feat: warn user when duty cycle limit reached

closes #540

app/src/main/java/com/geeksville/mesh/MainActivity.kt

@@ -334,6 +334,7 @@ class MainActivity : AppCompatActivity(), Logging {
         // val messageStr = getText(messageText)
 
         val builder = MaterialAlertDialogBuilder(this)
+            .setCancelable(false)
             .setTitle(titleText)
             .setMessage(messageText)
             .setPositiveButton(R.string.okay) { _, _ ->

app/src/main/java/com/geeksville/mesh/model/UIState.kt

@@ -34,6 +34,7 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.launchIn
@@ -143,6 +144,11 @@ class UIViewModel @Inject constructor(
     private val requestIds = MutableStateFlow<HashMap<Int, Boolean>>(hashMapOf())
 
     init {
+        radioInterfaceService.errorMessage.filterNotNull().onEach {
+            _snackbarText.value = it
+            radioInterfaceService.clearErrorMessage()
+        }.launchIn(viewModelScope)
+
         radioConfigRepository.nodeInfoFlow().onEach(nodeDB::setNodes)
             .launchIn(viewModelScope)
 

app/src/main/java/com/geeksville/mesh/repository/radio/RadioInterfaceService.kt

@@ -55,6 +55,18 @@ class RadioInterfaceService @Inject constructor(
     private val _receivedData = MutableSharedFlow<ByteArray>()
     val receivedData: SharedFlow<ByteArray> = _receivedData
 
+    private val _errorMessage = MutableStateFlow<String?>(null)
+    val errorMessage: SharedFlow<String?> = _errorMessage
+
+    fun setErrorMessage(text: String) {
+        errormsg(text)
+        _errorMessage.value = text
+    }
+
+    fun clearErrorMessage() {
+        _errorMessage.value = null
+    }
+
     private val logSends = false
     private val logReceives = false
     private lateinit var sentPacketsLog: BinaryLogFile // inited in onCreate

app/src/main/java/com/geeksville/mesh/service/MeshService.kt

@@ -664,12 +664,16 @@ class MeshService : Service(), Logging {
                         handleReceivedTelemetry(packet.from, u, dataPacket.time)
                     }
 
-                    // Handle new style routing info
                     Portnums.PortNum.ROUTING_APP_VALUE -> {
-                        shouldBroadcast =
-                            true // We always send acks to other apps, because they might care about the messages they sent
+                        // We always send ACKs to other apps, because they might care about the messages they sent
+                        shouldBroadcast = true
                         val u = MeshProtos.Routing.parseFrom(data.payload)
                         val isAck = u.errorReasonValue == MeshProtos.Routing.Error.NONE_VALUE
+
+                        if (u.errorReason == MeshProtos.Routing.Error.DUTY_CYCLE_LIMIT) {
+                            radioInterfaceService.setErrorMessage(getString(R.string.error_duty_cycle))
+                        }
+
                         handleAckNak(isAck, fromId, data.requestId)
                         queueResponse.remove(data.requestId)?.complete(true)
                     }

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

@@ -181,4 +181,5 @@
     <string name="waypoint_delete">Delete waypoint?</string>
     <string name="waypoint_new">New waypoint</string>
     <string name="waypoint_received">Received waypoint: %s</string>
+    <string name="error_duty_cycle">Duty Cycle limit reached. Cannot send messages right now, please try again later.</string>
 </resources>