fix(dashspend): eliminate crash issues when fragments/dialogs recreated and address network error (#1407)

* fix: save merchant info state to prevent crashes when recreating PurchaseGiftCardFragment

* fix: don't show PurchaseGiftCardConfirmDialog if there is no merchant info

* fix: prevent crash if assetLockPublicKeyId is null

* fix: properly handle restoring a merchant from the id

* fix: handle SSLHandshakeException

* fix: save EnterAmountFragment state

* fix: clear EnterAmountFragment state

* fix: save state for CoinbaseBuyDashFragment

* fix: allow destruction of SearchFragment if nav graph is not on the backstack

* fix: allow creation of EnterAmountToTransferFragment if nav graph is not on the backstack

* chore: ktlint

* chore: remove commented code

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* fix: pass exception object

* fix: remove extra call to setIsFixedDenomination

---------

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: HashEngineering

common/src/main/java/org/dash/wallet/common/ui/enter_amount/EnterAmountFragment.kt

@@ -199,6 +199,15 @@ class EnterAmountFragment : Fragment(R.layout.fragment_enter_amount) {
         }
     }
 
+    private fun setAmountFromSavedState() {
+        if (binding.amountView.dashToFiat) {
+            binding.amountView.input = viewModel.amount.value?.toPlainString() ?: Coin.ZERO.toPlainString()
+        } else {
+            binding.amountView.input = viewModel.fiatAmount.value?.toPlainString()
+                ?: Fiat.valueOf(viewModel.selectedCurrencyCode, 0).toPlainString()
+        }
+    }
+
     private fun setupAmountView(dashToFiat: Boolean) {
         pickedCurrencyOption = if (dashToFiat) 1 else 0
         binding.currencyOptions.setViewCompositionStrategy(
@@ -223,6 +232,7 @@ class EnterAmountFragment : Fragment(R.layout.fragment_enter_amount) {
                 binding.amountView.dashToFiat = currency.title == Constants.DASH_CURRENCY
             }
         }
+        setAmountFromSavedState()
 
         binding.maxButton.setOnClickListener {
             lifecycleScope.launch { onMaxAmountButtonClick() }

common/src/main/java/org/dash/wallet/common/ui/enter_amount/EnterAmountViewModel.kt

@@ -18,6 +18,7 @@
 package org.dash.wallet.common.ui.enter_amount
 
 import androidx.lifecycle.*
+import androidx.lifecycle.SavedStateHandle
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.*
@@ -34,14 +35,24 @@ import javax.inject.Inject
 @OptIn(ExperimentalCoroutinesApi::class)
 @HiltViewModel
 class EnterAmountViewModel @Inject constructor(
+    private val savedStateHandle: SavedStateHandle,
     val exchangeRates: ExchangeRatesProvider,
     private val walletUIConfig: WalletUIConfig
 ) : ViewModel() {
-    private val _selectedCurrencyCode = MutableStateFlow(Constants.DEFAULT_EXCHANGE_CURRENCY)
+    companion object {
+        private const val KEY_SELECTED_CURRENCY = "selected_currency_code"
+        private const val KEY_AMOUNT = "amount"
+        private const val KEY_FIAT_AMOUNT = "fiat_amount"
+    }
+
+    private val _selectedCurrencyCode = MutableStateFlow(
+        savedStateHandle.get<String>(KEY_SELECTED_CURRENCY) ?: Constants.DEFAULT_EXCHANGE_CURRENCY
+    )
     var selectedCurrencyCode: String
         get() = _selectedCurrencyCode.value
         set(value) {
             _selectedCurrencyCode.value = value
+            savedStateHandle[KEY_SELECTED_CURRENCY] = value
         }
 
     private val _selectedExchangeRate = MutableLiveData<ExchangeRate?>()
@@ -62,11 +73,23 @@ class EnterAmountViewModel @Inject constructor(
     val maxAmount: LiveData<Coin>
         get() = _maxAmount
 
-    internal val _amount = MutableLiveData<Coin>()
+    internal val _amount = MutableLiveData<Coin>().apply {
+        savedStateHandle.get<Long>(KEY_AMOUNT)?.let {
+            value = Coin.valueOf(it)
+        }
+    }
     val amount: LiveData<Coin>
         get() = _amount
 
-    internal val _fiatAmount = MutableLiveData<Fiat>()
+    internal val _fiatAmount = MutableLiveData<Fiat>().apply {
+        savedStateHandle.get<String>(KEY_FIAT_AMOUNT)?.let { fiatString ->
+            try {
+                value = Fiat.parseFiat(selectedCurrencyCode, fiatString)
+            } catch (_: Exception) {
+                // Ignore parsing errors for saved state
+            }
+        }
+    }
     val fiatAmount: LiveData<Fiat>
         get() = _fiatAmount
 
@@ -112,6 +135,16 @@ class EnterAmountViewModel @Inject constructor(
             .filterNotNull()
             .onEach { _selectedCurrencyCode.value = it }
             .launchIn(viewModelScope)
+
+        // Save amount changes to SavedStateHandle
+        _amount.observeForever { coin ->
+            savedStateHandle[KEY_AMOUNT] = coin?.value
+        }
+
+        // Save fiat amount changes to SavedStateHandle
+        _fiatAmount.observeForever { fiat ->
+            savedStateHandle[KEY_FIAT_AMOUNT] = fiat?.toPlainString()
+        }
     }
 
     fun setMaxAmount(coin: Coin) {
@@ -132,4 +165,12 @@ class EnterAmountViewModel @Inject constructor(
             _selectedCurrencyCode.value = walletUIConfig.getExchangeCurrencyCode()
         }
     }
+
+    fun clearSavedState() {
+        _amount.value = Coin.ZERO
+        _fiatAmount.value = Fiat.valueOf(selectedCurrencyCode, 0)
+        savedStateHandle.remove<String>(KEY_SELECTED_CURRENCY)
+        savedStateHandle.remove<Long>(KEY_AMOUNT)
+        savedStateHandle.remove<String>(KEY_FIAT_AMOUNT)
+    }
 }

features/exploredash/src/main/java/org/dash/wallet/features/exploredash/data/explore/ExploreDataSource.kt

@@ -81,6 +81,7 @@ interface ExploreDataSource {
     suspend fun getMerchantTerritories(): List<String>
     suspend fun getAtmTerritories(): List<String>
     fun sanitizeQuery(query: String): String
+    suspend fun getMerchantById(merchantId: String): Merchant?
 }
 
 open class MerchantAtmDataSource @Inject constructor(
@@ -509,4 +510,8 @@ open class MerchantAtmDataSource @Inject constructor(
         val escapedQuotes = query.replace(Regex.fromLiteral("\""), "\"\"")
         return "\"$escapedQuotes*\""
     }
+
+    override suspend fun getMerchantById(merchantId: String): Merchant? {
+        return merchantDao.getMerchantById(merchantId)
+    }
 }

features/exploredash/src/main/java/org/dash/wallet/features/exploredash/data/explore/MerchantDao.kt

@@ -489,4 +489,7 @@ interface MerchantDao : BaseDao<Merchant> {
 
     @Query("SELECT count(*) FROM merchant")
     suspend fun getCount(): Int
+
+    @Query("SELECT * FROM merchant where merchantId = :merchantId")
+    suspend fun getMerchantById(merchantId: String): Merchant?
 }

features/exploredash/src/main/java/org/dash/wallet/features/exploredash/repository/CTXSpendRepository.kt

@@ -34,12 +34,14 @@ import org.dash.wallet.features.exploredash.utils.CTXSpendConfig
 import java.util.UUID
 import java.util.concurrent.TimeUnit
 import javax.inject.Inject
+import javax.net.ssl.SSLHandshakeException
 
 class CTXSpendException(
     message: String,
     val errorCode: Int? = null,
-    val errorBody: String? = null
-) : Exception(message) {
+    val errorBody: String? = null,
+    cause: Exception? = null
+) : Exception(message, cause) {
     var resourceString: ResourceString? = null
     private val errorMap: Map<String, Any>
 
@@ -65,6 +67,8 @@ class CTXSpendException(
             val fiatAmount = ((errorMap["fields"] as? Map<*, *>)?.get("fiatAmount") as? List<*>)?.firstOrNull()
             return errorCode == 400 && (fiatAmount == "above threshold" || fiatAmount == "below threshold")
         }
+    val isNetworkError: Boolean
+        get() = cause?.let { it is SSLHandshakeException } ?: false
 }
 
 class CTXSpendRepository @Inject constructor(