From 2b79590881b3791713e504e0323ced4f66ec9818 Mon Sep 17 00:00:00 2001
From: Dane Evans <dane@goneepic.com>
Date: Fri, 31 Oct 2025 01:55:37 +1100
Subject: [PATCH] fix #2062:  Remap channels when rearranged (#3561)

---
 .../core/data/repository/PacketRepository.kt  |  4 +++
 .../meshtastic/core/database/dao/PacketDao.kt | 26 +++++++++++++++++++
 .../settings/radio/RadioConfigViewModel.kt    |  9 ++++++-
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/core/data/src/main/kotlin/org/meshtastic/core/data/repository/PacketRepository.kt b/core/data/src/main/kotlin/org/meshtastic/core/data/repository/PacketRepository.kt
index 87e24182f..d39c36147 100644
--- a/core/data/src/main/kotlin/org/meshtastic/core/data/repository/PacketRepository.kt
+++ b/core/data/src/main/kotlin/org/meshtastic/core/data/repository/PacketRepository.kt
@@ -29,6 +29,7 @@ import org.meshtastic.core.database.entity.ReactionEntity
 import org.meshtastic.core.database.model.Node
 import org.meshtastic.core.model.DataPacket
 import org.meshtastic.core.model.MessageStatus
+import org.meshtastic.proto.ChannelProtos.ChannelSettings
 import org.meshtastic.proto.Portnums.PortNum
 import javax.inject.Inject
 
@@ -103,4 +104,7 @@ class PacketRepository @Inject constructor(private val packetDaoLazy: Lazy<Packe
     suspend fun insertReaction(reaction: ReactionEntity) = withContext(Dispatchers.IO) { packetDao.insert(reaction) }
 
     suspend fun clearPacketDB() = withContext(Dispatchers.IO) { packetDao.deleteAll() }
+
+    suspend fun migrateChannelsByPSK(oldSettings: List<ChannelSettings>, newSettings: List<ChannelSettings>) =
+        packetDao.migrateChannelsByPSK(oldSettings, newSettings)
 }
diff --git a/core/database/src/main/kotlin/org/meshtastic/core/database/dao/PacketDao.kt b/core/database/src/main/kotlin/org/meshtastic/core/database/dao/PacketDao.kt
index 20d0e1111..7b9379ff0 100644
--- a/core/database/src/main/kotlin/org/meshtastic/core/database/dao/PacketDao.kt
+++ b/core/database/src/main/kotlin/org/meshtastic/core/database/dao/PacketDao.kt
@@ -30,6 +30,7 @@ import org.meshtastic.core.database.entity.PacketEntity
 import org.meshtastic.core.database.entity.ReactionEntity
 import org.meshtastic.core.model.DataPacket
 import org.meshtastic.core.model.MessageStatus
+import org.meshtastic.proto.ChannelProtos.ChannelSettings
 
 @Suppress("TooManyFunctions")
 @Dao
@@ -250,4 +251,29 @@ interface PacketDao {
 
     @Query("DELETE FROM packet")
     suspend fun deleteAll()
+
+    /**
+     * One-time migration: Remap all message DataPacket.channel indices to new mapping using PSK after a channel
+     * reorder. For each Packet (with port_num = 1), finds the old PSK then sets the channel index to the matching
+     * newSettings index. Skips if PSKs do not match or are missing.
+     */
+    @Transaction
+    suspend fun migrateChannelsByPSK(oldSettings: List<ChannelSettings>, newSettings: List<ChannelSettings>) {
+        val pskToNewIndex = newSettings.mapIndexed { idx, ch -> ch.psk to idx }.toMap()
+        val allPackets = getAllUserPacketsForMigration()
+        for (packet in allPackets) {
+            val oldIndex = packet.data.channel
+            val oldPSK = oldSettings.getOrNull(oldIndex)?.psk
+            val newIndex = if (oldPSK != null) pskToNewIndex[oldPSK] else null
+            if (oldPSK != null && newIndex != null && oldIndex != newIndex) {
+                // Rebuild contact_key with the new index, keeping the rest unchanged
+                val oldKeySuffix = packet.contact_key.drop(1) // removes only the channelIndex prefix
+                val newContactKey = "$newIndex$oldKeySuffix"
+                update(packet.copy(contact_key = newContactKey, data = packet.data.copy(channel = newIndex)))
+            }
+        }
+    }
+
+    @Query("SELECT * FROM packet WHERE port_num = 1")
+    suspend fun getAllUserPacketsForMigration(): List<Packet>
 }
diff --git a/feature/settings/src/main/kotlin/org/meshtastic/feature/settings/radio/RadioConfigViewModel.kt b/feature/settings/src/main/kotlin/org/meshtastic/feature/settings/radio/RadioConfigViewModel.kt
index 591338ea8..1b99cda5e 100644
--- a/feature/settings/src/main/kotlin/org/meshtastic/feature/settings/radio/RadioConfigViewModel.kt
+++ b/feature/settings/src/main/kotlin/org/meshtastic/feature/settings/radio/RadioConfigViewModel.kt
@@ -49,6 +49,7 @@ import kotlinx.coroutines.withContext
 import org.json.JSONObject
 import org.meshtastic.core.data.repository.LocationRepository
 import org.meshtastic.core.data.repository.NodeRepository
+import org.meshtastic.core.data.repository.PacketRepository
 import org.meshtastic.core.data.repository.RadioConfigRepository
 import org.meshtastic.core.database.entity.MyNodeEntity
 import org.meshtastic.core.database.model.Node
@@ -108,6 +109,7 @@ constructor(
     savedStateHandle: SavedStateHandle,
     private val app: Application,
     private val radioConfigRepository: RadioConfigRepository,
+    private val packetRepository: PacketRepository,
     private val serviceRepository: ServiceRepository,
     private val nodeRepository: NodeRepository,
     private val locationRepository: LocationRepository,
@@ -247,7 +249,12 @@ constructor(
         val destNum = destNode.value?.num ?: return
         getChannelList(new, old).forEach { setRemoteChannel(destNum, it) }
 
-        if (destNum == myNodeNum) viewModelScope.launch { radioConfigRepository.replaceAllSettings(new) }
+        if (destNum == myNodeNum) {
+            viewModelScope.launch {
+                packetRepository.migrateChannelsByPSK(old, new)
+                radioConfigRepository.replaceAllSettings(new)
+            }
+        }
         _radioConfigState.update { it.copy(channelList = new) }
     }