stacker.news/api/resolvers/wallet.js

import { createInvoice, decodePaymentRequest, subscribeToPayViaRequest } from 'ln-service'
import { UserInputError, AuthenticationError } from 'apollo-server-micro'
import serialize from './serial'
import { decodeCursor, LIMIT, nextCursorEncoded } from '../../lib/cursor'

export default {
  Query: {
    invoice: async (parent, { id }, { me, models, lnd }) => {
      if (!me) {
        throw new AuthenticationError('you must be logged in')
      }

      const inv = await models.invoice.findUnique({
        where: {
          id: Number(id)
        },
        include: {
          user: true
        }
      })

      if (inv.user.id !== me.id) {
        throw new AuthenticationError('not ur invoice')
      }

      return inv
    },
    withdrawl: async (parent, { id }, { me, models, lnd }) => {
      if (!me) {
        throw new AuthenticationError('you must be logged in')
      }

      const wdrwl = await models.withdrawl.findUnique({
        where: {
          id: Number(id)
        },
        include: {
          user: true
        }
      })

      if (wdrwl.user.id !== me.id) {
        throw new AuthenticationError('not ur withdrawal')
      }

      return wdrwl
    },
    connectAddress: async (parent, args, { lnd }) => {
      return process.env.LND_CONNECT_ADDRESS
    },
    walletHistory: async (parent, { cursor }, { me, models, lnd }) => {
      const decodedCursor = decodeCursor(cursor)
      // if (!me) {
      //   throw new AuthenticationError('you must be logged in')
      // }

      // TODO
      // 1. union invoices and withdrawals
      // 2. add to union spending and receiving

      const history = await models.$queryRaw(`
      (SELECT id, bolt11, created_at as "createdAt",
        "msatsReceived" as msats, NULL as "msatsFee",
        CASE WHEN "confirmedAt" IS NOT NULL THEN 'CONFIRMED'
             WHEN "expiresAt" IS NOT NULL THEN 'EXPIRED'
             WHEN cancelled THEN 'CANCELLED'
             ELSE 'PENDING' END as status,
        'invoice' as type
        FROM "Invoice"
        WHERE "userId" = $1
          AND created_at <= $2
        ORDER BY created_at desc
        LIMIT ${LIMIT}+$3)
      UNION ALL
      (SELECT id, bolt11, created_at as "createdAt",
        CASE WHEN status = 'CONFIRMED' THEN "msatsPaid"
        ELSE "msatsPaying" END as msats,
        CASE WHEN status = 'CONFIRMED' THEN "msatsFeePaid"
        ELSE "msatsFeePaying" END as "msatsFee",
        COALESCE(status::text, 'PENDING') as status,
        'withdrawal' as type
        FROM "Withdrawl"
        WHERE "userId" = $1
          AND created_at <= $2
        ORDER BY created_at desc
        LIMIT ${LIMIT}+$3)
      ORDER BY "createdAt" DESC
      OFFSET $3
      LIMIT ${LIMIT}`, 624, decodedCursor.time, decodedCursor.offset)

      return {
        cursor: history.length === LIMIT ? nextCursorEncoded(decodedCursor) : null,
        facts: history
      }
    }
  },

  Mutation: {
    createInvoice: async (parent, { amount }, { me, models, lnd }) => {
      if (!me) {
        throw new AuthenticationError('you must be logged in')
      }

      if (!amount || amount <= 0) {
        throw new UserInputError('amount must be positive', { argumentName: 'amount' })
      }

      // set expires at to 3 hours into future
      const expiresAt = new Date(new Date().setHours(new Date().getHours() + 3))
      const description = `${amount} sats for @${me.name} on stacker.news`
      try {
        const invoice = await createInvoice({
          description,
          lnd,
          tokens: amount,
          expires_at: expiresAt
        })

        const data = {
          hash: invoice.id,
          bolt11: invoice.request,
          expiresAt: expiresAt,
          msatsRequested: amount * 1000,
          user: {
            connect: {
              id: me.id
            }
          }
        }

        return await models.invoice.create({ data })
      } catch (error) {
        console.log(error)
        throw error
      }
    },
    createWithdrawl: async (parent, { invoice, maxFee }, { me, models, lnd }) => {
      // decode invoice to get amount
      let decoded
      try {
        decoded = await decodePaymentRequest({ lnd, request: invoice })
      } catch (error) {
        throw new UserInputError('could not decode invoice')
      }

      // TODO: test
      if (!decoded.mtokens || Number(decoded.mtokens) <= 0) {
        throw new UserInputError('you must specify amount')
      }

      const msatsFee = Number(maxFee) * 1000

      // create withdrawl transactionally (id, bolt11, amount, fee)
      const [withdrawl] = await serialize(models,
        models.$queryRaw`SELECT * FROM create_withdrawl(${decoded.id}, ${invoice},
          ${Number(decoded.mtokens)}, ${msatsFee}, ${me.name})`)

      // create the payment, subscribing to its status
      const sub = subscribeToPayViaRequest({
        lnd,
        request: invoice,
        // can't use max_fee_mtokens https://github.com/alexbosworth/ln-service/issues/141
        max_fee: Number(maxFee),
        pathfinding_timeout: 30000
      })

      // if it's confirmed, update confirmed returning extra fees to user
      sub.once('confirmed', async e => {
        console.log(e)

        sub.removeAllListeners()

        // mtokens also contains the fee
        const fee = Number(e.fee_mtokens)
        const paid = Number(e.mtokens) - fee
        await serialize(models, models.$queryRaw`
            SELECT confirm_withdrawl(${withdrawl.id}, ${paid}, ${fee})`)
      })

      // if the payment fails, we need to
      // 1. return the funds to the user
      // 2. update the widthdrawl as failed
      sub.once('failed', async e => {
        console.log(e)

        sub.removeAllListeners()

        let status = 'UNKNOWN_FAILURE'
        if (e.is_insufficient_balance) {
          status = 'INSUFFICIENT_BALANCE'
        } else if (e.is_invalid_payment) {
          status = 'INVALID_PAYMENT'
        } else if (e.is_pathfinding_timeout) {
          status = 'PATHFINDING_TIMEOUT'
        } else if (e.is_route_not_found) {
          status = 'ROUTE_NOT_FOUND'
        }
        await serialize(models, models.$queryRaw`
            SELECT reverse_withdrawl(${withdrawl.id}, ${status})`)
      })

      return withdrawl
    }
  },

  Withdrawl: {
    satsPaying: w => Math.floor(w.msatsPaying / 1000),
    satsPaid: w => Math.floor(w.msatsPaid / 1000),
    satsFeePaying: w => Math.floor(w.msatsFeePaying / 1000),
    satsFeePaid: w => Math.floor(w.msatsFeePaid / 1000)
  }
}