Add warning when using old server version

app/build.gradle

@@ -45,6 +45,7 @@ android {
         // get with unzip -p *.apk META-INF/CERT.RSA | keytool -printcert | grep SHA256 | sed -e 's/\s*SHA256: //' -e 's/://g'
         // set to empty string to disable this check
         buildConfigField 'String', 'updateServerBuildsCertificate', '"2170068198547F15129DE8CC46E2A8BF1485A6E5030916E26DDE41AE0E81DAC2"'
+        buildConfigField 'int', 'minimumRecommendServerVersion', '5'
     }
     buildFeatures {
         viewBinding true

app/src/main/java/io/timelimit/android/ui/overview/overview/OverviewFragmentAdapter.kt

@@ -77,6 +77,7 @@ class OverviewFragmentAdapter : RecyclerView.Adapter<OverviewFragmentViewHolder>
         is OverviewFragmentItemMessage -> OverviewFragmentViewType.ServerMessage
         is ShowMoreOverviewFragmentItem -> OverviewFragmentViewType.ShowMoreButton
         is TaskReviewOverviewItem -> OverviewFragmentViewType.TaskReview
+        is OverviewFragmentItemOutdatedServer -> OverviewFragmentViewType.ServerMessage
     }
 
     override fun getItemViewType(position: Int) = getItemType(getItem(position)).ordinal
@@ -170,6 +171,7 @@ class OverviewFragmentAdapter : RecyclerView.Adapter<OverviewFragmentViewHolder>
     }
 
     override fun onBindViewHolder(holder: OverviewFragmentViewHolder, position: Int) {
+        val context = holder.itemView.context
         val item = getItem(position)
 
         when (item) {
@@ -237,6 +239,7 @@ class OverviewFragmentAdapter : RecyclerView.Adapter<OverviewFragmentViewHolder>
             is OverviewFragmentItemMessage -> {
                 holder as ServerMessageViewHolder
 
+                holder.binding.title = context.getString(R.string.overview_server_message)
                 holder.binding.text = item.message
                 holder.binding.executePendingBindings()
             }
@@ -277,6 +280,13 @@ class OverviewFragmentAdapter : RecyclerView.Adapter<OverviewFragmentViewHolder>
 
                 holder.binding.executePendingBindings()
             }
+            is OverviewFragmentItemOutdatedServer -> {
+                holder as ServerMessageViewHolder
+
+                holder.binding.title = context.getString(R.string.overview_server_outdated_title)
+                holder.binding.text = context.getString(R.string.overview_server_outdated_text)
+                holder.binding.executePendingBindings()
+            }
         }.let {  }
     }
 }

app/src/main/java/io/timelimit/android/ui/overview/overview/OverviewFragmentItem.kt

@@ -39,6 +39,7 @@ object OverviewFragmentActionAddDevice: OverviewFragmentItem()
 object OverviewFragmentHeaderIntro: OverviewFragmentItem()
 object OverviewFragmentHeaderFinishSetup: OverviewFragmentItem()
 data class OverviewFragmentItemMessage(val message: String): OverviewFragmentItem()
+object OverviewFragmentItemOutdatedServer: OverviewFragmentItem()
 sealed class ShowMoreOverviewFragmentItem: OverviewFragmentItem() {
     object ShowAllUsers: ShowMoreOverviewFragmentItem()
     data class ShowMoreDevices(val level: DeviceListItemVisibility): ShowMoreOverviewFragmentItem()

app/src/main/java/io/timelimit/android/ui/overview/overview/OverviewFragmentModel.kt

@@ -19,12 +19,10 @@ import android.app.Application
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
+import io.timelimit.android.BuildConfig
 import io.timelimit.android.data.model.HintsToShow
 import io.timelimit.android.data.model.UserType
-import io.timelimit.android.livedata.ignoreUnchanged
-import io.timelimit.android.livedata.liveDataFromFunction
-import io.timelimit.android.livedata.map
-import io.timelimit.android.livedata.switchMap
+import io.timelimit.android.livedata.*
 import io.timelimit.android.logic.DefaultAppLogic
 import java.util.*
 
@@ -94,15 +92,19 @@ class OverviewFragmentModel(application: Application): AndroidViewModel(applicat
     private val isNoUserAssignedLive = logic.deviceUserEntry.map { it == null }.ignoreUnchanged()
     private val hasShownIntroduction = logic.database.config().wereHintsShown(HintsToShow.OVERVIEW_INTRODUCTION)
     private val messageLive = logic.database.config().getServerMessage()
-    private val introEntries = isNoUserAssignedLive.switchMap { noUserAssigned ->
-        hasShownIntroduction.switchMap { hasShownIntro ->
-            messageLive.map { message ->
+    private val serverVersion = logic.serverApiLevelLogic.infoLive
+    private val introEntries = mergeLiveDataWaitForValues(isNoUserAssignedLive, hasShownIntroduction, messageLive, serverVersion)
+        .map { (noUserAssigned, hasShownIntro, message, serverVersion) ->
             val result = mutableListOf<OverviewFragmentItem>()
 
             if (noUserAssigned) {
                 result.add(OverviewFragmentHeaderFinishSetup)
             }
 
+            if (!serverVersion.hasLevelOrIsOffline(BuildConfig.minimumRecommendServerVersion)) {
+                result.add(OverviewFragmentItemOutdatedServer)
+            }
+
             if (message != null) {
                 result.add(OverviewFragmentItemMessage(message))
             }
@@ -113,8 +115,6 @@ class OverviewFragmentModel(application: Application): AndroidViewModel(applicat
 
             result
         }
-        }
-    }
 
     private val hiddenTaskIdsLive = MutableLiveData<Set<String>>().apply { value = emptySet() }
     private val tasksWithPendingReviewLive = logic.database.childTasks().getPendingTasks()

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

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
-  TimeLimit Copyright <C> 2019 Jonas Lochmann
+  TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation version 3 of the License.
@@ -18,6 +18,10 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <data>
+        <variable
+            name="title"
+            type="String" />
+
         <variable
             name="text"
             type="String" />
@@ -35,7 +39,8 @@
             android:layout_height="wrap_content">
 
             <TextView
-                android:text="@string/overview_server_message"
+                tools:text="@string/overview_server_message"
+                android:text="@{title}"
                 android:textAppearance="?android:textAppearanceLarge"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content" />

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

@@ -1209,6 +1209,12 @@
 
     <string name="overview_server_message">Mitteilung</string>
 
+    <string name="overview_server_outdated_title">alte Serverversion</string>
+    <string name="overview_server_outdated_text">Sie verwenden eine ältere Version
+        des TimeLimit-Servers. Das kann zu einem eingeschränkten Funktionsumfang
+        und Sicherheitspropblemen führen.
+    </string>
+
     <string name="parent_limit_login_title">Anmeldeverhinderungskategorie</string>
     <string name="parent_limit_login_help">Hier können Sie eine Kategorie wählen.
         Sobald diese Kategorie gesperrt ist können Sie sich nicht mehr als Elternteil anmelden, sodass

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

@@ -1253,6 +1253,12 @@
 
     <string name="overview_server_message">Message</string>
 
+    <string name="overview_server_outdated_title">old server version</string>
+    <string name="overview_server_outdated_text">You are using an outdated version
+        of timelimit-server. This can limit the available features and can be
+        a security risk.
+    </string>
+
     <string name="parent_limit_login_title">Limit login category</string>
     <string name="parent_limit_login_help">Here you can select a category. As soon as Apps of this
         category are blocked, you can not sign in with your parent user. This