Persist and update lastPublishedDate to correctly handle deletions and updates of the latest measurement

Author: oliexdev

src/app/src/main/java/com/health/openscale/sync/core/model/MQTTViewModel.kt

@@ -32,6 +32,8 @@ class MQTTViewModel(private val sharedPreferences: SharedPreferences) : ViewMode
     private val _mqttUseSsl = MutableLiveData<Boolean>(sharedPreferences.getBoolean("mqtt_use_ssl", true))
     private val _mqttUseDiscovery = MutableLiveData<Boolean>(sharedPreferences.getBoolean("mqtt_use_discovery", true))
 
+    private val _lastPublishedDate = MutableLiveData<Long>(sharedPreferences.getLong("last_published_date", 0L))
+
     override fun getName(): String {
         return "MQTT"
     }
@@ -82,4 +84,11 @@ class MQTTViewModel(private val sharedPreferences: SharedPreferences) : ViewMode
         _mqttUseDiscovery.value = useDiscovery
         sharedPreferences.edit().putBoolean("mqtt_use_discovery", useDiscovery).apply()
     }
+
+    val lastPublishedDate: LiveData<Long> = _lastPublishedDate
+
+    fun setLastPublishedDate(date: Long) {
+        _lastPublishedDate.value = date
+        sharedPreferences.edit().putLong("last_published_date", date).apply()
+    }
 }

src/app/src/main/java/com/health/openscale/sync/core/service/MQTTService.kt

@@ -51,6 +51,7 @@ import com.health.openscale.sync.R
 import com.health.openscale.sync.core.datatypes.OpenScaleMeasurement
 import com.health.openscale.sync.core.model.MQTTViewModel
 import com.health.openscale.sync.core.model.ViewModelInterface
+import com.health.openscale.sync.core.service.SyncResult
 import com.health.openscale.sync.core.sync.MQTTSync
 import com.hivemq.client.mqtt.MqttClient
 import com.hivemq.client.mqtt.mqtt5.Mqtt5BlockingClient
@@ -123,31 +124,67 @@ class MQTTService(
 
     override suspend fun sync(measurements: List<OpenScaleMeasurement>): SyncResult<Unit> {
         return ensureConnectedAndExecute("fullSync") {syncHandler ->
-            syncHandler.fullSync(measurements)
+            val result = syncHandler.fullSync(measurements)
+            if (result is SyncResult.Success) {
+                measurements.maxByOrNull { it.date }?.let { publishLastMeasurement(it) }
+            }
+            result
         }
     }
 
     override suspend fun insert(measurement: OpenScaleMeasurement): SyncResult<Unit> {
         return ensureConnectedAndExecute("insert") { syncHandler ->
-            syncHandler.insert(measurement)
+            val result = syncHandler.insert(measurement)
+            if (result is SyncResult.Success) {
+                publishLastMeasurement(measurement)
+            }
+            result
         }
     }
 
     override suspend fun delete(date: Date): SyncResult<Unit> {
         return ensureConnectedAndExecute("delete") { syncHandler ->
-            syncHandler.delete(date)
+            val result = syncHandler.delete(date)
+            if (result is SyncResult.Success) {
+                val lastDate = viewModel.lastPublishedDate.value
+                if (lastDate != null && date.time >= lastDate) {
+                    publishLastMeasurement(null)
+                }
+            }
+            result
         }
     }
 
     override suspend fun clear(): SyncResult<Unit> {
         return ensureConnectedAndExecute("clear") { syncHandler ->
-            syncHandler.clear()
+            val result = syncHandler.clear()
+            if (result is SyncResult.Success) {
+                publishLastMeasurement(null)
+            }
+            result
         }
     }
 
     override suspend fun update(measurement: OpenScaleMeasurement): SyncResult<Unit> {
         return ensureConnectedAndExecute("update") { syncHandler ->
-            syncHandler.update(measurement)
+            val result = syncHandler.update(measurement)
+            if (result is SyncResult.Success) {
+                publishLastMeasurement(measurement)
+            }
+            result
+        }
+    }
+
+    private fun publishLastMeasurement(measurement: OpenScaleMeasurement?) {
+        if (measurement != null) {
+            val lastDate = viewModel.lastPublishedDate.value
+            if (lastDate == null || measurement.date.time >= lastDate) {
+                mqttSync.publishLastMeasurement(measurement)
+                viewModel.setLastPublishedDate(measurement.date.time)
+            }
+        } else {
+            mqttSync.publishLastMeasurement(null)
+            viewModel.setLastPublishedDate(0L)
         }
     }
 

src/app/src/main/java/com/health/openscale/sync/core/sync/MQTTSync.kt

@@ -17,6 +17,7 @@
  */
 package com.health.openscale.sync.core.sync
 
+import androidx.lifecycle.viewmodel.compose.viewModel
 import com.google.gson.GsonBuilder
 import com.google.gson.JsonParser
 import com.health.openscale.sync.BuildConfig
@@ -34,7 +35,7 @@ class MQTTSync(private val mqttClient: Mqtt5BlockingClient) : SyncInterface() {
         var failureCount = 0
 
         measurements.sortedBy { measurements -> measurements.date.time }.forEach { measurement ->
-            val syncResult = publishMeasurement(measurement, "openScaleSync/measurements/insert")
+            val syncResult = publishMeasurement(measurement, "openScaleSync/measurements/all")
 
             if (syncResult is SyncResult.Failure) {
                 failureCount++
@@ -65,6 +66,14 @@ class MQTTSync(private val mqttClient: Mqtt5BlockingClient) : SyncInterface() {
         return publishMeasurement(measurement, "openScaleSync/measurements/update")
     }
 
+    fun publishLastMeasurement(measurement: OpenScaleMeasurement?): SyncResult<Unit> {
+        return if (measurement != null) {
+            publishMeasurement(measurement, "openScaleSync/measurements/last")
+        } else {
+            publishMessage(mapOf<String, Any>(), "openScaleSync/measurements/last")
+        }
+    }
+
     fun publishHomeAssistantDiscovery(
         jsonPayloadString: String
     ): SyncResult<Unit> {

src/app/src/main/res/raw/homeassistant_payload.json

@@ -56,5 +56,5 @@
       "unique_id": "openscale_id"
     }
   },
-  "state_topic": "openScaleSync/measurements/insert"
+  "state_topic": "openScaleSync/measurements/last"
 }