fix: tune lightning probe routing (#623)

* fix: tune lightning probe routing

* fix: avoid scorer config startup crash

Author: pwltr

Bitkit/Services/LightningService.swift

@@ -28,6 +28,26 @@ class LightningService {
 
     static var shared = LightningService()
 
+    private static let scoringBasePenaltyMsat: UInt64 = 50000
+    private static let scoringLiquidityPenaltyMultiplierMsat: UInt64 = 10000
+    private static let scoringLiquidityPenaltyAmountMultiplierMsat: UInt64 = 10000
+    private static let scoringHistoricalLiquidityPenaltyAmountMultiplierMsat: UInt64 = 20000
+    private static let scoringConsideredImpossiblePenaltyMsat: UInt64 = 1_000_000_000_000
+    private static let scoringProbingDiversityPenaltyMsat: UInt64 = 60000
+
+    private static let defaultScoringFeeParameters = ScoringFeeParameters(
+        basePenaltyMsat: 1024,
+        basePenaltyAmountMultiplierMsat: 131_072,
+        liquidityPenaltyMultiplierMsat: 0,
+        liquidityPenaltyAmountMultiplierMsat: 0,
+        historicalLiquidityPenaltyMultiplierMsat: 10000,
+        historicalLiquidityPenaltyAmountMultiplierMsat: 1250,
+        antiProbingPenaltyMsat: 250,
+        consideredImpossiblePenaltyMsat: 100_000_000_000,
+        linearSuccessProbability: false,
+        probingDiversityPenaltyMsat: 0
+    )
+
     private init() {}
 
     /// Flag and lock to prevent concurrent setup calls
@@ -107,6 +127,8 @@ class LightningService {
             builder.setPathfindingScoresSource(url: scorerUrl)
         }
 
+        builder.setScoringFeeParams(params: Self.scoringFeeParameters(config: config))
+
         // Configure gossip source from current settings
         configureGossipSource(builder: builder, rgsServerUrl: rgsServerUrl)
 
@@ -1575,6 +1597,23 @@ extension LightningService {
 
     // MARK: - Probing
 
+    private static func scoringFeeParameters(config: Config) -> ScoringFeeParameters {
+        let defaultParameters = config.scoringFeeParams ?? defaultScoringFeeParameters
+
+        return ScoringFeeParameters(
+            basePenaltyMsat: scoringBasePenaltyMsat,
+            basePenaltyAmountMultiplierMsat: defaultParameters.basePenaltyAmountMultiplierMsat,
+            liquidityPenaltyMultiplierMsat: scoringLiquidityPenaltyMultiplierMsat,
+            liquidityPenaltyAmountMultiplierMsat: scoringLiquidityPenaltyAmountMultiplierMsat,
+            historicalLiquidityPenaltyMultiplierMsat: defaultParameters.historicalLiquidityPenaltyMultiplierMsat,
+            historicalLiquidityPenaltyAmountMultiplierMsat: scoringHistoricalLiquidityPenaltyAmountMultiplierMsat,
+            antiProbingPenaltyMsat: defaultParameters.antiProbingPenaltyMsat,
+            consideredImpossiblePenaltyMsat: scoringConsideredImpossiblePenaltyMsat,
+            linearSuccessProbability: defaultParameters.linearSuccessProbability,
+            probingDiversityPenaltyMsat: scoringProbingDiversityPenaltyMsat
+        )
+    }
+
     /// Sends a probe to test if a payment route exists for the given invoice.
     /// - Parameters:
     ///   - bolt11: The Lightning invoice string (BOLT 11)

Bitkit/ViewModels/WalletViewModel.swift

@@ -195,7 +195,7 @@ class WalletViewModel: ObservableObject {
                             success: false,
                             paymentId: paymentId,
                             paymentHash: paymentHash,
-                            shortChannelId: shortChannelId,
+                            shortChannelId: shortChannelId.map(String.init),
                             routeFeeMsat: routeFeeMsat
                         )
                     case let .paymentReceived(_, paymentHash, _, _):
@@ -681,7 +681,7 @@ class WalletViewModel: ObservableObject {
         let success: Bool
         let paymentId: PaymentId
         let paymentHash: PaymentHash
-        let shortChannelId: UInt64?
+        let shortChannelId: String?
         let routeFeeMsat: UInt64?
     }
 
@@ -724,7 +724,7 @@ class WalletViewModel: ObservableObject {
                         success: false,
                         paymentId: paymentId,
                         paymentHash: paymentHash,
-                        shortChannelId: shortChannelId,
+                        shortChannelId: shortChannelId.map(String.init),
                         routeFeeMsat: routeFeeMsat
                     )
                     if pendingPaymentIds.isEmpty, let lastFailure {
@@ -739,7 +739,7 @@ class WalletViewModel: ObservableObject {
         }
     }
 
-    private func cacheProbeOutcome(success: Bool, paymentId: PaymentId, paymentHash: PaymentHash, shortChannelId: UInt64?, routeFeeMsat: UInt64?) {
+    private func cacheProbeOutcome(success: Bool, paymentId: PaymentId, paymentHash: PaymentHash, shortChannelId: String?, routeFeeMsat: UInt64?) {
         probeOutcomes[paymentId] = ProbeOutcome(
             success: success,
             paymentId: paymentId,

Bitkit/Views/Settings/ProbingTool/ProbingToolScreen.swift

@@ -259,7 +259,7 @@ struct ProbingToolScreen: View {
                 }
                 app.toast(type: .success, title: "Probe Successful", description: "Route verified in \(durationMs) ms")
             } else {
-                let scidText = resolved.shortChannelId.map(String.init) ?? "unknown"
+                let scidText = resolved.shortChannelId ?? "unknown"
                 let message = "Hash: \(resolved.paymentHash), SCID: \(scidText)"
                 await MainActor.run {
                     probeResult = ProbeResult(

changelog.d/next/623.fixed.md

@@ -0,0 +1 @@
+Improved Lightning payment route selection reliability.