From b720736eea479b1b82ef74136739fdbe2915d6d9 Mon Sep 17 00:00:00 2001
From: Tom Kirkpatrick <tkp@kirkdesigns.co.uk>
Date: Thu, 18 Jun 2020 18:35:16 +0200
Subject: [PATCH] fix(wallet): use sendpaymentv2 for probing if available

---
 renderer/reducers/pay/reducer.js     | 14 ++++-
 renderer/reducers/payment/reducer.js | 11 +++-
 services/grpc/router.methods.js      | 86 ++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+), 4 deletions(-)

diff --git a/renderer/reducers/pay/reducer.js b/renderer/reducers/pay/reducer.js
index 0a8533bfa6b..8f3652d7410 100644
--- a/renderer/reducers/pay/reducer.js
+++ b/renderer/reducers/pay/reducer.js
@@ -94,12 +94,18 @@ export const queryRoutes = (payReqOrPubkey, amt, feeLimit) => async (dispatch, g
   let paymentHash
   let payload
 
-  const defaultPaymentOptions = pick(currentConfig.payments, [
+  const paymentOptions = pick(currentConfig.payments, [
     'allowSelfPayment',
     'timeoutSeconds',
     'feeLimit',
   ])
 
+  const defaultPaymentOptions = {
+    allowSelfPayment: paymentOptions.allowSelfPayment,
+    timeoutSeconds: paymentOptions.timeoutSeconds,
+    feeLimitSat: paymentOptions.feeLimit,
+  }
+
   // Prepare payload for lnd.
   if (isKeysend) {
     const options = prepareKeysendProbe(payReqOrPubkey, amt, feeLimit)
@@ -120,8 +126,12 @@ export const queryRoutes = (payReqOrPubkey, amt, feeLimit) => async (dispatch, g
   }
 
   const callProbePayment = async () => {
+    const routerProbePayment = infoSelectors.hasSendPaymentV2Support(getState())
+      ? grpc.services.Router.probePaymentV2
+      : grpc.services.Router.probePayment
+
     const routes = []
-    const route = await grpc.services.Router.probePayment(payload)
+    const route = await routerProbePayment(payload)
     // Flag this as an exact route. This can be used as a hint for whether to use sendToRoute to fulfil the payment.
     route.isExact = true
     // Store the payment hash for use with keysend.
diff --git a/renderer/reducers/payment/reducer.js b/renderer/reducers/payment/reducer.js
index bd744610ab5..7bd0654affd 100644
--- a/renderer/reducers/payment/reducer.js
+++ b/renderer/reducers/payment/reducer.js
@@ -228,13 +228,20 @@ export const payInvoice = ({
   const isKeysend = isPubkey(payReq)
   let payload
 
-  const defaultPaymentOptions = pick(currentConfig.payments, [
+  const paymentOptions = pick(currentConfig.payments, [
     'allowSelfPayment',
     'timeoutSeconds',
     'feeLimit',
     'maxParts',
   ])
-  defaultPaymentOptions.paymentId = paymentId
+
+  const defaultPaymentOptions = {
+    allowSelfPayment: paymentOptions.allowSelfPayment,
+    timeoutSeconds: paymentOptions.timeoutSeconds,
+    feeLimitSat: paymentOptions.feeLimit,
+    maxParts: paymentOptions.feeLimit,
+    paymentId,
+  }
 
   // Prepare payload for lnd.
   if (isKeysend) {
diff --git a/services/grpc/router.methods.js b/services/grpc/router.methods.js
index 0557d716a3f..04392f50c2e 100644
--- a/services/grpc/router.methods.js
+++ b/services/grpc/router.methods.js
@@ -87,6 +87,91 @@ async function probePayment(payload) {
   })
 }
 
+/**
+ * probePaymentV2 - Call lnd grpc sendPayment method with a fake payment hash in order to probe for a route.
+ *
+ * @param {object} payload Payload
+ * @returns {Promise} The route route when state is SUCCEEDED
+ */
+async function probePaymentV2(payload) {
+  // Use a payload that has the payment hash set to some random bytes.
+  // This will cause the payment to fail at the final destination.
+  payload.paymentHash = new Uint8Array(generatePreimage())
+
+  logGrpcCmd('Router.probePaymentV2', payload)
+
+  let result
+  let error
+
+  const decorateError = e => {
+    e.details = result
+    return e
+  }
+
+  return new Promise((resolve, reject) => {
+    grpcLog.time('probePayment')
+    const call = this.service.sendPaymentV2(payload)
+    let route
+
+    call.on('data', data => {
+      grpcLog.debug('PROBE DATA :%o', data)
+
+      switch (data.status) {
+        case 'IN_FLIGHT':
+          grpcLog.info('PROBE IN_FLIGHT...')
+          break
+
+        case 'FAILED':
+          if (data.failureReason !== 'FAILURE_REASON_INCORRECT_PAYMENT_DETAILS') {
+            grpcLog.warn('PROBE FAILED: %o', data)
+            error = new Error(data.status)
+            break
+          }
+
+          grpcLog.info('PROBE SUCCESS: %o', data)
+          // Prior to lnd v0.10.0 sendPayment would return a single route under the `route` key.
+          route = data.route || data.htlcs[0].route
+          // FIXME: For some reason the customRecords key is corrupt in the grpc response object.
+          // For now, assume that if a custom_record key is set that it is a keysend record and fix it accordingly.
+          route.hops = route.hops.map(hop => {
+            Object.keys(hop.customRecords).forEach(key => {
+              hop.customRecords[KEYSEND_PREIMAGE_TYPE] = hop.customRecords[key]
+              delete hop.customRecords[key]
+            })
+            return hop
+          })
+          result = route
+          break
+
+        default:
+          grpcLog.warn('PROBE FAILED: %o', data)
+          error = new Error(data.status)
+      }
+    })
+
+    call.on('status', status => {
+      grpcLog.info('PROBE STATUS :%o', status)
+    })
+
+    call.on('error', e => {
+      grpcLog.warn('PROBE ERROR :%o', e)
+      error = new Error(e.details || e.message)
+    })
+
+    call.on('end', () => {
+      grpcLog.timeEnd('probePaymentV2')
+      grpcLog.info('PROBE END')
+      if (error) {
+        return reject(decorateError(error))
+      }
+      if (!result) {
+        return reject(decorateError(new Error('TERMINATED_EARLY')))
+      }
+      return resolve(result)
+    })
+  })
+}
+
 /**
  * sendPayment - Call lnd grpc sendPayment method.
  *
@@ -224,6 +309,7 @@ async function sendPaymentV2(payload = {}) {
 
 export default {
   probePayment,
+  probePaymentV2,
   sendPayment,
   sendPaymentV2,
 }