Fix IAP payment card switching issue (#3649)

Co-authored-by: Marvin W <git@larma.de>

Author: DaVinci9196

vending-app/src/main/java/org/microg/vending/billing/core/ui/UIParser.kt

@@ -98,7 +98,10 @@ private fun parseAction(action: Action?, result: BAction): Boolean {
     }
     action.viewClickAction?.let { viewClickAction ->
         if (viewClickAction.uiInfo != null) {
-            result.uiInfo = parseUIInfo(viewClickAction.uiInfo!!)
+            val parsedUiInfo = parseUIInfo(viewClickAction.uiInfo!!)
+            if (parsedUiInfo.uiType != UIType.UNKNOWN) {
+                result.uiInfo = parsedUiInfo
+            }
         }
         return parseAction(viewClickAction.action, result)
     }
@@ -676,4 +679,4 @@ private fun extractPurchaseItemFromScreens(
         )
     }
     return mapOf<String, Any>("RESPONSE_CODE" to 0, "DEBUG_MESSAGE" to "") to null
-}
+}

vending-app/src/main/java/org/microg/vending/billing/ui/logic/BillingScreenHistory.kt

@@ -0,0 +1,37 @@
+/*
+ * SPDX-FileCopyrightText: 2026 microG Project Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.microg.vending.billing.ui.logic
+
+internal class BillingScreenHistory {
+    private companion object {
+        const val MAX_SIZE = 32
+    }
+
+    private val screenIds = mutableListOf<String>()
+
+    fun recordTransition(fromScreenId: String?, toScreenId: String?): Boolean {
+        if (fromScreenId == null || toScreenId == null || fromScreenId == toScreenId) return false
+
+        val targetIndex = screenIds.lastIndexOf(toScreenId)
+        if (targetIndex >= 0) {
+            screenIds.subList(targetIndex, screenIds.size).clear()
+            return true
+        }
+
+        if (screenIds.lastOrNull() == fromScreenId) return false
+        screenIds.add(fromScreenId)
+        if (screenIds.size > MAX_SIZE) screenIds.removeAt(0)
+        return true
+    }
+
+    fun popPrevious(currentScreenId: String?, isAvailable: (String) -> Boolean): String? {
+        while (screenIds.isNotEmpty()) {
+            val screenId = screenIds.removeAt(screenIds.lastIndex)
+            if (screenId != currentScreenId && isAvailable(screenId)) return screenId
+        }
+        return null
+    }
+}

vending-app/src/main/java/org/microg/vending/billing/ui/logic/InAppBillingViewModel.kt

@@ -75,6 +75,8 @@ class InAppBillingViewModel : ViewModel() {
         )
     )
     private lateinit var lastBuyFlowResult: BuyFlowResult
+    private val screenHistory = BillingScreenHistory()
+    private var currentScreenId: String? = null
 
     private fun finishWithResult(result: Bundle) {
         viewModelScope.launch {
@@ -268,14 +270,36 @@ class InAppBillingViewModel : ViewModel() {
                         }
                     }
 
+                    UIType.BILLING_PROFILE_SCREEN_ABANDON -> {
+                        if (showPreviousScreen()) return
+                        finishWithResult(billingUiViewState.result)
+                    }
+
                     else -> finishWithResult(billingUiViewState.result)
                 }
             }
         }
     }
 
-    private fun showScreen(screenId: String): Boolean {
+    private fun showPreviousScreen(): Boolean {
+        val previousScreenId = screenHistory.popPrevious(
+            currentScreenId,
+            billingUiViewState.screenMap::containsKey
+        )
+        return previousScreenId != null && showScreen(
+            previousScreenId,
+            recordHistory = false
+        )
+    }
+
+    private fun showScreen(
+        screenId: String,
+        recordHistory: Boolean = true
+    ): Boolean {
+        val previousScreenId = currentScreenId
         val showScreen = billingUiViewState.screenMap[screenId] ?: return false
+        if (recordHistory) screenHistory.recordTransition(previousScreenId, screenId)
+        currentScreenId = screenId
         billingUiViewState = billingUiViewState.copy(
             showScreen = showScreen,
             visible = true
@@ -300,11 +324,15 @@ class InAppBillingViewModel : ViewModel() {
         }
         val action = buyFlowResult.acquireResult?.action ?: return failAction()
         val screenMap = buyFlowResult.acquireResult.screenMap
-        val showScreen = screenMap[action.screenId] ?: return failAction()
+        val targetScreenId = action.screenId ?: return failAction()
+        val showScreen = screenMap[targetScreenId] ?: return failAction()
         if (Log.isLoggable(TAG, Log.DEBUG)) Log.d(TAG, "handleAcquireResult, showScreen:$showScreen result:${buyFlowResult.acquireResult}")
         if (action.type != ActionType.SHOW) return failAction()
         lastBuyFlowResult = buyFlowResult
+        val previousScreenId = currentScreenId
         billingUiViewState.screenMap.putAll(screenMap)
+        screenHistory.recordTransition(previousScreenId, targetScreenId)
+        currentScreenId = targetScreenId
         billingUiViewState = billingUiViewState.copy(
             showScreen = showScreen,
             result = buyFlowResult.result,
@@ -400,4 +428,4 @@ class InAppBillingViewModel : ViewModel() {
             resultBundle(BillingClient.BillingResponseCode.USER_CANCELED, "")
         finishWithResult(result)
     }
-}
+}