From 7ff20acfc02ef3bdd171abf7a1b85df235492c1c Mon Sep 17 00:00:00 2001
From: darken <darken@darken.eu>
Date: Wed, 26 Jan 2022 14:50:48 +0100
Subject: [PATCH] When bluetooth is disabled, stop emissions.

---
 .../capod/common/flow/FlowExtensions.kt       |  2 +-
 .../main/ui/overview/OverviewFragmentVM.kt    |  5 ++--
 .../darken/capod/monitor/core/PodMonitor.kt   | 26 ++++++++++++-------
 3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/app/src/main/java/eu/darken/capod/common/flow/FlowExtensions.kt b/app/src/main/java/eu/darken/capod/common/flow/FlowExtensions.kt
index c6a1ff25..ead424ae 100644
--- a/app/src/main/java/eu/darken/capod/common/flow/FlowExtensions.kt
+++ b/app/src/main/java/eu/darken/capod/common/flow/FlowExtensions.kt
@@ -34,7 +34,7 @@ fun <T : Any> Flow<T>.shareLatest(
     )
     .filterNotNull()
 
-fun <T : Any> Flow<T>.replayingShare(scope: CoroutineScope) = this.shareIn(
+fun <T : Any?> Flow<T>.replayingShare(scope: CoroutineScope) = this.shareIn(
     scope = scope,
     replay = 1,
     started = SharingStarted.WhileSubscribed(replayExpiration = Duration.ZERO)
diff --git a/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewFragmentVM.kt b/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewFragmentVM.kt
index dda0a21d..63ebe407 100644
--- a/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewFragmentVM.kt
+++ b/app/src/main/java/eu/darken/capod/main/ui/overview/OverviewFragmentVM.kt
@@ -106,11 +106,10 @@ class OverviewFragmentVM @Inject constructor(
         debugSettings.isDebugModeEnabled.flow,
         generalSettings.showAll.flow,
         bluetoothManager.isBluetoothEnabled,
-    ) { _, permissions, pods, isDebugMode, showAll, isBluetoothEnabled ->
+        podMonitor.mainDevice,
+    ) { _, permissions, pods, isDebugMode, showAll, isBluetoothEnabled, mainPod ->
         val items = mutableListOf<OverviewAdapter.Item>()
 
-        val mainPod = podMonitor.mainDevice.first()
-
         permissions
             .map { perm ->
                 PermissionCardVH.Item(
diff --git a/app/src/main/java/eu/darken/capod/monitor/core/PodMonitor.kt b/app/src/main/java/eu/darken/capod/monitor/core/PodMonitor.kt
index 5829aeb7..0e395088 100644
--- a/app/src/main/java/eu/darken/capod/monitor/core/PodMonitor.kt
+++ b/app/src/main/java/eu/darken/capod/monitor/core/PodMonitor.kt
@@ -35,18 +35,18 @@ class PodMonitor @Inject constructor(
     val devices: Flow<List<PodDevice>> = bluetoothManager.isBluetoothEnabled
         .flatMapLatest { isBluetoothEnabled ->
             if (isBluetoothEnabled) {
-                generalSettings.scannerMode.flow
+                log(TAG) { "Bluetooth is enabled" }
+                generalSettings.scannerMode.flow.flatMapLatest { bleScanner.scan(scannerMode = it) }
             } else {
                 log(TAG, WARN) { "Bluetooth is currently disabled" }
-                emptyFlow()
+                flowOf(null)
             }
         }
-        .flatMapLatest { bleScanner.scan(scannerMode = it) }
         .map { result ->
             // For each address we only want the newest result, upstream may batch data
-            result.groupBy { it.address }
-                .values
-                .map { sameAdrDevs ->
+            result?.groupBy { it.address }
+                ?.values
+                ?.map { sameAdrDevs ->
                     val newest = sameAdrDevs.maxByOrNull { it.generatedAtNanos }!!
                     sameAdrDevs.minus(newest).let {
                         if (it.isNotEmpty()) log(TAG, VERBOSE) { "Discarding stale results: $it" }
@@ -55,12 +55,16 @@ class PodMonitor @Inject constructor(
                 }
         }
         .map { scanResults ->
-            val newPods = scanResults
-                .mapNotNull { podFactory.createPod(it) }
-
             val pods = mutableMapOf<PodDevice.Id, PodDevice>()
 
             cacheLock.withLock {
+                if (scanResults == null) {
+                    log(TAG) { "Null result, Bluetooth is disabled." }
+                    deviceCache.clear()
+                    return@map emptyList()
+                }
+
+                val newPods = scanResults.mapNotNull { podFactory.createPod(it) }
                 val now = Instant.now()
                 deviceCache.toList().forEach { (key, value) ->
                     if (Duration.between(value.lastSeenAt, now) > Duration.ofSeconds(20)) {
@@ -103,7 +107,9 @@ class PodMonitor @Inject constructor(
         .replayingShare(appScope)
 
     val mainDevice: Flow<PodDevice?>
-        get() = devices.map { it.determineMainDevice() }
+        get() = devices
+            .map { it.determineMainDevice() }
+            .replayingShare(appScope)
 
     private fun Collection<PodDevice>.determineMainDevice(): PodDevice? =
         maxByOrNull { it.rssi }?.let filter@{ device ->