refactor: split `MetricsViewModel` state updates

- Consolidates `MetricViewModel` back to a single state flow
- Introduces a `MutableStateFlow` for state updates, allowing more independent control
- Moves `Telemetry`, `MeshPacket`, and config updates into separate coroutines

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

@@ -6,51 +6,47 @@ import com.geeksville.mesh.CoroutineDispatchers
 import com.geeksville.mesh.MeshProtos.MeshPacket
 import com.geeksville.mesh.Portnums.PortNum
 import com.geeksville.mesh.TelemetryProtos.Telemetry
+import com.geeksville.mesh.android.Logging
 import com.geeksville.mesh.database.MeshLogRepository
 import com.geeksville.mesh.database.entity.MeshLog
 import com.geeksville.mesh.repository.datastore.RadioConfigRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted.Companion.WhileSubscribed
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.flatMapLatest
-import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 data class MetricsState(
     val isManaged: Boolean = true,
+    val isFahrenheit: Boolean = false,
     val deviceMetrics: List<Telemetry> = emptyList(),
     val environmentMetrics: List<Telemetry> = emptyList(),
     val signalMetrics: List<MeshPacket> = emptyList(),
-    val hasTracerouteLogs: Boolean = false,
-    val environmentDisplayFahrenheit: Boolean = false,
+    val tracerouteRequests: List<MeshLog> = emptyList(),
+    val tracerouteResults: List<MeshPacket> = emptyList(),
 ) {
     fun hasDeviceMetrics() = deviceMetrics.isNotEmpty()
     fun hasEnvironmentMetrics() = environmentMetrics.isNotEmpty()
     fun hasSignalMetrics() = signalMetrics.isNotEmpty()
+    fun hasTracerouteLogs() = tracerouteRequests.isNotEmpty()
 
     companion object {
         val Empty = MetricsState()
     }
 }
 
-data class TracerouteLogState(
-    val requests: List<MeshLog> = emptyList(),
-    val results: List<MeshPacket> = emptyList(),
-) {
-    companion object {
-        val Empty = TracerouteLogState()
-    }
-}
-
 @HiltViewModel
 class MetricsViewModel @Inject constructor(
     private val dispatchers: CoroutineDispatchers,
     private val meshLogRepository: MeshLogRepository,
     private val radioConfigRepository: RadioConfigRepository,
-) : ViewModel() {
+) : ViewModel(), Logging {
     private val destNum = MutableStateFlow(0)
 
     private fun MeshPacket.hasValidSignal(): Boolean =
@@ -66,48 +62,65 @@ class MetricsViewModel @Inject constructor(
         meshLogRepository.deleteLog(uuid)
     }
 
-    @OptIn(ExperimentalCoroutinesApi::class)
-    val tracerouteState = destNum.flatMapLatest { destNum ->
-        combine(
-            meshLogRepository.getLogsFrom(nodeNum = 0, PortNum.TRACEROUTE_APP_VALUE),
-            meshLogRepository.getMeshPacketsFrom(destNum, PortNum.TRACEROUTE_APP_VALUE),
-        ) { request, response ->
-            TracerouteLogState(
-                requests = request.filter { it.hasValidTraceroute() },
-                results = response,
-            )
-        }
-    }.stateIn(
-        scope = viewModelScope,
-        started = WhileSubscribed(stopTimeoutMillis = 5000L),
-        initialValue = TracerouteLogState.Empty,
-    )
+    private val _state = MutableStateFlow(MetricsState.Empty)
+    val state: StateFlow<MetricsState> = _state
 
-    @OptIn(ExperimentalCoroutinesApi::class)
-    val state = destNum.flatMapLatest { destNum ->
-        combine(
-            meshLogRepository.getTelemetryFrom(destNum),
-            meshLogRepository.getMeshPacketsFrom(destNum),
-            meshLogRepository.getLogsFrom(nodeNum = 0, PortNum.TRACEROUTE_APP_VALUE),
-            radioConfigRepository.deviceProfileFlow,
-        ) { telemetry, meshPackets, traceroute, profile ->
+    init {
+        radioConfigRepository.deviceProfileFlow.onEach { profile ->
             val moduleConfig = profile.moduleConfig
-            MetricsState(
-                isManaged = profile.config.security.isManaged,
-                deviceMetrics = telemetry.filter { it.hasDeviceMetrics() },
-                environmentMetrics = telemetry.filter {
-                    it.hasEnvironmentMetrics() && it.environmentMetrics.relativeHumidity >= 0f
-                },
-                signalMetrics = meshPackets.filter { it.hasValidSignal() },
-                hasTracerouteLogs = traceroute.any { it.hasValidTraceroute() },
-                environmentDisplayFahrenheit = moduleConfig.telemetry.environmentDisplayFahrenheit,
-            )
-        }
-    }.stateIn(
-        scope = viewModelScope,
-        started = WhileSubscribed(stopTimeoutMillis = 5000L),
-        initialValue = MetricsState.Empty,
-    )
+            _state.update { state ->
+                state.copy(
+                    isManaged = profile.config.security.isManaged,
+                    isFahrenheit = moduleConfig.telemetry.environmentDisplayFahrenheit,
+                )
+            }
+        }.launchIn(viewModelScope)
+
+        @OptIn(ExperimentalCoroutinesApi::class)
+        destNum.flatMapLatest { destNum ->
+            meshLogRepository.getTelemetryFrom(destNum).onEach { telemetry ->
+                _state.update { state ->
+                    state.copy(
+                        deviceMetrics = telemetry.filter { it.hasDeviceMetrics() },
+                        environmentMetrics = telemetry.filter {
+                            it.hasEnvironmentMetrics() && it.environmentMetrics.relativeHumidity >= 0f
+                        },
+                    )
+                }
+            }
+        }.launchIn(viewModelScope)
+
+        @OptIn(ExperimentalCoroutinesApi::class)
+        destNum.flatMapLatest { destNum ->
+            meshLogRepository.getMeshPacketsFrom(destNum).onEach { meshPackets ->
+                _state.update { state ->
+                    state.copy(signalMetrics = meshPackets.filter { it.hasValidSignal() })
+                }
+            }
+        }.launchIn(viewModelScope)
+
+        @OptIn(ExperimentalCoroutinesApi::class)
+        destNum.flatMapLatest { destNum ->
+            combine(
+                meshLogRepository.getLogsFrom(nodeNum = 0, PortNum.TRACEROUTE_APP_VALUE),
+                meshLogRepository.getMeshPacketsFrom(destNum, PortNum.TRACEROUTE_APP_VALUE),
+            ) { request, response ->
+                _state.update { state ->
+                    state.copy(
+                        tracerouteRequests = request.filter { it.hasValidTraceroute() },
+                        tracerouteResults = response,
+                    )
+                }
+            }
+        }.launchIn(viewModelScope)
+
+        debug("MetricsViewModel created")
+    }
+
+    override fun onCleared() {
+        super.onCleared()
+        debug("MetricsViewModel cleared")
+    }
 
     /**
      * Used to set the Node for which the user will see charts for.

app/src/main/java/com/geeksville/mesh/ui/NodeDetail.kt

@@ -120,7 +120,7 @@ private fun NodeDetailList(
         if (node.hasEnvironmentMetrics) {
             item {
                 PreferenceCategory("Environment")
-                EnvironmentMetrics(node, metricsState.environmentDisplayFahrenheit)
+                EnvironmentMetrics(node, metricsState.isFahrenheit)
                 Spacer(modifier = Modifier.height(8.dp))
             }
         }
@@ -161,7 +161,7 @@ private fun NodeDetailList(
             NavCard(
                 title = stringResource(R.string.traceroute_logs),
                 icon = Icons.Default.Route,
-                enabled = metricsState.hasTracerouteLogs
+                enabled = metricsState.hasTracerouteLogs()
             ) {
                 onNavigate("TracerouteList")
             }

app/src/main/java/com/geeksville/mesh/ui/components/EnvironmentMetrics.kt

@@ -83,7 +83,7 @@ fun EnvironmentMetricsScreen(
         return (celsius * 1.8F) + 32
     }
 
-    val processedTelemetries: List<Telemetry> = if (state.environmentDisplayFahrenheit) {
+    val processedTelemetries: List<Telemetry> = if (state.isFahrenheit) {
         state.environmentMetrics.map { telemetry ->
             val temperatureFahrenheit =
                 celsiusToFahrenheit(telemetry.environmentMetrics.temperature)
@@ -124,7 +124,7 @@ fun EnvironmentMetricsScreen(
             items(processedTelemetries) { telemetry ->
                 EnvironmentMetricsCard(
                     telemetry,
-                    state.environmentDisplayFahrenheit
+                    state.isFahrenheit
                 )
             }
         }

app/src/main/java/com/geeksville/mesh/ui/components/TracerouteLog.kt

@@ -53,7 +53,7 @@ fun TracerouteLogScreen(
     viewModel: MetricsViewModel = hiltViewModel(),
     modifier: Modifier = Modifier,
 ) {
-    val state by viewModel.tracerouteState.collectAsStateWithLifecycle()
+    val state by viewModel.state.collectAsStateWithLifecycle()
     val dateFormat = remember {
         DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.MEDIUM)
     }
@@ -80,9 +80,9 @@ fun TracerouteLogScreen(
         modifier = modifier.fillMaxSize(),
         contentPadding = PaddingValues(horizontal = 16.dp),
     ) {
-        items(state.requests, key = { it.uuid }) { log ->
-            val result = remember(state.requests) {
-                state.results.find { it.decoded.requestId == log.fromRadio.packet.id }
+        items(state.tracerouteRequests, key = { it.uuid }) { log ->
+            val result = remember(state.tracerouteRequests) {
+                state.tracerouteResults.find { it.decoded.requestId == log.fromRadio.packet.id }
             }
             val route = remember(result) { result?.fullRouteDiscovery }