Show identity token at purchase screen when not using play store builds

app/src/main/java/io/timelimit/android/sync/network/api/Api.kt

@@ -1,5 +1,5 @@
 /*
- * TimeLimit Copyright <C> 2019 - 2021 Jonas Lochmann
+ * TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -55,6 +55,7 @@ interface ServerApi {
     suspend fun reportDeviceRemoved(deviceAuthToken: String)
     suspend fun removeDevice(deviceAuthToken: String, parentUserId: String, parentPasswordSecondHash: String, deviceId: String)
     suspend fun isDeviceRemoved(deviceAuthToken: String): Boolean
+    suspend fun createIdentityToken(deviceAuthToken: String, parentUserId: String, parentPasswordSecondHash: String): String
 }
 
 class MailServerBlacklistedException: RuntimeException()

app/src/main/java/io/timelimit/android/sync/network/api/DummyServerApi.kt

@@ -1,5 +1,5 @@
 /*
- * TimeLimit Copyright <C> 2019 - 2021 Jonas Lochmann
+ * TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -98,4 +98,12 @@ class DummyServerApi: ServerApi {
     override suspend fun isDeviceRemoved(deviceAuthToken: String): Boolean {
         throw IOException()
     }
+
+    override suspend fun createIdentityToken(
+        deviceAuthToken: String,
+        parentUserId: String,
+        parentPasswordSecondHash: String
+    ): String {
+        throw IOException()
+    }
 }

app/src/main/java/io/timelimit/android/sync/network/api/HttpServerApi.kt

@@ -1,5 +1,5 @@
 /*
- * TimeLimit Copyright <C> 2019 - 2021 Jonas Lochmann
+ * TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -626,4 +626,43 @@ class HttpServerApi(private val endpointWithoutSlashAtEnd: String): ServerApi {
             }
         }
     }
+
+    override suspend fun createIdentityToken(
+        deviceAuthToken: String,
+        parentUserId: String,
+        parentPasswordSecondHash: String
+    ): String {
+        httpClient.newCall(
+            Request.Builder()
+                .url("$endpointWithoutSlashAtEnd/parent/create-identity-token")
+                .post(createJsonRequestBody { writer ->
+                    writer.beginObject()
+                    writer.name(DEVICE_AUTH_TOKEN).value(deviceAuthToken)
+                    writer.name(PARENT_USER_ID).value(parentUserId)
+                    writer.name(PARENT_PASSWORD_SECOND_HASH).value(parentPasswordSecondHash)
+                    writer.name("purpose").value("purchase")
+                    writer.endObject()
+                })
+                .header("Content-Encoding", "gzip")
+                .build()
+        ).waitForResponse().use { response ->
+            response.assertSuccess()
+
+            return Threads.network.executeAndWait {
+                val reader = JsonReader(response.body!!.charStream())
+                var token: String? = null
+
+                reader.beginObject()
+                while (reader.hasNext()) {
+                    when (reader.nextName()) {
+                        "token" -> token = reader.nextString()
+                        else -> reader.skipValue()
+                    }
+                }
+                reader.endObject()
+
+                token!!
+            }
+        }
+    }
 }

app/src/main/java/io/timelimit/android/ui/diagnose/DiagnoseExceptionDialogFragment.kt

@@ -1,5 +1,5 @@
 /*
- * TimeLimit Copyright <C> 2019 Jonas Lochmann
+ * TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,16 +16,13 @@
 package io.timelimit.android.ui.diagnose
 
 import android.app.Dialog
-import android.content.ClipData
-import android.content.ClipboardManager
-import android.content.Context
 import android.os.Bundle
-import android.widget.Toast
 import androidx.appcompat.app.AlertDialog
 import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.FragmentManager
 import io.timelimit.android.R
 import io.timelimit.android.extensions.showSafe
+import io.timelimit.android.util.Clipboard
 import java.io.PrintWriter
 import java.io.StringWriter
 
@@ -51,16 +48,11 @@ class DiagnoseExceptionDialogFragment: DialogFragment() {
     }
 
     override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
-        val message = getStackTraceString(arguments!!.getSerializable(EXCEPTION) as Exception)
+        val message = getStackTraceString(requireArguments().getSerializable(EXCEPTION) as Exception)
-        val clipboard = context!!.getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager
 
-        return AlertDialog.Builder(context!!, theme)
+        return AlertDialog.Builder(requireContext(), theme)
                 .setMessage(message)
-                .setNeutralButton(R.string.diagnose_sync_copy_to_clipboard) { _, _ ->
+                .setNeutralButton(R.string.diagnose_sync_copy_to_clipboard) { _, _ -> Clipboard.setAndToast(requireContext(), message) }
-                    clipboard.setPrimaryClip(ClipData.newPlainText("TimeLimit", message))
-
-                    Toast.makeText(context, R.string.diagnose_sync_copied_to_clipboard, Toast.LENGTH_SHORT).show()
-                }
                 .setPositiveButton(R.string.generic_ok, null)
                 .create()
     }

app/src/main/java/io/timelimit/android/ui/payment/PurchaseFragment.kt

@@ -28,7 +28,10 @@ import io.timelimit.android.livedata.liveDataFromNullableValue
 import io.timelimit.android.livedata.mergeLiveData
 import io.timelimit.android.ui.MainActivity
 import io.timelimit.android.ui.diagnose.DiagnoseExceptionDialogFragment
+import io.timelimit.android.ui.main.ActivityViewModelHolder
 import io.timelimit.android.ui.main.FragmentWithCustomTitle
+import io.timelimit.android.ui.main.getActivityViewModel
+import io.timelimit.android.util.Clipboard
 import java.lang.RuntimeException
 
 class PurchaseFragment : Fragment(), FragmentWithCustomTitle {
@@ -40,6 +43,8 @@ class PurchaseFragment : Fragment(), FragmentWithCustomTitle {
         private const val PAGE_ERROR = 1
         private const val PAGE_WAIT = 2
         private const val PAGE_DONE = 3
+        private const val PAGE_AUTH = 4
+        private const val PAGE_TOKEN = 5
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -49,22 +54,18 @@ class PurchaseFragment : Fragment(), FragmentWithCustomTitle {
             activityModel.resetProcessPurchaseSuccess()
         }
 
-        model.retry(activityModel)
+        model.init(activityModel, getActivityViewModel(requireActivity()))
     }
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
         val binding = FragmentPurchaseBinding.inflate(inflater, container, false)
         var processingPurchaseError = false
 
-        mergeLiveData(activityModel.status, model.status).observe(viewLifecycleOwner, {
+        mergeLiveData(activityModel.status, model.status).observe(viewLifecycleOwner) { (activityStatus, fragmentStatus) ->
-            status ->
-
-            val (activityStatus, fragmentStatus) = status!!
-
             if (fragmentStatus != null) {
                 when (fragmentStatus) {
-                    PurchaseFragmentPreparing -> binding.flipper.displayedChild = PAGE_WAIT
+                    PurchaseModel.Status.Preparing -> binding.flipper.displayedChild = PAGE_WAIT
-                    is PurchaseFragmentReady -> {
+                    is PurchaseModel.Status.ReadyRegular -> {
                         when (activityStatus) {
                             null -> binding.flipper.displayedChild = PAGE_WAIT
                             ActivityPurchaseModelStatus.Working -> binding.flipper.displayedChild = PAGE_WAIT
@@ -82,42 +83,55 @@ class PurchaseFragment : Fragment(), FragmentWithCustomTitle {
                             ActivityPurchaseModelStatus.Done -> binding.flipper.displayedChild = PAGE_DONE
                         }.let {  }
                     }
-                    is PurchaseFragmentError -> {
+                    is PurchaseModel.Status.Error -> {
                         binding.flipper.displayedChild = PAGE_ERROR
 
                         binding.errorReason = when (fragmentStatus) {
-                            PurchaseFragmentErrorBillingNotSupportedByDevice -> getString(R.string.purchase_error_not_supported_by_device)
+                            PurchaseModel.Status.Error.Unrecoverable.BillingNotSupportedByDevice -> getString(R.string.purchase_error_not_supported_by_device)
-                            PurchaseFragmentErrorBillingNotSupportedByAppVariant -> getString(R.string.purchase_error_not_supported_by_app_variant)
+                            is PurchaseModel.Status.Error.Recoverable.NetworkError -> getString(R.string.error_network)
-                            is PurchaseFragmentNetworkError -> getString(R.string.error_network)
+                            PurchaseModel.Status.Error.Unrecoverable.ExistingPaymentError -> getString(R.string.purchase_error_existing_payment)
-                            PurchaseFragmentExistingPaymentError -> getString(R.string.purchase_error_existing_payment)
+                            PurchaseModel.Status.Error.Unrecoverable.ServerRejectedError -> getString(R.string.purchase_error_server_rejected)
-                            PurchaseFragmentServerRejectedError -> getString(R.string.purchase_error_server_rejected)
+                            PurchaseModel.Status.Error.Unrecoverable.ServerClientCombinationUnsupported -> getString(R.string.purchase_error_server_different_key)
-                            PurchaseFragmentServerHasDifferentPublicKey -> getString(R.string.purchase_error_server_different_key)
                         }
 
                         binding.showRetryButton = when (fragmentStatus) {
-                            is PurchaseFragmentRecoverableError -> true
+                            is PurchaseModel.Status.Error.Recoverable -> true
-                            is PurchaseFragmentUnrecoverableError -> false
+                            is PurchaseModel.Status.Error.Unrecoverable -> false
                         }
 
                         binding.showErrorDetailsButton = when (fragmentStatus) {
-                            is PurchaseFragmentNetworkError -> true
+                            is PurchaseModel.Status.Error.Recoverable.NetworkError -> true
                             else -> false
                         }
 
                         processingPurchaseError = false
                     }
+                    PurchaseModel.Status.WaitingForAuth -> {
+                        binding.flipper.displayedChild = PAGE_AUTH
+                    }
+                    is PurchaseModel.Status.ReadyToken -> {
+                       binding.flipper.displayedChild = PAGE_TOKEN
+
+                       binding.purchaseToken = fragmentStatus.token
+                    }
                 }.let { }
             } else {
                 binding.flipper.displayedChild = PAGE_WAIT
             }
-        })
+        }
+
+        getActivityViewModel(requireActivity()).authenticatedUser.observe(viewLifecycleOwner) { user ->
+            if (user != null && model.status.value is PurchaseModel.Status.WaitingForAuth) {
+                model.retry()
+            }
+        }
 
         binding.handlers = object: PurchaseFragmentHandlers {
             override fun retryAtErrorScreenClicked() {
                 if (processingPurchaseError) {
                     activityModel.queryAndProcessPurchasesAsync()
                 } else {
-                    model.retry(activityModel)
+                    model.retry()
                 }
             }
 
@@ -125,7 +139,7 @@ class PurchaseFragment : Fragment(), FragmentWithCustomTitle {
                 val status = model.status.value
 
                 val exception = when (status) {
-                    is PurchaseFragmentNetworkError -> status.exception
+                    is PurchaseModel.Status.Error.Recoverable.NetworkError -> status.exception
                     else -> RuntimeException("other error")
                 }
 
@@ -139,6 +153,18 @@ class PurchaseFragment : Fragment(), FragmentWithCustomTitle {
             override fun buyForOneYear() {
                 activityModel.startPurchase(PurchaseIds.SKU_YEAR, checkAtBackend = true, activity = requireActivity())
             }
+
+            override fun showAuthDialog() {
+                (requireActivity() as ActivityViewModelHolder).showAuthenticationScreen()
+            }
+
+            override fun copyPurchaseTokenToClipboard() {
+                model.status.value?.also {
+                    if (it is PurchaseModel.Status.ReadyToken) {
+                        Clipboard.setAndToast(requireContext(), it.token)
+                    }
+                }
+            }
         }
 
         return binding.root
@@ -152,4 +178,6 @@ interface PurchaseFragmentHandlers {
     fun showErrorDetails()
     fun buyForOneMonth()
     fun buyForOneYear()
+    fun showAuthDialog()
+    fun copyPurchaseTokenToClipboard()
 }

app/src/main/java/io/timelimit/android/ui/payment/PurchaseModel.kt

@@ -25,77 +25,128 @@ import io.timelimit.android.extensions.BillingNotSupportedException
 import io.timelimit.android.livedata.castDown
 import io.timelimit.android.logic.AppLogic
 import io.timelimit.android.logic.DefaultAppLogic
+import io.timelimit.android.sync.actions.apply.ApplyActionChildAddLimitAuthentication
+import io.timelimit.android.sync.actions.apply.ApplyActionParentDeviceAuthentication
+import io.timelimit.android.sync.actions.apply.ApplyActionParentPasswordAuthentication
 import io.timelimit.android.sync.network.CanDoPurchaseStatus
+import io.timelimit.android.sync.network.api.NotFoundHttpError
+import io.timelimit.android.ui.main.ActivityViewModel
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 
 class PurchaseModel(application: Application): AndroidViewModel(application) {
     private val logic: AppLogic by lazy { DefaultAppLogic.with(application) }
-    private val statusInternal = MutableLiveData<PurchaseFragmentStatus>()
+    private val statusInternal = MutableLiveData<Status>()
     private val lock = Mutex()
+    private var activityPurchaseModel: ActivityPurchaseModel? = null
+    private var auth: ActivityViewModel? = null
 
     val status = statusInternal.castDown()
 
-    fun retry(activityPurchaseModel: ActivityPurchaseModel) {
+    fun init(activityPurchaseModel: ActivityPurchaseModel, auth: ActivityViewModel) {
-        if (this.status.value is PurchaseFragmentRecoverableError || this.status.value == null) {
+        this.activityPurchaseModel = activityPurchaseModel
-            prepare(activityPurchaseModel)
+        this.auth = auth
+
+        retry()
+    }
+
+    fun retry() {
+        if (
+            this.status.value is Status.Error.Recoverable ||
+            this.status.value is Status.WaitingForAuth ||
+            this.status.value == null
+        ) {
+            val activityPurchaseModel = activityPurchaseModel
+            val auth = auth
+
+            if (activityPurchaseModel != null && auth != null) {
+                prepare(activityPurchaseModel, auth)
+            }
         }
     }
 
-    private fun prepare(activityPurchaseModel: ActivityPurchaseModel) {
+    private fun prepare(activityPurchaseModel: ActivityPurchaseModel, auth: ActivityViewModel) {
         runAsync {
             lock.withLock {
                 try {
-                    statusInternal.value = PurchaseFragmentPreparing
+                    statusInternal.value = Status.Preparing
 
-                    if (!BuildConfig.storeCompilant) {
-                        statusInternal.value = PurchaseFragmentErrorBillingNotSupportedByAppVariant
-                    } else {
                     val server = logic.serverLogic.getServerConfigCoroutine()
 
-                        val canDoPurchase = if (server.hasAuthToken)
+                    suspend fun canDoPurchase() = if (server.hasAuthToken) server.api.canDoPurchase(server.deviceAuthToken)
-                            server.api.canDoPurchase(server.deviceAuthToken)
+                    else CanDoPurchaseStatus.NoForUnknownReason
-                        else
+
-                            CanDoPurchaseStatus.NoForUnknownReason
+                    if (!BuildConfig.storeCompilant) {
+                        if (auth.isParentAuthenticated()) {
+                            val authData = auth.authenticatedUser.value?.first
+
+                            try {
+                                val token = when (authData) {
+                                    ApplyActionParentDeviceAuthentication -> server.api.createIdentityToken(
+                                        deviceAuthToken = server.deviceAuthToken,
+                                        parentUserId = "",
+                                        parentPasswordSecondHash = "device"
+                                    )
+                                    is ApplyActionParentPasswordAuthentication -> server.api.createIdentityToken(
+                                        deviceAuthToken = server.deviceAuthToken,
+                                        parentUserId = authData.parentUserId,
+                                        parentPasswordSecondHash = authData.secondPasswordHash
+                                    )
+                                    is ApplyActionChildAddLimitAuthentication -> throw RuntimeException(
+                                        "child can not do that"
+                                    )
+                                    null -> throw RuntimeException("missing user")
+                                }
+
+                                statusInternal.value = Status.ReadyToken(token)
+                            } catch (ex: NotFoundHttpError) {
+                                statusInternal.value = Status.Error.Unrecoverable.ServerClientCombinationUnsupported
+                            }
+                        } else statusInternal.value = Status.WaitingForAuth
+                    } else {
+                        val canDoPurchase = canDoPurchase()
 
                         if (canDoPurchase is CanDoPurchaseStatus.Yes) {
                             if (canDoPurchase.publicKey?.contentEquals(Base64.decode(BuildConfig.googlePlayKey, 0)) == false) {
-                                statusInternal.value = PurchaseFragmentServerHasDifferentPublicKey
+                                statusInternal.value = Status.Error.Unrecoverable.ServerClientCombinationUnsupported
                             } else {
                                 val skus = activityPurchaseModel.queryProducts(PurchaseIds.BUY_SKUS)
 
-                                statusInternal.value = PurchaseFragmentReady(
+                                statusInternal.value = Status.ReadyRegular(
                                         monthPrice = skus.find { it.productId == PurchaseIds.SKU_MONTH }?.oneTimePurchaseOfferDetails?.formattedPrice.toString(),
                                         yearPrice = skus.find { it.productId == PurchaseIds.SKU_YEAR }?.oneTimePurchaseOfferDetails?.formattedPrice.toString()
                                 )
                             }
                         } else if (canDoPurchase == CanDoPurchaseStatus.NotDueToOldPurchase) {
-                            statusInternal.value = PurchaseFragmentExistingPaymentError
+                            statusInternal.value = Status.Error.Unrecoverable.ExistingPaymentError
                         } else {
-                            statusInternal.value = PurchaseFragmentServerRejectedError
+                            statusInternal.value = Status.Error.Unrecoverable.ServerRejectedError
                         }
                     }
                 } catch (ex: BillingNotSupportedException) {
-                    statusInternal.value = PurchaseFragmentErrorBillingNotSupportedByDevice
+                    statusInternal.value = Status.Error.Unrecoverable.BillingNotSupportedByDevice
                 } catch (ex: Exception) {
-                    statusInternal.value = PurchaseFragmentNetworkError(ex)
+                    statusInternal.value = Status.Error.Recoverable.NetworkError(ex)
                 }
             }
         }
     }
+
+    sealed class Status {
+        sealed class Error: Status() {
+            sealed class Recoverable: Error() {
+                data class NetworkError(val exception: Exception): Recoverable()
+            }
+            sealed class Unrecoverable: Error() {
+                object BillingNotSupportedByDevice: Unrecoverable()
+                object ExistingPaymentError: Unrecoverable()
+                object ServerRejectedError: Unrecoverable()
+                object ServerClientCombinationUnsupported: Unrecoverable()
+            }
+        }
+        class ReadyRegular(val monthPrice: String, val yearPrice: String): Status()
+        class ReadyToken(val token: String): Status()
+        object Preparing: Status()
+        object WaitingForAuth: Status()
+    }
 }
-
-sealed class PurchaseFragmentStatus
-sealed class PurchaseFragmentError: PurchaseFragmentStatus()
-class PurchaseFragmentReady(val monthPrice: String, val yearPrice: String): PurchaseFragmentStatus()
-object PurchaseFragmentPreparing: PurchaseFragmentStatus()
-
-sealed class PurchaseFragmentUnrecoverableError: PurchaseFragmentError()
-sealed class PurchaseFragmentRecoverableError: PurchaseFragmentError()
-
-object PurchaseFragmentErrorBillingNotSupportedByDevice: PurchaseFragmentUnrecoverableError()
-object PurchaseFragmentErrorBillingNotSupportedByAppVariant: PurchaseFragmentUnrecoverableError()
-data class PurchaseFragmentNetworkError(val exception: Exception): PurchaseFragmentRecoverableError()
-object PurchaseFragmentExistingPaymentError: PurchaseFragmentUnrecoverableError()
-object PurchaseFragmentServerRejectedError: PurchaseFragmentUnrecoverableError()
-object PurchaseFragmentServerHasDifferentPublicKey: PurchaseFragmentUnrecoverableError()

app/src/main/java/io/timelimit/android/util/Clipboard.kt

@@ -0,0 +1,33 @@
+/*
+ * TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package io.timelimit.android.util
+
+import android.content.ClipData
+import android.content.ClipboardManager
+import android.content.Context
+import android.widget.Toast
+import androidx.core.content.getSystemService
+import io.timelimit.android.R
+
+object Clipboard {
+    fun setAndToast(context: Context, content: String) {
+        context.getSystemService<ClipboardManager>()?.also { clipboard ->
+            clipboard.setPrimaryClip(ClipData.newPlainText("TimeLimit", content))
+
+            Toast.makeText(context, R.string.diagnose_sync_copied_to_clipboard, Toast.LENGTH_SHORT).show()
+        }
+    }
+}

app/src/main/res/layout/fragment_purchase.xml

@@ -36,7 +36,11 @@
 
         <variable
             name="priceData"
-            type="io.timelimit.android.ui.payment.PurchaseFragmentReady" />
+            type="io.timelimit.android.ui.payment.PurchaseModel.Status.ReadyRegular" />
+
+        <variable
+            name="purchaseToken"
+            type="String" />
 
         <import type="android.view.View" />
     </data>
@@ -196,5 +200,75 @@
             </LinearLayout>
         </RelativeLayout>
 
+        <RelativeLayout
+            android:layout_width="match_parent"
+            android:layout_height="match_parent">
+
+            <LinearLayout
+                android:padding="8dp"
+                android:orientation="vertical"
+                android:layout_centerVertical="true"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <TextView
+                    android:textAppearance="?android:textAppearanceMedium"
+                    android:gravity="center_horizontal"
+                    android:text="@string/purchase_requires_auth_text"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content" />
+
+                <Button
+                    android:layout_marginTop="4dp"
+                    android:onClick="@{() -> handlers.showAuthDialog()}"
+                    android:text="@string/add_user_authentication_required_btn"
+                    android:layout_gravity="center_horizontal"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content" />
+
+            </LinearLayout>
+
+        </RelativeLayout>
+
+        <RelativeLayout
+            android:layout_width="match_parent"
+            android:layout_height="match_parent">
+
+            <LinearLayout
+                android:padding="8dp"
+                android:orientation="vertical"
+                android:layout_centerVertical="true"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <TextView
+                    android:textAppearance="?android:textAppearanceMedium"
+                    android:gravity="center_horizontal"
+                    android:text="@string/purchase_token_explain"
+                    android:autoLink="web"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content" />
+
+                <TextView
+                    android:paddingTop="8dp"
+                    android:paddingBottom="8dp"
+                    android:textAppearance="?android:textAppearanceSmall"
+                    android:layout_gravity="center_horizontal"
+                    tools:text="12345678"
+                    android:text="@{purchaseToken}"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content" />
+
+                <Button
+                    android:layout_marginTop="4dp"
+                    android:onClick="@{() -> handlers.copyPurchaseTokenToClipboard()}"
+                    android:text="@string/diagnose_sync_copy_to_clipboard"
+                    android:layout_gravity="center_horizontal"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content" />
+
+            </LinearLayout>
+
+        </RelativeLayout>
     </io.timelimit.android.ui.view.SafeViewFlipper>
 </layout>

app/src/main/res/values-de/strings.xml

@@ -1293,11 +1293,17 @@
         Sie haben bereits bezahlt. Sie können die Vollversion erst kurz vor dem Ablaufen (oder danach) verlängern
     </string>
     <string name="purchase_error_server_rejected">Der Server akzeptiert momentan keine Bezahlungen</string>
-    <string name="purchase_error_server_different_key">Der Server unterstützt Bezahlungen, aber nicht über diesen App-Build</string>
+    <string name="purchase_error_server_different_key">Der Server unterstützt möglicherweise Bezahlungen, aber nicht über diesen App-Build</string>
 
     <string name="purchase_done_title">Bezahlung abgeschlossen</string>
     <string name="purchase_done_text">Betätigen Sie die Zurück-Taste, um zur App zurückzukehren</string>
 
+    <string name="purchase_requires_auth_text">Sie müssen sich für den Kauf anmelden</string>
+    <string name="purchase_token_explain">Unter https://timelimit.io/de/#how-to-purchase erfahren Sie,
+        wie Sie den Kauf durchführen können.
+        Ihr Kauftoken lautet:
+    </string>
+
     <string name="purchase_required_dialog_title">Vollversion erforderlich</string>
     <string name="purchase_required_dialog_text">
         Diese Funktion benötigt die Vollversion.

app/src/main/res/values/strings.xml

@@ -1335,11 +1335,16 @@
         You can only extend the premium version if it expired or shortly before that.
     </string>
     <string name="purchase_error_server_rejected">The server does not accept payments currently</string>
-    <string name="purchase_error_server_different_key">The server does support payments, but not using this app build</string>
+    <string name="purchase_error_server_different_key">The server maybe does support payments, but not using this app build</string>
 
     <string name="purchase_done_title">Purchase succeeded</string>
     <string name="purchase_done_text">Press back to go back to the App</string>
 
+    <string name="purchase_requires_auth_text">You have to authenticate for the purchase</string>
+    <string name="purchase_token_explain">See https://timelimit.io/en/#how-to-purchase for details on the purchase.
+        Your purchase token is:
+    </string>
+
     <string name="purchase_required_dialog_title">Premium version required</string>
     <string name="purchase_required_dialog_text">
         The feature requires the premium version.