "receiver_name="))
+        if ("bitcoin".equals(uri.authority, true)) {
+            val msg = uri.getQueryParameter("message").orEmpty()
+            val reg = "\\b([A-Z0-9]{52})\\b".toRegex().find(msg)
+            val reserve = reg?.value ?: uri.getQueryParameter("subject")!!
+            val segwitAddresses = Bech32.generateFakeSegwitAddress(reserve, uri.pathSegments.first())
+            TransferData.Bitcoin(
+                uri = uri,
+                account = uri.lastPathSegment!!,
+                segwitAddresses = segwitAddresses,
+                subject = reserve,
+                amountRaw = amountRaw,
+                amountEffective = amountEffective,
+            )
+        } else TransferData.IBAN(
             uri = uri,
-            account = uri.lastPathSegment!!,
-            segwitAddrs = segwitAddrs,
-            subject = reserve,
-            amountRaw = amount,
-            transactionId = transactionId,
+            iban = uri.lastPathSegment!!,
+            subject = uri.getQueryParameter("message") ?: "Error: No message in URI",
+            amountRaw = amountRaw,
+            amountEffective = amountEffective,
         )
-    }
-    return WithdrawStatus.ManualTransferRequiredIBAN(
-        exchangeBaseUrl = exchangeBaseUrl,
-        uri = uri,
-        iban = uri.lastPathSegment!!,
-        subject = uri.getQueryParameter("message") ?: "Error: No message in URI",
-        amountRaw = amount,
-        transactionId = transactionId,
-    )
-}
+    },
+)
+
+fun createManualTransferRequired(
+    status: ReceivedDetails,
+    response: AcceptManualWithdrawalResponse,
+): WithdrawStatus.ManualTransferRequired = createManualTransferRequired(
+    transactionId = response.transactionId,
+    exchangeBaseUrl = status.exchangeBaseUrl,
+    amountRaw = status.amountRaw,
+    amountEffective = status.amountEffective,
+    withdrawalAccountList = response.withdrawalAccountsList,
+)
\ No newline at end of file
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/manual/ManualWithdrawSuccessFragment.kt b/wallet/src/main/java/net/taler/wallet/withdraw/manual/ManualWithdrawSuccessFragment.kt
index fa3f38b..44bb1f8 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/manual/ManualWithdrawSuccessFragment.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/manual/ManualWithdrawSuccessFragment.kt
@@ -32,47 +32,49 @@ import net.taler.wallet.R
 import net.taler.wallet.TAG
 import net.taler.wallet.compose.TalerSurface
 import net.taler.wallet.showError
+import net.taler.wallet.withdraw.TransferData
 import net.taler.wallet.withdraw.WithdrawStatus
 
 class ManualWithdrawSuccessFragment : Fragment() {
     private val model: MainViewModel by activityViewModels()
     private val transactionManager by lazy { model.transactionManager }
     private val withdrawManager by lazy { model.withdrawManager }
+
+    private lateinit var status: WithdrawStatus.ManualTransferRequired
+
     override fun onCreateView(
         inflater: LayoutInflater, container: ViewGroup?,
         savedInstanceState: Bundle?,
     ): View = ComposeView(requireContext()).apply {
-        val status = withdrawManager.withdrawStatus.value as WithdrawStatus.ManualTransferRequired
-        val intent = Intent().apply {
-            data = status.uri
+        status = withdrawManager.withdrawStatus.value as WithdrawStatus.ManualTransferRequired
+
+        setContent {
+            TalerSurface {
+                ScreenTransfer(
+                    status = status,
+                    bankAppClick = { onBankAppClick(it) },
+                    onCancelClick = { onCancelClick() },
+                )
+            }
         }
-        // TODO test if this works with an actual payto:// handling app
+    }
+
+    private fun onBankAppClick(transfer: TransferData) {
+        val intent = Intent().apply { data = transfer.uri }
         val componentName = intent.resolveActivity(requireContext().packageManager)
-        val onBankAppClick = if (componentName == null) null else {
-            { requireContext().startActivitySafe(intent) }
-        }
-        val tid = status.transactionId
-        val onCancelClick = if (tid == null) null else {
-            {
-                transactionManager.deleteTransaction(tid) {
-                    Log.e(TAG, "Error deleteTransaction $it")
-                    showError(it)
-                }
-                findNavController().navigate(R.id.action_nav_exchange_manual_withdrawal_success_to_nav_main)
-            }
+        if (componentName != null) {
+            requireContext().startActivitySafe(intent)
         }
-        setContent {
-            TalerSurface {
-                when (status) {
-                    is WithdrawStatus.ManualTransferRequiredBitcoin -> {
-                        ScreenBitcoin(status, onBankAppClick, onCancelClick)
-                    }
+    }
 
-                    is WithdrawStatus.ManualTransferRequiredIBAN -> {
-                        ScreenIBAN(status, onBankAppClick, onCancelClick)
-                    }
-                }
+    private fun onCancelClick() {
+        status.transactionId?.let { tid ->
+            transactionManager.deleteTransaction(tid) {
+                Log.e(TAG, "Error deleteTransaction $it")
+                showError(it)
             }
+
+            findNavController().navigate(R.id.action_nav_exchange_manual_withdrawal_success_to_nav_main)
         }
     }
 
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/manual/ScreenIBAN.kt b/wallet/src/main/java/net/taler/wallet/withdraw/manual/ScreenTransfer.kt
index 537f3ad..ad74363 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/manual/ScreenIBAN.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/manual/ScreenTransfer.kt
@@ -1,6 +1,6 @@
 /*
  * This file is part of GNU Taler
- * (C) 2022 Taler Systems S.A.
+ * (C) 2023 Taler Systems S.A.
  *
  * GNU Taler is free software; you can redistribute it and/or modify it under the
  * terms of the GNU General Public License as published by the Free Software
@@ -17,15 +17,13 @@
 package net.taler.wallet.withdraw.manual
 
 import android.net.Uri
-import androidx.compose.foundation.BorderStroke
-import androidx.compose.foundation.background
-import androidx.compose.foundation.border
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.wrapContentWidth
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ContentCopy
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Icon
@@ -33,78 +31,89 @@ import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.ContentCopy
 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.draw.alpha
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.res.colorResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import net.taler.common.Amount
+import net.taler.wallet.CURRENCY_BTC
 import net.taler.wallet.R
 import net.taler.wallet.compose.copyToClipBoard
+import net.taler.wallet.withdraw.TransferCurrencyChooser
+import net.taler.wallet.withdraw.TransferData
 import net.taler.wallet.withdraw.WithdrawStatus
 
 @Composable
-fun ScreenIBAN(
-    status: WithdrawStatus.ManualTransferRequiredIBAN,
-    bankAppClick: (() -> Unit)?,
+fun ScreenTransfer(
+    status: WithdrawStatus.ManualTransferRequired,
+    bankAppClick: ((transfer: TransferData) -> Unit)?,
     onCancelClick: (() -> Unit)?,
 ) {
+    // TODO: show some placeholder
+    if (status.withdrawalTransfers.isEmpty()) return
+
     val scrollState = rememberScrollState()
-    Column(modifier = Modifier
-        .wrapContentWidth(Alignment.CenterHorizontally)
-        .verticalScroll(scrollState)
-        .padding(all = 16.dp)
+    Column(
+        modifier = Modifier
+            .verticalScroll(scrollState)
+            .padding(all = 16.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
     ) {
         Text(
             text = stringResource(R.string.withdraw_manual_ready_title),
             style = MaterialTheme.typography.headlineSmall,
         )
-        Text(
-            text = stringResource(R.string.withdraw_manual_ready_intro,
-                status.amountRaw.toString()),
-            style = MaterialTheme.typography.bodyLarge,
-            modifier = Modifier
-                .padding(vertical = 8.dp)
-        )
-        DetailRow(stringResource(R.string.withdraw_manual_ready_iban), status.iban)
-        DetailRow(stringResource(R.string.withdraw_manual_ready_subject), status.subject)
-        DetailRow(stringResource(R.string.amount_chosen), status.amountRaw.toString())
-        DetailRow(stringResource(R.string.withdraw_exchange), status.exchangeBaseUrl, false)
-        Text(
-            text = stringResource(R.string.withdraw_manual_ready_warning),
-            style = MaterialTheme.typography.bodyMedium,
-            color = colorResource(R.color.notice_text),
-            modifier = Modifier
-                .align(Alignment.CenterHorizontally)
-                .padding(all = 8.dp)
-                .background(colorResource(R.color.notice_background))
-                .border(BorderStroke(2.dp, colorResource(R.color.notice_border)))
-                .padding(all = 16.dp)
-        )
-        if (bankAppClick != null) {
+
+        val defaultCurrency = status.withdrawalTransfers[0].currency
+        var selectedCurrency by remember { mutableStateOf(defaultCurrency) }
+        val selectedTransfer = status.withdrawalTransfers.firstOrNull { it.currency == selectedCurrency }
+
+        if (status.withdrawalTransfers.size > 1) {
+            TransferCurrencyChooser(
+                currencies = status.withdrawalTransfers.map { it.currency },
+                selectedCurrency = selectedCurrency,
+                onSelectedCurrency = { selectedCurrency = it }
+            )
+        }
+
+        when (selectedTransfer) {
+            is TransferData.IBAN -> TransferIBAN(
+                data = selectedTransfer,
+                exchangeBaseUrl = status.exchangeBaseUrl,
+            )
+            is TransferData.Bitcoin -> TransferBitcoin(
+                data = selectedTransfer,
+            )
+            else -> {
+                // TODO: show some placeholder
+            }
+        }
+
+        if (bankAppClick != null && selectedTransfer != null) {
             Button(
-                onClick = bankAppClick,
+                onClick = { bankAppClick(selectedTransfer) },
                 modifier = Modifier
-                    .padding(vertical = 16.dp)
-                    .align(Alignment.CenterHorizontally),
+                    .padding(top = 16.dp)
             ) {
                 Text(text = stringResource(R.string.withdraw_manual_ready_bank_button))
             }
         }
+
         if (onCancelClick != null) {
             Button(
                 onClick = onCancelClick,
                 colors = ButtonDefaults.buttonColors(containerColor = MaterialTheme.colorScheme.error),
                 modifier = Modifier
                     .padding(vertical = 16.dp)
-                    .align(Alignment.End),
             ) {
                 Text(
                     text = stringResource(R.string.withdraw_manual_ready_cancel),
@@ -146,15 +155,35 @@ fun DetailRow(label: String, content: String, copy: Boolean = true) {
 
 @Preview
 @Composable
-fun PreviewScreenIBAN() {
+fun ScreenTransferPreview() {
     Surface {
-        ScreenIBAN(WithdrawStatus.ManualTransferRequiredIBAN(
-            exchangeBaseUrl = "test.exchange.taler.net",
-            uri = Uri.parse("https://taler.net"),
-            iban = "ASDQWEASDZXCASDQWE",
-            subject = "Taler Withdrawal P2T19EXRBY4B145JRNZ8CQTD7TCS03JE9VZRCEVKVWCP930P56WG",
-            amountRaw = Amount("KUDOS", 10, 0),
-            transactionId = "",
-        ), {}) {}
+        ScreenTransfer(
+            status = WithdrawStatus.ManualTransferRequired(
+                transactionId = "",
+                exchangeBaseUrl = "test.exchange.taler.net",
+                withdrawalTransfers = listOf(
+                    TransferData.IBAN(
+                        uri = Uri.parse("https://taler.net"),
+                        iban = "ASDQWEASDZXCASDQWE",
+                        subject = "Taler Withdrawal P2T19EXRBY4B145JRNZ8CQTD7TCS03JE9VZRCEVKVWCP930P56WG",
+                        amountRaw = Amount("KUDOS", 10, 0),
+                        amountEffective = Amount("KUDOS", 9, 5),
+                    ),
+                    TransferData.Bitcoin(
+                        uri = Uri.parse("https://taler.net"),
+                        account = "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4",
+                        segwitAddresses = listOf(
+                            "bc1qqleages8702xvg9qcyu02yclst24xurdrynvxq",
+                            "bc1qsleagehks96u7jmqrzcf0fw80ea5g57qm3m84c"
+                        ),
+                        subject = "0ZSX8SH0M30KHX8K3Y1DAMVGDQV82XEF9DG1HC4QMQ3QWYT4AF00",
+                        amountRaw = Amount(CURRENCY_BTC, 0, 14000000),
+                        amountEffective = Amount(CURRENCY_BTC, 0, 14000000),
+                    )
+                ),
+            ),
+            bankAppClick = {},
+            onCancelClick = {},
+        )
     }
-}
+}
\ No newline at end of file
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/manual/ScreenBitcoin.kt b/wallet/src/main/java/net/taler/wallet/withdraw/manual/TransferBitcoin.kt
index fa20072..c89b7cc 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/manual/ScreenBitcoin.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/manual/TransferBitcoin.kt
@@ -1,6 +1,6 @@
 /*
  * This file is part of GNU Taler
- * (C) 2022 Taler Systems S.A.
+ * (C) 2023 Taler Systems S.A.
  *
  * GNU Taler is free software; you can redistribute it and/or modify it under the
  * terms of the GNU General Public License as published by the Free Software
@@ -16,17 +16,11 @@
 
 package net.taler.wallet.withdraw.manual
 
-import android.net.Uri
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.wrapContentWidth
-import androidx.compose.foundation.rememberScrollState
-import androidx.compose.foundation.verticalScroll
-import androidx.compose.material3.Button
-import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
@@ -34,81 +28,48 @@ import androidx.compose.ui.Alignment.Companion.End
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.em
 import net.taler.common.Amount
-import net.taler.wallet.CURRENCY_BTC
 import net.taler.wallet.R
 import net.taler.wallet.compose.CopyToClipboardButton
-import net.taler.wallet.withdraw.WithdrawStatus
+import net.taler.wallet.withdraw.TransferData
 
 @Composable
-fun ScreenBitcoin(
-    status: WithdrawStatus.ManualTransferRequiredBitcoin,
-    bankAppClick: (() -> Unit)?,
-    onCancelClick: (() -> Unit)?,
+fun TransferBitcoin(
+    data: TransferData.Bitcoin,
 ) {
-    val scrollState = rememberScrollState()
     Column(modifier = Modifier
         .wrapContentWidth(Alignment.CenterHorizontally)
-        .verticalScroll(scrollState)
         .padding(all = 16.dp)
     ) {
         Text(
-            text = stringResource(R.string.withdraw_manual_bitcoin_title),
-            style = MaterialTheme.typography.headlineSmall,
-        )
-        Text(
             text = stringResource(R.string.withdraw_manual_bitcoin_intro),
             style = MaterialTheme.typography.bodyLarge,
             modifier = Modifier
                 .padding(vertical = 8.dp)
         )
-        BitcoinSegwitAddrs(
-            amount = status.amountRaw,
-            addr = status.account,
-            segwitAddresses = status.segwitAddrs
+
+        BitcoinSegwitAddresses(
+            amount = data.amountRaw,
+            address = data.account,
+            segwitAddresses = data.segwitAddresses,
         )
-        if (bankAppClick != null) {
-            Button(
-                onClick = bankAppClick,
-                modifier = Modifier
-                    .padding(vertical = 16.dp)
-                    .align(Alignment.CenterHorizontally),
-            ) {
-                Text(text = stringResource(R.string.withdraw_manual_ready_bank_button))
-            }
-        }
-        if (onCancelClick != null) {
-            Button(
-                onClick = onCancelClick,
-                colors = ButtonDefaults.buttonColors(containerColor = MaterialTheme.colorScheme.error),
-                modifier = Modifier
-                    .padding(vertical = 16.dp)
-                    .align(End),
-            ) {
-                Text(
-                    text = stringResource(R.string.withdraw_manual_ready_cancel),
-                    color = MaterialTheme.colorScheme.onError,
-                )
-            }
-        }
     }
 }
 
 @Composable
-fun BitcoinSegwitAddrs(amount: Amount, addr: String, segwitAddresses: List<String>) {
+fun BitcoinSegwitAddresses(amount: Amount, address: String, segwitAddresses: List<String>) {
     Column {
         CopyToClipboardButton(
             modifier = Modifier.align(End),
             label = "Bitcoin",
-            content = getCopyText(amount, addr, segwitAddresses),
+            content = getCopyText(amount, address, segwitAddresses),
         )
         Row(modifier = Modifier.padding(vertical = 8.dp)) {
             Column(modifier = Modifier.weight(0.3f)) {
                 Text(
-                    text = addr,
+                    text = address,
                     style = MaterialTheme.typography.bodyLarge,
                     fontWeight = FontWeight.Normal,
                     fontSize = 3.em
@@ -147,23 +108,4 @@ private fun getCopyText(amount: Amount, addr: String, segwitAddresses: List<Stri
         "\n$s ${SEGWIT_MIN}\n"
     }
     return "$addr ${amount.withCurrency("BTC")}\n$sr"
-}
-
-@Preview
-@Composable
-fun PreviewScreenBitcoin() {
-    Surface {
-        ScreenBitcoin(WithdrawStatus.ManualTransferRequiredBitcoin(
-            exchangeBaseUrl = "bitcoin.ice.bfh.ch",
-            uri = Uri.parse("https://taler.net"),
-            account = "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4",
-            segwitAddrs = listOf(
-                "bc1qqleages8702xvg9qcyu02yclst24xurdrynvxq",
-                "bc1qsleagehks96u7jmqrzcf0fw80ea5g57qm3m84c"
-            ),
-            subject = "0ZSX8SH0M30KHX8K3Y1DAMVGDQV82XEF9DG1HC4QMQ3QWYT4AF00",
-            amountRaw = Amount(CURRENCY_BTC, 0, 14000000),
-            transactionId = "",
-        ), {}) {}
-    }
-}
+}
\ No newline at end of file
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/manual/TransferIBAN.kt b/wallet/src/main/java/net/taler/wallet/withdraw/manual/TransferIBAN.kt
new file mode 100644
index 0000000..d94cdff
--- /dev/null
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/manual/TransferIBAN.kt
@@ -0,0 +1,71 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.wallet.withdraw.manual
+
+import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.wrapContentWidth
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.colorResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import net.taler.wallet.R
+import net.taler.wallet.withdraw.TransferData
+
+@Composable
+fun TransferIBAN(
+    data: TransferData.IBAN,
+    exchangeBaseUrl: String,
+) {
+    Column(modifier = Modifier
+        .wrapContentWidth(Alignment.CenterHorizontally)
+        .padding(all = 16.dp)
+    ) {
+        Text(
+            text = stringResource(
+                R.string.withdraw_manual_ready_intro,
+                data.amountRaw.toString()),
+            style = MaterialTheme.typography.bodyLarge,
+            modifier = Modifier
+                .padding(vertical = 8.dp)
+        )
+
+        DetailRow(stringResource(R.string.withdraw_manual_ready_iban), data.iban)
+        DetailRow(stringResource(R.string.withdraw_manual_ready_subject), data.subject)
+        DetailRow(stringResource(R.string.amount_chosen), data.amountRaw.toString())
+        DetailRow(stringResource(R.string.withdraw_exchange), exchangeBaseUrl, false)
+
+        Text(
+            text = stringResource(R.string.withdraw_manual_ready_warning),
+            style = MaterialTheme.typography.bodyMedium,
+            color = colorResource(R.color.notice_text),
+            modifier = Modifier
+                .align(Alignment.CenterHorizontally)
+                .padding(all = 8.dp)
+                .background(colorResource(R.color.notice_background))
+                .border(BorderStroke(2.dp, colorResource(R.color.notice_border)))
+                .padding(all = 16.dp)
+        )
+    }
+}
\ No newline at end of file