Sync only high and normal messages with low battery

app/src/main/java/org/unifiedpush/distributor/nextpush/AppCompanion.kt

@@ -18,6 +18,11 @@ object AppCompanion {
      */
     val hasInternet = AtomicBoolean(true)
 
+    /**
+     * If we have low battery, we listen for normal and high events only
+     */
+    val lowBattery = AtomicBoolean(false)
+
     /** Have we received the start event ? To check the reverse proxy timeout is high enough */
     val started = AtomicBoolean(false)
 

app/src/main/java/org/unifiedpush/distributor/nextpush/api/Api.kt

@@ -14,6 +14,7 @@ import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.sse.EventSource
 import okhttp3.sse.EventSources
+import org.unifiedpush.distributor.nextpush.AppCompanion
 import org.unifiedpush.distributor.nextpush.AppStore
 import org.unifiedpush.distributor.nextpush.LastEventId
 import org.unifiedpush.distributor.nextpush.account.AccountFactory.getAccount
@@ -99,6 +100,10 @@ class Api(context: Context) {
                     LastEventId(store).get()?.let {
                         header("Last-Event-ID", it)
                     }
+                    if (AppCompanion.lowBattery.get()) {
+                        Log.d(TAG, "Battery is low, registering normal and high only")
+                        header("Urgency", "normal")
+                    }
                 }
                 .build()
 

app/src/main/java/org/unifiedpush/distributor/nextpush/callback/BatteryCallback.kt

@@ -0,0 +1,68 @@
+package org.unifiedpush.distributor.nextpush.callback
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.os.BatteryManager
+import android.util.Log
+import org.unifiedpush.distributor.nextpush.AppCompanion
+import org.unifiedpush.distributor.nextpush.services.FailureHandler
+import org.unifiedpush.distributor.nextpush.services.RestartWorker
+import org.unifiedpush.distributor.nextpush.services.StartService
+import org.unifiedpush.distributor.nextpush.utils.TAG
+
+class BatteryCallback : BroadcastReceiver() {
+    override fun onReceive(context: Context, intent: Intent) {
+        when (intent.action) {
+            Intent.ACTION_BATTERY_LOW -> onBatteryLow(context)
+            Intent.ACTION_BATTERY_OKAY -> onBatteryOk(context)
+        }
+    }
+
+    private fun onBatteryLow(context: Context) {
+        // If it was OK
+        if (!AppCompanion.lowBattery.getAndSet(true)) {
+            Log.d(TAG, "The battery is now low.")
+            restartServer(context)
+        }
+    }
+
+    private fun onBatteryOk(context: Context) {
+        // If it was low
+        if (AppCompanion.lowBattery.getAndSet(false)) {
+            Log.d(TAG, "The battery is now OK.")
+            restartServer(context)
+        }
+    }
+
+    private fun restartServer(context: Context) {
+        if (!FailureHandler.hasFailed()) {
+            StartService.stopService {
+                RestartWorker.run(context, delay = 0)
+            }
+        }
+    }
+
+    companion object {
+        /**
+         * Register an instance of [BatteryCallback] and returns it
+         *
+         * Initiates value of AppCompanion.lowBattery
+         */
+        fun register(context: Context): BatteryCallback {
+            // First we initiate the value
+            val bm = context.getSystemService(Context.BATTERY_SERVICE) as BatteryManager
+            val level = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY)
+            AppCompanion.lowBattery.set(level <= 20)
+            // Then we register the receiver
+            val filter = IntentFilter().apply {
+                addAction(Intent.ACTION_BATTERY_LOW)
+                addAction(Intent.ACTION_BATTERY_OKAY)
+            }
+            return BatteryCallback().also {
+                context.registerReceiver(it, filter)
+            }
+        }
+    }
+}

app/src/main/java/org/unifiedpush/distributor/nextpush/services/StartService.kt

@@ -11,6 +11,7 @@ import org.unifiedpush.distributor.nextpush.AppCompanion
 import org.unifiedpush.distributor.nextpush.WakeLock
 import org.unifiedpush.distributor.nextpush.account.AccountFactory.getAccount
 import org.unifiedpush.distributor.nextpush.api.Api
+import org.unifiedpush.distributor.nextpush.callback.BatteryCallback
 import org.unifiedpush.distributor.nextpush.callback.NetworkCallback
 import org.unifiedpush.distributor.nextpush.utils.ForegroundNotification
 import org.unifiedpush.distributor.nextpush.utils.NOTIFICATION_ID_FOREGROUND
@@ -19,6 +20,7 @@ import org.unifiedpush.distributor.nextpush.utils.TAG
 class StartService : Service() {
 
     private val networkCallback = NetworkCallback(this)
+    private var batteryCallback: BatteryCallback? = null
     private var api: Api? = null
 
     override fun onBind(intent: Intent?): IBinder? {
@@ -38,6 +40,7 @@ class StartService : Service() {
             Log.d(TAG, "onStartCommand: regular start")
             // That's a normal start
             networkCallback.register()
+            batteryCallback = BatteryCallback.register(this)
             startService()
         } else {
             Log.d(TAG, "onStartCommand: to destroy")
@@ -62,6 +65,8 @@ class StartService : Service() {
             RestartWorker.run(this, delay = 0)
         } else {
             networkCallback.unregister()
+            batteryCallback?.let { unregisterReceiver(it) }
+            batteryCallback = null
             RestartWorker.stopPeriodic(this)
         }
     }