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A Kotlin Multiplatform implementation of the Lightning Network
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package fr.acinq.lightning.payment
import fr.acinq.bitcoin.ByteVector32
import fr.acinq.bitcoin.utils.Either
import fr.acinq.bitcoin.utils.Try
import fr.acinq.lightning.*
import fr.acinq.lightning.channel.ChannelAction
import fr.acinq.lightning.channel.ChannelException
import fr.acinq.lightning.channel.states.Channel
import fr.acinq.lightning.channel.states.ChannelState
import fr.acinq.lightning.crypto.sphinx.FailurePacket
import fr.acinq.lightning.crypto.sphinx.SharedSecrets
import fr.acinq.lightning.db.HopDesc
import fr.acinq.lightning.db.LightningOutgoingPayment
import fr.acinq.lightning.db.OutgoingPaymentsDb
import fr.acinq.lightning.io.PayInvoice
import fr.acinq.lightning.io.WrappedChannelCommand
import fr.acinq.lightning.logging.MDCLogger
import fr.acinq.lightning.logging.error
import fr.acinq.lightning.logging.mdc
import fr.acinq.lightning.router.ChannelHop
import fr.acinq.lightning.router.NodeHop
import fr.acinq.lightning.utils.UUID
import fr.acinq.lightning.utils.msat
import fr.acinq.lightning.utils.sum
import fr.acinq.lightning.wire.*
class OutgoingPaymentHandler(val nodeParams: NodeParams, val walletParams: WalletParams, val db: OutgoingPaymentsDb) {
interface SendPaymentResult
interface ProcessFailureResult
interface ProcessFulfillResult
/** A payment attempt has been made: we provide information about the fees we're paying, which may increase as we re-try our payment. */
data class Progress(val request: PayInvoice, val fees: MilliSatoshi, val actions: List) : SendPaymentResult, ProcessFailureResult
/** The payment could not be sent. */
data class Failure(val request: PayInvoice, val failure: OutgoingPaymentFailure) : SendPaymentResult, ProcessFailureResult
/** The recipient released the preimage, but we are still waiting for some partial payments to settle. */
data class PreimageReceived(val request: PayInvoice, val preimage: ByteVector32) : ProcessFulfillResult
/** The payment was successfully made. */
data class Success(val request: PayInvoice, val payment: LightningOutgoingPayment, val preimage: ByteVector32) : ProcessFailureResult, ProcessFulfillResult
private val logger = nodeParams.loggerFactory.newLogger(this::class)
private val childToParentId = mutableMapOf()
private val pending = mutableMapOf()
private val routeCalculation = RouteCalculation(nodeParams.loggerFactory)
// NB: this function should only be used in tests.
fun getPendingPayment(parentId: UUID): PaymentAttempt? = pending[parentId]
private fun getPaymentAttempt(childId: UUID): PaymentAttempt? = childToParentId[childId]?.let { pending[it] }
suspend fun sendPayment(request: PayInvoice, channels: Map, currentBlockHeight: Int): SendPaymentResult {
val logger = MDCLogger(logger, staticMdc = request.mdc())
logger.info { "sending ${request.amount} to ${request.recipient}" }
if (request.amount <= 0.msat) {
logger.warning { "payment amount must be positive (${request.amount})" }
return Failure(request, FinalFailure.InvalidPaymentAmount.toPaymentFailure())
}
if (!nodeParams.features.areSupported(request.paymentDetails.paymentRequest.features.invoiceFeatures())) {
logger.warning { "invoice contains mandatory features that we don't support" }
return Failure(request, FinalFailure.FeaturesNotSupported.toPaymentFailure())
}
if (pending.containsKey(request.paymentId)) {
logger.error { "contract violation: caller is recycling uuid's" }
return Failure(request, FinalFailure.InvalidPaymentId.toPaymentFailure())
}
if (db.listLightningOutgoingPayments(request.paymentHash).find { it.status is LightningOutgoingPayment.Status.Completed.Succeeded } != null) {
logger.error { "invoice has already been paid" }
return Failure(request, FinalFailure.AlreadyPaid.toPaymentFailure())
}
val trampolineFees = request.trampolineFeesOverride ?: walletParams.trampolineFees
val (trampolineAmount, trampolineExpiry, trampolinePacket) = createTrampolinePayload(request, trampolineFees.first(), currentBlockHeight)
return when (val result = routeCalculation.findRoutes(request.paymentId, trampolineAmount, channels)) {
is Either.Left -> {
logger.warning { "payment failed: ${result.value}" }
db.addOutgoingPayment(LightningOutgoingPayment(request.paymentId, request.amount, request.recipient, request.paymentDetails))
val finalFailure = result.value
db.completeOutgoingPaymentOffchain(request.paymentId, finalFailure)
Failure(request, finalFailure.toPaymentFailure())
}
is Either.Right -> {
// We generate a random secret for this payment to avoid leaking the invoice secret to the trampoline node.
val trampolinePaymentSecret = Lightning.randomBytes32()
val trampolinePayload = PaymentAttempt.TrampolinePayload(trampolineAmount, trampolineExpiry, trampolinePaymentSecret, trampolinePacket)
val childPayments = createChildPayments(request, result.value, trampolinePayload)
db.addOutgoingPayment(LightningOutgoingPayment(request.paymentId, request.amount, request.recipient, request.paymentDetails, childPayments.map { it.first }, LightningOutgoingPayment.Status.Pending))
val payment = PaymentAttempt.PaymentInProgress(request, 0, trampolinePayload, childPayments.associate { it.first.id to Pair(it.first, it.second) }, setOf(), listOf())
pending[request.paymentId] = payment
Progress(request, payment.fees, childPayments.map { it.third })
}
}
}
private fun createChildPayments(request: PayInvoice, routes: List, trampolinePayload: PaymentAttempt.TrampolinePayload): List> {
val logger = MDCLogger(logger, staticMdc = request.mdc())
val childPayments = routes.map { createOutgoingPart(request, it, trampolinePayload) }
childToParentId.putAll(childPayments.map { it.first.id to request.paymentId })
childPayments.forEach { logger.info(mapOf("childPaymentId" to it.first.id)) { "sending ${it.first.amount} to channel ${it.third.channelId}" } }
return childPayments
}
suspend fun processAddFailed(channelId: ByteVector32, event: ChannelAction.ProcessCmdRes.AddFailed, channels: Map): ProcessFailureResult? {
val add = event.cmd
val payment = getPaymentAttempt(add.paymentId) ?: return processPostRestartFailure(add.paymentId, Either.Left(event.error))
val logger = MDCLogger(logger, staticMdc = mapOf("channelId" to channelId, "childPaymentId" to add.paymentId) + payment.request.mdc())
logger.debug { "could not send HTLC: ${event.error.message}" }
db.completeOutgoingLightningPart(add.paymentId, OutgoingPaymentFailure.convertFailure(Either.Left(event.error)))
val (updated, result) = when (payment) {
is PaymentAttempt.PaymentInProgress -> {
val ignore = payment.ignore + channelId // we ignore the failing channel in retries
when (val routes = routeCalculation.findRoutes(payment.request.paymentId, add.amount, channels - ignore)) {
is Either.Left -> PaymentAttempt.PaymentAborted(payment.request, routes.value, payment.pending, payment.failures).failChild(add.paymentId, Either.Left(event.error), db, logger)
is Either.Right -> {
val newPayments = createChildPayments(payment.request, routes.value, payment.trampolinePayload)
db.addOutgoingLightningParts(payment.request.paymentId, newPayments.map { it.first })
val updatedPayments = payment.pending - add.paymentId + newPayments.map { it.first.id to Pair(it.first, it.second) }
val updated = payment.copy(ignore = ignore, failures = payment.failures + Either.Left(event.error), pending = updatedPayments)
val result = Progress(payment.request, updated.fees, newPayments.map { it.third })
Pair(updated, result)
}
}
}
is PaymentAttempt.PaymentAborted -> payment.failChild(add.paymentId, Either.Left(event.error), db, logger)
is PaymentAttempt.PaymentSucceeded -> payment.failChild(add.paymentId, db, logger)
}
updateGlobalState(add.paymentId, updated)
return result
}
suspend fun processAddSettled(channelId: ByteVector32, event: ChannelAction.ProcessCmdRes.AddSettledFail, channels: Map, currentBlockHeight: Int): ProcessFailureResult? {
val payment = getPaymentAttempt(event.paymentId) ?: return processPostRestartFailure(event.paymentId, Either.Right(UnknownFailureMessage(0)))
val logger = MDCLogger(logger, staticMdc = mapOf("channelId" to channelId, "childPaymentId" to event.paymentId) + payment.request.mdc())
val failure: FailureMessage = when (event.result) {
is ChannelAction.HtlcResult.Fail.RemoteFail -> when (val part = payment.pending[event.paymentId]) {
null -> UnknownFailureMessage(0)
else -> when (val decrypted = FailurePacket.decrypt(event.result.fail.reason.toByteArray(), part.second)) {
is Try.Failure -> UnknownFailureMessage(1)
is Try.Success -> decrypted.result.failureMessage
}
}
else -> UnknownFailureMessage(FailureMessage.BADONION)
}
logger.debug { "HTLC failed: ${failure.message}" }
db.completeOutgoingLightningPart(event.paymentId, OutgoingPaymentFailure.convertFailure(Either.Right(failure)))
val (updated, result) = when (payment) {
is PaymentAttempt.PaymentInProgress -> {
val trampolineFees = payment.request.trampolineFeesOverride ?: walletParams.trampolineFees
val finalError = when {
trampolineFees.size <= payment.attemptNumber + 1 -> FinalFailure.RetryExhausted
failure == UnknownNextPeer -> FinalFailure.RecipientUnreachable
failure != TrampolineExpiryTooSoon && failure != TrampolineFeeInsufficient -> FinalFailure.UnknownError // non-retriable error
else -> null
}
if (finalError != null) {
PaymentAttempt.PaymentAborted(payment.request, finalError, payment.pending, listOf()).failChild(event.paymentId, Either.Right(failure), db, logger)
} else {
// The trampoline node is asking us to retry the payment with more fees.
logger.debug { "child payment failed because of fees" }
val updated = payment.copy(pending = payment.pending - event.paymentId)
if (updated.pending.isNotEmpty()) {
// We wait for all pending HTLCs to be settled before retrying.
// NB: we don't update failures here to avoid duplicate trampoline errors
Pair(updated, null)
} else {
val nextFees = trampolineFees[payment.attemptNumber + 1]
logger.info { "retrying payment with higher fees (base=${nextFees.feeBase}, proportional=${nextFees.feeProportional})..." }
val (trampolineAmount, trampolineExpiry, trampolinePacket) = createTrampolinePayload(payment.request, nextFees, currentBlockHeight)
when (val routes = routeCalculation.findRoutes(payment.request.paymentId, trampolineAmount, channels)) {
is Either.Left -> {
logger.warning { "payment failed: ${routes.value}" }
val aborted = PaymentAttempt.PaymentAborted(payment.request, routes.value, mapOf(), payment.failures + Either.Right(failure))
val result = Failure(payment.request, OutgoingPaymentFailure(aborted.reason, aborted.failures))
db.completeOutgoingPaymentOffchain(payment.request.paymentId, result.failure.reason)
Pair(aborted, result)
}
is Either.Right -> {
// We generate a random secret for this payment to avoid leaking the invoice secret to the trampoline node.
val trampolinePaymentSecret = Lightning.randomBytes32()
val trampolinePayload = PaymentAttempt.TrampolinePayload(trampolineAmount, trampolineExpiry, trampolinePaymentSecret, trampolinePacket)
val childPayments = createChildPayments(payment.request, routes.value, trampolinePayload)
db.addOutgoingLightningParts(payment.request.paymentId, childPayments.map { it.first })
val newAttempt = PaymentAttempt.PaymentInProgress(
payment.request,
payment.attemptNumber + 1,
trampolinePayload,
childPayments.associate { it.first.id to Pair(it.first, it.second) },
setOf(), // we reset ignored channels
payment.failures + Either.Right(failure)
)
val result = Progress(newAttempt.request, newAttempt.fees, childPayments.map { it.third })
Pair(newAttempt, result)
}
}
}
}
}
is PaymentAttempt.PaymentAborted -> payment.failChild(event.paymentId, Either.Right(failure), db, logger)
is PaymentAttempt.PaymentSucceeded -> payment.failChild(event.paymentId, db, logger)
}
updateGlobalState(event.paymentId, updated)
return result
}
private suspend fun processPostRestartFailure(partId: UUID, failure: Either): ProcessFailureResult? {
when (val payment = db.getLightningOutgoingPaymentFromPartId(partId)) {
null -> {
logger.error { "paymentId=$partId doesn't match any known payment attempt" }
return null
}
else -> {
val logger = MDCLogger(logger, staticMdc = mapOf("childPaymentId" to partId) + payment.mdc())
logger.debug { "could not send HTLC (wallet restart): ${failure.fold({ it.message }, { it.message })}" }
val status = LightningOutgoingPayment.Part.Status.Failed(OutgoingPaymentFailure.convertFailure(failure))
db.completeOutgoingLightningPart(partId, status.failure)
val hasMorePendingParts = payment.parts.any { it.status == LightningOutgoingPayment.Part.Status.Pending && it.id != partId }
return if (!hasMorePendingParts) {
logger.warning { "payment failed: ${FinalFailure.WalletRestarted}" }
db.completeOutgoingPaymentOffchain(payment.id, FinalFailure.WalletRestarted)
val request = when (payment.details) {
is LightningOutgoingPayment.Details.Normal -> PayInvoice(payment.id, payment.recipientAmount, payment.details)
else -> {
logger.debug { "cannot recreate send-payment-request failure from db data with details=${payment.details}" }
return null
}
}
Failure(
request = request,
failure = OutgoingPaymentFailure(
reason = FinalFailure.WalletRestarted,
failures = payment.parts.map { it.status }.filterIsInstance() + status
)
)
} else {
null
}
}
}
}
suspend fun processAddSettled(event: ChannelAction.ProcessCmdRes.AddSettledFulfill): ProcessFulfillResult? {
val preimage = event.result.paymentPreimage
val payment = getPaymentAttempt(event.paymentId) ?: return processPostRestartFulfill(event.paymentId, preimage)
val logger = MDCLogger(logger, staticMdc = mapOf("childPaymentId" to event.paymentId) + payment.request.mdc())
logger.debug { "HTLC fulfilled" }
val part = payment.pending[event.paymentId]?.first?.copy(status = LightningOutgoingPayment.Part.Status.Succeeded(preimage))
db.completeOutgoingLightningPart(event.paymentId, preimage)
val updated = when (payment) {
is PaymentAttempt.PaymentInProgress -> PaymentAttempt.PaymentSucceeded(payment.request, preimage, part?.let { listOf(it) } ?: listOf(), payment.pending - event.paymentId)
is PaymentAttempt.PaymentSucceeded -> payment.copy(pending = payment.pending - event.paymentId, parts = part?.let { payment.parts + it } ?: payment.parts)
is PaymentAttempt.PaymentAborted -> {
// The recipient released the preimage without receiving the full payment amount.
// This is a spec violation and is too bad for them, we obtained a proof of payment without paying the full amount.
logger.warning { "payment succeeded after partial failure: we may have paid less than the full amount" }
PaymentAttempt.PaymentSucceeded(payment.request, preimage, part?.let { listOf(it) } ?: listOf(), payment.pending - event.paymentId)
}
}
updateGlobalState(event.paymentId, updated)
return if (updated.isComplete()) {
logger.info { "payment successfully sent (fees=${updated.fees})" }
db.completeOutgoingPaymentOffchain(payment.request.paymentId, preimage)
val r = payment.request
Success(r, LightningOutgoingPayment(r.paymentId, r.amount, r.recipient, r.paymentDetails, updated.parts, LightningOutgoingPayment.Status.Completed.Succeeded.OffChain(preimage)), preimage)
} else {
PreimageReceived(payment.request, preimage)
}
}
private suspend fun processPostRestartFulfill(partId: UUID, preimage: ByteVector32): ProcessFulfillResult? {
when (val payment = db.getLightningOutgoingPaymentFromPartId(partId)) {
null -> {
logger.error { "paymentId=$partId doesn't match any known payment attempt" }
return null
}
else -> {
val logger = MDCLogger(logger, staticMdc = mapOf("childPaymentId" to partId) + payment.mdc())
logger.debug { "HTLC succeeded (wallet restart): $preimage" }
db.completeOutgoingLightningPart(partId, preimage)
// We try to re-create the request from what we have in the DB.
val request = when (payment.details) {
is LightningOutgoingPayment.Details.Normal -> PayInvoice(payment.id, payment.recipientAmount, payment.details)
else -> {
logger.warning { "cannot recreate send-payment-request fulfill from db data with details=${payment.details}" }
return null
}
}
val hasMorePendingParts = payment.parts.any { it.status == LightningOutgoingPayment.Part.Status.Pending && it.id != partId }
return if (!hasMorePendingParts) {
logger.info { "payment successfully sent (wallet restart)" }
db.completeOutgoingPaymentOffchain(payment.id, preimage)
// NB: we reload the payment to ensure all parts status are updated
// this payment cannot be null
val succeeded = db.getLightningOutgoingPayment(payment.id)!!
Success(request, succeeded, preimage)
} else {
PreimageReceived(request, preimage)
}
}
}
}
private fun updateGlobalState(processedChildId: UUID, updatedPayment: PaymentAttempt) {
childToParentId.remove(processedChildId)
if (updatedPayment.isComplete()) {
pending.remove(updatedPayment.request.paymentId)
} else {
pending[updatedPayment.request.paymentId] = updatedPayment
}
}
private fun createOutgoingPart(request: PayInvoice, route: RouteCalculation.Route, trampolinePayload: PaymentAttempt.TrampolinePayload): Triple {
val childId = UUID.randomUUID()
val outgoingPayment = LightningOutgoingPayment.Part(
id = childId,
amount = route.amount,
route = listOf(HopDesc(nodeParams.nodeId, route.channel.commitments.remoteNodeId, route.channel.shortChannelId), HopDesc(route.channel.commitments.remoteNodeId, request.recipient)),
status = LightningOutgoingPayment.Part.Status.Pending
)
val channelHops: List = listOf(ChannelHop(nodeParams.nodeId, route.channel.commitments.remoteNodeId, route.channel.channelUpdate))
val (cmdAdd, secrets) = OutgoingPaymentPacket.buildCommand(childId, request.paymentHash, channelHops, trampolinePayload.createFinalPayload(route.amount))
return Triple(outgoingPayment, secrets, WrappedChannelCommand(route.channel.channelId, cmdAdd))
}
private fun createTrampolinePayload(request: PayInvoice, fees: TrampolineFees, currentBlockHeight: Int): Triple {
// We are either directly paying our peer (the trampoline node) or a remote node via our peer (using trampoline).
val trampolineRoute = when (request.recipient) {
walletParams.trampolineNode.id -> listOf(
NodeHop(nodeParams.nodeId, request.recipient, /* ignored */ CltvExpiryDelta(0), /* ignored */ 0.msat)
)
else -> listOf(
NodeHop(nodeParams.nodeId, walletParams.trampolineNode.id, /* ignored */ CltvExpiryDelta(0), /* ignored */ 0.msat),
NodeHop(walletParams.trampolineNode.id, request.recipient, fees.cltvExpiryDelta, fees.calculateFees(request.amount))
)
}
when (val paymentRequest = request.paymentDetails.paymentRequest) {
is Bolt11Invoice -> {
val minFinalExpiryDelta = paymentRequest.minFinalExpiryDelta ?: Channel.MIN_CLTV_EXPIRY_DELTA
val finalExpiry = nodeParams.paymentRecipientExpiryParams.computeFinalExpiry(currentBlockHeight, minFinalExpiryDelta)
val finalPayload = PaymentOnion.FinalPayload.Standard.createSinglePartPayload(request.amount, finalExpiry, paymentRequest.paymentSecret, paymentRequest.paymentMetadata)
val invoiceFeatures = paymentRequest.features
val (trampolineAmount, trampolineExpiry, trampolineOnion) = if (invoiceFeatures.hasFeature(Feature.TrampolinePayment) || invoiceFeatures.hasFeature(Feature.ExperimentalTrampolinePayment)) {
// We may be paying an older version of lightning-kmp that only supports trampoline packets of size 400.
OutgoingPaymentPacket.buildPacket(request.paymentHash, trampolineRoute, finalPayload, 400)
} else {
OutgoingPaymentPacket.buildTrampolineToNonTrampolinePacket(paymentRequest, trampolineRoute, finalPayload)
}
return Triple(trampolineAmount, trampolineExpiry, trampolineOnion.packet)
}
is Bolt12Invoice -> {
val finalExpiry = nodeParams.paymentRecipientExpiryParams.computeFinalExpiry(currentBlockHeight, CltvExpiryDelta(0))
val (trampolineAmount, trampolineExpiry, trampolineOnion) = OutgoingPaymentPacket.buildTrampolineToNonTrampolinePacket(paymentRequest, trampolineRoute.last(), request.amount, finalExpiry)
return Triple(trampolineAmount, trampolineExpiry, trampolineOnion.packet)
}
}
}
sealed class PaymentAttempt {
abstract val request: PayInvoice
abstract val pending: Map>
abstract val fees: MilliSatoshi
fun isComplete(): Boolean = pending.isEmpty()
/**
* @param totalAmount total amount that the trampoline node should receive.
* @param expiry expiry at the trampoline node.
* @param paymentSecret trampoline payment secret (should be different from the invoice payment secret).
* @param packet trampoline onion packet.
*/
data class TrampolinePayload(val totalAmount: MilliSatoshi, val expiry: CltvExpiry, val paymentSecret: ByteVector32, val packet: OnionRoutingPacket) {
fun createFinalPayload(partialAmount: MilliSatoshi): PaymentOnion.FinalPayload = PaymentOnion.FinalPayload.Standard.createTrampolinePayload(partialAmount, totalAmount, expiry, paymentSecret, packet)
}
/**
* While a payment is in progress, we listen to child payments failures.
* When we receive failures, we retry the failed amount with different routes/fees.
*
* @param request payment request containing the total amount to send.
* @param attemptNumber number of failed previous payment attempts.
* @param trampolinePayload trampoline payload for the current payment attempt.
* @param pending pending child payments (HTLCs were sent, we are waiting for a fulfill or a failure).
* @param ignore channels that should be ignored (previously returned an error).
* @param failures previous child payment failures.
*/
data class PaymentInProgress(
override val request: PayInvoice,
val attemptNumber: Int,
val trampolinePayload: TrampolinePayload,
override val pending: Map>,
val ignore: Set,
val failures: List>
) : PaymentAttempt() {
override val fees: MilliSatoshi = pending.values.map { it.first.amount }.sum() - request.amount
}
/**
* When we exhaust our retry attempts without success or encounter a non-recoverable error, we abort the payment.
* Once we're in that state, we wait for all the pending child payments to settle.
*
* @param request payment request containing the total amount to send.
* @param reason failure reason.
* @param pending pending child payments (we are waiting for them to be failed downstream).
* @param failures child payment failures.
*/
data class PaymentAborted(
override val request: PayInvoice,
val reason: FinalFailure,
override val pending: Map>,
val failures: List>
) : PaymentAttempt() {
override val fees: MilliSatoshi = 0.msat
suspend fun failChild(childId: UUID, failure: Either, db: OutgoingPaymentsDb, logger: MDCLogger): Pair {
val updated = copy(pending = pending - childId, failures = failures + failure)
val result = if (updated.isComplete()) {
logger.warning { "payment failed: ${updated.reason}" }
db.completeOutgoingPaymentOffchain(request.paymentId, updated.reason)
Failure(request, OutgoingPaymentFailure(updated.reason, updated.failures))
} else {
null
}
return Pair(updated, result)
}
}
/**
* Once we receive a first fulfill for a child payment, we can consider that the whole payment succeeded (because we
* received the payment preimage that we can use as a proof of payment).
* Once we're in that state, we wait for all the pending child payments to fulfill.
*
* @param request payment request containing the total amount to send.
* @param preimage payment preimage.
* @param parts fulfilled child payments.
* @param pending pending child payments (we are waiting for them to be fulfilled downstream).
*/
data class PaymentSucceeded(
override val request: PayInvoice,
val preimage: ByteVector32,
val parts: List,
override val pending: Map>
) : PaymentAttempt() {
override val fees: MilliSatoshi = parts.map { it.amount }.sum() + pending.values.map { it.first.amount }.sum() - request.amount
// The recipient released the preimage without receiving the full payment amount.
// This is a spec violation and is too bad for them, we obtained a proof of payment without paying the full amount.
suspend fun failChild(childId: UUID, db: OutgoingPaymentsDb, logger: MDCLogger): Pair {
logger.warning { "partial payment failure after fulfill: we may have paid less than the full amount" }
val updated = copy(pending = pending - childId)
val result = if (updated.isComplete()) {
logger.info { "payment successfully sent (fees=${updated.fees})" }
db.completeOutgoingPaymentOffchain(request.paymentId, preimage)
Success(request, LightningOutgoingPayment(request.paymentId, request.amount, request.recipient, request.paymentDetails, parts, LightningOutgoingPayment.Status.Completed.Succeeded.OffChain(preimage)), preimage)
} else {
null
}
return Pair(updated, result)
}
}
}
}