feat: add boltz savings swap

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

@@ -0,0 +1,202 @@
+package to.bitkit.services
+
+import com.synonym.bitkitcore.BoltzEventListener
+import com.synonym.bitkitcore.BoltzNetwork
+import com.synonym.bitkitcore.BoltzPairInfo
+import com.synonym.bitkitcore.BoltzSwap
+import com.synonym.bitkitcore.BoltzSwapEvent
+import com.synonym.bitkitcore.ReverseSwapResponse
+import com.synonym.bitkitcore.SubmarineSwapResponse
+import com.synonym.bitkitcore.boltzClaimReverseSwap
+import com.synonym.bitkitcore.boltzCreateReverseSwap
+import com.synonym.bitkitcore.boltzCreateSubmarineSwap
+import com.synonym.bitkitcore.boltzGetReverseLimits
+import com.synonym.bitkitcore.boltzGetSubmarineLimits
+import com.synonym.bitkitcore.boltzGetSwap
+import com.synonym.bitkitcore.boltzListPendingSwaps
+import com.synonym.bitkitcore.boltzListSwaps
+import com.synonym.bitkitcore.boltzRefundSubmarineSwap
+import com.synonym.bitkitcore.boltzStartSwapUpdates
+import com.synonym.bitkitcore.boltzStopSwapUpdates
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.asSharedFlow
+import kotlinx.coroutines.flow.first
+import org.lightningdevkit.ldknode.Network
+import to.bitkit.data.SettingsStore
+import to.bitkit.data.keychain.Keychain
+import to.bitkit.env.Env
+import to.bitkit.utils.Logger
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Thin wrapper around the bitkit-core Boltz swaps FFI (submarine + reverse swaps
+ * between onchain Bitcoin and Lightning).
+ *
+ * Mirrors the existing service pattern (e.g. [TrezorService]): a Hilt singleton
+ * that wraps the FFI and bridges the [BoltzEventListener] foreign callback to a
+ * [SharedFlow]. bitkit-core persists only a derivation index, never key material;
+ * swap keys are re-derived on demand from the wallet mnemonic.
+ *
+ * The Lightning side (issuing/paying invoices, fresh onchain addresses) is owned
+ * by [LightningService]; this service only talks to Boltz + the chain.
+ */
+@Suppress("TooManyFunctions")
+@Singleton
+class BoltzService @Inject constructor(
+    private val keychain: Keychain,
+    private val settingsStore: SettingsStore,
+) {
+    private val _events = MutableSharedFlow<BoltzSwapEvent>(extraBufferCapacity = 64)
+
+    /** Swap lifecycle events emitted while the updates stream is running. */
+    val events: SharedFlow<BoltzSwapEvent> = _events.asSharedFlow()
+
+    private val listener = object : BoltzEventListener {
+        override fun onEvent(event: BoltzSwapEvent) {
+            Logger.info("Boltz event: $event", context = TAG)
+            _events.tryEmit(event)
+        }
+    }
+
+    // region Limits
+
+    suspend fun submarineLimits(network: BoltzNetwork = boltzNetwork()): BoltzPairInfo =
+        boltzGetSubmarineLimits(network = network)
+
+    suspend fun reverseLimits(network: BoltzNetwork = boltzNetwork()): BoltzPairInfo =
+        boltzGetReverseLimits(network = network)
+
+    // endregion
+
+    // region Create
+
+    /** Submarine swap: onchain BTC -> Lightning. Fund the returned lockup address. */
+    suspend fun createSubmarineSwap(
+        invoice: String,
+        network: BoltzNetwork = boltzNetwork(),
+        electrumUrl: String? = null,
+    ): SubmarineSwapResponse {
+        val (mnemonic, passphrase) = credentials()
+        return boltzCreateSubmarineSwap(
+            network = network,
+            electrumUrl = electrumUrl ?: electrumUrl(),
+            invoice = invoice,
+            mnemonic = mnemonic,
+            bip39Passphrase = passphrase,
+        ).also { Logger.info("Created Boltz submarine swap ${it.id}", context = TAG) }
+    }
+
+    /** Reverse swap: Lightning -> onchain BTC. Pay the returned hold invoice. */
+    suspend fun createReverseSwap(
+        amountSat: ULong,
+        claimAddress: String,
+        network: BoltzNetwork = boltzNetwork(),
+        electrumUrl: String? = null,
+    ): ReverseSwapResponse {
+        val (mnemonic, passphrase) = credentials()
+        return boltzCreateReverseSwap(
+            network = network,
+            electrumUrl = electrumUrl ?: electrumUrl(),
+            amountSat = amountSat,
+            claimAddress = claimAddress,
+            mnemonic = mnemonic,
+            bip39Passphrase = passphrase,
+        ).also { Logger.info("Created Boltz reverse swap ${it.id}", context = TAG) }
+    }
+
+    // endregion
+
+    // region Query
+
+    suspend fun listSwaps(): List<BoltzSwap> = boltzListSwaps()
+
+    suspend fun listPendingSwaps(): List<BoltzSwap> = boltzListPendingSwaps()
+
+    suspend fun getSwap(id: String): BoltzSwap? = boltzGetSwap(swapId = id)
+
+    // endregion
+
+    // region Manual claim / refund
+
+    suspend fun claimReverseSwap(id: String, feeRateSatPerVb: Double? = null): String {
+        val (mnemonic, passphrase) = credentials()
+        return boltzClaimReverseSwap(
+            swapId = id,
+            mnemonic = mnemonic,
+            bip39Passphrase = passphrase,
+            feeRateSatPerVb = feeRateSatPerVb,
+        )
+    }
+
+    suspend fun refundSubmarineSwap(id: String, refundAddress: String, feeRateSatPerVb: Double? = null): String {
+        val (mnemonic, passphrase) = credentials()
+        return boltzRefundSubmarineSwap(
+            swapId = id,
+            refundAddress = refundAddress,
+            mnemonic = mnemonic,
+            bip39Passphrase = passphrase,
+            feeRateSatPerVb = feeRateSatPerVb,
+        )
+    }
+
+    // endregion
+
+    // region Updates stream
+
+    /**
+     * Open the Boltz updates WebSocket, subscribe all pending swaps and auto-claim
+     * confirmed reverse swaps. [feeRateSatPerVb] is the rate used for those
+     * auto-claims (Bitkit owns fee estimation). Replaces any running stream.
+     */
+    suspend fun startUpdates(
+        feeRateSatPerVb: Double?,
+        network: BoltzNetwork = boltzNetwork(),
+    ) {
+        val (mnemonic, passphrase) = credentials()
+        boltzStartSwapUpdates(
+            network = network,
+            listener = listener,
+            mnemonic = mnemonic,
+            bip39Passphrase = passphrase,
+            feeRateSatPerVb = feeRateSatPerVb,
+        )
+        Logger.info("Started Boltz updates stream on $network", context = TAG)
+    }
+
+    suspend fun stopUpdates() {
+        boltzStopSwapUpdates()
+        Logger.info("Stopped Boltz updates stream", context = TAG)
+    }
+
+    // endregion
+
+    // region Helpers
+
+    /** The Boltz network matching the app's configured network. */
+    fun boltzNetwork(network: Network = Env.network): BoltzNetwork = when (network) {
+        Network.BITCOIN -> BoltzNetwork.MAINNET
+        Network.TESTNET -> BoltzNetwork.TESTNET
+        Network.REGTEST -> BoltzNetwork.REGTEST
+        // Boltz does not operate on signet; fall back to testnet for development.
+        else -> BoltzNetwork.TESTNET
+    }
+
+    /** Current Electrum URL, used by Boltz for claim/refund broadcasting. */
+    suspend fun electrumUrl(): String = settingsStore.data.first().electrumServer
+
+    private suspend fun credentials(): Pair<String, String?> {
+        val mnemonic = keychain.loadString(Keychain.Key.BIP39_MNEMONIC.name)
+            ?: error("Mnemonic not found")
+        val passphrase = keychain.loadString(Keychain.Key.BIP39_PASSPHRASE.name)
+            ?.takeIf { it.isNotEmpty() }
+        return mnemonic to passphrase
+    }
+
+    // endregion
+
+    companion object {
+        private const val TAG = "BoltzService"
+    }
+}

app/src/main/java/to/bitkit/ui/ContentView.kt

@@ -155,6 +155,8 @@ import to.bitkit.ui.settings.LogDetailScreen
 import to.bitkit.ui.settings.LogsScreen
 import to.bitkit.ui.settings.OrderDetailScreen
 import to.bitkit.ui.settings.SettingsScreen
+import to.bitkit.ui.settings.SwapDetailScreen
+import to.bitkit.ui.settings.SwapsScreen
 import to.bitkit.ui.settings.advanced.AddressTypePreferenceScreen
 import to.bitkit.ui.settings.advanced.AddressViewerScreen
 import to.bitkit.ui.settings.advanced.CoinSelectPreferenceScreen
@@ -688,6 +690,8 @@ private fun RootNavHost(
         channelOrdersSettings(navController)
         orderDetailSettings(navController)
         cjitDetailSettings(navController)
+        swapsSettings(navController)
+        swapDetailSettings(navController)
         lightningConnections(navController)
         activityItem(activityListViewModel, navController, settingsViewModel)
         authCheck(navController)
@@ -1564,6 +1568,28 @@ private fun NavGraphBuilder.cjitDetailSettings(
     }
 }
 
+private fun NavGraphBuilder.swapsSettings(
+    navController: NavHostController,
+) {
+    composableWithDefaultTransitions<Routes.SwapsSettings> {
+        SwapsScreen(
+            onBackClick = { navController.popBackStack() },
+            onSwapItemClick = { navController.navigateToSwapDetail(it) },
+        )
+    }
+}
+
+private fun NavGraphBuilder.swapDetailSettings(
+    navController: NavHostController,
+) {
+    composableWithDefaultTransitions<Routes.SwapDetail> {
+        SwapDetailScreen(
+            swapItem = it.toRoute(),
+            onBackClick = { navController.popBackStack() },
+        )
+    }
+}
+
 private fun NavGraphBuilder.lightningConnections(
     navController: NavHostController,
 ) {
@@ -1824,6 +1850,7 @@ fun NavController.navigateToLocalCurrencySettings() = navigateTo(Routes.LocalCur
 fun NavController.navigateToBackupSettings() = navigateTo(Routes.BackupSettings)
 
 fun NavController.navigateToOrderDetail(id: String) = navigateTo(Routes.OrderDetail(id))
+fun NavController.navigateToSwapDetail(id: String) = navigateTo(Routes.SwapDetail(id))
 
 fun NavController.navigateToCjitDetail(id: String) = navigateTo(Routes.CjitDetail(id))
 
@@ -1960,6 +1987,12 @@ sealed interface Routes {
     @Serializable
     data object ChannelOrdersSettings : Routes
 
+    @Serializable
+    data object SwapsSettings : Routes
+
+    @Serializable
+    data class SwapDetail(val id: String) : Routes
+
     @Serializable
     data object Logs : Routes