Remove redundant P2P groups if found

If more than one group is found owned by the device, Android system will cycle through these groups using an LRU cache which is undesirable.

The reason for causing >1 groups is unknown.

mobile/src/main/java/be/mygod/vpnhotspot/RepeaterService.kt

@@ -58,8 +58,6 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, SharedPrefere
         val statusChanged = StickyEvent0()
         val groupChanged = StickyEvent1 { group }
 
-        private var groups: Collection<WifiP2pGroup> = emptyList()
-
         fun startWps(pin: String? = null) {
             val channel = channel
             if (channel == null) SmartSnackbar.make(R.string.repeater_failure_disconnected).show()
@@ -84,22 +82,30 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, SharedPrefere
         fun resetCredentials() {
             val channel = channel
             if (channel == null) SmartSnackbar.make(R.string.repeater_failure_disconnected).show()
-            else (groups + group).filterNotNull().forEach {
+            else p2pManager.deletePersistentGroup(channel, (group ?: return).netId,
-                p2pManager.deletePersistentGroup(channel, it.netId, object : WifiP2pManager.ActionListener {
+                    object : WifiP2pManager.ActionListener {
                         override fun onSuccess() = SmartSnackbar.make(R.string.repeater_reset_credentials_success)
                                 .shortToast().show()
                         override fun onFailure(reason: Int) = SmartSnackbar.make(
                                 formatReason(R.string.repeater_reset_credentials_failure, reason)).show()
                     })
         }
-        }
 
         fun requestGroupUpdate() {
             group = null
+            val channel = channel ?: return
             try {
-                p2pManager.requestPersistentGroupInfo(channel ?: return) {
+                p2pManager.requestPersistentGroupInfo(channel) {
-                    groups = it
+                    val ownedGroups = it.filter { it.isGroupOwner }
-                    if (it.size == 1) group = it.single()
+                    val main = ownedGroups.minBy { it.netId }
+                    group = main
+                    if (main != null) ownedGroups.filter { it.netId != main.netId }.forEach {
+                        p2pManager.deletePersistentGroup(channel, it.netId, object : WifiP2pManager.ActionListener {
+                            override fun onSuccess() = Timber.i("Removed redundant owned group: $it")
+                            override fun onFailure(reason: Int) = SmartSnackbar.make(
+                                    formatReason(R.string.repeater_clean_pog_failure, reason)).show()
+                        })
+                    }
                 }
             } catch (e: ReflectiveOperationException) {
                 Timber.w(e)

mobile/src/main/res/values/strings.xml

@@ -27,6 +27,7 @@
     <string name="repeater_reset_credentials">Reset</string>
     <string name="repeater_reset_credentials_success">Credentials reset.</string>
     <string name="repeater_reset_credentials_failure">Failed to reset credentials (reason: %s)</string>
+    <string name="repeater_clean_pog_failure">Failed to remove redundant P2P group (reason: %s)</string>
 
     <string name="repeater_p2p_unavailable">Wi\u2011Fi direct unavailable, please enable Wi\u2011Fi</string>
     <string name="repeater_create_group_failure">Failed to create P2P group (reason: %s)</string>