Add minimum amount error for boosts.

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/subscription/DonationsConfigurationExtensions.kt

@@ -85,6 +85,16 @@ fun DonationsConfiguration.getSubscriptionLevels(): Map<Int, LevelConfiguration>
   return levels.filterKeys { SUBSCRIPTION_LEVELS.contains(it) }.toSortedMap()
 }
 
+/**
+ * Get a map describing the minimum donation amounts per currency.
+ * This returns only the currencies available to the user.
+ */
+fun DonationsConfiguration.getMinimumDonationAmounts(paymentMethodAvailability: PaymentMethodAvailability = DefaultPaymentMethodAvailability): Map<Currency, FiatMoney> {
+  return getFilteredCurrencies(paymentMethodAvailability)
+    .mapKeys { Currency.getInstance(it.key.uppercase()) }
+    .mapValues { FiatMoney(it.value.minimum, it.key) }
+}
+
 private fun DonationsConfiguration.getFilteredCurrencies(paymentMethodAvailability: PaymentMethodAvailability): Map<String, DonationsConfiguration.CurrencyConfiguration> {
   val userPaymentMethods = paymentMethodAvailability.toSet()
   val availableCurrencyCodes = PlatformCurrencyUtil.getAvailableCurrencyCodes()

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/subscription/OneTimeDonationRepository.kt

@@ -64,6 +64,13 @@ class OneTimeDonationRepository(private val donationsService: DonationsService)
       .map { it.getBoostBadges().first() }
   }
 
+  fun getMinimumDonationAmounts(): Single<Map<Currency, FiatMoney>> {
+    return Single.fromCallable { donationsService.getDonationsConfiguration(Locale.getDefault()) }
+      .flatMap { it.flattenResult() }
+      .subscribeOn(Schedulers.io())
+      .map { it.getMinimumDonationAmounts() }
+  }
+
   fun waitForOneTimeRedemption(
     price: FiatMoney,
     paymentIntentId: String,

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/subscription/boost/Boost.kt

@@ -10,6 +10,7 @@ import android.text.Spanned
 import android.text.TextWatcher
 import android.text.method.DigitsKeyListener
 import android.view.View
+import android.widget.TextView
 import androidx.annotation.VisibleForTesting
 import androidx.appcompat.widget.AppCompatEditText
 import androidx.core.animation.doOnEnd
@@ -26,6 +27,7 @@ import org.thoughtcrime.securesms.util.ViewUtil
 import org.thoughtcrime.securesms.util.adapter.mapping.LayoutFactory
 import org.thoughtcrime.securesms.util.adapter.mapping.MappingAdapter
 import org.thoughtcrime.securesms.util.adapter.mapping.MappingViewHolder
+import org.thoughtcrime.securesms.util.visible
 import java.lang.Integer.min
 import java.text.DecimalFormatSymbols
 import java.text.NumberFormat
@@ -102,7 +104,9 @@ data class Boost(
     val currency: Currency,
     override val isEnabled: Boolean,
     val onBoostClick: (View, Boost) -> Unit,
+    val minimumAmount: FiatMoney,
     val isCustomAmountFocused: Boolean,
+    val isCustomAmountTooSmall: Boolean,
     val onCustomAmountChanged: (String) -> Unit,
     val onCustomAmountFocusChanged: (Boolean) -> Unit,
   ) : PreferenceModel<SelectionModel>(isEnabled = isEnabled) {
@@ -113,7 +117,10 @@ data class Boost(
         newItem.boosts == boosts &&
         newItem.selectedBoost == selectedBoost &&
         newItem.currency == currency &&
-        newItem.isCustomAmountFocused == isCustomAmountFocused
+        newItem.isCustomAmountFocused == isCustomAmountFocused &&
+        newItem.isCustomAmountTooSmall == isCustomAmountTooSmall &&
+        newItem.minimumAmount.amount == minimumAmount.amount &&
+        newItem.minimumAmount.currency == minimumAmount.currency
     }
   }
 
@@ -126,6 +133,7 @@ data class Boost(
     private val boost5: MaterialButton = itemView.findViewById(R.id.boost_5)
     private val boost6: MaterialButton = itemView.findViewById(R.id.boost_6)
     private val custom: AppCompatEditText = itemView.findViewById(R.id.boost_custom)
+    private val error: TextView = itemView.findViewById(R.id.boost_custom_too_small)
 
     private val boostButtons: List<MaterialButton>
       get() {
@@ -145,6 +153,16 @@ data class Boost(
     override fun bind(model: SelectionModel) {
       itemView.isEnabled = model.isEnabled
 
+      error.text = context.getString(
+        R.string.Boost__the_minimum_amount_you_can_donate_is_s,
+        FiatMoneyUtil.format(
+          context.resources, model.minimumAmount,
+          FiatMoneyUtil.formatOptions().trimZerosAfterDecimal()
+        )
+      )
+
+      error.visible = model.isCustomAmountTooSmall
+
       model.boosts.zip(boostButtons).forEach { (boost, button) ->
         val isSelected = boost == model.selectedBoost && !model.isCustomAmountFocused
         button.isSelected = isSelected

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/subscription/donate/DonateToSignalFragment.kt

@@ -242,6 +242,7 @@ class DonateToSignalFragment :
       when (state.donateToSignalType) {
         DonateToSignalType.ONE_TIME -> displayOneTimeSelection(state.areFieldsEnabled, state.oneTimeDonationState)
         DonateToSignalType.MONTHLY -> displayMonthlySelection(state.areFieldsEnabled, state.monthlyDonationState)
+        DonateToSignalType.GIFT -> error("This fragment does not support gifts.")
       }
 
       space(20.dp)
@@ -310,6 +311,8 @@ class DonateToSignalFragment :
             selectedBoost = state.selectedBoost,
             currency = state.customAmount.currency,
             isCustomAmountFocused = state.isCustomAmountFocused,
+            isCustomAmountTooSmall = state.shouldDisplayCustomAmountTooSmallError,
+            minimumAmount = state.minimumDonationAmountOfSelectedCurrency,
             isEnabled = areFieldsEnabled,
             onBoostClick = { view, boost ->
               startAnimationAboveSelectedBoost(view)

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/subscription/donate/DonateToSignalState.kt

@@ -81,9 +81,15 @@ data class DonateToSignalState(
     val customAmount: FiatMoney = FiatMoney(BigDecimal.ZERO, selectedCurrency),
     val isCustomAmountFocused: Boolean = false,
     val donationStage: DonationStage = DonationStage.INIT,
-    val selectableCurrencyCodes: List<String> = emptyList()
+    val selectableCurrencyCodes: List<String> = emptyList(),
+    private val minimumDonationAmounts: Map<Currency, FiatMoney> = emptyMap()
   ) {
-    val isSelectionValid: Boolean = if (isCustomAmountFocused) customAmount.amount > BigDecimal.ZERO else selectedBoost != null
+    val minimumDonationAmountOfSelectedCurrency: FiatMoney = minimumDonationAmounts[selectedCurrency] ?: FiatMoney(BigDecimal.ZERO, selectedCurrency)
+    private val isCustomAmountTooSmall: Boolean = if (isCustomAmountFocused) customAmount.amount < minimumDonationAmountOfSelectedCurrency.amount else false
+    private val isCustomAmountZero: Boolean = customAmount.amount == BigDecimal.ZERO
+
+    val isSelectionValid: Boolean = if (isCustomAmountFocused) !isCustomAmountTooSmall else selectedBoost != null
+    val shouldDisplayCustomAmountTooSmallError: Boolean = isCustomAmountTooSmall && !isCustomAmountZero
   }
 
   data class MonthlyDonationState(

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/subscription/donate/DonateToSignalViewModel.kt

@@ -214,6 +214,15 @@ class DonateToSignalViewModel(
       }
     )
 
+    oneTimeDonationDisposables += oneTimeDonationRepository.getMinimumDonationAmounts().subscribeBy(
+      onSuccess = { amountMap ->
+        store.update { it.copy(oneTimeDonationState = it.oneTimeDonationState.copy(minimumDonationAmounts = amountMap)) }
+      },
+      onError = {
+        Log.w(TAG, "Could not load minimum custom donation amounts.", it)
+      }
+    )
+
     val boosts: Observable<Map<Currency, List<Boost>>> = oneTimeDonationRepository.getBoosts().toObservable()
     val oneTimeCurrency: Observable<Currency> = SignalStore.donationsValues().observableOneTimeCurrency