Use a foreground service for reliable background transmitting

[dshokouhi]

Summary

Hopefully fixes: #3159 by implementing a similar foreground service like in #3369 based on the docs to create a "fake" scanner that looks for nothing to help keep the transmitter alive.

Needs end user testing. 🤞

Screenshots

Link to pull request in Documentation repository

Documentation: home-assistant/companion.home-assistant#pending

Any other notes

Code may not look pretty for now but wanted to get end user feedback

[jpelgrom]

Maybe it's good to split the Bluetooth scan permission into its own PR which we can quickly approve+merge as that fixes an obvious oversight/bug, whereas the foreground service is an effort to improve things but also introduces new behavior?

[dshokouhi]

Maybe it's good to split the Bluetooth scan permission into its own PR which we can quickly approve+merge as that fixes an obvious oversight/bug, whereas the foreground service is an effort to improve things but also introduces new behavior?

actually the scan permission is required in this PR because we are now using the scanner in this sensor where we were not before

[jpelgrom]

I missed that's new, sorry. In that case never mind and let's wait for positive results.

[dshokouhi]

Agreed this requires end users to confirm its working for them as I cannot reproduce

[dshokouhi]

May have taken some time but we got end user confirmation :) probably want to keep this in beta for a lil bit to let it soak

this is now ready for review!

[jpelgrom]

Not really able to test this myself but user comment sounds promising, and I don't see it causing any harm at the moment.

Edit: actually, have you tested this when scanning and transmitting is enabled? Do these changes interfere with regular scanning?

[jpelgrom]

Might be good to add a comment here explaining this enables a foreground service to improve reliability, so that one doesn't need to blame the code to find out why we are monitoring in a transmitting service.

Minor cleanup so you don't need beaconManager?. everywhere:

beaconManager?.apply {
    enableForegroundServiceScanning(builder.build(), 445)
    setEnableScheduledScanJobs(false)
    // etc
}

[dshokouhi]

Edit: actually, have you tested this when scanning and transmitting is enabled? Do these changes interfere with regular scanning?

I thought I did that test before but now it seems that only one foreground service can be up at a time 🤔 not sure what to do here. I dont think we can share them either.

2024-06-15 17:39:46.481 18736-18736 SensorDetailViewModel   io....stant.companion.android.debug  E  Exception while requesting update for sensor ble_emitter (Ask Gemini)
                                                                                                    java.lang.IllegalStateException: May not be called after consumers are already bound.
                                                                                                    	at org.altbeacon.beacon.BeaconManager.enableForegroundServiceScanning(BeaconManager.java:1792)
                                                                                                    	at io.homeassistant.companion.android.common.bluetooth.ble.TransmitterManager.startTransmitting(TransmitterManager.kt:76)
                                                                                                    	at io.homeassistant.companion.android.common.sensors.BluetoothSensorManager.updateBLESensor(BluetoothSensorManager.kt:360)
                                                                                                    	at io.homeassistant.companion.android.common.sensors.BluetoothSensorManager.requestSensorUpdate(BluetoothSensorManager.kt:198)
                                                                                                    	at io.homeassistant.companion.android.settings.sensor.SensorDetailViewModel$setEnabled$2.invokeSuspend(SensorDetailViewModel.kt:217)
                                                                                                    	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
                                                                                                    	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104)
                                                                                                    	at android.os.Handler.handleCallback(Handler.java:959)
                                                                                                    	at android.os.Handler.dispatchMessage(Handler.java:100)
                                                                                                    	at android.os.Looper.loopOnce(Looper.java:232)
                                                                                                    	at android.os.Looper.loop(Looper.java:317)
                                                                                                    	at android.app.ActivityThread.main(ActivityThread.java:8592)
                                                                                                    	at java.lang.reflect.Method.invoke(Native Method)
                                                                                                    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
                                                                                                    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:878)

[dshokouhi]

putting this back in draft while considering new changes based on the latest test comment

[dshokouhi]

Based on the most recent comment I am thinking of maybe updating our docs and sensor string description to mention the beacon monitor being enabled.