lnurl-withdrawal support

api/resolvers/lnurl.js

@@ -1,26 +1,52 @@
 import { randomBytes } from 'crypto'
 import { bech32 } from 'bech32'
+import { AuthenticationError } from 'apollo-server-micro'
+
+function encodedUrl (iurl, tag, k1) {
+  const url = new URL(iurl)
+  url.searchParams.set('tag', tag)
+  url.searchParams.set('k1', k1)
+  // bech32 encode url
+  const words = bech32.toWords(Buffer.from(url.toString(), 'utf8'))
+  return bech32.encode('lnurl', words, 1023)
+}
+
+function k1 () {
+  return randomBytes(32).toString('hex')
+}
 
 export default {
   Query: {
     lnAuth: async (parent, { k1 }, { models }) => {
       return await models.lnAuth.findUnique({ where: { k1 } })
+    },
+    lnWith: async (parent, { k1 }, { models }) => {
+      return await models.lnWith.findUnique({ where: { k1 } })
     }
   },
   Mutation: {
     createAuth: async (parent, args, { models }) => {
-      const k1 = randomBytes(32).toString('hex')
+      return await models.lnAuth.create({ data: { k1: k1() } })
-      return await models.lnAuth.create({ data: { k1 } })
+    },
+    createWith: async (parent, args, { me, models }) => {
+      if (!me) {
+        throw new AuthenticationError('you must be logged in')
+      }
+
+      return await models.lnWith.create({ data: { k1: k1(), userId: me.id } })
     }
   },
   LnAuth: {
     encodedUrl: async (lnAuth, args, { models }) => {
-      const url = new URL(process.env.LNAUTH_URL)
+      return encodedUrl(process.env.LNAUTH_URL, 'login', lnAuth.k1)
-      url.searchParams.set('tag', 'login')
+    }
-      url.searchParams.set('k1', lnAuth.k1)
+  },
-      // bech32 encode url
+  LnWith: {
-      const words = bech32.toWords(Buffer.from(url.toString(), 'utf8'))
+    encodedUrl: async (lnWith, args, { models }) => {
-      return bech32.encode('lnurl', words, 1023)
+      return encodedUrl(process.env.LNWITH_URL, 'withdrawRequest', lnWith.k1)
+    },
+    user: async (lnWith, args, { models }) => {
+      return await models.user.findUnique({ where: { id: lnWith.userId } })
     }
   }
 }

api/resolvers/wallet.js

@@ -89,10 +89,6 @@ export default {
       }
     },
     createWithdrawl: async (parent, { invoice, maxFee }, { me, models, lnd }) => {
-      if (!me) {
-        throw new AuthenticationError('you must be logged in')
-      }
-
       // decode invoice to get amount
       let decoded
       try {

api/ssrApollo.js

@@ -6,8 +6,9 @@ import resolvers from './resolvers'
 import typeDefs from './typeDefs'
 import models from './models'
 import { print } from 'graphql'
+import lnd from './lnd'
 
-export default async function getSSRApolloClient (req) {
+export default async function getSSRApolloClient (req, me = null) {
   const session = req && await getSession({ req })
   return new ApolloClient({
     ssrMode: true,
@@ -18,7 +19,8 @@ export default async function getSSRApolloClient (req) {
       }),
       context: {
         models,
-        me: session ? session.user : null
+        me: session ? session.user : me,
+        lnd
       }
     }),
     cache: new InMemoryCache()

api/typeDefs/lnurl.js

@@ -3,10 +3,12 @@ import { gql } from 'apollo-server-micro'
 export default gql`
   extend type Query {
     lnAuth(k1: String!): LnAuth!
+    lnWith(k1: String!): LnWith!
   }
 
   extend type Mutation {
     createAuth: LnAuth!
+    createWith: LnWith!
   }
 
   type LnAuth {
@@ -16,4 +18,13 @@ export default gql`
     pubkey: String
     encodedUrl: String!
   }
+
+  type LnWith {
+    id: ID!
+    createdAt: String!
+    k1: String!
+    user: User!
+    withdrawalId: Int
+    encodedUrl: String!
+  }
 `

fragments/wallet.js

@@ -23,3 +23,10 @@ export const WITHDRAWL = gql`
       status
     }
   }`
+
+export const CREATE_WITHDRAWL = gql`
+  mutation createWithdrawl($invoice: String!, $maxFee: Int!) {
+    createWithdrawl(invoice: $invoice, maxFee: $maxFee) {
+      id
+    }
+}`

pages/api/lnwith.js

@@ -0,0 +1,71 @@
+// verify k1 exists
+// send back
+import models from '../../api/models'
+import getSSRApolloClient from '../../api/ssrApollo'
+import { CREATE_WITHDRAWL } from '../../fragments/wallet'
+
+export default async ({ query }, res) => {
+  if (query.pr) {
+    return doWithdrawal(query, res)
+  }
+
+  let reason
+  try {
+    // TODO: make sure lnwith was recently generated ... or better use a stateless
+    // bearer token to auth user
+    const lnwith = await models.lnWith.findUnique({ where: { k1: query.k1 } })
+    if (lnwith) {
+      const user = await models.user.findUnique({ where: { id: lnwith.userId } })
+      if (user) {
+        return res.status(200).json({
+          tag: 'withdrawRequest', // type of LNURL
+          callback: process.env.LNWITH_URL, // The URL which LN SERVICE would accept a withdrawal Lightning invoice as query parameter
+          k1: query.k1, // Random or non-random string to identify the user's LN WALLET when using the callback URL
+          defaultDescription: `Withdrawal for @${user.name} on SN`, // A default withdrawal invoice description
+          minWithdrawable: 1000, // Min amount (in millisatoshis) the user can withdraw from LN SERVICE, or 0
+          maxWithdrawable: user.msats - 10000 // Max amount (in millisatoshis) the user can withdraw from LN SERVICE, or equal to minWithdrawable if the user has no choice over the amounts
+        })
+      } else {
+        reason = 'user not found'
+      }
+    } else {
+      reason = 'withdrawal not found'
+    }
+  } catch (error) {
+    console.log(error)
+    reason = 'internal server error'
+  }
+
+  return res.status(400).json({ status: 'ERROR', reason })
+}
+
+async function doWithdrawal (query, res) {
+  if (!query.k1) {
+    return res.status(400).json({ status: 'ERROR', reason: 'k1 not provided' })
+  }
+
+  const lnwith = await models.lnWith.findUnique({ where: { k1: query.k1 } })
+  if (!lnwith) {
+    return res.status(400).json({ status: 'ERROR', reason: 'invalid k1' })
+  }
+  const me = await models.user.findUnique({ where: { id: lnwith.userId } })
+  if (!me) {
+    return res.status(400).json({ status: 'ERROR', reason: 'user not found' })
+  }
+
+  // create withdrawal in gql
+  const client = await getSSRApolloClient(null, me)
+  const { error, data } = await client.mutate({
+    mutation: CREATE_WITHDRAWL,
+    variables: { invoice: query.pr, maxFee: 10 }
+  })
+
+  if (error || !data?.createWithdrawl) {
+    return res.status(400).json({ status: 'ERROR', reason: error?.toString() || 'could not generate withdrawl' })
+  }
+
+  // store withdrawal id lnWith so client can show it
+  await models.lnWith.update({ where: { k1: query.k1 }, data: { withdrawalId: Number(data.createWithdrawl.id) } })
+
+  return res.status(200).json({ status: 'OK' })
+}

pages/wallet.js

@@ -3,8 +3,8 @@ import { Form, Input, SubmitButton } from '../components/form'
 import Link from 'next/link'
 import Button from 'react-bootstrap/Button'
 import * as Yup from 'yup'
-import { gql, useMutation } from '@apollo/client'
+import { gql, useMutation, useQuery } from '@apollo/client'
-import { LnQRSkeleton } from '../components/lnqr'
+import LnQR, { LnQRSkeleton } from '../components/lnqr'
 import LayoutCenter from '../components/layout-center'
 import InputGroup from 'react-bootstrap/InputGroup'
 import { WithdrawlSkeleton } from './withdrawals/[id]'
@@ -12,6 +12,7 @@ import { useMe } from '../components/me'
 import { useEffect, useState } from 'react'
 import { requestProvider } from 'webln'
 import { Alert } from 'react-bootstrap'
+import { CREATE_WITHDRAWL } from '../fragments/wallet'
 
 export default function Wallet () {
   return (
@@ -49,8 +50,10 @@ export function WalletForm () {
 
   if (router.query.type === 'fund') {
     return <FundForm />
-  } else {
+  } else if (router.query.type === 'withdraw') {
     return <WithdrawlForm />
+  } else {
+    return <LnWithdrawal />
   }
 }
 
@@ -125,12 +128,7 @@ export function WithdrawlForm () {
   const router = useRouter()
   const me = useMe()
 
-  const [createWithdrawl, { called, error }] = useMutation(gql`
+  const [createWithdrawl, { called, error }] = useMutation(CREATE_WITHDRAWL)
-    mutation createWithdrawl($invoice: String!, $maxFee: Int!) {
-      createWithdrawl(invoice: $invoice, maxFee: $maxFee) {
-        id
-      }
-  }`)
 
   useEffect(async () => {
     try {
@@ -153,7 +151,6 @@ export function WithdrawlForm () {
     <>
       <YouHaveSats />
       <Form
-        className='pt-3'
         initial={{
           invoice: '',
           maxFee: MAX_FEE_DEFAULT
@@ -179,6 +176,49 @@ export function WithdrawlForm () {
         />
         <SubmitButton variant='success' className='mt-2'>withdraw</SubmitButton>
       </Form>
+      <span className='my-3 font-weight-bold text-muted'>or</span>
+      <Link href='/wallet?type=lnurl-withdraw'>
+        <Button variant='grey'>QR code</Button>
+      </Link>
     </>
   )
 }
+
+function LnQRWith ({ k1, encodedUrl }) {
+  const router = useRouter()
+  const query = gql`
+  {
+    lnWith(k1: "${k1}") {
+      withdrawalId
+      k1
+    }
+  }`
+  const { data } = useQuery(query, { pollInterval: 1000, fetchPolicy: 'cache-first' })
+
+  if (data?.lnWith?.withdrawalId) {
+    router.push(`/withdrawals/${data.lnWith.withdrawalId}`)
+  }
+
+  return <LnQR value={encodedUrl} status='waiting for you' />
+}
+
+export function LnWithdrawal () {
+  // query for challenge
+  const [createAuth, { data, error }] = useMutation(gql`
+    mutation createAuth {
+      createWith {
+        k1
+        encodedUrl
+      }
+    }`)
+
+  useEffect(createAuth, [])
+
+  if (error) return <div>error</div>
+
+  if (!data) {
+    return <LnQRSkeleton status='generating' />
+  }
+
+  return <LnQRWith {...data.createWith} />
+}

prisma/migrations/20211027230800_lnwith/migration.sql

@@ -0,0 +1,14 @@
+-- CreateTable
+CREATE TABLE "LnWith" (
+    "id" SERIAL NOT NULL,
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updated_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "k1" TEXT NOT NULL,
+    "userId" INTEGER NOT NULL,
+    "withdrawalId" INTEGER NOT NULL,
+
+    PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "LnWith.k1_unique" ON "LnWith"("k1");

prisma/migrations/20211027231327_lnwith_withid_optional/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "LnWith" ALTER COLUMN "withdrawalId" DROP NOT NULL;

prisma/schema.prisma

@@ -48,6 +48,15 @@ model LnAuth {
   pubkey    String?
 }
 
+model LnWith {
+  id           Int      @id @default(autoincrement())
+  createdAt    DateTime @default(now()) @map(name: "created_at")
+  updatedAt    DateTime @default(now()) @updatedAt @map(name: "updated_at")
+  k1           String   @unique
+  userId       Int
+  withdrawalId Int?
+}
+
 model Invite {
   id        String   @id @default(cuid())
   createdAt DateTime @default(now()) @map(name: "created_at")

styles/globals.scss

@@ -5,7 +5,8 @@ $theme-colors: (
   "info" : #007cbe,
   "success" : #5c8001,
   "twitter" : #1da1f2,
-  "boost" : #8c25f4
+  "boost" : #8c25f4,
+  "grey" : #e9ecef
 );
 
 $body-bg: #f5f5f5;