1 files changed, 104 insertions, 2 deletions

diff --git a/lib/payments.js b/lib/payments.js
index 369d0aec..098c16f7 100644
--- a/lib/payments.js
+++ b/lib/payments.js
@@ -15,6 +15,7 @@ import fs from "fs";
 import EventEmitter from "events";
 import crc32 from "buffer-crc32";
 import { mqtt1, mqtt2 } from "$lib/mqtt";
+import ln from "$lib/ln";
 
 export const types = {
   internal: "internal",
@@ -72,7 +73,6 @@ export let debit = async (
     ourfee || 0
   );
 
-
   if (r !== "ok") fail("Insufficient funds");
 
   let p = {
@@ -160,7 +160,7 @@ export let credit = async (hash, amount, memo, ref, type = types.internal) => {
     await s(`payment:${txid}:${vout}`, id);
   } else {
     await s(`payment:${hash}`, id);
-  } 
+  }
 
   let m = await db.multi();
 
@@ -210,3 +210,105 @@ export let confirm = async (address, txid, vout) => {
     .incrBy(`balance:${p.uid}`, p.amount)
     .exec();
 };
+
+export let payLightning = async (user, payreq, amount, maxfee, memo) => {
+  let p;
+  let hash = payreq;
+
+  amount = parseInt(amount);
+  if (amount < 0) fail("Invalid amount");
+
+  maxfee = maxfee ? parseInt(maxfee) : 0;
+  if (maxfee < 0) fail("Max fee cannot be negative");
+
+  let total = amount;
+  let { amount_msat, payment_hash } = await ln.decode(payreq);
+  if (amount_msat) total = Math.round(amount_msat / 1000);
+
+  let iid = await g(`invoice:${hash}`);
+  if (iid && iid.hash) iid = iid.hash;
+  let invoice = await g(`invoice:${iid}`);
+
+  if (invoice) {
+    if (invoice.uid === user.id) fail("Cannot send to self");
+    hash = payreq;
+  } else {
+    let r;
+
+    let { pays } = await ln.listpays(payreq);
+    if (pays.find(p => p.status === "complete"))
+      fail("Invoice has already been paid");
+
+    if (pays.find(p => p.status === "pending"))
+      fail("Payment is already underway");
+
+    p = await debit(payreq, total, maxfee, memo, user, types.lightning);
+
+    let check = async () => {
+      try {
+        let { pays } = await ln.listpays(payreq);
+
+        let recordExists = !!(await g(`payment:${p.id}`));
+        let paymentFailed =
+          !pays.length || pays.every(p => p.status === "failed");
+
+        l("checking", payreq, recordExists, paymentFailed);
+
+        if (recordExists && paymentFailed) {
+          await db.del(`payment:${p.id}`);
+
+          let credit = Math.round(total * config.fee) - p.ourfee;
+          warn("crediting balance", total + maxfee + p.ourfee);
+          await db.incrBy(`balance:${p.uid}`, total + maxfee + p.ourfee);
+
+          warn("crediting credits", credit);
+          await db.incrBy(`credit:${types.lightning}:${p.uid}`, credit);
+
+          warn("reversing payment", p.id);
+          await db.lRem(`${p.uid}:payments`, 1, p.id);
+
+          clearInterval(interval);
+        }
+      } catch (e) {
+        console.log(e);
+        err("Failed to reverse payment", r);
+      }
+    };
+
+    let interval = setInterval(check, 5000);
+
+    try {
+      l("paying lightning invoice", payreq);
+
+      r = await ln.pay({
+        bolt11: payreq.replace(/\s/g, "").toLowerCase(),
+        amount_msat: amount_msat ? undefined : amount * 1000,
+        maxfee: maxfee * 1000,
+        retry_for: 5
+      });
+
+      if (!(r.status === "complete" && r.payment_preimage))
+        fail("Payment did not complete");
+
+      l("payment completed", p.id, r.payment_preimage);
+
+      p.amount = -amount;
+      p.tip = total - amount;
+      p.fee = Math.round((r.amount_sent_msat - r.amount_msat) / 1000);
+      p.ref = r.payment_preimage;
+
+      await s(`payment:${p.id}`, p);
+
+      l("refunding fee", maxfee, p.fee, maxfee - p.fee, p.ref);
+      await db.incrBy(`balance:${p.uid}`, maxfee - p.fee);
+    } catch (e) {
+      warn("something went wrong", e.message);
+      await check();
+      throw e;
+    }
+
+    clearInterval(interval);
+  }
+
+  return p;
+};