fix: handle deleted channels in ChannelSet DataStore

adds `removeSettings` method to delete channels with `Role.DISABLED`

app/src/main/java/com/geeksville/mesh/repository/datastore/ChannelSetRepository.kt

@@ -7,7 +7,7 @@ import com.geeksville.mesh.ChannelProtos
 import com.geeksville.mesh.ConfigProtos
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.catch
-import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.firstOrNull
 import java.io.IOException
 import javax.inject.Inject
 
@@ -40,14 +40,23 @@ class ChannelSetRepository @Inject constructor(
         }
     }
 
-    suspend fun addSettings(channel: ChannelProtos.Channel) {
+    /**
+     * Updates the ChannelSettings list with the provided channel and returns the index of the
+     * admin channel after the update (if not found, returns 0).
+     */
+    suspend fun updateChannelSettings(channel: ChannelProtos.Channel): Int {
         channelSetStore.updateData { preference ->
             if (preference.settingsCount > channel.index) {
-                preference.toBuilder().setSettings(channel.index, channel.settings).build()
+                if (channel.role == ChannelProtos.Channel.Role.DISABLED) {
+                    preference.toBuilder().removeSettings(channel.index).build()
+                } else {
+                    preference.toBuilder().setSettings(channel.index, channel.settings).build()
+                }
             } else {
-                preference.toBuilder().addSettings(channel.settings).build()
+                preference.toBuilder().addSettings(channel.index, channel.settings).build()
             }
         }
+        return getAdminChannel()
     }
 
     suspend fun addAllSettings(channelSet: ChannelSet) {
@@ -62,6 +71,13 @@ class ChannelSetRepository @Inject constructor(
         }
     }
 
-    suspend fun fetchInitialChannelSet() = channelSetStore.data.first()
+    /**
+     * Returns the index of the admin channel (or 0 if not found).
+     */
+    private suspend fun getAdminChannel(): Int = fetchInitialChannelSet()?.settingsList
+        ?.indexOfFirst { it.name.lowercase() == "admin" }
+        ?.coerceAtLeast(0) ?: 0
+
+    suspend fun fetchInitialChannelSet() = channelSetStore.data.firstOrNull()
 
 }

app/src/main/java/com/geeksville/mesh/service/MeshService.kt

@@ -963,11 +963,8 @@ class MeshService : Service(), Logging {
         }
     }
 
-    private fun addChannelSettings(ch: ChannelProtos.Channel) {
-        if (ch.index == 0 || ch.settings.name.lowercase() == "admin") adminChannelIndex = ch.index
-        serviceScope.handledLaunch {
-            channelSetRepository.addSettings(ch)
-        }
+    private fun updateChannelSettings(ch: ChannelProtos.Channel) = serviceScope.handledLaunch {
+        adminChannelIndex = channelSetRepository.updateChannelSettings(ch)
     }
 
     private fun currentSecond() = (System.currentTimeMillis() / 1000).toInt()
@@ -1207,7 +1204,7 @@ class MeshService : Service(), Logging {
             ch.toString()
         )
         insertMeshLog(packetToSave)
-        if (ch.role != ChannelProtos.Channel.Role.DISABLED) addChannelSettings(ch)
+        if (ch.role != ChannelProtos.Channel.Role.DISABLED) updateChannelSettings(ch)
     }
 
     /**
@@ -1407,13 +1404,6 @@ class MeshService : Service(), Logging {
         }.forEach(::requestConfig)
     }
 
-    private fun setChannel(ch: ChannelProtos.Channel) {
-        if (ch.index == 0 || ch.settings.name.lowercase() == "admin") adminChannelIndex = ch.index
-        sendToRadio(newMeshPacketTo(myNodeNum).buildAdminPacket(wantResponse = true) {
-            setChannel = ch
-        })
-    }
-
     /**
      * Start the modern (REV2) API configuration flow
      */
@@ -1725,17 +1715,13 @@ class MeshService : Service(), Logging {
         }
 
         override fun setChannel(payload: ByteArray?) = toRemoteExceptions {
-            with(ChannelProtos.Channel.parseFrom(payload)) {
-                if (index == 0 || settings.name.lowercase() == "admin") adminChannelIndex = index
-            }
             setRemoteChannel(myNodeNum, payload)
         }
 
         override fun setRemoteChannel(destNum: Int, payload: ByteArray?) = toRemoteExceptions {
             val channel = ChannelProtos.Channel.parseFrom(payload)
-            sendToRadio(newMeshPacketTo(destNum).buildAdminPacket(wantResponse = true) {
-                setChannel = channel
-            })
+            sendToRadio(newMeshPacketTo(destNum).buildAdminPacket { setChannel = channel })
+            if (destNum == myNodeNum) updateChannelSettings(channel) // Update our local copy
         }
 
         override fun getRemoteChannel(id: Int, destNum: Int, index: Int) = toRemoteExceptions {