Require valid configuration before showing UI

17 files changed, 297 insertions, 172 deletions

diff --git a/app/src/main/java/net/taler/merchantpos/MainActivity.kt b/app/src/main/java/net/taler/merchantpos/MainActivity.kt
index 9841339..e26146d 100644
--- a/app/src/main/java/net/taler/merchantpos/MainActivity.kt
+++ b/app/src/main/java/net/taler/merchantpos/MainActivity.kt
@@ -10,7 +10,7 @@ import androidx.core.view.GravityCompat.START
 import androidx.drawerlayout.widget.DrawerLayout
 import androidx.lifecycle.Observer
 import androidx.navigation.NavController
-import androidx.navigation.findNavController
+import androidx.navigation.fragment.NavHostFragment
 import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.setupWithNavController
 import com.google.android.material.navigation.NavigationView
@@ -22,6 +22,7 @@ class MainActivity : AppCompatActivity(), OnNavigationItemSelectedListener {
     private val nfcManager = NfcManager()
     private var nfcAdapter: NfcAdapter? = null
 
+    private lateinit var nav: NavController
     private lateinit var drawerLayout: DrawerLayout
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -40,10 +41,7 @@ class MainActivity : AppCompatActivity(), OnNavigationItemSelectedListener {
 
         drawerLayout = findViewById(R.id.drawer_layout)
         val navView: NavigationView = findViewById(R.id.nav_view)
-
         navView.setNavigationItemSelectedListener(this)
-
-        val navController = findNavController(R.id.nav_host_fragment)
         val appBarConfiguration = AppBarConfiguration(
             setOf(
                 R.id.order,
@@ -51,7 +49,20 @@ class MainActivity : AppCompatActivity(), OnNavigationItemSelectedListener {
                 R.id.merchantHistory
             ), drawerLayout
         )
-        toolbar.setupWithNavController(navController, appBarConfiguration)
+
+        val navHostFragment =
+            supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment
+        nav = navHostFragment.navController
+        toolbar.setupWithNavController(nav, appBarConfiguration)
+    }
+
+    override fun onStart() {
+        super.onStart()
+        if (!model.configManager.config.isValid()) {
+            nav.navigate(R.id.action_global_merchantSettings)
+        } else if (model.configManager.merchantConfig == null) {
+            nav.navigate(R.id.action_global_configFetcher)
+        }
     }
 
     public override fun onResume() {
@@ -67,7 +78,6 @@ class MainActivity : AppCompatActivity(), OnNavigationItemSelectedListener {
 
     override fun onNavigationItemSelected(item: MenuItem): Boolean {
         // Handle navigation view item clicks here.
-        val nav: NavController = findNavController(R.id.nav_host_fragment)
         when (item.itemId) {
             R.id.nav_order -> nav.navigate(R.id.action_global_order)
             R.id.nav_history -> nav.navigate(R.id.action_global_merchantHistory)
diff --git a/app/src/main/java/net/taler/merchantpos/MainViewModel.kt b/app/src/main/java/net/taler/merchantpos/MainViewModel.kt
index c07c996..c14ab66 100644
--- a/app/src/main/java/net/taler/merchantpos/MainViewModel.kt
+++ b/app/src/main/java/net/taler/merchantpos/MainViewModel.kt
@@ -29,7 +29,7 @@ class MainViewModel(app: Application) : AndroidViewModel(app) {
         get() = configManager.merchantConfig
 
     init {
-        if (configManager.merchantConfig == null) {
+        if (configManager.merchantConfig == null && configManager.config.isValid()) {
             configManager.fetchConfig(configManager.config, false)
         }
     }
diff --git a/app/src/main/java/net/taler/merchantpos/MerchantHistory.kt b/app/src/main/java/net/taler/merchantpos/MerchantHistory.kt
index 167bb9d..eb8288c 100644
--- a/app/src/main/java/net/taler/merchantpos/MerchantHistory.kt
+++ b/app/src/main/java/net/taler/merchantpos/MerchantHistory.kt
@@ -1,6 +1,5 @@
 package net.taler.merchantpos
 
-
 import android.annotation.SuppressLint
 import android.os.Bundle
 import android.util.Log
@@ -11,85 +10,42 @@ import android.widget.TextView
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.lifecycle.MutableLiveData
+import androidx.navigation.fragment.findNavController
 import androidx.recyclerview.widget.DividerItemDecoration
+import androidx.recyclerview.widget.DividerItemDecoration.VERTICAL
 import androidx.recyclerview.widget.LinearLayoutManager
-import androidx.recyclerview.widget.RecyclerView
-import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
-import com.android.volley.Request
+import androidx.recyclerview.widget.RecyclerView.Adapter
+import androidx.recyclerview.widget.RecyclerView.ViewHolder
+import com.android.volley.Request.Method.GET
 import com.android.volley.RequestQueue
-import com.android.volley.Response
-import com.android.volley.VolleyError
+import com.android.volley.Response.ErrorListener
+import com.android.volley.Response.Listener
 import com.android.volley.toolbox.Volley
 import com.google.android.material.snackbar.Snackbar
+import com.google.android.material.snackbar.Snackbar.LENGTH_SHORT
+import kotlinx.android.synthetic.main.fragment_merchant_history.*
+import net.taler.merchantpos.HistoryItemAdapter.HistoryItemViewHolder
 import net.taler.merchantpos.config.MerchantRequest
 import org.json.JSONObject
 import java.time.Instant
 import java.time.ZoneId
 import java.time.format.DateTimeFormatter
-import java.time.format.FormatStyle
+import java.time.format.FormatStyle.SHORT
 import java.util.*
 
-
-
-data class HistoryItem(
-    val orderId: String,
-    val amount: Amount,
-    val summary: String,
-    val timestamp: Instant
-)
-
-class MyAdapter(private var myDataset: List<HistoryItem>) :
-    RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
-    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
-        val view =
-            LayoutInflater.from(parent.context).inflate(R.layout.history_row, parent, false)
-        return MyViewHolder(view)
-    }
-
-    override fun getItemCount(): Int {
-        return myDataset.size
-    }
-
-    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
-        val item = myDataset[position]
-        val summaryTextView = holder.rowView.findViewById<TextView>(R.id.text_history_summary)
-        summaryTextView.text = myDataset[position].summary
-
-        val amount = myDataset[position].amount
-        val amountTextView = holder.rowView.findViewById<TextView>(R.id.text_history_amount)
-        @SuppressLint("SetTextI18n")
-        amountTextView.text = "${amount.amount} ${amount.currency}"
-
-        val formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.SHORT)
-            .withLocale(Locale.UK)
-            .withZone(ZoneId.systemDefault())
-        val timestampTextView = holder.rowView.findViewById<TextView>(R.id.text_history_time)
-        timestampTextView.text = formatter.format(item.timestamp)
-
-        val orderIdTextView =  holder.rowView.findViewById<TextView>(R.id.text_history_order_id)
-        orderIdTextView.text = item.orderId
-    }
-
-    fun setData(dataset: List<HistoryItem>) {
-        this.myDataset = dataset
-        this.notifyDataSetChanged()
-    }
-
-    class MyViewHolder(val rowView: View) : RecyclerView.ViewHolder(rowView)
-}
-
-fun parseTalerTimestamp(s: String): Instant {
-    return Instant.ofEpochSecond(s.substringAfterLast('(').substringBeforeLast(')').toLong())
-}
-
 /**
  * Fragment to display the merchant's payment history,
  * received from the backend.
  */
 class MerchantHistory : Fragment() {
+
+    companion object {
+        const val TAG = "taler-merchant"
+    }
+
     private lateinit var queue: RequestQueue
     private val model: MainViewModel by activityViewModels()
-    private val historyListAdapter = MyAdapter(listOf())
+    private val historyListAdapter = HistoryItemAdapter(listOf())
 
     private val isLoading = MutableLiveData<Boolean>().apply { value = false }
 
@@ -99,10 +55,49 @@ class MerchantHistory : Fragment() {
         queue = Volley.newRequestQueue(context)
     }
 
-    private fun onNetworkError(volleyError: VolleyError?) {
-        this.isLoading.value = false
-        val mySnackbar = Snackbar.make(view!!, "Network Error", Snackbar.LENGTH_SHORT)
-        mySnackbar.show()
+    override fun onCreateView(
+        inflater: LayoutInflater, container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
+        return inflater.inflate(R.layout.fragment_merchant_history, container, false)
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        list_history.apply {
+            layoutManager = LinearLayoutManager(requireContext())
+            addItemDecoration(DividerItemDecoration(context, VERTICAL))
+            adapter = historyListAdapter
+        }
+
+        swiperefresh.isRefreshing = false
+        swiperefresh.setOnRefreshListener {
+            Log.v(TAG, "refreshing!")
+            fetchHistory()
+        }
+
+        this.isLoading.observe(viewLifecycleOwner, androidx.lifecycle.Observer { loading ->
+            Log.v(TAG, "setting refreshing to $loading")
+            swiperefresh.isRefreshing = loading
+        })
+    }
+
+    override fun onStart() {
+        super.onStart()
+        if (model.configManager.merchantConfig?.instance == null) {
+            findNavController().navigate(R.id.action_global_merchantSettings)
+        } else {
+            fetchHistory()
+        }
+    }
+
+    private fun fetchHistory() {
+        isLoading.value = true
+        val merchantConfig = model.configManager.merchantConfig!!
+        val params = mapOf("instance" to merchantConfig.instance)
+        val req = MerchantRequest(GET, merchantConfig, "history", params, null,
+            Listener { onHistoryResponse(it) },
+            ErrorListener { onNetworkError() })
+        queue.add(req)
     }
 
     private fun onHistoryResponse(body: JSONObject) {
@@ -123,55 +118,56 @@ class MerchantHistory : Fragment() {
         historyListAdapter.setData(data)
     }
 
-    private fun fetchHistory() {
-        isLoading.value = true
-        val instance = model.merchantConfig!!.instance
-        val req = MerchantRequest(
-            Request.Method.GET,
-            model.merchantConfig!!,
-            "history",
-            mapOf("instance" to instance),
-            null,
-            Response.Listener { onHistoryResponse(it) },
-            Response.ErrorListener { onNetworkError(it) })
-        queue.add(req)
+    private fun onNetworkError() {
+        this.isLoading.value = false
+        Snackbar.make(view!!, "Network Error", LENGTH_SHORT).show()
     }
 
-    override fun onResume() {
-        super.onResume()
-        fetchHistory()
-    }
+}
 
-    override fun onCreateView(
-        inflater: LayoutInflater, container: ViewGroup?,
-        savedInstanceState: Bundle?
-    ): View? {
-        val myLayoutManager = LinearLayoutManager(this@MerchantHistory.context)
-        val myItemDecoration = DividerItemDecoration(context, myLayoutManager.orientation)
-        // Inflate the layout for this fragment
-        val view = inflater.inflate(R.layout.fragment_merchant_history, container, false)
-        view.findViewById<RecyclerView>(R.id.list_history).apply {
-            layoutManager = myLayoutManager
-            adapter = historyListAdapter
-            addItemDecoration(myItemDecoration)
-        }
+data class HistoryItem(
+    val orderId: String,
+    val amount: Amount,
+    val summary: String,
+    val timestamp: Instant
+)
 
-        val refreshLayout = view.findViewById<SwipeRefreshLayout>(R.id.swiperefresh)
-        refreshLayout.isRefreshing = false
-        refreshLayout.setOnRefreshListener {
-            Log.v(TAG, "refreshing!")
-            fetchHistory()
-        }
+class HistoryItemAdapter(private var items: List<HistoryItem>) : Adapter<HistoryItemViewHolder>() {
 
-        this.isLoading.observe(viewLifecycleOwner, androidx.lifecycle.Observer { loading ->
-            Log.v(TAG, "setting refreshing to $loading")
-            refreshLayout.isRefreshing = loading
-        })
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): HistoryItemViewHolder {
+        val v = LayoutInflater.from(parent.context).inflate(R.layout.history_row, parent, false)
+        return HistoryItemViewHolder(v)
+    }
 
-        return view
+    override fun getItemCount() = items.size
+
+    override fun onBindViewHolder(holder: HistoryItemViewHolder, position: Int) {
+        holder.bind(items[position])
     }
 
-    companion object {
-        const val TAG = "taler-merchant"
+    fun setData(items: List<HistoryItem>) {
+        this.items = items
+        this.notifyDataSetChanged()
     }
+
+    class HistoryItemViewHolder(v: View) : ViewHolder(v) {
+
+        private val summaryTextView: TextView = v.findViewById(R.id.text_history_summary)
+        private val amountTextView: TextView = v.findViewById(R.id.text_history_amount)
+        private val timestampTextView: TextView = v.findViewById(R.id.text_history_time)
+        private val orderIdTextView: TextView = v.findViewById(R.id.text_history_order_id)
+        private val formatter: DateTimeFormatter = DateTimeFormatter.ofLocalizedDateTime(SHORT)
+            .withLocale(Locale.getDefault())
+            .withZone(ZoneId.systemDefault())
+
+        fun bind(item: HistoryItem) {
+            summaryTextView.text = item.summary
+            val amount = item.amount
+            @SuppressLint("SetTextI18n")
+            amountTextView.text = "${amount.amount} ${amount.currency}"
+            timestampTextView.text = formatter.format(item.timestamp)
+            orderIdTextView.text = item.orderId
+        }
+    }
+
 }
diff --git a/app/src/main/java/net/taler/merchantpos/config/ConfigFetcherFragment.kt b/app/src/main/java/net/taler/merchantpos/config/ConfigFetcherFragment.kt
new file mode 100644
index 0000000..4d387da
--- /dev/null
+++ b/app/src/main/java/net/taler/merchantpos/config/ConfigFetcherFragment.kt
@@ -0,0 +1,46 @@
+package net.taler.merchantpos.config
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.activityViewModels
+import androidx.lifecycle.Observer
+import androidx.navigation.fragment.findNavController
+import com.google.android.material.snackbar.Snackbar
+import com.google.android.material.snackbar.Snackbar.LENGTH_SHORT
+import net.taler.merchantpos.MainViewModel
+import net.taler.merchantpos.R
+
+class ConfigFetcherFragment : Fragment() {
+
+    private val model: MainViewModel by activityViewModels()
+    private val configManager by lazy { model.configManager }
+
+    override fun onCreateView(
+        inflater: LayoutInflater, container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
+        return inflater.inflate(R.layout.fragment_config_fetcher, container, false)
+    }
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+
+        configManager.configUpdateResult.observe(viewLifecycleOwner, Observer { result ->
+            when {
+                result == null -> return@Observer
+                result.error -> onNetworkError(result.authError)
+                else -> findNavController().navigate(R.id.order)
+            }
+        })
+    }
+
+    private fun onNetworkError(authError: Boolean) {
+        val res = if (authError) R.string.config_auth_error else R.string.config_error
+        Snackbar.make(view!!, res, LENGTH_SHORT).show()
+        findNavController().navigate(R.id.action_configFetcher_to_merchantSettings)
+    }
+
+}
diff --git a/app/src/main/java/net/taler/merchantpos/config/MerchantConfig.kt b/app/src/main/java/net/taler/merchantpos/config/MerchantConfig.kt
index 63dd487..c237a24 100644
--- a/app/src/main/java/net/taler/merchantpos/config/MerchantConfig.kt
+++ b/app/src/main/java/net/taler/merchantpos/config/MerchantConfig.kt
@@ -7,7 +7,9 @@ data class Config(
     val configUrl: String,
     val username: String,
     val password: String
-)
+) {
+    fun isValid() = !configUrl.isBlank()
+}
 
 data class MerchantConfig(
     @JsonProperty("base_url")
diff --git a/app/src/main/java/net/taler/merchantpos/config/MerchantConfigFragment.kt b/app/src/main/java/net/taler/merchantpos/config/MerchantConfigFragment.kt
index b824d38..27e22ad 100644
--- a/app/src/main/java/net/taler/merchantpos/config/MerchantConfigFragment.kt
+++ b/app/src/main/java/net/taler/merchantpos/config/MerchantConfigFragment.kt
@@ -8,6 +8,7 @@ import android.view.ViewGroup
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.lifecycle.Observer
+import androidx.navigation.fragment.findNavController
 import com.google.android.material.snackbar.Snackbar
 import com.google.android.material.snackbar.Snackbar.LENGTH_SHORT
 import kotlinx.android.synthetic.main.fragment_merchant_settings.*
@@ -51,10 +52,6 @@ class MerchantConfigFragment : Fragment() {
                 configManager.configUpdateResult.removeObservers(viewLifecycleOwner)
             })
         }
-    }
-
-    override fun onStart() {
-        super.onStart()
         updateView()
     }
 
@@ -85,6 +82,7 @@ class MerchantConfigFragment : Fragment() {
         onResultReceived()
         updateView()
         Snackbar.make(view!!, "Changed to new $currency merchant", LENGTH_SHORT).show()
+        findNavController().navigate(R.id.order)
     }
 
     private fun onNetworkError(authError: Boolean) {
diff --git a/app/src/main/java/net/taler/merchantpos/order/OrderFragment.kt b/app/src/main/java/net/taler/merchantpos/order/OrderFragment.kt
index f4c5a15..99f6c57 100644
--- a/app/src/main/java/net/taler/merchantpos/order/OrderFragment.kt
+++ b/app/src/main/java/net/taler/merchantpos/order/OrderFragment.kt
@@ -35,9 +35,11 @@ class OrderFragment : Fragment() {
             if (state == UNDO) {
                 restartButton.setText(R.string.order_undo)
                 restartButton.isEnabled = true
+                completeButton.isEnabled = false
             } else {
                 restartButton.setText(R.string.order_restart)
                 restartButton.isEnabled = state == ENABLED
+                completeButton.isEnabled = state == ENABLED
             }
         })
     }
@@ -45,13 +47,13 @@ class OrderFragment : Fragment() {
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
         val nav: NavController = findNavController(requireActivity(), R.id.nav_host_fragment)
-        reconfigureButton.setOnClickListener { nav.navigate(R.id.action_global_merchantSettings) }
-        historyButton.setOnClickListener { nav.navigate(R.id.action_global_merchantHistory) }
-        logoutButton.setOnClickListener { nav.navigate(R.id.action_global_merchantSettings) }
+        reconfigureButton.setOnClickListener { nav.navigate(R.id.action_order_to_merchantSettings) }
+        historyButton.setOnClickListener { nav.navigate(R.id.action_order_to_merchantHistory) }
+        logoutButton.setOnClickListener { nav.navigate(R.id.action_order_to_merchantSettings) }
         completeButton.setOnClickListener {
             val order = orderManager.order.value ?: return@setOnClickListener
             paymentManager.createPayment(order)
-            nav.navigate(R.id.action_createPayment_to_processPayment)
+            nav.navigate(R.id.action_order_to_processPayment)
         }
     }
 
diff --git a/app/src/main/java/net/taler/merchantpos/payment/PaymentManager.kt b/app/src/main/java/net/taler/merchantpos/payment/PaymentManager.kt
index bb030e2..3e6ee2c 100644
--- a/app/src/main/java/net/taler/merchantpos/payment/PaymentManager.kt
+++ b/app/src/main/java/net/taler/merchantpos/payment/PaymentManager.kt
@@ -32,7 +32,7 @@ class PaymentManager(
 ) {
 
     private val mPayment = MutableLiveData<Payment>()
-    var payment: LiveData<Payment> = mPayment
+    val payment: LiveData<Payment> = mPayment
 
     private val checkTimer = object : CountDownTimer(TIMEOUT, CHECK_INTERVAL) {
         override fun onTick(millisUntilFinished: Long) {
@@ -111,12 +111,13 @@ class PaymentManager(
      * Called when the /check-payment response gave a result.
      */
     private fun onPaymentChecked(checkPaymentResponse: JSONObject) {
+        val currentValue = requireNotNull(mPayment.value)
         if (checkPaymentResponse.getBoolean("paid")) {
-            mPayment.value = mPayment.value!!.copy(paid = true)
+            mPayment.value = currentValue.copy(paid = true)
             checkTimer.cancel()
-        } else {
+        } else if (currentValue.talerPayUri == null) {
             val talerPayUri = checkPaymentResponse.getString("taler_pay_uri")
-            mPayment.value = mPayment.value!!.copy(talerPayUri = talerPayUri)
+            mPayment.value = currentValue.copy(talerPayUri = talerPayUri)
         }
     }
 
diff --git a/app/src/main/java/net/taler/merchantpos/payment/PaymentSuccess.kt b/app/src/main/java/net/taler/merchantpos/payment/PaymentSuccess.kt
deleted file mode 100644
index c62abbc..0000000
--- a/app/src/main/java/net/taler/merchantpos/payment/PaymentSuccess.kt
+++ /dev/null
@@ -1,30 +0,0 @@
-package net.taler.merchantpos.payment
-
-
-import android.os.Bundle
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
-import android.widget.Button
-import androidx.fragment.app.Fragment
-import androidx.navigation.findNavController
-import net.taler.merchantpos.R
-
-/**
- * A simple [Fragment] subclass.
- */
-class PaymentSuccess : Fragment() {
-
-    override fun onCreateView(
-        inflater: LayoutInflater, container: ViewGroup?,
-        savedInstanceState: Bundle?
-    ): View? {
-        val view = inflater.inflate(R.layout.fragment_payment_success, container, false)
-        view.findViewById<Button>(R.id.button_success_back).setOnClickListener {
-            activity!!.findNavController(R.id.nav_host_fragment).navigateUp()
-        }
-        return view
-    }
-
-
-}
diff --git a/app/src/main/java/net/taler/merchantpos/payment/PaymentSuccessFragment.kt b/app/src/main/java/net/taler/merchantpos/payment/PaymentSuccessFragment.kt
new file mode 100644
index 0000000..176b6fc
--- /dev/null
+++ b/app/src/main/java/net/taler/merchantpos/payment/PaymentSuccessFragment.kt
@@ -0,0 +1,27 @@
+package net.taler.merchantpos.payment
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+import androidx.navigation.findNavController
+import kotlinx.android.synthetic.main.fragment_payment_success.*
+import net.taler.merchantpos.R
+
+class PaymentSuccessFragment : Fragment() {
+
+    override fun onCreateView(
+        inflater: LayoutInflater, container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
+        return inflater.inflate(R.layout.fragment_payment_success, container, false)
+    }
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        button_success_back.setOnClickListener {
+            requireActivity().findNavController(R.id.nav_host_fragment).navigateUp()
+        }
+    }
+}
diff --git a/app/src/main/java/net/taler/merchantpos/payment/ProcessPaymentFragment.kt b/app/src/main/java/net/taler/merchantpos/payment/ProcessPaymentFragment.kt
index 67a913f..4a235da 100644
--- a/app/src/main/java/net/taler/merchantpos/payment/ProcessPaymentFragment.kt
+++ b/app/src/main/java/net/taler/merchantpos/payment/ProcessPaymentFragment.kt
@@ -50,6 +50,7 @@ class ProcessPaymentFragment : Fragment() {
         }
         if (payment.paid) {
             findNavController().navigate(R.id.action_processPayment_to_paymentSuccess)
+            model.orderManager.restartOrUndo()
             return
         }
         text_view_amount.text = "${payment.order.getTotalAsString()} ${payment.currency}"
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index f67c32c..5f21a42 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -20,6 +20,7 @@
             android:layout_height="match_parent"
             android:layout_gravity="start"
             android:fitsSystemWindows="true"
+            app:menu="@menu/activity_main_drawer"
             app:headerLayout="@layout/nav_header_main" />
 
 </androidx.drawerlayout.widget.DrawerLayout>
diff --git a/app/src/main/res/layout/content_main.xml b/app/src/main/res/layout/content_main.xml
index 112382e..a87cf40 100644
--- a/app/src/main/res/layout/content_main.xml
+++ b/app/src/main/res/layout/content_main.xml
@@ -9,7 +9,7 @@
         tools:showIn="@layout/app_bar_main"
         tools:context=".MainActivity">
 
-    <fragment
+    <androidx.fragment.app.FragmentContainerView
             android:id="@+id/nav_host_fragment"
             android:name="androidx.navigation.fragment.NavHostFragment"
             android:layout_width="0dp"
@@ -21,4 +21,4 @@
             app:defaultNavHost="true"
             app:navGraph="@navigation/nav_graph" />
 
-</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
+</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/app/src/main/res/layout/fragment_config_fetcher.xml b/app/src/main/res/layout/fragment_config_fetcher.xml
new file mode 100644
index 0000000..e00a307
--- /dev/null
+++ b/app/src/main/res/layout/fragment_config_fetcher.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+        xmlns:app="http://schemas.android.com/apk/res-auto"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:layout_margin="16dp">
+
+    <TextView
+            android:id="@+id/titleView"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_margin="16dp"
+            android:text="@string/config_fetching"
+            android:textAppearance="@style/TextAppearance.AppCompat.Headline"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent" />
+
+    <ProgressBar
+            android:id="@+id/progressBar"
+            style="?android:attr/progressBarStyleLarge"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_margin="16dp"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/titleView" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/app/src/main/res/layout/fragment_order.xml b/app/src/main/res/layout/fragment_order.xml
index 968544e..bcf8be8 100644
--- a/app/src/main/res/layout/fragment_order.xml
+++ b/app/src/main/res/layout/fragment_order.xml
@@ -89,6 +89,7 @@
             android:layout_marginStart="16dp"
             android:backgroundTint="@color/logoutButton"
             android:text="@string/button_logout"
+            android:visibility="gone"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintStart_toEndOf="@+id/historyButton" />
 
diff --git a/app/src/main/res/navigation/nav_graph.xml b/app/src/main/res/navigation/nav_graph.xml
index a1c0d8d..f615ba2 100644
--- a/app/src/main/res/navigation/nav_graph.xml
+++ b/app/src/main/res/navigation/nav_graph.xml
@@ -11,27 +11,67 @@
             android:label="Order"
             tools:layout="@layout/fragment_order">
         <action
-                android:id="@+id/action_createPayment_to_processPayment"
+                android:id="@+id/action_order_to_processPayment"
                 app:destination="@id/processPayment" />
+        <action
+                android:id="@+id/action_order_to_merchantHistory"
+                app:destination="@id/merchantHistory" />
+        <action
+                android:id="@+id/action_order_to_merchantSettings"
+                app:destination="@id/merchantSettings" />
     </fragment>
 
-    <fragment android:id="@+id/processPayment" android:name="net.taler.merchantpos.payment.ProcessPaymentFragment"
-              android:label="Payment Prompt" tools:layout="@layout/fragment_process_payment">
+    <fragment
+            android:id="@+id/processPayment"
+            android:name="net.taler.merchantpos.payment.ProcessPaymentFragment"
+            android:label="Payment Prompt"
+            tools:layout="@layout/fragment_process_payment">
         <action
                 android:id="@+id/action_processPayment_to_paymentSuccess"
                 app:destination="@id/paymentSuccess"
-                app:popUpTo="@id/order"/>
+                app:popUpTo="@id/order" />
+    </fragment>
+
+    <fragment
+            android:id="@+id/merchantHistory"
+            android:name="net.taler.merchantpos.MerchantHistory"
+            android:label="Payment History"
+            tools:layout="@layout/fragment_merchant_history" />
+
+    <fragment
+            android:id="@+id/merchantSettings"
+            android:name="net.taler.merchantpos.config.MerchantConfigFragment"
+            android:label="Merchant Settings"
+            tools:layout="@layout/fragment_merchant_settings"/>
+
+    <fragment
+            android:id="@+id/configFetcher"
+            android:name="net.taler.merchantpos.config.ConfigFetcherFragment"
+            android:label="Fetching Configuration"
+            tools:layout="@layout/fragment_config_fetcher">
+        <action
+                android:id="@+id/action_configFetcher_to_merchantSettings"
+                app:destination="@id/merchantSettings"
+                app:popUpToInclusive="true" />
     </fragment>
-    <fragment android:id="@+id/merchantHistory" android:name="net.taler.merchantpos.MerchantHistory"
-              android:label="Payment History" tools:layout="@layout/fragment_merchant_history"/>
-    <action android:id="@+id/action_global_merchantHistory" app:destination="@id/merchantHistory"/>
-    <action android:id="@+id/action_global_order" app:destination="@id/order"/>
-    <fragment android:id="@+id/merchantSettings" android:name="net.taler.merchantpos.config.MerchantConfigFragment"
-              android:label="Merchant Settings" tools:layout="@layout/fragment_merchant_settings"/>
-    <action android:id="@+id/action_global_merchantSettings" app:destination="@id/merchantSettings"/>
+
     <fragment
             android:id="@+id/paymentSuccess"
-            android:name="net.taler.merchantpos.payment.PaymentSuccess"
+            android:name="net.taler.merchantpos.payment.PaymentSuccessFragment"
             android:label="Payment Received"
             tools:layout="@layout/fragment_payment_success" />
-</navigation>
\ No newline at end of file
+
+    <action
+            android:id="@+id/action_global_order"
+            app:destination="@id/order" />
+    <action
+            android:id="@+id/action_global_merchantHistory"
+            app:destination="@id/merchantHistory" />
+    <action
+            android:id="@+id/action_global_merchantSettings"
+            app:destination="@id/merchantSettings" />
+    <action
+            android:id="@+id/action_global_configFetcher"
+            app:destination="@id/configFetcher" />
+
+</navigation>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index f179915..8e5511e 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -33,5 +33,6 @@
     <string name="config_malformed_url">Invalid URL</string>
     <string name="config_auth_error">Invalid username or password</string>
     <string name="config_error">Error: Invalid Configuration</string>
+    <string name="config_fetching">Fetching Configuration…</string>
 
 </resources>