fix: reconnect custom channel peers after migration

app/src/main/java/to/bitkit/services/MigrationService.kt

@@ -90,6 +90,7 @@ class MigrationService @Inject constructor(
         private const val RN_PENDING_METADATA_KEY = "rnPendingMetadata"
         private const val RN_PENDING_TRANSFERS_KEY = "rnPendingTransfers"
         private const val RN_PENDING_BOOSTS_KEY = "rnPendingBoosts"
+        private const val RN_DID_ATTEMPT_PEER_RECOVERY_KEY = "rnDidAttemptMigrationPeerRecovery"
         private const val OPENING_CURLY_BRACE = "{"
         private const val MMKV_ROOT = "persist:root"
         private const val RN_WALLET_NAME = "wallet0"
@@ -1251,6 +1252,44 @@ class MigrationService @Inject constructor(
         Logger.info("RN migration completed, marked for post-migration sync", context = TAG)
     }
 
+    private suspend fun isRnMigrationCompleted(): Boolean {
+        val key = stringPreferencesKey(RN_MIGRATION_COMPLETED_KEY)
+        return rnMigrationStore.data.first()[key] == "true"
+    }
+
+    private suspend fun didAttemptPeerRecovery(): Boolean {
+        val key = stringPreferencesKey(RN_DID_ATTEMPT_PEER_RECOVERY_KEY)
+        return rnMigrationStore.data.first()[key] == "true"
+    }
+
+    private suspend fun setDidAttemptPeerRecovery() {
+        val key = stringPreferencesKey(RN_DID_ATTEMPT_PEER_RECOVERY_KEY)
+        rnMigrationStore.edit { it[key] = "true" }
+    }
+
+    suspend fun tryFetchMigrationPeersFromBackup(): List<String> {
+        if (!isRnMigrationCompleted()) return emptyList()
+        if (didAttemptPeerRecovery()) return emptyList()
+
+        setDidAttemptPeerRecovery()
+
+        return runCatching {
+            val data = rnBackupClient.retrieve("peers", fileGroup = "ldk") ?: return emptyList()
+            val peers = json.decodeFromString<List<BackupPeerEntry>>(String(data))
+            if (peers.isEmpty()) return emptyList()
+
+            val trustedIds = Env.trustedLnPeers.map { it.nodeId }.toSet()
+            val uris = peers
+                .filter { it.pubKey !in trustedIds }
+                .map { "${it.pubKey}@${it.address}:${it.port}" }
+
+            Logger.info("Migration peer recovery: fetched ${uris.size} peer(s) from remote backup", context = TAG)
+            uris
+        }.onFailure {
+            Logger.warn("Migration peer recovery failed (will not retry)", it, context = TAG)
+        }.getOrDefault(emptyList())
+    }
+
     suspend fun cleanupAfterMigration() {
         clearPersistedMigrationData()
         setNeedsPostMigrationSync(false)
@@ -2076,6 +2115,13 @@ data class RNWidgetsWithOptions(
     val widgetOptions: Map<String, ByteArray>,
 )
 
+@Serializable
+data class BackupPeerEntry(
+    val pubKey: String,
+    val address: String,
+    val port: UShort,
+)
+
 private val Context.rnMigrationDataStore: DataStore<Preferences> by preferencesDataStore("rn_migration")
 private val Context.rnKeychainDataStore: DataStore<Preferences> by preferencesDataStore("RN_KEYCHAIN")
 

app/src/main/java/to/bitkit/viewmodels/WalletViewModel.kt

@@ -26,6 +26,7 @@ import org.lightningdevkit.ldknode.PeerDetails
 import to.bitkit.R
 import to.bitkit.data.SettingsStore
 import to.bitkit.di.BgDispatcher
+import to.bitkit.ext.of
 import to.bitkit.models.Toast
 import to.bitkit.repositories.BackupRepo
 import to.bitkit.repositories.BlocktankRepo
@@ -291,6 +292,7 @@ class WalletViewModel @Inject constructor(
                     migrationService.consumePendingChannelMigration()
                 }
                 walletRepo.setWalletExistsState()
+                connectMigrationPeers()
                 walletRepo.syncBalances()
                 if (_restoreState.value.isIdle()) {
                     walletRepo.refreshBip21()
@@ -304,6 +306,18 @@ class WalletViewModel @Inject constructor(
             }
     }
 
+    private suspend fun connectMigrationPeers() {
+        val peerUris = migrationService.tryFetchMigrationPeersFromBackup()
+        for (uri in peerUris) {
+            runCatching {
+                val peer = PeerDetails.of(uri)
+                lightningRepo.connectPeer(peer)
+            }.onFailure {
+                Logger.error("Failed to connect migration peer: $uri", it, context = TAG)
+            }
+        }
+    }
+
     fun stop() {
         if (!walletExists) return
 

app/src/test/java/to/bitkit/ui/WalletViewModelTest.kt

@@ -57,6 +57,7 @@ class WalletViewModelTest : BaseUnitTest() {
         whenever(walletRepo.walletState).thenReturn(walletState)
         whenever(lightningRepo.lightningState).thenReturn(lightningState)
         whenever(migrationService.isMigrationChecked()).thenReturn(true)
+        whenever(migrationService.tryFetchMigrationPeersFromBackup()).thenReturn(emptyList())
         whenever(connectivityRepo.isOnline).thenReturn(isOnline)
 
         sut = WalletViewModel(