feat(send): improve Lightning send failure recovery

app/src/main/java/to/bitkit/ext/Lnurl.kt

@@ -32,6 +32,8 @@ fun LnurlPayData.isFixedAmount(): Boolean =
 fun LnurlPayData.callbackAmountMsats(userSats: ULong? = null): ULong =
     if (isFixedAmount()) minSendable else (userSats ?: minSendableSat()) * MSat.PER_SAT
 
+fun LnurlPayData.supportPaymentRequest(): String = "LNURL: $uri"
+
 fun LnurlWithdrawData.minWithdrawableSat(): ULong = msatCeilOf(minWithdrawable ?: 0u)
 fun LnurlWithdrawData.maxWithdrawableSat(): ULong = msatFloorOf(maxWithdrawable)
 

app/src/main/java/to/bitkit/ext/PaymentFailureReasonExt.kt

@@ -3,15 +3,111 @@ package to.bitkit.ext
 import android.content.Context
 import org.lightningdevkit.ldknode.PaymentFailureReason
 import to.bitkit.R
+import to.bitkit.models.SendFailureDetails
+import to.bitkit.utils.LdkError
 
 fun PaymentFailureReason?.toUserMessage(context: Context): String = when (this) {
     PaymentFailureReason.RECIPIENT_REJECTED ->
-        context.getString(R.string.wallet__toast_payment_failed_recipient_rejected)
+        context.getString(R.string.wallet__payment_recipient_rejected)
+    PaymentFailureReason.USER_ABANDONED ->
+        context.getString(R.string.wallet__payment_abandoned)
     PaymentFailureReason.RETRIES_EXHAUSTED ->
-        context.getString(R.string.wallet__toast_payment_failed_retries_exhausted)
+        context.getString(R.string.wallet__payment_retries_exhausted)
     PaymentFailureReason.ROUTE_NOT_FOUND ->
-        context.getString(R.string.wallet__toast_payment_failed_route_not_found)
+        context.getString(R.string.wallet__payment_route_not_found)
     PaymentFailureReason.PAYMENT_EXPIRED ->
-        context.getString(R.string.wallet__toast_payment_failed_timeout)
-    else -> context.getString(R.string.wallet__toast_payment_failed_description)
+        context.getString(R.string.wallet__payment_expired)
+    PaymentFailureReason.UNKNOWN_REQUIRED_FEATURES ->
+        context.getString(R.string.wallet__payment_unknown_required_features)
+    PaymentFailureReason.INVOICE_REQUEST_EXPIRED ->
+        context.getString(R.string.wallet__payment_invoice_request_expired)
+    PaymentFailureReason.INVOICE_REQUEST_REJECTED ->
+        context.getString(R.string.wallet__payment_invoice_request_rejected)
+    else -> context.getString(R.string.wallet__payment_failed_description)
 }
+
+fun PaymentFailureReason?.shouldResetRoutingCachesOnRetry(): Boolean =
+    this == PaymentFailureReason.ROUTE_NOT_FOUND || this == PaymentFailureReason.RETRIES_EXHAUSTED
+
+fun PaymentFailureReason?.toCompactFailureType(): String {
+    return this?.name?.snakeToLowerCamel() ?: UNKNOWN_FAILURE_TYPE
+}
+
+fun PaymentFailureReason?.toSendFailureDetails(
+    context: Context,
+    paymentRequest: String? = null,
+): SendFailureDetails {
+    return SendFailureDetails(
+        message = toUserMessage(context),
+        failureType = toCompactFailureType(),
+        resetRoutingCachesOnRetry = shouldResetRoutingCachesOnRetry(),
+        paymentRequest = paymentRequest,
+    )
+}
+
+fun Throwable.toSendFailureMessage(context: Context): String {
+    val fallbackMessage = context.getString(R.string.wallet__payment_failed_description)
+    val rawMessage = message?.trim().orEmpty()
+
+    if (this is LdkError || rawMessage.isBlank() || rawMessage.looksInternalPaymentError()) {
+        return fallbackMessage
+    }
+
+    return rawMessage
+}
+
+fun Throwable.toCompactFailureType(): String {
+    val rawValue = message?.trim()?.takeIf { it.isNotEmpty() }
+        ?: this::class.simpleName
+        ?: UNKNOWN_FAILURE_TYPE
+
+    return rawValue.compactFailureType()
+}
+
+fun Throwable.toSendFailureDetails(
+    context: Context,
+    paymentRequest: String? = null,
+): SendFailureDetails {
+    return SendFailureDetails(
+        message = toSendFailureMessage(context),
+        failureType = toCompactFailureType(),
+        resetRoutingCachesOnRetry = false,
+        paymentRequest = paymentRequest,
+    )
+}
+
+private fun String.snakeToLowerCamel(): String {
+    return lowercase()
+        .split("_")
+        .filter { it.isNotBlank() }
+        .mapIndexed { index, segment ->
+            if (index == 0) segment else segment.replaceFirstChar { it.titlecase() }
+        }
+        .joinToString("")
+        .ifBlank { UNKNOWN_FAILURE_TYPE }
+}
+
+private fun String.compactFailureType(): String {
+    val unwrappedOptional = removeSurrounding("Optional(", ")")
+    val unwrappedNodeError = unwrappedOptional.removeSurrounding("NodeError(", ")")
+    return unwrappedNodeError
+        .substringBefore("(")
+        .substringAfterLast(".")
+        .trim()
+        .ifBlank { UNKNOWN_FAILURE_TYPE }
+}
+
+private fun String.looksInternalPaymentError(): Boolean {
+    return INTERNAL_PAYMENT_ERROR_MARKERS.any { contains(it, ignoreCase = true) }
+}
+
+private val INTERNAL_PAYMENT_ERROR_MARKERS = listOf(
+    "Optional(",
+    "NodeError",
+    "DuplicatePayment",
+    "PaymentFailureReason",
+    "ldknode",
+    "LDK",
+)
+
+private const val UNKNOWN_FAILURE_TYPE = "Unknown"

app/src/main/java/to/bitkit/models/SendFailureDetails.kt

@@ -0,0 +1,12 @@
+package to.bitkit.models
+
+data class SendFailureDetails(
+    val message: String,
+    val failureType: String,
+    val resetRoutingCachesOnRetry: Boolean,
+    val paymentRequest: String? = null,
+) {
+    fun shouldResetRoutingCaches(routingCacheResetAttempted: Boolean): Boolean {
+        return resetRoutingCachesOnRetry && !routingCacheResetAttempted
+    }
+}

app/src/main/java/to/bitkit/repositories/LightningRepo.kt

@@ -48,6 +48,7 @@ import org.lightningdevkit.ldknode.ChannelDetails
 import org.lightningdevkit.ldknode.ClosureReason
 import org.lightningdevkit.ldknode.CoinSelectionAlgorithm
 import org.lightningdevkit.ldknode.Event
+import org.lightningdevkit.ldknode.Network
 import org.lightningdevkit.ldknode.NodeStatus
 import org.lightningdevkit.ldknode.PaymentDetails
 import org.lightningdevkit.ldknode.PaymentHash
@@ -92,6 +93,7 @@ import to.bitkit.services.LnurlChannelResponse
 import to.bitkit.services.LnurlService
 import to.bitkit.services.LnurlWithdrawResponse
 import to.bitkit.services.LspNotificationsService
+import to.bitkit.services.NetworkGraphInfo
 import to.bitkit.services.NodeEventHandler
 import to.bitkit.utils.AppError
 import to.bitkit.utils.Logger
@@ -637,8 +639,14 @@ class LightningRepo @Inject constructor(
     }
 
     private suspend fun clearNetworkGraph(walletIndex: Int): Result<Unit> {
-        lightningService.resetNetworkGraph(walletIndex)
-        return runCatching {
+        runSuspendCatching {
+            lightningService.resetNetworkGraph(walletIndex)
+        }.onFailure {
+            Logger.warn("Failed to clear local network graph", it, context = TAG)
+            return Result.failure(it)
+        }
+
+        return runSuspendCatching {
             vssBackupClientLdk.setup(walletIndex).getOrThrow()
             vssBackupClientLdk.deleteObject("network_graph").getOrThrow()
             Logger.info("Cleared network graph from VSS", context = TAG)
@@ -1859,20 +1867,127 @@ class LightningRepo @Inject constructor(
             vssBackupClientLdk.deleteObject(VSS_KEY_EXTERNAL_SCORES_CACHE).getOrThrow()
         }.onFailure {
             Logger.error("Failed to delete pathfinding scores from VSS", it, context = TAG)
-            start(walletIndex = walletIndex, shouldRetry = false).onFailure { startError ->
+            start(walletIndex = walletIndex, shouldRetry = false, shouldValidateGraph = false).onFailure { startError ->
                 Logger.error("Failed to restart node after pathfinding scores reset failure", startError, context = TAG)
             }
             return@withContext Result.failure(it)
         }
 
         val resetAtSecs = nowMillis() / 1000
 
-        start(walletIndex = walletIndex, shouldRetry = false)
+        start(walletIndex = walletIndex, shouldRetry = false, shouldValidateGraph = false)
             .map { resetAtSecs }
             .onSuccess {
                 Logger.info("Pathfinding scores reset at '$resetAtSecs'", context = TAG)
             }
     }
+
+    suspend fun resetPaymentRoutingCachesAndWait(walletIndex: Int = 0): Result<Unit> = withContext(bgDispatcher) {
+        val refreshStartedAtMs = nowMillis()
+        val refreshStartedAtSecs = (refreshStartedAtMs / 1000).toULong()
+        val requiresRgsRefresh = Env.network != Network.REGTEST &&
+            !settingsStore.data.first().rgsServerUrl.isNullOrEmpty()
+        val requiresScorerRefresh = Env.ldkScorerUrl != null
+        val resetErrors = mutableListOf<Throwable>()
+
+        Logger.info(
+            "Started payment routing refresh rgs='$requiresRgsRefresh' scorer='$requiresScorerRefresh'",
+            context = TAG,
+        )
+
+        val resetResult = withContext(NonCancellable) reset@{
+            stop().onFailure {
+                start(
+                    walletIndex = walletIndex,
+                    shouldRetry = false,
+                    shouldValidateGraph = false,
+                ).onFailure { startError ->
+                    Logger.error(
+                        "Failed to restart node after payment routing refresh stop failure",
+                        startError,
+                        context = TAG,
+                    )
+                }
+                return@reset Result.failure(it)
+            }
+
+            clearNetworkGraph(walletIndex).onFailure {
+                resetErrors.add(it)
+            }
+
+            resetPathfindingScores(walletIndex).onFailure {
+                resetErrors.add(it)
+            }
+
+            resetErrors.firstOrNull()?.let {
+                Result.failure(it)
+            } ?: Result.success(Unit)
+        }
+        resetResult.onFailure {
+            return@withContext Result.failure(it)
+        }
+
+        val result = waitForPaymentRoutingDataRefresh(
+            walletIndex = walletIndex,
+            refreshStartedAtMs = refreshStartedAtMs,
+            refreshStartedAtSecs = refreshStartedAtSecs,
+            requiresRgsRefresh = requiresRgsRefresh,
+            requiresScorerRefresh = requiresScorerRefresh,
+        )
+        result.onSuccess {
+            Logger.info(
+                "Finished payment routing refresh elapsedMs='${nowMillis() - refreshStartedAtMs}'",
+                context = TAG,
+            )
+        }
+    }
+
+    private suspend fun waitForPaymentRoutingDataRefresh(
+        walletIndex: Int,
+        refreshStartedAtMs: Long,
+        refreshStartedAtSecs: ULong,
+        requiresRgsRefresh: Boolean,
+        requiresScorerRefresh: Boolean,
+    ): Result<Unit> = withContext(bgDispatcher) {
+        if (!requiresRgsRefresh && !requiresScorerRefresh) {
+            Logger.info(
+                "Skipped payment routing refresh wait because no routing sources are required",
+                context = TAG,
+            )
+            return@withContext Result.success(Unit)
+        }
+
+        var lastStatus: PaymentRoutingRefreshStatus? = null
+        val refreshed = withTimeoutOrNull(PAYMENT_ROUTING_REFRESH_TIMEOUT) {
+            while (isActive) {
+                syncState()
+                val status = _lightningState.value.paymentRoutingRefreshStatus(
+                    graphCacheModificationDate = lightningService.networkGraphCacheModificationDate(walletIndex),
+                    networkGraphInfo = getNetworkGraphInfo(),
+                    refreshStartedAtSecs = refreshStartedAtSecs,
+                    requiresRgsRefresh = requiresRgsRefresh,
+                    requiresScorerRefresh = requiresScorerRefresh,
+                )
+                lastStatus = status
+                if (status.isFresh) {
+                    return@withTimeoutOrNull true
+                }
+                delay(PAYMENT_ROUTING_REFRESH_POLL_DELAY)
+            }
+            false
+        } == true
+
+        if (refreshed) {
+            Result.success(Unit)
+        } else {
+            Logger.warn(
+                "Timed out payment routing refresh elapsedMs='${nowMillis() - refreshStartedAtMs}' " +
+                    lastStatus?.toLogFields().orEmpty(),
+                context = TAG,
+            )
+            Result.failure(PaymentRoutingRefreshTimeoutError())
+        }
+    }
     // endregion
 
     suspend fun restartNode(): Result<Unit> = withContext(bgDispatcher) {
@@ -1901,6 +2016,64 @@ class LightningRepo @Inject constructor(
         private val NO_USABLE_CHANNELS_FEEDBACK_DELAY = 2_500.milliseconds
         val SEND_LN_TIMEOUT = 10.seconds
         private val PROBE_TIMEOUT = 60.seconds
+        private val PAYMENT_ROUTING_REFRESH_TIMEOUT = 20.seconds
+        private val PAYMENT_ROUTING_REFRESH_POLL_DELAY = 500.milliseconds
+    }
+}
+
+private fun LightningState.paymentRoutingRefreshStatus(
+    graphCacheModificationDate: Long?,
+    networkGraphInfo: NetworkGraphInfo?,
+    refreshStartedAtSecs: ULong,
+    requiresRgsRefresh: Boolean,
+    requiresScorerRefresh: Boolean,
+): PaymentRoutingRefreshStatus {
+    val status = nodeStatus
+    val nodeRunning = nodeLifecycleState.isRunning()
+    val graphNodeCount = networkGraphInfo?.nodeCount
+    val graphChannelCount = networkGraphInfo?.channelCount
+    val hasInMemoryGraph = (graphNodeCount ?: 0) > 0 && (graphChannelCount ?: 0) > 0
+
+    val hasFreshRgs = !requiresRgsRefresh ||
+        graphCacheModificationDate != null && (graphCacheModificationDate / 1000).toULong() >= refreshStartedAtSecs ||
+        hasInMemoryGraph
+
+    val latestScoresTimestamp = status?.latestPathfindingScoresSyncTimestamp
+    val hasFreshScores = !requiresScorerRefresh ||
+        latestScoresTimestamp != null && latestScoresTimestamp >= refreshStartedAtSecs
+
+    return PaymentRoutingRefreshStatus(
+        nodeRunning = nodeRunning,
+        graphFresh = hasFreshRgs,
+        scorerFresh = hasFreshScores,
+        graphCacheModificationDate = graphCacheModificationDate,
+        graphNodeCount = graphNodeCount,
+        graphChannelCount = graphChannelCount,
+        latestPathfindingScoresSyncTimestamp = latestScoresTimestamp,
+        refreshStartedAtSecs = refreshStartedAtSecs,
+    )
+}
+
+private data class PaymentRoutingRefreshStatus(
+    val nodeRunning: Boolean,
+    val graphFresh: Boolean,
+    val scorerFresh: Boolean,
+    val graphCacheModificationDate: Long?,
+    val graphNodeCount: Int?,
+    val graphChannelCount: Int?,
+    val latestPathfindingScoresSyncTimestamp: ULong?,
+    val refreshStartedAtSecs: ULong,
+) {
+    val isFresh: Boolean = nodeRunning && graphFresh && scorerFresh
+
+    fun toLogFields(): String {
+        return "nodeRunning='$nodeRunning' graphFresh='$graphFresh' scorerFresh='$scorerFresh' " +
+            "graphMtime='${graphCacheModificationDate ?: "-"}' " +
+            "graphMtimeSecs='${graphCacheModificationDate?.let { it / 1000 } ?: "-"}' " +
+            "graphNodes='${graphNodeCount ?: "-"}' " +
+            "graphChannels='${graphChannelCount ?: "-"}' " +
+            "scorerTs='${latestPathfindingScoresSyncTimestamp ?: "-"}' " +
+            "refreshStartedAtSecs='$refreshStartedAtSecs'"
     }
 }
 
@@ -1912,6 +2085,7 @@ class NodeRunTimeoutError(opName: String) : AppError("Timeout waiting for node t
 class GetPaymentsError : AppError("It wasn't possible get the payments")
 class SyncUnhealthyError : AppError("Wallet sync failed before send")
 class LnurlPayInvoiceMismatchError : AppError("The invoice did not match the requested payment. Payment cancelled.")
+class PaymentRoutingRefreshTimeoutError : AppError("Timeout waiting for payment routing data refresh")
 
 data class NodeEventUpdate(
     val event: Event,

app/src/main/java/to/bitkit/repositories/PendingPaymentRepo.kt

@@ -6,6 +6,7 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
+import org.lightningdevkit.ldknode.PaymentFailureReason
 import to.bitkit.R
 import to.bitkit.models.NotificationDetails
 import to.bitkit.utils.AppError
@@ -48,7 +49,10 @@ sealed interface PendingPaymentResolution {
     val paymentHash: String
 
     data class Success(override val paymentHash: String) : PendingPaymentResolution
-    data class Failure(override val paymentHash: String) : PendingPaymentResolution
+    data class Failure(
+        override val paymentHash: String,
+        val reason: PaymentFailureReason? = null,
+    ) : PendingPaymentResolution
 }
 
 object PendingPaymentNotification {