qtart integration + first functional screens

Signed-off-by: Iván Ávalos <avalos@disroot.org>

45 files changed, 990 insertions, 472 deletions

diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
index bf1d698..fef7018 100644
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -1,6 +1,43 @@
 <component name="InspectionProjectProfileManager">
   <profile version="1.0">
     <option name="myName" value="Project Default" />
+    <inspection_tool class="PreviewAnnotationInFunctionWithParameters" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewApiLevelMustBeValid" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewDimensionRespectsLimit" enabled="true" level="WARNING" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewFontScaleMustBeGreaterThanZero" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewMultipleParameterProviders" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewMustBeTopLevelFunction" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewNeedsComposableAnnotation" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewNotSupportedInUnitTestFiles" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="PreviewPickerAnnotation" enabled="true" level="ERROR" enabled_by_default="true">
+      <option name="composableFile" value="true" />
+      <option name="previewFile" value="true" />
+    </inspection_tool>
+    <inspection_tool class="StaticImport" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="UnnecessaryVariable" enabled="false" level="WEAK WARNING" enabled_by_default="false" />
   </profile>
 </component>
\ No newline at end of file
diff --git a/anastasis/build.gradle.kts b/anastasis/build.gradle.kts
index 85fb2ec..7aceb34 100644
--- a/anastasis/build.gradle.kts
+++ b/anastasis/build.gradle.kts
@@ -6,7 +6,7 @@ plugins {
     id("com.google.dagger.hilt.android")
 }
 
-val qtartVersion = "0.9.3-dev.13"
+val qtartVersion = "0.9.3-dev.14"
 
 @Suppress("UnstableApiUsage")
 android {
@@ -57,6 +57,7 @@ android {
 dependencies {
     implementation(project(":taler-kotlin-android"))
     implementation("net.taler:qtart:$qtartVersion@aar")
+    implementation("net.java.dev.jna:jna:5.13.0@aar")
     implementation("androidx.core:core-ktx:1.10.1")
     implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.8.0"))
     implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.6.1")
@@ -71,7 +72,12 @@ dependencies {
     implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.1")
     implementation("org.jetbrains.kotlinx:kotlinx-datetime:0.4.0")
     implementation("com.google.dagger:hilt-android:2.44")
+    implementation("androidx.hilt:hilt-navigation-compose:1.0.0")
     kapt("com.google.dagger:hilt-android-compiler:2.44")
     debugImplementation("androidx.compose.ui:ui-tooling")
     debugImplementation("androidx.compose.ui:ui-test-manifest")
+}
+
+kapt {
+    correctErrorTypes = true
 }
\ No newline at end of file
diff --git a/anastasis/src/main/AndroidManifest.xml b/anastasis/src/main/AndroidManifest.xml
index 8c22a46..ce3333f 100644
--- a/anastasis/src/main/AndroidManifest.xml
+++ b/anastasis/src/main/AndroidManifest.xml
@@ -3,6 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <application
+        android:name=".AnastasisApp"
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
diff --git a/anastasis/src/main/java/net/taler/anastasis/AnastasisApp.kt b/anastasis/src/main/java/net/taler/anastasis/AnastasisApp.kt
new file mode 100644
index 0000000..8fc38fa
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/AnastasisApp.kt
@@ -0,0 +1,7 @@
+package net.taler.anastasis
+
+import android.app.Application
+import dagger.hilt.android.HiltAndroidApp
+
+@HiltAndroidApp
+class AnastasisApp: Application()
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/MainActivity.kt b/anastasis/src/main/java/net/taler/anastasis/MainActivity.kt
index 24f604a..4868357 100644
--- a/anastasis/src/main/java/net/taler/anastasis/MainActivity.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/MainActivity.kt
@@ -8,19 +8,19 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
-import androidx.navigation.compose.NavHost
-import androidx.navigation.compose.composable
-import androidx.navigation.compose.rememberNavController
-import net.taler.anastasis.models.ContinentInfo
-import net.taler.anastasis.models.CountryInfo
-import net.taler.anastasis.models.UserAttributeSpec
-import net.taler.anastasis.ui.backup.BackupContinentScreen
-import net.taler.anastasis.ui.backup.BackupCountryScreen
-import net.taler.anastasis.ui.backup.BackupUserAttributesScreen
+import androidx.hilt.navigation.compose.hiltViewModel
+import dagger.hilt.android.AndroidEntryPoint
+import net.taler.anastasis.ui.common.SelectContinentScreen
+import net.taler.anastasis.ui.common.SelectCountryScreen
+import net.taler.anastasis.ui.common.SelectUserAttributesScreen
 import net.taler.anastasis.ui.home.HomeScreen
 import net.taler.anastasis.ui.theme.AnastasisTheme
+import net.taler.anastasis.viewmodels.ReducerViewModel
 
+@AndroidEntryPoint
 class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -38,66 +38,24 @@ class MainActivity : ComponentActivity() {
 }
 
 @Composable
-fun MainNavHost() {
-    val navController = rememberNavController()
-    NavHost(
-        navController = navController,
-        startDestination = Routes.Home.route,
-    ) {
-        composable(Routes.Home.route) {
-            HomeScreen(navController = navController)
+fun MainNavHost(
+    viewModel: ReducerViewModel = hiltViewModel(),
+) {
+    val navRoute by viewModel.navRoute.collectAsState()
+    when (navRoute) {
+        Routes.Home.route -> {
+            HomeScreen()
         }
-        composable(Routes.BackupContinent.route) {
-            BackupContinentScreen(
-                navController = navController,
-                continents = listOf(
-                    ContinentInfo("Europe"),
-                    ContinentInfo("India"),
-                    ContinentInfo("Asia"),
-                    ContinentInfo("North America")
-                ),
-                onSelectContinent = {},
-            )
+        Routes.SelectContinent.route -> {
+            SelectContinentScreen()
         }
-        composable(Routes.BackupCountry.route) {
-            BackupCountryScreen(
-                navController = navController,
-                countries = listOf(
-                    CountryInfo("ch", "Switzerland", "Europe"),
-                    CountryInfo("de", "Germany", "Europe"),
-                ),
-                onSelectCountry = {},
-            )
+        Routes.SelectCountry.route -> {
+            SelectCountryScreen()
         }
-        composable(Routes.BackupUserAttributes.route) {
-            BackupUserAttributesScreen(
-                navController = navController,
-                userAttributes = listOf(
-                    UserAttributeSpec(
-                        type = "string",
-                        name = "full_name",
-                        label = "Full name",
-                        widget = "anastasis_gtk_ia_full_name",
-                        uuid = "9e8f463f-575f-42cb-85f3-759559997331",
-                        validationLogic = null,
-                        validationRegex = null,
-                    ),
-                    UserAttributeSpec(
-                        type = "date",
-                        name = "birthdate",
-                        label = "Birthdate",
-                        uuid = "83d655c7-bdb6-484d-904e-80c1058c8854",
-                        widget = "anastasis_gtk_ia_birthdate",
-                        validationLogic = null,
-                        validationRegex = null,
-                    ),
-                ),
-            )
+        Routes.SelectUserAttributes.route -> {
+            SelectUserAttributesScreen()
         }
-        composable(Routes.RecoveryCountry.route) {
-            Text("This is the recover screen!")
-        }
-        composable(Routes.RestoreInit.route) {
+        Routes.RestoreInit.route -> {
             Text("This is the restore session screen!")
         }
     }
diff --git a/anastasis/src/main/java/net/taler/anastasis/Routes.kt b/anastasis/src/main/java/net/taler/anastasis/Routes.kt
index 18db321..1a0accc 100644
--- a/anastasis/src/main/java/net/taler/anastasis/Routes.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/Routes.kt
@@ -6,13 +6,10 @@ sealed class Routes(
 ) {
     object Home: Routes("home")
 
-    // Backup
-    object BackupContinent: Routes("backup_continent")
-    object BackupCountry: Routes("backup_country")
-    object BackupUserAttributes: Routes("backup_user_attributes")
-
-    // Recovery
-    object RecoveryCountry: Routes("recovery_country")
+    // Common
+    object SelectContinent: Routes("select_continent")
+    object SelectCountry: Routes("select_country")
+    object SelectUserAttributes: Routes("select_user_attributes")
 
     // Restore
     object RestoreInit: Routes("restore")
diff --git a/anastasis/src/main/java/net/taler/anastasis/backend/AnastasisReducerApi.kt b/anastasis/src/main/java/net/taler/anastasis/backend/AnastasisReducerApi.kt
new file mode 100644
index 0000000..42ce566
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/backend/AnastasisReducerApi.kt
@@ -0,0 +1,86 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.backend
+
+import kotlinx.coroutines.DelicateCoroutinesApi
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.decodeFromJsonElement
+import net.taler.anastasis.models.ReducerState
+import net.taler.common.ApiResponse
+import net.taler.common.ApiResponse.*
+import net.taler.common.TalerErrorCode.NONE
+import org.json.JSONObject
+
+@OptIn(DelicateCoroutinesApi::class)
+class AnastasisReducerApi() {
+
+    private val backendManager = BackendManager()
+
+    init {
+        GlobalScope.launch(Dispatchers.IO) {
+            backendManager.run()
+        }
+    }
+
+    suspend fun sendRequest(operation: String, args: JSONObject? = null): ApiResponse {
+        return backendManager.send(operation, args)
+    }
+
+    suspend inline fun startBackup(): ReducerState = withContext(Dispatchers.Default) {
+        val json = BackendManager.json
+        when (val response = sendRequest("anastasisStartBackup")) {
+            is Response -> json.decodeFromJsonElement(response.result)
+            is Error -> error("invalid reducer response")
+        }
+    }
+
+    suspend inline fun startRecovery(): ReducerState = withContext(Dispatchers.Default) {
+        val json = BackendManager.json
+        when (val response = sendRequest("anastasisStartRecovery")) {
+            is Response -> json.decodeFromJsonElement(response.result)
+            is Error -> error("invalid reducer response")
+        }
+    }
+
+    suspend inline fun reduceAction(
+        state: ReducerState,
+        action: String,
+        noinline args: (JSONObject.() -> JSONObject)? = null,
+    ): WalletResponse<ReducerState> = withContext(Dispatchers.Default) {
+        val json = BackendManager.json
+        val body = JSONObject().apply {
+            put("state", JSONObject(json.encodeToString(ReducerState.serializer(), state)))
+            put("action", action)
+            if (args != null) put("args", args.invoke(JSONObject()))
+        }
+        try {
+            when (val response = sendRequest("anastasisReduce", body)) {
+                is Response -> {
+                    val t = json.decodeFromJsonElement<ReducerState>(response.result)
+                    WalletResponse.Success(t)
+                }
+                is Error -> error("invalid reducer response")
+            }
+        } catch (e: Exception) {
+            val info = TalerErrorInfo(NONE, "", e.toString())
+            WalletResponse.Error(info)
+        }
+    }
+}
diff --git a/anastasis/src/main/java/net/taler/anastasis/backend/BackendManager.kt b/anastasis/src/main/java/net/taler/anastasis/backend/BackendManager.kt
new file mode 100644
index 0000000..8ba6025
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/backend/BackendManager.kt
@@ -0,0 +1,81 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2022 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.backend
+
+import android.util.Log
+import kotlinx.serialization.json.Json
+import net.taler.common.ApiMessage
+import net.taler.common.ApiResponse
+import net.taler.qtart.TalerWalletCore
+import net.taler.anastasis.BuildConfig
+import org.json.JSONObject
+import kotlin.coroutines.resume
+import kotlin.coroutines.suspendCoroutine
+
+class BackendManager {
+
+    companion object {
+        private const val TAG = "BackendManager"
+        private const val TAG_CORE = "taler-wallet-embedded"
+        val json = Json {
+            ignoreUnknownKeys = true
+        }
+    }
+
+    private val walletCore = TalerWalletCore()
+    private val requestManager = RequestManager()
+
+    init {
+        walletCore.setMessageHandler { onMessageReceived(it) }
+        if (BuildConfig.DEBUG) walletCore.setStdoutHandler {
+            Log.d(TAG_CORE, it)
+        }
+    }
+
+    fun run() {
+        walletCore.run()
+    }
+
+    suspend fun send(operation: String, args: JSONObject? = null): ApiResponse =
+        suspendCoroutine { cont ->
+            requestManager.addRequest(cont) { id ->
+                val request = JSONObject().apply {
+                    put("id", id)
+                    put("operation", operation)
+                    if (args != null) put("args", args)
+                }
+                Log.d(TAG, "sending message:\n${request.toString(2)}")
+                walletCore.sendRequest(request.toString())
+            }
+        }
+
+    private fun onMessageReceived(msg: String) {
+        Log.d(TAG, "message received: $msg")
+        when (val message = json.decodeFromString<ApiMessage>(msg)) {
+            is ApiMessage.Notification -> {}
+            is ApiResponse -> {
+                val id = message.id
+                val cont = requestManager.getAndRemoveContinuation(id)
+                if (cont == null) {
+                    Log.e(TAG, "wallet returned unknown request ID ($id)")
+                } else {
+                    cont.resume(message)
+                }
+            }
+        }
+    }
+}
diff --git a/anastasis/src/main/java/net/taler/anastasis/backend/RequestManager.kt b/anastasis/src/main/java/net/taler/anastasis/backend/RequestManager.kt
new file mode 100644
index 0000000..70f81b3
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/backend/RequestManager.kt
@@ -0,0 +1,45 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.backend
+
+import androidx.annotation.GuardedBy
+import net.taler.common.ApiResponse
+import java.util.concurrent.ConcurrentHashMap
+import kotlin.coroutines.Continuation
+
+class RequestManager {
+
+    @GuardedBy("this")
+    private val contMap = ConcurrentHashMap<Int, Continuation<ApiResponse>>()
+
+    @Volatile
+    @GuardedBy("this")
+    private var currentId = 0
+
+    @Synchronized
+    fun addRequest(cont: Continuation<ApiResponse>, block: (Int) -> Unit) {
+        val id = currentId++
+        contMap[id] = cont
+        block(id)
+    }
+
+    @Synchronized
+    fun getAndRemoveContinuation(id: Int): Continuation<ApiResponse>? {
+        return contMap.remove(id)
+    }
+
+}
diff --git a/anastasis/src/main/java/net/taler/anastasis/backend/WalletResponse.kt b/anastasis/src/main/java/net/taler/anastasis/backend/WalletResponse.kt
new file mode 100644
index 0000000..29ca6b2
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/backend/WalletResponse.kt
@@ -0,0 +1,134 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.backend
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.builtins.MapSerializer
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.buildJsonObject
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+import net.taler.common.TalerErrorCode
+
+@Serializable
+sealed class WalletResponse<T> {
+    @Serializable
+    @SerialName("response")
+    data class Success<T>(
+        val result: T,
+    ) : WalletResponse<T>()
+
+    @Serializable
+    @SerialName("error")
+    data class Error<T>(
+        val error: TalerErrorInfo,
+    ) : WalletResponse<T>()
+
+    fun onSuccess(block: (result: T) -> Unit): WalletResponse<T> {
+        if (this is Success) block(this.result)
+        return this
+    }
+
+    fun onError(block: (result: TalerErrorInfo) -> Unit): WalletResponse<T> {
+        if (this is Error) block(this.error)
+        return this
+    }
+}
+
+@Serializable(with = TalerErrorInfoSerializer::class)
+data class TalerErrorInfo(
+    // Numeric error code defined defined in the
+    // GANA gnu-taler-error-codes registry.
+    val code: TalerErrorCode,
+
+    // English description of the error code.
+    val hint: String? = null,
+
+    // English diagnostic message that can give details
+    // for the instance of the error.
+    val message: String? = null,
+
+    // Error extra details
+    val extra: Map<String, JsonElement> = mapOf(),
+) {
+    val userFacingMsg: String
+        get() {
+            return StringBuilder().apply {
+                // If there's a hint in errorResponse, use it.
+                extra["errorResponse"]
+                    ?.jsonObject
+                    ?.get("hint")
+                    ?.let {
+                        append(it.jsonPrimitive.content)
+                    } ?: {
+                    // Otherwise, use the standard ones.
+                    hint?.let { append(it) }
+                    message?.let { append(" ").append(it) }
+                }
+            }.toString()
+        }
+
+    fun getStringExtra(key: String): String? =
+        extra[key]?.jsonPrimitive?.content
+}
+
+class TalerErrorInfoSerializer : KSerializer<TalerErrorInfo> {
+    private val stringToJsonElementSerializer = MapSerializer(String.serializer(), JsonElement.serializer())
+
+    override val descriptor: SerialDescriptor
+        get() = stringToJsonElementSerializer.descriptor
+
+    override fun deserialize(decoder: Decoder): TalerErrorInfo {
+        // Decoder -> JsonInput
+        require(decoder is JsonDecoder)
+        val json = decoder.json
+        val filtersMap = decoder.decodeSerializableValue(stringToJsonElementSerializer)
+
+        val code = filtersMap["code"]?.let {
+            json.decodeFromJsonElement(TalerErrorCode.serializer(), it)
+        } ?: TalerErrorCode.UNKNOWN
+        val hint = filtersMap["hint"]?.let {
+            json.decodeFromJsonElement(String.serializer(), it)
+        }
+        val message = filtersMap["message"]?.let {
+            json.decodeFromJsonElement(String.serializer(), it)
+        }
+
+        val knownKeys = setOf("code", "hint", "message")
+        val unknownFilters = filtersMap.filter { (key, _) -> !knownKeys.contains(key) }
+
+        return TalerErrorInfo(code, hint, message, unknownFilters)
+    }
+
+    override fun serialize(encoder: Encoder, value: TalerErrorInfo) {
+        encoder.encodeSerializableValue(JsonObject.serializer(), buildJsonObject {
+            put("code", JsonPrimitive(value.code.code))
+            put("hint", JsonPrimitive(value.hint))
+            put("message", JsonPrimitive(value.message))
+            value.extra.forEach { (key, value) -> put(key, value) }
+        })
+    }
+}
diff --git a/anastasis/src/main/java/net/taler/anastasis/models/ReducerState.kt b/anastasis/src/main/java/net/taler/anastasis/models/ReducerState.kt
index 85494f0..37f380f 100644
--- a/anastasis/src/main/java/net/taler/anastasis/models/ReducerState.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/models/ReducerState.kt
@@ -7,10 +7,110 @@ import kotlinx.serialization.json.JsonClassDiscriminator
 import net.taler.common.Amount
 import net.taler.common.Timestamp
 
-@OptIn(ExperimentalSerializationApi::class)
 @Serializable
+@OptIn(ExperimentalSerializationApi::class)
 @JsonClassDiscriminator("reducer_type")
-abstract class ReducerState
+sealed class ReducerState {
+    @Serializable
+    @SerialName("backup")
+    data class Backup(
+        @SerialName("backup_state")
+        val backupState: BackupStates,
+        val continents: List<ContinentInfo>? = null,
+        val countries: List<CountryInfo>? = null,
+        @SerialName("identity_attributes")
+        val identityAttributes: Map<String, String>? = null,
+        @SerialName("authentication_providers")
+        val authenticationProviders: Map<String, AuthenticationProviderStatus>? = null,
+        @SerialName("authentication_methods")
+        val authenticationMethods: List<AuthMethod>? = null,
+        @SerialName("required_attributes")
+        val requiredAttributes: List<UserAttributeSpec>? = null,
+        @SerialName("selected_continent")
+        val selectedContinent: String? = null,
+        @SerialName("selected_country")
+        val selectedCountry: String? = null,
+        @SerialName("secret_name")
+        val secretName: String? = null,
+        val policies: List<Policy>? = null,
+        @SerialName("recovery_data")
+        val recoveryData: RecoveryData? = null,
+        @SerialName("policy_providers")
+        val policyProviders: List<PolicyProvider>? = null,
+        @SerialName("success_details")
+        val successDetails: Map<String, SuccessDetail>? = null,
+        val payments: List<String>? = null,
+        @SerialName("policy_payment_requests")
+        val policyPaymentRequests: List<PolicyPaymentRequest>? = null,
+        @SerialName("core_secret")
+        val coreSecret: CoreSecret? = null,
+        val expiration: Timestamp? = null,
+        @SerialName("upload_fees")
+        val uploadFees: List<UploadFee>? = null,
+        @SerialName("truth_upload_payment_secrets")
+        val truthUploadPaymentSecrets: Map<String, String>? = null,
+    ): ReducerState() {
+        @Serializable
+        data class RecoveryData(
+            @SerialName("truth_metadata")
+            val truthMetadata: Map<String, TruthMetaData>,
+            @SerialName("recovery_document")
+            val recoveryDocument: RecoveryDocument,
+        )
+
+        @Serializable
+        data class PolicyPaymentRequest(
+            val payto: String,
+            val provider: String,
+        )
+
+        @Serializable
+        data class UploadFee(
+            val fee: Amount,
+        )
+    }
+
+    @Serializable
+    @SerialName("recovery")
+    data class Recovery(
+        @SerialName("recovery_state")
+        val recoveryState: RecoveryStates,
+        @SerialName("identity_attributes")
+        val identityAttributes: Map<String, String>? = null,
+        val continents: List<ContinentInfo>? = null,
+        val countries: List<CountryInfo>? = null,
+        @SerialName("selected_continent")
+        val selectedContinent: String? = null,
+        @SerialName("selected_country")
+        val selectedCountry: String? = null,
+        @SerialName("required_attributes")
+        val requiredAttributes: List<UserAttributeSpec>? = null,
+        @SerialName("recovery_information")
+        val recoveryInformation: RecoveryInformation? = null,
+        @SerialName("recovery_document")
+        val recoveryDocument: RecoveryInternalData? = null,
+        @SerialName("verbatim_recovery_document")
+        val verbatimRecoveryDocument: RecoveryDocument? = null,
+        @SerialName("selected_challenge_uuid")
+        val selectedChallengeUuid: String? = null,
+        @SerialName("selected_version")
+        val selectedVersion: SelectedVersionInfo? = null,
+        @SerialName("challenge_feedback")
+        val challengeFeedback: Map<String, ChallengeFeedback>? = null,
+        // TODO: recovered_key_shares
+        val coreSecret: CoreSecret? = null,
+        @SerialName("authentication_providers")
+        val authenticationProviders: Map<String, AuthenticationProviderStatus>? = null,
+    ): ReducerState()
+
+    @Serializable
+    @SerialName("error")
+    data class Error(
+        val code: Int,
+        val hint: String? = null,
+        val detail: String? = null,
+    ): ReducerState()
+}
 
 @Serializable
 data class ContinentInfo(
@@ -58,65 +158,6 @@ data class CoreSecret(
 )
 
 @Serializable
-@SerialName("backup")
-data class ReducerStateBackup(
-    @SerialName("backup_state")
-    val backupState: BackupStates,
-    val continents: List<ContinentInfo>? = null,
-    val countries: List<CountryInfo>? = null,
-    @SerialName("identity_attributes")
-    val identityAttributes: Map<String, String>? = null,
-    @SerialName("authentication_providers")
-    val authenticationProviders: Map<String, AuthenticationProviderStatus>? = null,
-    @SerialName("authentication_methods")
-    val authenticationMethods: List<AuthMethod>? = null,
-    @SerialName("required_attributes")
-    val requiredAttributes: List<UserAttributeSpec>? = null,
-    @SerialName("selected_continent")
-    val selectedContinent: String? = null,
-    @SerialName("selected_country")
-    val selectedCountry: String? = null,
-    @SerialName("secret_name")
-    val secretName: String? = null,
-    val policies: List<Policy>? = null,
-    @SerialName("recovery_data")
-    val recoveryData: RecoveryData? = null,
-    @SerialName("policy_providers")
-    val policyProviders: List<PolicyProvider>? = null,
-    @SerialName("success_details")
-    val successDetails: Map<String, SuccessDetail>? = null,
-    val payments: List<String>? = null,
-    @SerialName("policy_payment_requests")
-    val policyPaymentRequests: List<PolicyPaymentRequest>? = null,
-    @SerialName("core_secret")
-    val coreSecret: CoreSecret? = null,
-    val expiration: Timestamp? = null,
-    @SerialName("upload_fees")
-    val uploadFees: List<UploadFee>? = null,
-    @SerialName("truth_upload_payment_secrets")
-    val truthUploadPaymentSecrets: Map<String, String>? = null,
-): ReducerState() {
-    @Serializable
-    data class RecoveryData(
-        @SerialName("truth_metadata")
-        val truthMetadata: Map<String, TruthMetaData>,
-        @SerialName("recovery_document")
-        val recoveryDocument: RecoveryDocument,
-    )
-
-    @Serializable
-    data class PolicyPaymentRequest(
-        val payto: String,
-        val provider: String,
-    )
-
-    @Serializable
-    data class UploadFee(
-        val fee: Amount,
-    )
-}
-
-@Serializable
 data class AuthMethod(
     val type: String,
     val instructions: String,
@@ -141,9 +182,9 @@ data class UserAttributeSpec(
     val widget: String,
     val optional: Boolean? = null,
     @SerialName("validation-regex")
-    val validationRegex: String?,
+    val validationRegex: String? = null,
     @SerialName("validation-logic")
-    val validationLogic: String?,
+    val validationLogic: String? = null,
     val autocomplete: String? = null,
 )
 
@@ -168,38 +209,6 @@ data class RecoveryInformation(
 }
 
 @Serializable
-@SerialName("recovery")
-data class ReducerStateRecovery(
-    val recoveryState: RecoveryStates,
-    @SerialName("identity_attributes")
-    val identityAttributes: Map<String, String>? = null,
-    val continents: List<ContinentInfo>? = null,
-    val countries: List<CountryInfo>? = null,
-    @SerialName("selected_continent")
-    val selectedContinent: String? = null,
-    @SerialName("selected_country")
-    val selectedCountry: String? = null,
-    @SerialName("required_attributes")
-    val requiredAttributes: List<UserAttributeSpec>? = null,
-    @SerialName("recovery_information")
-    val recoveryInformation: RecoveryInformation? = null,
-    @SerialName("recovery_document")
-    val recoveryDocument: RecoveryInternalData? = null,
-    @SerialName("verbatim_recovery_document")
-    val verbatimRecoveryDocument: RecoveryDocument? = null,
-    @SerialName("selected_challenge_uuid")
-    val selectedChallengeUuid: String? = null,
-    @SerialName("selected_version")
-    val selectedVersion: SelectedVersionInfo? = null,
-    @SerialName("challenge_feedback")
-    val challengeFeedback: Map<String, ChallengeFeedback>? = null,
-    // TODO: recovered_key_shares
-    val coreSecret: CoreSecret? = null,
-    @SerialName("authentication_providers")
-    val authenticationProviders: Map<String, AuthenticationProviderStatus>,
-): ReducerState()
-
-@Serializable
 data class TruthMetaData(
     val uuid: String,
     @SerialName("key_share")
@@ -216,14 +225,6 @@ data class TruthMetaData(
 )
 
 @Serializable
-@SerialName("error")
-data class ReducerStateError(
-    val code: Int,
-    val hint: String? = null,
-    val detail: String? = null,
-): ReducerState()
-
-@Serializable
 enum class BackupStates {
     @SerialName("CONTINENT_SELECTING")
     ContinentSelecting,
@@ -287,48 +288,50 @@ data class MethodSpec(
     val usageFee: String,
 )
 
-@Serializable
-@SerialName("not-contacted")
-class AuthenticationProviderStatusNotContacted: AuthenticationProviderStatus()
-
-@Serializable
-@SerialName("ok")
-data class AuthenticationProviderStatusOk(
-    @SerialName("annual_fee")
-    val annualFee: String,
-    @SerialName("business_name")
-    val businessName: String,
-    val currency: String,
-    @SerialName("http_status")
-    val httpStatus: Int,
-    @SerialName("liability_limit")
-    val liabilityLimit: String,
-    @SerialName("provider_salt")
-    val providerSalt: String,
-    @SerialName("storage_limit_in_megabytes")
-    val storageLimitInMegabytes: Int,
-    @SerialName("truth_upload_fee")
-    val truthUploadFee: String,
-    val methods: List<MethodSpec>,
-): AuthenticationProviderStatus()
-
-@Serializable
-@SerialName("disabled")
-class AuthenticationProviderStatusDisabled: AuthenticationProviderStatus()
 
-@Serializable
-@SerialName("error")
-data class AuthenticationProviderStatusError(
-    @SerialName("http_status")
-    val httpStatus: Int? = null,
-    val code: Int,
-    val hint: String? = null,
-): AuthenticationProviderStatus()
 
 @OptIn(ExperimentalSerializationApi::class)
 @Serializable
 @JsonClassDiscriminator("status")
-abstract class AuthenticationProviderStatus()
+sealed class AuthenticationProviderStatus {
+    @Serializable
+    @SerialName("not-contacted")
+    object NotContacted: AuthenticationProviderStatus()
+
+    @Serializable
+    @SerialName("ok")
+    data class Ok(
+        @SerialName("annual_fee")
+        val annualFee: String,
+        @SerialName("business_name")
+        val businessName: String,
+        val currency: String,
+        @SerialName("http_status")
+        val httpStatus: Int,
+        @SerialName("liability_limit")
+        val liabilityLimit: String,
+        @SerialName("provider_salt")
+        val providerSalt: String,
+        @SerialName("storage_limit_in_megabytes")
+        val storageLimitInMegabytes: Int,
+        @SerialName("truth_upload_fee")
+        val truthUploadFee: String,
+        val methods: List<MethodSpec>,
+    ): AuthenticationProviderStatus()
+
+    @Serializable
+    @SerialName("disabled")
+    object Disabled : AuthenticationProviderStatus()
+
+    @Serializable
+    @SerialName("error")
+    data class Error(
+        @SerialName("http_status")
+        val httpStatus: Int? = null,
+        val code: Int,
+        val hint: String? = null,
+    ): AuthenticationProviderStatus()
+}
 
 // TODO: ReducerStateBackupUserAttributesCollecting
 
diff --git a/anastasis/src/main/java/net/taler/anastasis/reducers/ReducerManager.kt b/anastasis/src/main/java/net/taler/anastasis/reducers/ReducerManager.kt
new file mode 100644
index 0000000..90a5158
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/reducers/ReducerManager.kt
@@ -0,0 +1,84 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.reducers
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.launch
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.encodeToJsonElement
+import net.taler.anastasis.backend.AnastasisReducerApi
+import net.taler.anastasis.models.ContinentInfo
+import net.taler.anastasis.models.CountryInfo
+import net.taler.anastasis.models.ReducerState
+
+class ReducerManager(
+    private val state: MutableStateFlow<ReducerState?>,
+    private val api: AnastasisReducerApi,
+    private val scope: CoroutineScope,
+) {
+    // TODO: error handling!
+
+    fun startBackup() = scope.launch {
+        state.value = api.startBackup()
+    }
+
+    fun startRecovery() = scope.launch {
+        state.value = api.startRecovery()
+    }
+
+    fun back() = scope.launch {
+        state.value?.let { initialState ->
+            api.reduceAction(initialState, "back")
+                .onSuccess { newState ->
+                    state.value = newState
+                }
+        }
+    }
+
+    fun selectContinent(continent: ContinentInfo) = scope.launch {
+        state.value?.let { initialState ->
+            api.reduceAction(initialState, "select_continent") {
+                put("continent", continent.name)
+            }.onSuccess { newState ->
+                state.value = newState
+            }
+        }
+    }
+
+    fun selectCountry(country: CountryInfo) = scope.launch {
+        state.value?.let { initialState ->
+            api.reduceAction(initialState, "select_country") {
+                put("country_code", country.code)
+                // TODO: stop hardcoding currency!
+                put("currency", "EUR")
+            }.onSuccess { newState ->
+                state.value = newState
+            }
+        }
+    }
+
+    fun enterUserAttributes(userAttributes: Map<String, String>) = scope.launch {
+        state.value?.let {  initialState ->
+            api.reduceAction(initialState, "enter_user_attributes") {
+                put("identity_attributes", Json.encodeToJsonElement(userAttributes))
+            }.onSuccess { newState ->
+                state.value = newState
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupContinentScreen.kt b/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupContinentScreen.kt
deleted file mode 100644
index 9638ba2..0000000
--- a/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupContinentScreen.kt
+++ /dev/null
@@ -1,76 +0,0 @@
-package net.taler.anastasis.ui.backup
-
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.ArrowBack
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.navigation.NavController
-import androidx.navigation.compose.rememberNavController
-import net.taler.anastasis.R
-import net.taler.anastasis.Routes
-import net.taler.anastasis.models.ContinentInfo
-import net.taler.anastasis.ui.reusable.components.Picker
-import net.taler.anastasis.ui.reusable.pages.WizardPage
-import net.taler.anastasis.ui.theme.LocalSpacing
-
-@Composable
-fun BackupContinentScreen(
-    navController: NavController,
-    continents: List<ContinentInfo>,
-    onSelectContinent: (continent: ContinentInfo) -> Unit,
-) {
-    WizardPage(
-        title = stringResource(R.string.backup_country_title),
-        navigationIcon = {
-            IconButton(onClick = {
-                navController.navigate(Routes.Home.route)
-            }) {
-                Icon(Icons.Default.ArrowBack, "back")
-            }
-        },
-        showPrev = false,
-        onNextClicked = {
-            navController.navigate(Routes.BackupCountry.route)
-        },
-    ) {
-        Column(
-            modifier = Modifier
-                .fillMaxSize()
-                .padding(LocalSpacing.current.medium),
-            verticalArrangement = Arrangement.Top,
-        ) {
-            Picker(
-                label = stringResource(R.string.continent),
-                options = continents.map { it.name }.toSet(),
-                onOptionChanged = { option ->
-                    continents.find { it.name == option }?.let { continent ->
-                        onSelectContinent(continent)
-                    }
-                },
-            )
-        }
-    }
-}
-
-@Composable
-@Preview
-fun BackupContinentScreenPreview() {
-    val navController = rememberNavController()
-    BackupContinentScreen(
-        navController = navController,
-        continents = listOf(
-            ContinentInfo("Europe"),
-            ContinentInfo("India"),
-            ContinentInfo("Asia"),
-            ContinentInfo("North America")),
-        onSelectContinent = {},
-    )
-}
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupCountryScreen.kt b/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupCountryScreen.kt
deleted file mode 100644
index dfb974f..0000000
--- a/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupCountryScreen.kt
+++ /dev/null
@@ -1,77 +0,0 @@
-package net.taler.anastasis.ui.backup
-
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.ArrowBack
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.navigation.NavController
-import androidx.navigation.compose.rememberNavController
-import net.taler.anastasis.R
-import net.taler.anastasis.Routes
-import net.taler.anastasis.models.CountryInfo
-import net.taler.anastasis.ui.reusable.components.Picker
-import net.taler.anastasis.ui.reusable.pages.WizardPage
-import net.taler.anastasis.ui.theme.LocalSpacing
-
-@Composable
-fun BackupCountryScreen(
-    navController: NavController,
-    countries: List<CountryInfo>,
-    onSelectCountry: (country: CountryInfo) -> Unit,
-) {
-    WizardPage(
-        title = stringResource(R.string.backup_country_title),
-        navigationIcon = {
-            IconButton(onClick = {
-                navController.navigate(Routes.Home.route)
-            }) {
-                Icon(Icons.Default.ArrowBack, "back")
-            }
-        },
-        onPrevClicked = {
-            navController.navigate(Routes.BackupContinent.route)
-        },
-        onNextClicked = {
-            navController.navigate(Routes.BackupUserAttributes.route)
-        },
-    ) {
-        Column(
-            modifier = Modifier
-                .fillMaxSize()
-                .padding(LocalSpacing.current.medium),
-            verticalArrangement = Arrangement.Top,
-        ) {
-            Picker(
-                label = stringResource(R.string.country),
-                options = countries.map { it.name }.toSet(),
-                onOptionChanged = { option ->
-                    countries.find { it.name == option }?.let { country ->
-                        onSelectCountry(country)
-                    }
-                },
-            )
-        }
-    }
-}
-
-@Composable
-@Preview
-fun BackupCountryScreenPreview() {
-    val navController = rememberNavController()
-    BackupCountryScreen(
-        navController = navController,
-        countries = listOf(
-            CountryInfo("ch", "Switzerland", "Europe"),
-            CountryInfo("de", "Germany", "Europe"),
-        ),
-        onSelectCountry = {},
-    )
-}
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectContinentScreen.kt b/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectContinentScreen.kt
new file mode 100644
index 0000000..b8ec266
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectContinentScreen.kt
@@ -0,0 +1,90 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.ui.common
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.hilt.navigation.compose.hiltViewModel
+import net.taler.anastasis.R
+import net.taler.anastasis.models.ContinentInfo
+import net.taler.anastasis.models.ReducerState
+import net.taler.anastasis.ui.reusable.components.Picker
+import net.taler.anastasis.ui.reusable.pages.WizardPage
+import net.taler.anastasis.ui.theme.LocalSpacing
+import net.taler.anastasis.viewmodels.ReducerViewModel
+
+@Composable
+fun SelectContinentScreen(
+    viewModel: ReducerViewModel = hiltViewModel(),
+) {
+    val reducerState by viewModel.reducerState.collectAsState()
+    val continents = when (val state = reducerState) {
+        is ReducerState.Backup -> state.continents
+        is ReducerState.Recovery -> state.continents
+        else -> null
+    } ?: emptyList()
+
+    var selectedContinent by remember { mutableStateOf<ContinentInfo?>(null) }
+
+    WizardPage(
+        title = stringResource(R.string.select_country_title),
+        navigationIcon = {
+            IconButton(onClick = {
+                viewModel.goHome()
+            }) {
+                Icon(Icons.Default.ArrowBack, "back")
+            }
+        },
+        showPrev = false,
+        onNextClicked = {
+            selectedContinent?.let {
+                viewModel.reducerManager.selectContinent(it)
+            }
+        },
+    ) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(LocalSpacing.current.medium),
+            verticalArrangement = Arrangement.Top,
+        ) {
+            Picker(
+                label = stringResource(R.string.continent),
+                options = continents.map { it.name }.toSet(),
+                onOptionChanged = { option ->
+                    continents.find { it.name == option }?.let { continent ->
+                        selectedContinent = continent
+                    }
+                },
+            )
+        }
+    }
+}
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectCountryScreen.kt b/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectCountryScreen.kt
new file mode 100644
index 0000000..1c4fa49
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectCountryScreen.kt
@@ -0,0 +1,92 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.ui.common
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.hilt.navigation.compose.hiltViewModel
+import net.taler.anastasis.R
+import net.taler.anastasis.models.CountryInfo
+import net.taler.anastasis.models.ReducerState
+import net.taler.anastasis.ui.reusable.components.Picker
+import net.taler.anastasis.ui.reusable.pages.WizardPage
+import net.taler.anastasis.ui.theme.LocalSpacing
+import net.taler.anastasis.viewmodels.ReducerViewModel
+
+@Composable
+fun SelectCountryScreen(
+    viewModel: ReducerViewModel = hiltViewModel(),
+) {
+    val reducerState by viewModel.reducerState.collectAsState()
+    val countries = when (val state = reducerState) {
+        is ReducerState.Backup -> state.countries
+        is ReducerState.Recovery -> state.countries
+        else -> null
+    } ?: emptyList()
+
+    var selectedCountry by remember { mutableStateOf<CountryInfo?>(null) }
+
+    WizardPage(
+        title = stringResource(R.string.select_country_title),
+        navigationIcon = {
+            IconButton(onClick = {
+                viewModel.goHome()
+            }) {
+                Icon(Icons.Default.ArrowBack, "back")
+            }
+        },
+        onPrevClicked = {
+            viewModel.reducerManager.back()
+        },
+        onNextClicked = {
+            selectedCountry?.let {
+                viewModel.reducerManager.selectCountry(it)
+            }
+        },
+    ) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(LocalSpacing.current.medium),
+            verticalArrangement = Arrangement.Top,
+        ) {
+            Picker(
+                label = stringResource(R.string.country),
+                options = countries.map { it.name }.toSet(),
+                onOptionChanged = { option ->
+                    countries.find { it.name == option }?.let { country ->
+                        selectedCountry = country
+                    }
+                },
+            )
+        }
+    }
+}
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupUserAttributesScreen.kt b/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectUserAttributesScreen.kt
index bbd0147..6fa9f97 100644
--- a/anastasis/src/main/java/net/taler/anastasis/ui/backup/BackupUserAttributesScreen.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/ui/common/SelectUserAttributesScreen.kt
@@ -14,7 +14,7 @@
  * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
  */
 
-package net.taler.anastasis.ui.backup
+package net.taler.anastasis.ui.common
 
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Spacer
@@ -32,6 +32,7 @@ import androidx.compose.material3.IconButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateMapOf
 import androidx.compose.runtime.mutableStateOf
@@ -39,38 +40,44 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.navigation.NavController
-import androidx.navigation.compose.rememberNavController
+import androidx.hilt.navigation.compose.hiltViewModel
 import net.taler.anastasis.R
-import net.taler.anastasis.Routes
-import net.taler.anastasis.models.UserAttributeSpec
+import net.taler.anastasis.models.ReducerState
 import net.taler.anastasis.ui.reusable.components.DatePickerField
 import net.taler.anastasis.ui.reusable.pages.WizardPage
 import net.taler.anastasis.ui.theme.LocalSpacing
+import net.taler.anastasis.viewmodels.ReducerViewModel
 import java.util.Calendar
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
-fun BackupUserAttributesScreen(
-    navController: NavController,
-    userAttributes: List<UserAttributeSpec>,
+fun SelectUserAttributesScreen(
+    viewModel: ReducerViewModel = hiltViewModel(),
 ) {
+    val reducerState by viewModel.reducerState.collectAsState()
+    val userAttributes = when (val state = reducerState) {
+        is ReducerState.Backup -> state.requiredAttributes
+        is ReducerState.Recovery -> state.requiredAttributes
+        else -> null
+    } ?: emptyList()
+
     val values = remember { mutableStateMapOf<String, String>() }
 
     WizardPage(
-        title = stringResource(R.string.backup_user_attributes_title),
+        title = stringResource(R.string.select_user_attributes_title),
         navigationIcon = {
             IconButton(onClick = {
-                navController.navigate(Routes.Home.route)
+                viewModel.goHome()
             }) {
                 Icon(Icons.Default.ArrowBack, "back")
             }
         },
         onPrevClicked = {
-            navController.navigate(Routes.BackupCountry.route)
+            viewModel.reducerManager.back()
+        },
+        onNextClicked = {
+            viewModel.reducerManager.enterUserAttributes(values)
         },
-        onNextClicked = {},
     ) {
         LazyColumn(
             modifier = Modifier
@@ -82,8 +89,8 @@ fun BackupUserAttributesScreen(
                 when (attr.type) {
                     "string" -> OutlinedTextField(
                         modifier = Modifier.fillMaxWidth(),
-                        value = values[attr.uuid] ?: "",
-                        onValueChange = { values[attr.uuid] = it },
+                        value = values[attr.name] ?: "",
+                        onValueChange = { values[attr.name] = it },
                         label = { Text(attr.label) },
                     )
                     "date" -> @Composable {
@@ -109,33 +116,4 @@ fun BackupUserAttributesScreen(
             }
         }
     }
-}
-
-@Preview
-@Composable
-fun BackupUserAttributesScreenPreview() {
-    val navController = rememberNavController()
-    BackupUserAttributesScreen(
-        navController = navController,
-        userAttributes = listOf(
-            UserAttributeSpec(
-                type = "string",
-                name = "full_name",
-                label = "Full name",
-                widget = "anastasis_gtk_ia_full_name",
-                uuid = "9e8f463f-575f-42cb-85f3-759559997331",
-                validationLogic = null,
-                validationRegex = null,
-            ),
-            UserAttributeSpec(
-                type = "date",
-                name = "birthdate",
-                label = "Birthdate",
-                uuid = "83d655c7-bdb6-484d-904e-80c1058c8854",
-                widget = "anastasis_gtk_ia_birthdate",
-                validationLogic = null,
-                validationRegex = null,
-            ),
-        ),
-    )
 }
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/ui/home/HomeScreen.kt b/anastasis/src/main/java/net/taler/anastasis/ui/home/HomeScreen.kt
index 98a70b4..f79c3a2 100644
--- a/anastasis/src/main/java/net/taler/anastasis/ui/home/HomeScreen.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/ui/home/HomeScreen.kt
@@ -16,18 +16,16 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
-import androidx.navigation.NavController
-import androidx.navigation.compose.rememberNavController
+import androidx.hilt.navigation.compose.hiltViewModel
 import net.taler.anastasis.R
-import net.taler.anastasis.Routes
 import net.taler.anastasis.ui.reusable.components.ActionCard
+import net.taler.anastasis.viewmodels.ReducerViewModel
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun HomeScreen(
-    navController: NavController,
+    viewModel: ReducerViewModel = hiltViewModel(),
 ) {
     Scaffold(
         topBar = {
@@ -53,7 +51,7 @@ fun HomeScreen(
                 icon = { Icon(Icons.Outlined.Upload, null) },
                 headline = stringResource(R.string.backup_secret),
                 onClick = {
-                    navController.navigate(Routes.BackupContinent.route)
+                    viewModel.reducerManager.startBackup()
                 },
             )
 
@@ -66,7 +64,7 @@ fun HomeScreen(
                 icon = { Icon(Icons.Outlined.Download, null) },
                 headline = stringResource(R.string.recover_secret),
                 onClick = {
-                    navController.navigate(Routes.RecoveryCountry.route)
+                    viewModel.reducerManager.startRecovery()
                 },
             )
 
@@ -78,17 +76,8 @@ fun HomeScreen(
                     .fillMaxWidth(),
                 icon = { Icon(Icons.Outlined.Restore, null) },
                 headline = stringResource(R.string.restore_session),
-                onClick = {
-                    navController.navigate(Routes.RestoreInit.route)
-                },
+                onClick = {},
             )
         }
     }
-}
-
-@Composable
-@Preview
-fun HomeScreenPreview() {
-    val navController = rememberNavController()
-    HomeScreen(navController = navController)
 }
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/viewmodels/ReducerViewModel.kt b/anastasis/src/main/java/net/taler/anastasis/viewmodels/ReducerViewModel.kt
new file mode 100644
index 0000000..3f5671b
--- /dev/null
+++ b/anastasis/src/main/java/net/taler/anastasis/viewmodels/ReducerViewModel.kt
@@ -0,0 +1,81 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.anastasis.viewmodels
+
+import android.util.Log
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import net.taler.anastasis.Routes
+import net.taler.anastasis.backend.AnastasisReducerApi
+import net.taler.anastasis.models.BackupStates
+import net.taler.anastasis.models.RecoveryStates
+import net.taler.anastasis.models.ReducerState
+import net.taler.anastasis.reducers.ReducerManager
+import javax.inject.Inject
+
+@HiltViewModel
+class ReducerViewModel @Inject constructor(): ViewModel() {
+    private val api = AnastasisReducerApi()
+    val reducerManager: ReducerManager
+
+    private val _reducerState = MutableStateFlow<ReducerState?>(null)
+    val reducerState = _reducerState.asStateFlow()
+    private val _navRoute = MutableStateFlow(Routes.Home.route)
+    val navRoute = _navRoute.asStateFlow()
+
+    init {
+        reducerManager = ReducerManager(_reducerState, api, viewModelScope)
+        viewModelScope.launch {
+            _reducerState.collect {
+                Log.d("ReducerViewModel", it?.toString() ?: "nothing")
+                _navRoute.value = when (it) {
+                    is ReducerState.Backup -> when (it.backupState) {
+                        BackupStates.ContinentSelecting -> Routes.SelectContinent.route
+                        BackupStates.CountrySelecting -> Routes.SelectCountry.route
+                        BackupStates.UserAttributesCollecting -> Routes.SelectUserAttributes.route
+                        BackupStates.AuthenticationsEditing -> TODO()
+                        BackupStates.PoliciesReviewing -> TODO()
+                        BackupStates.SecretEditing -> TODO()
+                        BackupStates.TruthsPaying -> TODO()
+                        BackupStates.PoliciesPaying -> TODO()
+                        BackupStates.BackupFinished -> TODO()
+                    }
+                    is ReducerState.Recovery -> when (it.recoveryState) {
+                        RecoveryStates.ContinentSelecting -> Routes.SelectContinent.route
+                        RecoveryStates.CountrySelecting -> Routes.SelectCountry.route
+                        RecoveryStates.UserAttributesCollecting -> Routes.SelectUserAttributes.route
+                        RecoveryStates.SecretSelecting -> TODO()
+                        RecoveryStates.ChallengeSelecting -> TODO()
+                        RecoveryStates.ChallengePaying -> TODO()
+                        RecoveryStates.ChallengeSolving -> TODO()
+                        RecoveryStates.RecoveryFinished -> TODO()
+                    }
+                    is ReducerState.Error -> TODO()
+                    else -> Routes.Home.route
+                }
+            }
+        }
+    }
+
+    fun goHome() {
+        _reducerState.value = null
+    }
+}
\ No newline at end of file
diff --git a/anastasis/src/main/res/values/strings.xml b/anastasis/src/main/res/values/strings.xml
index 9e974f2..de788ce 100644
--- a/anastasis/src/main/res/values/strings.xml
+++ b/anastasis/src/main/res/values/strings.xml
@@ -7,9 +7,12 @@
     <string name="recover_secret">Recover a secret</string>
     <string name="restore_session">Restore session</string>
 
-    <string name="backup_country_title">Where do you live?</string>
+    <!-- Shared -->
     <string name="country">Country</string>
     <string name="continent">Continent</string>
-    <string name="backup_user_attributes_title">Who are you?</string>
-    <string name="backup_auth_methods_title">Authentication methods</string>
+
+    <!-- Common -->
+    <string name="select_country_title">Where do you live?</string>
+    <string name="select_user_attributes_title">Who are you?</string>
+    <string name="select_auth_methods_title">Authentication methods</string>
 </resources>
\ No newline at end of file
diff --git a/wallet/src/main/java/net/taler/wallet/backend/ApiResponse.kt b/taler-kotlin-android/src/main/java/net/taler/common/ApiResponse.kt
index 46eb2f0..d51d2c0 100644
--- a/wallet/src/main/java/net/taler/wallet/backend/ApiResponse.kt
+++ b/taler-kotlin-android/src/main/java/net/taler/common/ApiResponse.kt
@@ -14,7 +14,7 @@
  * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
  */
 
-package net.taler.wallet.backend
+package net.taler.common
 
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
diff --git a/wallet/src/main/java/net/taler/wallet/backend/TalerErrorCode.kt b/taler-kotlin-android/src/main/java/net/taler/common/TalerErrorCode.kt
index 2242e33..dbe59a4 100644
--- a/wallet/src/main/java/net/taler/wallet/backend/TalerErrorCode.kt
+++ b/taler-kotlin-android/src/main/java/net/taler/common/TalerErrorCode.kt
@@ -1,26 +1,19 @@
 /*
-     This file is part of GNU Taler
-     Copyright (C) 2012-2020 Taler Systems SA
-
-     GNU Taler is free software: you can redistribute it and/or modify it
-     under the terms of the GNU Lesser General Public License as published
-     by the Free Software Foundation, either version 3 of the License,
-     or (at your option) any later version.
-
-     GNU Taler 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
-     Lesser General Public License for more details.
-
-     You should have received a copy of the GNU Lesser General Public License
-     along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-     SPDX-License-Identifier: LGPL3.0-or-later
-
-     Note: the LGPL does not apply to all components of GNU Taler,
-     but it does apply to this file.
+ * This file is part of GNU Taler
+ * (C) 2023 Taler Systems S.A.
+ *
+ * GNU Taler 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; either version 3, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
  */
-package net.taler.wallet.backend
+package net.taler.common
 
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.KSerializer
diff --git a/wallet/src/main/java/net/taler/wallet/MainViewModel.kt b/wallet/src/main/java/net/taler/wallet/MainViewModel.kt
index 15fe7e4..083d1be 100644
--- a/wallet/src/main/java/net/taler/wallet/MainViewModel.kt
+++ b/wallet/src/main/java/net/taler/wallet/MainViewModel.kt
@@ -32,7 +32,7 @@ import net.taler.common.AmountParserException
 import net.taler.common.Event
 import net.taler.common.toEvent
 import net.taler.wallet.accounts.AccountManager
-import net.taler.wallet.backend.NotificationPayload
+import net.taler.common.NotificationPayload
 import net.taler.wallet.backend.NotificationReceiver
 import net.taler.wallet.backend.VersionReceiver
 import net.taler.wallet.backend.WalletBackendApi
diff --git a/wallet/src/main/java/net/taler/wallet/Utils.kt b/wallet/src/main/java/net/taler/wallet/Utils.kt
index d1cdf8c..96b88d1 100644
--- a/wallet/src/main/java/net/taler/wallet/Utils.kt
+++ b/wallet/src/main/java/net/taler/wallet/Utils.kt
@@ -40,7 +40,7 @@ import net.taler.common.Amount
 import net.taler.common.AmountParserException
 import net.taler.common.showError
 import net.taler.common.startActivitySafe
-import net.taler.wallet.backend.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.transactions.Transaction
 
diff --git a/wallet/src/main/java/net/taler/wallet/backend/BackendManager.kt b/wallet/src/main/java/net/taler/wallet/backend/BackendManager.kt
index b2f1f10..23594ae 100644
--- a/wallet/src/main/java/net/taler/wallet/backend/BackendManager.kt
+++ b/wallet/src/main/java/net/taler/wallet/backend/BackendManager.kt
@@ -19,6 +19,9 @@ package net.taler.wallet.backend
 import android.util.Log
 import kotlinx.serialization.decodeFromString
 import kotlinx.serialization.json.Json
+import net.taler.common.ApiMessage
+import net.taler.common.ApiResponse
+import net.taler.common.NotificationPayload
 import net.taler.qtart.TalerWalletCore
 import net.taler.wallet.BuildConfig
 import org.json.JSONObject
diff --git a/wallet/src/main/java/net/taler/wallet/backend/RequestManager.kt b/wallet/src/main/java/net/taler/wallet/backend/RequestManager.kt
index 041656e..5e7ce40 100644
--- a/wallet/src/main/java/net/taler/wallet/backend/RequestManager.kt
+++ b/wallet/src/main/java/net/taler/wallet/backend/RequestManager.kt
@@ -17,6 +17,7 @@
 package net.taler.wallet.backend
 
 import androidx.annotation.GuardedBy
+import net.taler.common.ApiResponse
 import java.util.concurrent.ConcurrentHashMap
 import kotlin.coroutines.Continuation
 
diff --git a/wallet/src/main/java/net/taler/wallet/backend/WalletBackendApi.kt b/wallet/src/main/java/net/taler/wallet/backend/WalletBackendApi.kt
index bf6f371..f68c8b6 100644
--- a/wallet/src/main/java/net/taler/wallet/backend/WalletBackendApi.kt
+++ b/wallet/src/main/java/net/taler/wallet/backend/WalletBackendApi.kt
@@ -24,7 +24,8 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlinx.serialization.KSerializer
 import kotlinx.serialization.json.decodeFromJsonElement
-import net.taler.wallet.backend.TalerErrorCode.NONE
+import net.taler.common.ApiResponse
+import net.taler.common.TalerErrorCode.NONE
 import org.json.JSONObject
 
 const val WALLET_DB = "talerwalletdb.sql"
diff --git a/wallet/src/main/java/net/taler/wallet/backend/WalletResponse.kt b/wallet/src/main/java/net/taler/wallet/backend/WalletResponse.kt
index 8ef135f..2ece261 100644
--- a/wallet/src/main/java/net/taler/wallet/backend/WalletResponse.kt
+++ b/wallet/src/main/java/net/taler/wallet/backend/WalletResponse.kt
@@ -31,6 +31,7 @@ import kotlinx.serialization.json.JsonPrimitive
 import kotlinx.serialization.json.buildJsonObject
 import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
+import net.taler.common.TalerErrorCode
 
 @Serializable
 sealed class WalletResponse<T> {
diff --git a/wallet/src/main/java/net/taler/wallet/deposit/TransactionDepositComposable.kt b/wallet/src/main/java/net/taler/wallet/deposit/TransactionDepositComposable.kt
index 1d5c91e..f575081 100644
--- a/wallet/src/main/java/net/taler/wallet/deposit/TransactionDepositComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/deposit/TransactionDepositComposable.kt
@@ -35,7 +35,7 @@ import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.common.toAbsoluteTime
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.transactions.AmountType
 import net.taler.wallet.transactions.ErrorTransactionButton
diff --git a/wallet/src/main/java/net/taler/wallet/payment/TransactionPaymentComposable.kt b/wallet/src/main/java/net/taler/wallet/payment/TransactionPaymentComposable.kt
index c08bc76..8a3c4b5 100644
--- a/wallet/src/main/java/net/taler/wallet/payment/TransactionPaymentComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/payment/TransactionPaymentComposable.kt
@@ -35,7 +35,7 @@ import net.taler.common.ContractMerchant
 import net.taler.common.Timestamp
 import net.taler.common.toAbsoluteTime
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode
+import net.taler.common.TalerErrorCode
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.TalerSurface
 import net.taler.wallet.transactions.AmountType
diff --git a/wallet/src/main/java/net/taler/wallet/peer/IncomingComposable.kt b/wallet/src/main/java/net/taler/wallet/peer/IncomingComposable.kt
index 0c118e6..1f9ed72 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/IncomingComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/IncomingComposable.kt
@@ -48,7 +48,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import net.taler.common.Amount
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 
 data class IncomingData(
diff --git a/wallet/src/main/java/net/taler/wallet/peer/OutgoingPullResultComposable.kt b/wallet/src/main/java/net/taler/wallet/peer/OutgoingPullResultComposable.kt
index de62cda..edcd61c 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/OutgoingPullResultComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/OutgoingPullResultComposable.kt
@@ -38,7 +38,7 @@ import androidx.compose.ui.unit.dp
 import kotlinx.serialization.json.JsonPrimitive
 import net.taler.common.QrCodeManager
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.QrCodeUriComposable
 import net.taler.wallet.compose.TalerSurface
diff --git a/wallet/src/main/java/net/taler/wallet/peer/OutgoingPushResultComposable.kt b/wallet/src/main/java/net/taler/wallet/peer/OutgoingPushResultComposable.kt
index 0a4ee70..0d51ca9 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/OutgoingPushResultComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/OutgoingPushResultComposable.kt
@@ -38,7 +38,7 @@ import androidx.compose.ui.unit.dp
 import kotlinx.serialization.json.JsonPrimitive
 import net.taler.common.QrCodeManager
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.WALLET_WITHDRAWAL_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.QrCodeUriComposable
 import net.taler.wallet.compose.TalerSurface
diff --git a/wallet/src/main/java/net/taler/wallet/peer/PeerManager.kt b/wallet/src/main/java/net/taler/wallet/peer/PeerManager.kt
index 6e65e0b..6191d58 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/PeerManager.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/PeerManager.kt
@@ -28,7 +28,7 @@ import net.taler.common.Amount
 import net.taler.common.QrCodeManager
 import net.taler.common.Timestamp
 import net.taler.wallet.TAG
-import net.taler.wallet.backend.TalerErrorCode.UNKNOWN
+import net.taler.common.TalerErrorCode.UNKNOWN
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.backend.WalletBackendApi
 import net.taler.wallet.exchanges.ExchangeItem
diff --git a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullCredit.kt b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullCredit.kt
index b04a756..7749f10 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullCredit.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullCredit.kt
@@ -29,7 +29,7 @@ import androidx.compose.ui.unit.dp
 import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.QrCodeUriComposable
 import net.taler.wallet.transactions.AmountType
diff --git a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullDebit.kt b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullDebit.kt
index aa12a8e..3240d3d 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullDebit.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPullDebit.kt
@@ -23,7 +23,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.transactions.AmountType
 import net.taler.wallet.transactions.PeerInfoShort
diff --git a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushCredit.kt b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushCredit.kt
index 2c1c24c..75346c5 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushCredit.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushCredit.kt
@@ -23,7 +23,7 @@ import androidx.compose.ui.tooling.preview.Preview
 import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.transactions.AmountType
 import net.taler.wallet.transactions.PeerInfoShort
diff --git a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushDebit.kt b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushDebit.kt
index 2587ea9..dcc9811 100644
--- a/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushDebit.kt
+++ b/wallet/src/main/java/net/taler/wallet/peer/TransactionPeerPushDebit.kt
@@ -29,7 +29,7 @@ import androidx.compose.ui.unit.dp
 import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.QrCodeUriComposable
 import net.taler.wallet.transactions.AmountType
diff --git a/wallet/src/main/java/net/taler/wallet/pending/PendingOperationsManager.kt b/wallet/src/main/java/net/taler/wallet/pending/PendingOperationsManager.kt
index f5079f6..03c27da 100644
--- a/wallet/src/main/java/net/taler/wallet/pending/PendingOperationsManager.kt
+++ b/wallet/src/main/java/net/taler/wallet/pending/PendingOperationsManager.kt
@@ -22,7 +22,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 import kotlinx.serialization.json.jsonArray
 import net.taler.wallet.TAG
-import net.taler.wallet.backend.ApiResponse
+import net.taler.common.ApiResponse
 import net.taler.wallet.backend.WalletBackendApi
 import org.json.JSONObject
 
diff --git a/wallet/src/main/java/net/taler/wallet/refund/TransactionRefundComposable.kt b/wallet/src/main/java/net/taler/wallet/refund/TransactionRefundComposable.kt
index ac5e2da..1580502 100644
--- a/wallet/src/main/java/net/taler/wallet/refund/TransactionRefundComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/refund/TransactionRefundComposable.kt
@@ -34,7 +34,7 @@ import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.common.toAbsoluteTime
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode
+import net.taler.common.TalerErrorCode
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.TalerSurface
 import net.taler.wallet.transactions.AmountType
diff --git a/wallet/src/main/java/net/taler/wallet/transactions/ActionButtonComposable.kt b/wallet/src/main/java/net/taler/wallet/transactions/ActionButtonComposable.kt
index d4c12aa..cd43c7b 100644
--- a/wallet/src/main/java/net/taler/wallet/transactions/ActionButtonComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/transactions/ActionButtonComposable.kt
@@ -28,7 +28,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode
+import net.taler.common.TalerErrorCode
 import net.taler.wallet.transactions.WithdrawalDetails.ManualTransfer
 import net.taler.wallet.transactions.WithdrawalDetails.TalerBankIntegrationApi
 
diff --git a/wallet/src/main/java/net/taler/wallet/transactions/TransactionRefreshFragment.kt b/wallet/src/main/java/net/taler/wallet/transactions/TransactionRefreshFragment.kt
index da4b14d..22ef503 100644
--- a/wallet/src/main/java/net/taler/wallet/transactions/TransactionRefreshFragment.kt
+++ b/wallet/src/main/java/net/taler/wallet/transactions/TransactionRefreshFragment.kt
@@ -41,7 +41,7 @@ import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.common.toAbsoluteTime
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode
+import net.taler.common.TalerErrorCode
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.TalerSurface
 import net.taler.wallet.transactions.TransactionAction.Abort
diff --git a/wallet/src/main/java/net/taler/wallet/transactions/TransactionTipFragment.kt b/wallet/src/main/java/net/taler/wallet/transactions/TransactionTipFragment.kt
index c15f931..29793e7 100644
--- a/wallet/src/main/java/net/taler/wallet/transactions/TransactionTipFragment.kt
+++ b/wallet/src/main/java/net/taler/wallet/transactions/TransactionTipFragment.kt
@@ -41,7 +41,7 @@ import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.common.toAbsoluteTime
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
+import net.taler.common.TalerErrorCode.EXCHANGE_GENERIC_KYC_REQUIRED
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.compose.TalerSurface
 import net.taler.wallet.transactions.TransactionAction.Abort
diff --git a/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt b/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt
index 6b1d135..91daf07 100644
--- a/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt
+++ b/wallet/src/main/java/net/taler/wallet/transactions/Transactions.kt
@@ -39,7 +39,7 @@ import net.taler.common.ContractProduct
 import net.taler.common.Timestamp
 import net.taler.wallet.R
 import net.taler.wallet.TAG
-import net.taler.wallet.backend.TalerErrorCode
+import net.taler.common.TalerErrorCode
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.cleanExchange
 import net.taler.wallet.refund.RefundPaymentInfo
diff --git a/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt b/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt
index 79cfc5e..1ba5e90 100644
--- a/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt
+++ b/wallet/src/main/java/net/taler/wallet/withdraw/TransactionWithdrawalComposable.kt
@@ -35,7 +35,7 @@ import net.taler.common.Amount
 import net.taler.common.Timestamp
 import net.taler.common.toAbsoluteTime
 import net.taler.wallet.R
-import net.taler.wallet.backend.TalerErrorCode
+import net.taler.common.TalerErrorCode
 import net.taler.wallet.backend.TalerErrorInfo
 import net.taler.wallet.cleanExchange
 import net.taler.wallet.transactions.ActionButton