Updated on 2026-08-14

features/onboarding-v2/impl/src/main/kotlin/com/tangem/features/onboarding/v2/visa/impl/child/pincode/model/OnboardingVisaPinCodeModel.kt

@@ -5,6 +5,7 @@ import com.tangem.common.extensions.toHexString
 import com.tangem.core.decompose.di.ModelScoped
 import com.tangem.core.decompose.model.Model
 import com.tangem.core.decompose.model.ParamsContainer
+import com.tangem.core.ui.extensions.stringReference
 import com.tangem.datasource.local.visa.VisaAuthTokenStorage
 import com.tangem.domain.models.scan.ScanResponse
 import com.tangem.domain.visa.SetVisaPinCodeUseCase
@@ -57,24 +58,28 @@ internal class OnboardingVisaPinCodeModel @Inject constructor(
     }
 
     private fun onPinCodeChange(pin: String) {
-        if (pin.all { it.isDigit() }) {
+        if (PinCodeValidation.validateAllDigits(pin)) {
+            val isError = PinCodeValidation.validateLength(pin) && PinCodeValidation.validate(pin).not()
+
             _uiState.update {
                 it.copy(
                     pinCode = pin,
-                    submitButtonEnabled = checkPinCode(pin),
+                    submitButtonEnabled = PinCodeValidation.validate(pin),
+                    error = if (isError) stringReference("Invalid PIN: avoid sequences or repeats") else null,
                 )
             }
         }
     }
 
     private fun onSubmitClick() {
-        if (checkPinCode(_uiState.value.pinCode).not()) return
+        val pinCode = _uiState.value.pinCode
+        if (PinCodeValidation.validate(pinCode).not()) return
 
         modelScope.launch {
             loading(true)
 
             setVisaPinCodeUseCase(
-                pinCode = _uiState.value.pinCode,
+                pinCode = pinCode,
                 visaCardId = visaCardId,
                 activationOrderId = params.activationOrderInfo.orderId,
             ).onLeft {
@@ -88,10 +93,6 @@ internal class OnboardingVisaPinCodeModel @Inject constructor(
         }
     }
 
-    private fun checkPinCode(pin: String): Boolean {
-        return pin.length == PIN_CODE_LENGTH
-    }
-
     private fun loading(state: Boolean) {
         _uiState.update { it.copy(submitButtonLoading = state) }
     }

features/onboarding-v2/impl/src/main/kotlin/com/tangem/features/onboarding/v2/visa/impl/child/pincode/model/PinCodeValidation.kt

@@ -0,0 +1,31 @@
+package com.tangem.features.onboarding.v2.visa.impl.child.pincode.model
+
+internal object PinCodeValidation {
+
+    private const val PIN_CODE_LENGTH = 4
+
+    fun validate(pinCode: String): Boolean {
+        return sequenceOf(
+            ::validateAllDigits,
+            ::validateLength,
+            ::validateNoRepeatedDigits,
+            ::validateNoConsecutiveDigits,
+        ).all { it(pinCode) }
+    }
+
+    fun validateAllDigits(pinCode: String): Boolean {
+        return pinCode.all { it.isDigit() }
+    }
+
+    fun validateLength(pinCode: String): Boolean {
+        return pinCode.length == PIN_CODE_LENGTH
+    }
+
+    private fun validateNoRepeatedDigits(pinCode: String): Boolean {
+        return pinCode.toSet().size == PIN_CODE_LENGTH
+    }
+
+    private fun validateNoConsecutiveDigits(pinCode: String): Boolean {
+        return pinCode.windowed(2).all { it[0] + 1 == it[1] }.not()
+    }
+}

features/onboarding-v2/impl/src/main/kotlin/com/tangem/features/onboarding/v2/visa/impl/child/pincode/ui/OnboardingVisaPinCode.kt

@@ -1,5 +1,6 @@
 package com.tangem.features.onboarding.v2.visa.impl.child.pincode.ui
 
+import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
@@ -31,7 +32,10 @@ import com.tangem.common.ui.navigationButtons.NavigationButton
 import com.tangem.common.ui.navigationButtons.NavigationPrimaryButton
 import com.tangem.core.ui.components.SpacerH
 import com.tangem.core.ui.components.SpacerH16
+import com.tangem.core.ui.components.SpacerH4
 import com.tangem.core.ui.extensions.TextReference
+import com.tangem.core.ui.extensions.resolveReference
+import com.tangem.core.ui.extensions.stringReference
 import com.tangem.core.ui.res.TangemTheme
 import com.tangem.core.ui.res.TangemThemePreview
 import com.tangem.features.onboarding.v2.visa.impl.child.pincode.ui.state.OnboardingVisaPinCodeUM
@@ -91,13 +95,29 @@ internal fun OnboardingVisaPinCode(state: OnboardingVisaPinCodeUM, modifier: Mod
 @Composable
 private fun PinCodeSection(state: OnboardingVisaPinCodeUM, modifier: Modifier = Modifier) {
     val focusRequester = remember { FocusRequester() }
+    Column(horizontalAlignment = Alignment.CenterHorizontally) {
+        PinCode(
+            modifier = modifier,
+            value = state.pinCode,
+            onValueChange = state.onPinCodeChange,
+            focusRequester = focusRequester,
+        )
 
-    PinCode(
-        modifier = modifier,
-        value = state.pinCode,
-        onValueChange = state.onPinCodeChange,
-        focusRequester = focusRequester,
-    )
+        AnimatedVisibility(
+            visible = state.error != null,
+        ) {
+            val error = remember(this) { requireNotNull(state.error) }
+            Column {
+                SpacerH4()
+                Text(
+                    text = error.resolveReference(),
+                    style = TangemTheme.typography.caption2,
+                    color = TangemTheme.colors.text.warning,
+                    textAlign = TextAlign.Center,
+                )
+            }
+        }
+    }
 
     LaunchedEffect(Unit) {
         delay(timeMillis = 300)
@@ -134,9 +154,11 @@ private fun PinCode(
                 keyboardType = KeyboardType.Number,
                 imeAction = ImeAction.Done,
             ),
-            keyboardActions = KeyboardActions(onDone = {
-                keyboardController?.hide()
-            },),
+            keyboardActions = KeyboardActions(
+                onDone = {
+                    keyboardController?.hide()
+                },
+            ),
             modifier = Modifier
                 .alpha(alpha = 0.01f)
                 .focusRequester(focusRequester),
@@ -194,6 +216,7 @@ private fun Preview() {
         OnboardingVisaPinCode(
             state = OnboardingVisaPinCodeUM(
                 pinCode = "1234",
+                error = stringReference("PIN Code error"),
             ),
         )
     }

features/onboarding-v2/impl/src/main/kotlin/com/tangem/features/onboarding/v2/visa/impl/child/pincode/ui/state/OnboardingVisaPinCodeUM.kt

@@ -1,7 +1,10 @@
 package com.tangem.features.onboarding.v2.visa.impl.child.pincode.ui.state
 
+import com.tangem.core.ui.extensions.TextReference
+
 internal data class OnboardingVisaPinCodeUM(
     val pinCode: String = "",
+    val error: TextReference? = null,
     val onPinCodeChange: (String) -> Unit = {},
     val submitButtonLoading: Boolean = false,
     val submitButtonEnabled: Boolean = true,