Updated on 2026-08-14

features/swap/impl/src/main/java/com/tangem/feature/swap/model/SwapModel.kt

@@ -43,10 +43,10 @@ import com.tangem.datasource.local.appsflyer.AppsFlyerStore
 import com.tangem.domain.account.status.usecase.GetAccountCurrencyStatusUseCase
 import com.tangem.domain.account.status.usecase.GetFeePaidCryptoCurrencyStatusSyncUseCase
 import com.tangem.domain.account.status.usecase.IsAccountsModeEnabledUseCase
-import com.tangem.domain.card.IsWalletBackupProblematicUseCase
 import com.tangem.domain.appcurrency.GetSelectedAppCurrencyUseCase
 import com.tangem.domain.appcurrency.model.AppCurrency
 import com.tangem.domain.balancehiding.GetBalanceHidingSettingsUseCase
+import com.tangem.domain.card.IsWalletBackupProblematicUseCase
 import com.tangem.domain.express.models.ExpressOperationType
 import com.tangem.domain.express.models.ProviderFilterType
 import com.tangem.domain.feedback.GetWalletMetaInfoUseCase
@@ -541,6 +541,10 @@ internal class SwapModel @Inject constructor(
                         )
                     },
                 ),
+                isTransferMode = swapTransferInteractor.shouldTransferInsteadOfSwap(
+                    fromSwapCurrency = fromSwapCurrencyStatus?.currency,
+                    toSwapCurrency = toSwapCurrencyStatus?.currency,
+                ),
             ),
             fromSwapCurrencyStatus = fromSwapCurrencyStatus,
             toSwapCurrencyStatus = toSwapCurrencyStatus,
@@ -623,6 +627,10 @@ internal class SwapModel @Inject constructor(
                             )
                         },
                     ),
+                    isTransferMode = swapTransferInteractor.shouldTransferInsteadOfSwap(
+                        fromSwapCurrency = newFromSwapCurrencyStatus?.currency,
+                        toSwapCurrency = newToSwapCurrencyStatus?.currency,
+                    ),
                 ),
                 fromSwapCurrencyStatus = newFromSwapCurrencyStatus,
                 toSwapCurrencyStatus = newToSwapCurrencyStatus,
@@ -741,6 +749,10 @@ internal class SwapModel @Inject constructor(
                         )
                     },
                 ),
+                isTransferMode = swapTransferInteractor.shouldTransferInsteadOfSwap(
+                    fromSwapCurrency = fromSwapCurrencyStatus.currency,
+                    toSwapCurrency = toSwapCurrencyStatus.currency,
+                ),
             ),
             fromSwapCurrencyStatus = fromSwapCurrencyStatus,
             toSwapCurrencyStatus = toSwapCurrencyStatus,

features/swap/impl/src/main/java/com/tangem/feature/swap/ui/StateBuilder.kt

@@ -153,10 +153,15 @@ internal class StateBuilder(
                 isHoldToConfirm = fromSwapCurrencyStatus?.userWallet?.isHotWallet == true,
                 onClick = { },
             ),
-            shouldShowMaxAmount = shouldShowMaxAmount(fromSwapCurrencyStatus?.currency, toSwapCurrencyStatus?.currency),
-            predefinedButtons = createPredefinedButtons(
+            shouldShowMaxAmount = shouldShowMaxAmount(
                 fromSwapCurrencyStatus?.currency,
                 toSwapCurrencyStatus?.currency,
+                emptyAmountState.isTransferMode,
+            ),
+            predefinedButtons = createPredefinedButtons(
+                fromToken = fromSwapCurrencyStatus?.currency,
+                toCurrency = toSwapCurrencyStatus?.currency,
+                isTransferMode = emptyAmountState.isTransferMode,
             ),
             changeCardsButtonState = ChangeCardsButtonState.ENABLED,
             providerState = ProviderState.Empty(),
@@ -244,6 +249,11 @@ internal class StateBuilder(
         toSwapCurrencyStatus: SwapCurrencyStatus?,
         shouldResetAmount: Boolean,
     ): SwapStateHolder {
+        val shouldShowMaxAmount = shouldShowMaxAmount(
+            fromSwapCurrencyStatus?.currency,
+            toSwapCurrencyStatus?.currency,
+            emptyAmountState.isTransferMode,
+        )
         return uiStateHolder.copy(
             sendCardData = uiStateHolder.sendCardData.updateCurrencyStatus(
                 swapCurrencyStatus = fromSwapCurrencyStatus,
@@ -267,10 +277,11 @@ internal class StateBuilder(
                 isHoldToConfirm = fromSwapCurrencyStatus?.userWallet?.isHotWallet == true,
                 onClick = { },
             ),
-            shouldShowMaxAmount = shouldShowMaxAmount(fromSwapCurrencyStatus?.currency, toSwapCurrencyStatus?.currency),
+            shouldShowMaxAmount = shouldShowMaxAmount,
             predefinedButtons = createPredefinedButtons(
-                fromSwapCurrencyStatus?.currency,
-                toSwapCurrencyStatus?.currency,
+                fromToken = fromSwapCurrencyStatus?.currency,
+                toCurrency = toSwapCurrencyStatus?.currency,
+                isTransferMode = emptyAmountState.isTransferMode,
             ),
             changeCardsButtonState = ChangeCardsButtonState.ENABLED,
             providerState = ProviderState.Empty(),
@@ -683,7 +694,12 @@ internal class StateBuilder(
         )
     }
 
-    private fun shouldShowMaxAmount(fromToken: CryptoCurrency?, toCurrency: CryptoCurrency?): Boolean {
+    private fun shouldShowMaxAmount(
+        fromToken: CryptoCurrency?,
+        toCurrency: CryptoCurrency?,
+        isTransferMode: Boolean = false,
+    ): Boolean {
+        if (isTransferMode) return true
         return !(fromToken is CryptoCurrency.Coin && fromToken.network.id == toCurrency?.network?.id)
     }
 
@@ -696,9 +712,10 @@ internal class StateBuilder(
     private fun createPredefinedButtons(
         fromToken: CryptoCurrency?,
         toCurrency: CryptoCurrency?,
+        isTransferMode: Boolean = false,
     ): ImmutableList<PredefinedPercentButtonUM> {
         if (!swapFeatureToggles.isSwapPredefinedButtonsEnabled) return persistentListOf()
-        val shouldShowMaxAmount = shouldShowMaxAmount(fromToken, toCurrency)
+        val shouldShowMaxAmount = shouldShowMaxAmount(fromToken, toCurrency, isTransferMode)
         return PredefinedPercentAmount.entries
             .filter { it != PredefinedPercentAmount.MAX || shouldShowMaxAmount }
             .map { percent ->

features/swap/impl/src/test/java/com/tangem/feature/swap/StateBuilderInitialStateTest.kt

@@ -7,6 +7,7 @@ import com.tangem.domain.express.models.ExpressError
 import com.tangem.domain.models.account.Account
 import com.tangem.domain.models.currency.CryptoCurrency
 import com.tangem.domain.models.currency.CryptoCurrencyStatus
+import com.tangem.domain.models.network.Network
 import com.tangem.domain.models.wallet.UserWallet
 import com.tangem.domain.models.wallet.UserWalletId
 import com.tangem.domain.swap.models.SwapCurrencyStatus
@@ -270,6 +271,50 @@ internal class StateBuilderInitialStateTest {
 
             assertThat(result.notifications).isEmpty()
         }
+
+        @Test
+        fun `GIVEN same coin on different wallets in transfer mode WHEN called THEN shouldShowMaxAmount is true`() {
+            // Arrange — same coin (shared network id) moved between two wallets => transfer mode
+            val sharedNetwork = buildSharedNetwork()
+            val walletA: UserWallet.Cold = mockk(relaxed = true) { every { walletId } returns UserWalletId("aabb") }
+            val walletB: UserWallet.Cold = mockk(relaxed = true) { every { walletId } returns UserWalletId("ccdd") }
+            val fromStatus = buildCoinSwapCurrencyStatus(walletA, sharedNetwork)
+            val toStatus = buildCoinSwapCurrencyStatus(walletB, sharedNetwork)
+            val transferState = SwapState.EmptyAmountState(
+                zeroAmountEquivalent = com.tangem.core.ui.extensions.stringReference("$0.00"),
+                isTransferMode = true,
+            )
+
+            // Act
+            val result = sut.createInitialReadyState(
+                uiStateHolder = baseState,
+                emptyAmountState = transferState,
+                fromSwapCurrencyStatus = fromStatus,
+                toSwapCurrencyStatus = toStatus,
+            )
+
+            // Assert
+            assertThat(result.shouldShowMaxAmount).isTrue()
+        }
+
+        @Test
+        fun `GIVEN same-network coin swap not in transfer mode WHEN called THEN shouldShowMaxAmount is false`() {
+            // Arrange — same network coin pair, regular swap => MAX hidden to keep balance for the fee
+            val sharedNetwork = buildSharedNetwork()
+            val fromStatus = buildCoinSwapCurrencyStatus(userWallet, sharedNetwork)
+            val toStatus = buildCoinSwapCurrencyStatus(userWallet, sharedNetwork)
+
+            // Act
+            val result = sut.createInitialReadyState(
+                uiStateHolder = baseState,
+                emptyAmountState = emptyAmountState,
+                fromSwapCurrencyStatus = fromStatus,
+                toSwapCurrencyStatus = toStatus,
+            )
+
+            // Assert
+            assertThat(result.shouldShowMaxAmount).isFalse()
+        }
     }
 
     // endregion
@@ -574,4 +619,43 @@ internal fun buildSwapCurrencyStatus(
         status = cryptoCurrencyStatus,
         account = account,
     )
+}
+
+/**
+ * A single [Network] mock whose [Network.id] resolves to one shared instance, so two currencies built from
+ * it compare equal on `network.id` — the condition that gates [StateBuilder.shouldShowMaxAmount].
+ */
+internal fun buildSharedNetwork(): Network = mockk(relaxed = true) {
+    every { id } returns mockk(relaxed = true)
+    every { name } returns "Ethereum"
+    every { currencySymbol } returns "ETH"
+    every { rawId } returns "ethereum"
+}
+
+/**
+ * Builds a [SwapCurrencyStatus] backed by a [CryptoCurrency.Coin] on the given [network]. Pass the same
+ * [network] instance to two calls to model the "same coin on different wallets" (transfer) case.
+ */
+internal fun buildCoinSwapCurrencyStatus(
+    userWallet: UserWallet,
+    network: Network,
+): SwapCurrencyStatus {
+    val account = Account.CryptoPortfolio.createMainAccount(userWallet.walletId)
+    val currency = mockk<CryptoCurrency.Coin>(relaxed = true) {
+        every { symbol } returns "ETH"
+        every { decimals } returns 18
+        every { name } returns "Ethereum"
+        every { this@mockk.network } returns network
+    }
+    val statusValue: CryptoCurrencyStatus.Value = mockk(relaxed = true) {
+        every { amount } returns java.math.BigDecimal("1.0")
+        every { fiatRate } returns java.math.BigDecimal("2000.00")
+        every { fiatAmount } returns java.math.BigDecimal("2000.00")
+    }
+    val cryptoCurrencyStatus = CryptoCurrencyStatus(currency = currency, value = statusValue)
+    return SwapCurrencyStatus(
+        userWallet = userWallet,
+        status = cryptoCurrencyStatus,
+        account = account,
+    )
 }