[wallet] implement exchange selection for withdrawals

2 files changed, 94 insertions, 46 deletions

diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/PromptWithdrawFragment.kt b/wallet/src/main/java/net/taler/wallet/withdraw/PromptWithdrawFragment.kt
index 0c7687c..38e09fa 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/PromptWithdrawFragment.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/PromptWithdrawFragment.kt
@@ -20,13 +20,12 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import android.widget.Toast
-import android.widget.Toast.LENGTH_SHORT
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.navigation.fragment.findNavController
 import com.google.android.material.snackbar.Snackbar
 import com.google.android.material.snackbar.Snackbar.LENGTH_LONG
+import net.taler.common.EventObserver
 import net.taler.common.fadeIn
 import net.taler.common.fadeOut
 import net.taler.lib.common.Amount
@@ -35,6 +34,7 @@ import net.taler.wallet.R
 import net.taler.wallet.cleanExchange
 import net.taler.wallet.databinding.FragmentPromptWithdrawBinding
 import net.taler.wallet.withdraw.WithdrawStatus.Loading
+import net.taler.wallet.withdraw.WithdrawStatus.ReceivedDetails
 import net.taler.wallet.withdraw.WithdrawStatus.TosReviewRequired
 import net.taler.wallet.withdraw.WithdrawStatus.Withdrawing
 
@@ -46,8 +46,9 @@ class PromptWithdrawFragment : Fragment() {
     private lateinit var ui: FragmentPromptWithdrawBinding
 
     override fun onCreateView(
-        inflater: LayoutInflater, container: ViewGroup?,
-        savedInstanceState: Bundle?
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?,
     ): View? {
         ui = FragmentPromptWithdrawBinding.inflate(inflater, container, false)
         return ui.root
@@ -59,21 +60,26 @@ class PromptWithdrawFragment : Fragment() {
         withdrawManager.withdrawStatus.observe(viewLifecycleOwner, {
             showWithdrawStatus(it)
         })
+        withdrawManager.exchangeSelection.observe(viewLifecycleOwner, EventObserver {
+            findNavController().navigate(R.id.action_promptWithdraw_to_selectExchangeFragment)
+        })
     }
 
     private fun showWithdrawStatus(status: WithdrawStatus?): Any = when (status) {
-        is WithdrawStatus.ReceivedDetails -> {
-            showContent(status.amountRaw, status.amountEffective, status.exchangeBaseUrl)
-            ui.confirmWithdrawButton.apply {
-                text = getString(R.string.withdraw_button_confirm)
-                setOnClickListener {
-                    it.fadeOut()
-                    ui.confirmProgressBar.fadeIn()
-                    withdrawManager.acceptWithdrawal()
-                }
-                isEnabled = true
+        null -> model.showProgressBar.value = false
+        is Loading -> model.showProgressBar.value = true
+        is WithdrawStatus.NeedsExchange -> {
+            model.showProgressBar.value = false
+            val exchangeSelection = status.exchangeSelection.getIfNotConsumed()
+            if (exchangeSelection == null) { // already consumed
+                findNavController().popBackStack()
+            } else {
+                withdrawManager.selectExchange(exchangeSelection)
             }
         }
+        is TosReviewRequired -> onTosReviewRequired(status)
+        is ReceivedDetails -> onReceivedDetails(status)
+        is Withdrawing -> model.showProgressBar.value = true
         is WithdrawStatus.Success -> {
             model.showProgressBar.value = false
             withdrawManager.withdrawStatus.value = null
@@ -81,14 +87,18 @@ class PromptWithdrawFragment : Fragment() {
             model.showTransactions(status.currency)
             Snackbar.make(requireView(), R.string.withdraw_initiated, LENGTH_LONG).show()
         }
-        is Loading -> {
-            model.showProgressBar.value = true
-        }
-        is Withdrawing -> {
-            model.showProgressBar.value = true
+        is WithdrawStatus.Error -> {
+            model.showProgressBar.value = false
+            findNavController().navigate(R.id.action_promptWithdraw_to_errorFragment)
         }
-        is TosReviewRequired -> {
-            showContent(status.amountRaw, status.amountEffective, status.exchangeBaseUrl)
+    }
+
+    private fun onTosReviewRequired(s: TosReviewRequired) {
+        model.showProgressBar.value = false
+        if (s.showImmediately.getIfNotConsumed() == true) {
+            findNavController().navigate(R.id.action_promptWithdraw_to_reviewExchangeTOS)
+        } else {
+            showContent(s.amountRaw, s.amountEffective, s.exchangeBaseUrl, s.talerWithdrawUri)
             ui.confirmWithdrawButton.apply {
                 text = getString(R.string.withdraw_button_tos)
                 setOnClickListener {
@@ -97,14 +107,27 @@ class PromptWithdrawFragment : Fragment() {
                 isEnabled = true
             }
         }
-        is WithdrawStatus.Error -> {
-            model.showProgressBar.value = false
-            findNavController().navigate(R.id.action_promptWithdraw_to_errorFragment)
+    }
+
+    private fun onReceivedDetails(s: ReceivedDetails) {
+        showContent(s.amountRaw, s.amountEffective, s.exchangeBaseUrl, s.talerWithdrawUri)
+        ui.confirmWithdrawButton.apply {
+            text = getString(R.string.withdraw_button_confirm)
+            setOnClickListener {
+                it.fadeOut()
+                ui.confirmProgressBar.fadeIn()
+                withdrawManager.acceptWithdrawal()
+            }
+            isEnabled = true
         }
-        null -> model.showProgressBar.value = false
     }
 
-    private fun showContent(amountRaw: Amount, amountEffective: Amount, exchange: String) {
+    private fun showContent(
+        amountRaw: Amount,
+        amountEffective: Amount,
+        exchange: String,
+        uri: String?,
+    ) {
         model.showProgressBar.value = false
         ui.progressBar.fadeOut()
 
@@ -117,15 +140,20 @@ class PromptWithdrawFragment : Fragment() {
         ui.chosenAmountView.fadeIn()
 
         ui.feeLabel.fadeIn()
-        ui.feeView.text = getString(R.string.amount_negative, (amountRaw - amountEffective).toString())
+        ui.feeView.text =
+            getString(R.string.amount_negative, (amountRaw - amountEffective).toString())
         ui.feeView.fadeIn()
 
         ui.exchangeIntroView.fadeIn()
         ui.withdrawExchangeUrl.text = cleanExchange(exchange)
         ui.withdrawExchangeUrl.fadeIn()
-        ui.selectExchangeButton.fadeIn()
-        ui.selectExchangeButton.setOnClickListener {
-            Toast.makeText(context, "Not yet implemented", LENGTH_SHORT).show()
+
+        if (uri != null) {  // no Uri for manual withdrawals
+            ui.selectExchangeButton.fadeIn()
+            ui.selectExchangeButton.setOnClickListener {
+                val exchangeSelection = ExchangeSelection(amountRaw, uri)
+                withdrawManager.selectExchange(exchangeSelection)
+            }
         }
 
         ui.withdrawCard.fadeIn()
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 25c5b72..5e11c04 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/WithdrawManager.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/WithdrawManager.kt
@@ -18,10 +18,13 @@ package net.taler.wallet.withdraw
 
 import android.util.Log
 import androidx.annotation.UiThread
+import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 import kotlinx.serialization.Serializable
+import net.taler.common.Event
+import net.taler.common.toEvent
 import net.taler.lib.common.Amount
 import net.taler.wallet.TAG
 import net.taler.wallet.backend.TalerErrorInfo
@@ -32,20 +35,23 @@ 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(
         val talerWithdrawUri: String? = null,
         val exchangeBaseUrl: String,
         val amountRaw: Amount,
         val amountEffective: Amount,
         val tosText: String,
-        val tosEtag: String
+        val tosEtag: String,
+        val showImmediately: Event<Boolean>,
     ) : WithdrawStatus()
 
     data class ReceivedDetails(
         val talerWithdrawUri: String? = null,
         val exchangeBaseUrl: String,
         val amountRaw: Amount,
-        val amountEffective: Amount
+        val amountEffective: Amount,
     ) : WithdrawStatus()
 
     object Withdrawing : WithdrawStatus()
@@ -57,24 +63,31 @@ sealed class WithdrawStatus {
 data class WithdrawalDetailsForUri(
     val amount: Amount,
     val defaultExchangeBaseUrl: String?,
-    val possibleExchanges: List<ExchangeItem>
+    val possibleExchanges: List<ExchangeItem>,
 )
 
 @Serializable
 data class WithdrawalDetails(
     val tosAccepted: Boolean,
     val amountRaw: Amount,
-    val amountEffective: Amount
+    val amountEffective: Amount,
+)
+
+data class ExchangeSelection(
+    val amount: Amount,
+    val talerWithdrawUri: String,
 )
 
 class WithdrawManager(
     private val api: WalletBackendApi,
-    private val scope: CoroutineScope
+    private val scope: CoroutineScope,
 ) {
 
     val withdrawStatus = MutableLiveData<WithdrawStatus>()
     val testWithdrawalInProgress = MutableLiveData(false)
 
+    private val _exchangeSelection = MutableLiveData<Event<ExchangeSelection>>()
+    val exchangeSelection: LiveData<Event<ExchangeSelection>> = _exchangeSelection
     var exchangeFees: ExchangeFees? = null
         private set
 
@@ -87,6 +100,11 @@ class WithdrawManager(
         }
     }
 
+    @UiThread
+    fun selectExchange(selection: ExchangeSelection) {
+        _exchangeSelection.value = selection.toEvent()
+    }
+
     fun getWithdrawalDetails(uri: String) = scope.launch {
         withdrawStatus.value = WithdrawStatus.Loading(uri)
         api.request("getWithdrawalDetailsForUri", WithdrawalDetailsForUri.serializer()) {
@@ -95,11 +113,10 @@ class WithdrawManager(
             handleError("getWithdrawalDetailsForUri", error)
         }.onSuccess { details ->
             if (details.defaultExchangeBaseUrl == null) {
-                // TODO go to exchange selection screen instead
-                val chosenExchange = details.possibleExchanges[0].exchangeBaseUrl
-                getWithdrawalDetails(chosenExchange, details.amount, uri)
+                val exchangeSelection = ExchangeSelection(details.amount, uri)
+                withdrawStatus.value = WithdrawStatus.NeedsExchange(exchangeSelection.toEvent())
             } else {
-                getWithdrawalDetails(details.defaultExchangeBaseUrl, details.amount, uri)
+                getWithdrawalDetails(details.defaultExchangeBaseUrl, details.amount, false, uri)
             }
         }
     }
@@ -107,7 +124,8 @@ class WithdrawManager(
     fun getWithdrawalDetails(
         exchangeBaseUrl: String,
         amount: Amount,
-        uri: String? = null
+        showTosImmediately: Boolean = false,
+        uri: String? = null,
     ) = scope.launch {
         withdrawStatus.value = WithdrawStatus.Loading(uri)
         api.request("getWithdrawalDetailsForAmount", WithdrawalDetails.serializer()) {
@@ -121,16 +139,17 @@ class WithdrawManager(
                     talerWithdrawUri = uri,
                     exchangeBaseUrl = exchangeBaseUrl,
                     amountRaw = details.amountRaw,
-                    amountEffective = details.amountEffective
+                    amountEffective = details.amountEffective,
                 )
-            } else getExchangeTos(exchangeBaseUrl, details, uri)
+            } else getExchangeTos(exchangeBaseUrl, details, showTosImmediately, uri)
         }
     }
 
     private fun getExchangeTos(
         exchangeBaseUrl: String,
         details: WithdrawalDetails,
-        uri: String?
+        showImmediately: Boolean,
+        uri: String?,
     ) = scope.launch {
         api.request("getExchangeTos", TosResponse.serializer()) {
             put("exchangeBaseUrl", exchangeBaseUrl)
@@ -143,7 +162,8 @@ class WithdrawManager(
                 amountRaw = details.amountRaw,
                 amountEffective = details.amountEffective,
                 tosText = it.tos,
-                tosEtag = it.currentEtag
+                tosEtag = it.currentEtag,
+                showImmediately = showImmediately.toEvent(),
             )
         }
     }
@@ -163,7 +183,7 @@ class WithdrawManager(
                 talerWithdrawUri = s.talerWithdrawUri,
                 exchangeBaseUrl = s.exchangeBaseUrl,
                 amountRaw = s.amountRaw,
-                amountEffective = s.amountEffective
+                amountEffective = s.amountEffective,
             )
         }
     }
@@ -181,7 +201,7 @@ class WithdrawManager(
         api.request<Unit>(operation) {
             put("exchangeBaseUrl", status.exchangeBaseUrl)
             if (status.talerWithdrawUri == null) {
-                put("amount", status.amountRaw)
+                put("amount", status.amountRaw.toJSONString())
             } else {
                 put("talerWithdrawUri", status.talerWithdrawUri)
             }