Include local mining fees for pure liquidity purchases

src/commonMain/kotlin/fr/acinq/lightning/channel/ChannelAction.kt

@@ -88,7 +88,7 @@ sealed class ChannelAction {
             abstract val txId: TxId
             data class ViaSpliceOut(val amount: Satoshi, override val miningFees: Satoshi, val address: String, override val txId: TxId) : StoreOutgoingPayment()
             data class ViaSpliceCpfp(override val miningFees: Satoshi, override val txId: TxId) : StoreOutgoingPayment()
-            data class ViaInboundLiquidityRequest(override val txId: TxId, val purchase: LiquidityAds.Purchase) : StoreOutgoingPayment() { override val miningFees: Satoshi = purchase.fees.miningFee }
+            data class ViaInboundLiquidityRequest(override val txId: TxId, val localMiningFees: Satoshi, val purchase: LiquidityAds.Purchase) : StoreOutgoingPayment() { override val miningFees: Satoshi = localMiningFees + purchase.fees.miningFee }
             data class ViaClose(val amount: Satoshi, override val miningFees: Satoshi, val address: String, override val txId: TxId, val isSentToDefaultAddress: Boolean, val closingType: ChannelClosingType) : StoreOutgoingPayment()
         }
         data class SetLocked(val txId: TxId) : Storage()

src/commonMain/kotlin/fr/acinq/lightning/channel/states/Normal.kt

@@ -874,14 +874,22 @@ data class Normal(
             action.fundingTx.signedTx?.let { add(ChannelAction.Blockchain.PublishTx(it, ChannelAction.Blockchain.PublishTx.Type.FundingTx)) }
             add(ChannelAction.Blockchain.SendWatch(watchConfirmed))
             add(ChannelAction.Message.Send(action.localSigs))
-            // If we purchased liquidity as part of the channel creation, we will add it to our payments db
+            // If we purchased liquidity as part of the splice, we will add it to our payments db.
             liquidityPurchase?.let { purchase ->
-                // We only count fees corresponding to the liquidity purchase (i.e. their inputs).
-                add(ChannelAction.Storage.StoreOutgoingPayment.ViaInboundLiquidityRequest(txId = action.fundingTx.txId, purchase = purchase))
+                // If we are purchasing liquidity without any other operation (splice-in, splice-out or splice-cpfp),
+                // we must include the mining fees we're paying for the shared input and shared output.
+                // Otherwise, we only count the mining fees that we must refund to our peer as part of the liquidity
+                // purchase: the mining fees we pay for our inputs/outputs and the shared input/output will be recorded
+                // in the dedicated splice entry below.
+                val isPurchaseOnly = action.fundingTx.sharedTx.tx.let {
+                    action.fundingTx.fundingParams.isInitiator && it.localInputs.isEmpty() && it.localOutputs.isEmpty() && it.remoteInputs.isNotEmpty()
+                }
+                val localMiningFees = if (isPurchaseOnly) action.fundingTx.sharedTx.tx.localFees.truncateToSatoshi() else 0.sat
+                add(ChannelAction.Storage.StoreOutgoingPayment.ViaInboundLiquidityRequest(txId = action.fundingTx.txId, localMiningFees = localMiningFees, purchase = purchase))
                 add(ChannelAction.EmitEvent(LiquidityEvents.Purchased(purchase)))
             }
-            // NB: the following assume that there can't be a splice-in and a splice-out simultaneously, because we attribute
-            // all local mining fees to both.
+            // NB: the following assumes that there can't be a splice-in and a splice-out simultaneously,
+            // or more than one splice-out, because we attribute all local mining fees to each payment entry.
             if (action.fundingTx.sharedTx.tx.localInputs.isNotEmpty()) add(
                 ChannelAction.Storage.StoreIncomingPayment.ViaSpliceIn(
                     amountReceived = action.fundingTx.sharedTx.tx.localInputs.map { i -> i.txOut.amount }.sum().toMilliSatoshi() - action.fundingTx.sharedTx.tx.localFees,
@@ -900,7 +908,7 @@ data class Normal(
                     txId = action.fundingTx.txId
                 )
             })
-            // If we initiated the splice but there are no new inputs on either side and no new output on our side, it's a cpfp
+            // If we initiated the splice but there are no new inputs on either side and no new output on our side, it's a cpfp.
             if (action.fundingTx.fundingParams.isInitiator && action.fundingTx.sharedTx.tx.localInputs.isEmpty() && action.fundingTx.sharedTx.tx.remoteInputs.isEmpty() && action.fundingTx.fundingParams.localOutputs.isEmpty()) {
                 add(ChannelAction.Storage.StoreOutgoingPayment.ViaSpliceCpfp(miningFees = action.fundingTx.sharedTx.tx.localFees.truncateToSatoshi(), txId = action.fundingTx.txId))
             }

src/commonMain/kotlin/fr/acinq/lightning/channel/states/WaitForFundingSigned.kt

@@ -10,7 +10,7 @@ import fr.acinq.lightning.blockchain.WatchConfirmed
 import fr.acinq.lightning.channel.*
 import fr.acinq.lightning.crypto.ShaChain
 import fr.acinq.lightning.utils.msat
-import fr.acinq.lightning.utils.toMilliSatoshi
+import fr.acinq.lightning.utils.sat
 import fr.acinq.lightning.wire.*
 import kotlin.math.absoluteValue
 
@@ -119,21 +119,23 @@ data class WaitForFundingSigned(
             action.fundingTx.signedTx?.let { add(ChannelAction.Blockchain.PublishTx(it, ChannelAction.Blockchain.PublishTx.Type.FundingTx)) }
             add(ChannelAction.Blockchain.SendWatch(watchConfirmed))
             add(ChannelAction.Message.Send(action.localSigs))
-            // If we purchased liquidity as part of the channel creation, we will add it to our payments db
+            // If we purchased liquidity as part of the channel creation, we will add it to our payments db.
             liquidityPurchase?.let { purchase ->
                 if (channelParams.localParams.isChannelOpener) {
-                    // We only count fees corresponding to the liquidity purchase (i.e. their inputs).
-                    add(ChannelAction.Storage.StoreOutgoingPayment.ViaInboundLiquidityRequest(txId = action.fundingTx.txId, purchase = purchase))
+                    // We only count the mining fees that we must refund to our peer as part of the liquidity purchase.
+                    // If we're also contributing to the funding transaction, the mining fees we pay for our inputs and
+                    // outputs will be recorded in the ViaNewChannel incoming payment entry below.
+                    add(ChannelAction.Storage.StoreOutgoingPayment.ViaInboundLiquidityRequest(txId = action.fundingTx.txId, localMiningFees = 0.sat, purchase = purchase))
                     add(ChannelAction.EmitEvent(LiquidityEvents.Purchased(purchase)))
                 }
             }
-            // If we receive funds as part of the channel creation, we will add it to our payments db
+            // If we receive funds as part of the channel creation, we will add it to our payments db.
             if (action.commitment.localCommit.spec.toLocal > 0.msat) add(
-                // We only count the mining fees corresponding to the inputs and outputs we paid for in the interactive-tx transaction
-                // (i.e. our wallet inputs and the shared output).
                 ChannelAction.Storage.StoreIncomingPayment.ViaNewChannel(
                     amountReceived = action.commitment.localCommit.spec.toLocal,
                     serviceFee = 0.msat,
+                    // We only count the mining fees we're paying for our inputs and outputs.
+                    // The mining fees for the remote inputs and outputs are paid by the remote node.
                     miningFee = action.fundingTx.sharedTx.tx.localFees.truncateToSatoshi(),
                     localInputs = action.fundingTx.sharedTx.tx.localInputs.map { it.outPoint }.toSet(),
                     txId = action.fundingTx.txId,

src/commonMain/kotlin/fr/acinq/lightning/db/PaymentsDb.kt

@@ -177,7 +177,7 @@ data class IncomingPayment(val preimage: ByteVector32, val origin: Origin, val r
         }
 
         /**
-         * Payment was added to our fee credit for future on-chain operations (see [Feature.FundingFeeCredit]).
+         * Payment was added to our fee credit for future on-chain operations (see [fr.acinq.lightning.Feature.FundingFeeCredit]).
          * We didn't really receive this amount yet, but we trust our peer to use it for future on-chain operations.
          */
         data class AddedToFeeCredit(override val amountReceived: MilliSatoshi) : ReceivedWith() {
@@ -427,14 +427,15 @@ data class InboundLiquidityOutgoingPayment(
     override val id: UUID,
     override val channelId: ByteVector32,
     override val txId: TxId,
+    val localMiningFees: Satoshi,
     val purchase: LiquidityAds.Purchase,
     override val createdAt: Long,
     override val confirmedAt: Long?,
     override val lockedAt: Long?,
 ) : OnChainOutgoingPayment() {
-    override val miningFees: Satoshi = purchase.fees.miningFee
+    override val miningFees: Satoshi = localMiningFees + purchase.fees.miningFee
     val serviceFees: Satoshi = purchase.fees.serviceFee
-    override val fees: MilliSatoshi = purchase.fees.total.toMilliSatoshi()
+    override val fees: MilliSatoshi = (localMiningFees + purchase.fees.total).toMilliSatoshi()
     override val amount: MilliSatoshi = fees
     override val completedAt: Long? = lockedAt
     val fundingFee: LiquidityAds.FundingFee = LiquidityAds.FundingFee(purchase.fees.total.toMilliSatoshi(), txId)

src/commonMain/kotlin/fr/acinq/lightning/io/Peer.kt

@@ -887,6 +887,7 @@ class Peer(
                                     id = UUID.randomUUID(),
                                     channelId = channelId,
                                     txId = action.txId,
+                                    localMiningFees = action.localMiningFees,
                                     purchase = action.purchase,
                                     createdAt = currentTimestampMillis(),
                                     confirmedAt = null,

src/commonTest/kotlin/fr/acinq/lightning/payment/IncomingPaymentHandlerTestsCommon.kt

@@ -863,7 +863,7 @@ class IncomingPaymentHandlerTestsCommon : LightningTestSuite() {
                 splice.fees(TestConstants.feeratePerKw, isChannelCreation = false),
                 LiquidityAds.PaymentDetails.FromFutureHtlc(listOf(incomingPayment.paymentHash)),
             )
-            val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), purchase, 0, null, null)
+            val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), 0.sat, purchase, 0, null, null)
             paymentHandler.db.addOutgoingPayment(payment)
             payment
         }
@@ -911,7 +911,7 @@ class IncomingPaymentHandlerTestsCommon : LightningTestSuite() {
                 splice.fees(TestConstants.feeratePerKw, isChannelCreation = false),
                 LiquidityAds.PaymentDetails.FromChannelBalanceForFutureHtlc(listOf(incomingPayment.paymentHash)),
             )
-            val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), purchase, 0, null, null)
+            val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), 500.sat, purchase, 0, null, null)
             paymentHandler.db.addOutgoingPayment(payment)
             payment
         }
@@ -963,7 +963,7 @@ class IncomingPaymentHandlerTestsCommon : LightningTestSuite() {
             LiquidityAds.Fees(2000.sat, 3000.sat),
             LiquidityAds.PaymentDetails.FromFutureHtlc(listOf(incomingPayment.paymentHash)),
         )
-        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), purchase, 0, null, null)
+        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), 100.sat, purchase, 0, null, null)
         paymentHandler.db.addOutgoingPayment(payment)
 
         run {
@@ -999,7 +999,7 @@ class IncomingPaymentHandlerTestsCommon : LightningTestSuite() {
             LiquidityAds.Fees(2000.sat, 3000.sat),
             LiquidityAds.PaymentDetails.FromChannelBalanceForFutureHtlc(listOf(incomingPayment.paymentHash)),
         )
-        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), purchase, 0, null, null)
+        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), 0.sat, purchase, 0, null, null)
         paymentHandler.db.addOutgoingPayment(payment)
 
         val add = makeUpdateAddHtlc(0, channelId, paymentHandler, incomingPayment.paymentHash, makeMppPayload(defaultAmount, defaultAmount, paymentSecret), fundingFee = payment.fundingFee)
@@ -1022,7 +1022,7 @@ class IncomingPaymentHandlerTestsCommon : LightningTestSuite() {
             250_000.msat,
             LiquidityAds.PaymentDetails.FromFutureHtlc(listOf(randomBytes32())),
         )
-        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), purchase, 0, null, null)
+        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), 0.sat, purchase, 0, null, null)
         paymentHandler.db.addOutgoingPayment(payment)
 
         val add = makeUpdateAddHtlc(0, channelId, paymentHandler, incomingPayment.paymentHash, makeMppPayload(defaultAmount, defaultAmount, paymentSecret), fundingFee = payment.fundingFee)
@@ -1658,7 +1658,7 @@ class IncomingPaymentHandlerTestsCommon : LightningTestSuite() {
             500.msat,
             LiquidityAds.PaymentDetails.FromFutureHtlcWithPreimage(listOf(preimage)),
         )
-        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), purchase, 0, null, null)
+        val payment = InboundLiquidityOutgoingPayment(UUID.randomUUID(), channelId, TxId(randomBytes32()), 500.sat, purchase, 0, null, null)
         paymentHandler.db.addOutgoingPayment(payment)
 
         val cltvExpiry = TestConstants.Bob.nodeParams.minFinalCltvExpiryDelta.toCltvExpiry(TestConstants.defaultBlockHeight.toLong())