Add controller

server/api/controllers/claim.js

@@ -0,0 +1,161 @@
+import ClaimTx from '../models/ClaimTx'
+import { wrapAsync } from '../utils'
+import sdk from '@linkdrop/binance-sdk'
+import Table from 'cli-table'
+
+const config = require('../../config/config.json')
+
+/**
+ * Function to check whether a `linkId` has already been claimed
+ */
+const isClaimed = wrapAsync(async (req, res) => {
+  const linkId = req.params.linkId
+
+  // Check whether a claim tx exists in database
+  const oldClaimTx = await ClaimTx.findOne({
+    linkId
+  })
+
+  if (oldClaimTx && oldClaimTx.txHash) {
+    return res.json({
+      isClaimed: true,
+      txHash: oldClaimTx.txHash
+    })
+  } else return res.json({ isClaimed: false })
+})
+
+/**
+ * Helper function to transfer funds
+ * @param {String} privateKey Private key to send funds from
+ * @param {String} to Address to send funds to
+ * @param {String} asset Asset symbol
+ * @param {String} amount Asset amount in decimal form, e.g. 1.00000000
+ * @param {String} memo An optional message to send along with funds
+ * @return {Promise<Object>) `{success, txHash, error}`
+ */
+const transfer = async ({ privateKey, to, asset, amount, memo }) => {
+  try {
+    const from = sdk.utils.getAddressFromPrivateKey(privateKey)
+    const sequence = await sdk.utils.getSequence(from)
+    const bncClient = await sdk.utils.initBncClient(privateKey)
+
+    const result = await bncClient.transfer(
+      from,
+      to,
+      amount,
+      asset,
+      memo,
+      sequence
+    )
+
+    if (result.status === 200) {
+      return { success: true, txHash: result.result[0].hash }
+    } else {
+      return { success: false, error: result }
+    }
+  } catch (err) {
+    throw new Error(err)
+  }
+}
+
+const claim = wrapAsync(async (req, res) => {
+  const {
+    asset,
+    amount,
+    linkId,
+    verifierSignature,
+    receiverAddress,
+    receiverSignature
+  } = req.body
+
+  const VERIFIER_ADDRESS =
+    process.env.VERIFIER_ADDRESS || config.VERIFIER_ADDRESS
+  const SENDER_PRIVATE_KEY =
+    process.env.SENDER_PRIVATE_KEY || config.SENDER_PRIVATE_KEY
+  const senderAddress = sdk.utils.getAddressFromPrivateKey(SENDER_PRIVATE_KEY)
+
+  const table = new Table()
+
+  // Check whether a claim tx exists in database
+  const oldClaimTx = await ClaimTx.findOne({
+    linkId
+  })
+
+  if (oldClaimTx && oldClaimTx.txHash) {
+    table.push(['Tx hash', oldClaimTx.toObject().txHash])
+
+    console.log('\n✅  Submitted claim transaction')
+    console.log(table.toString(), '\n')
+
+    return res.json({
+      success: true,
+      txHash: oldClaimTx.txHash
+    })
+  } else {
+    if (
+      (await LinkdropSDK.binance.checkLinkParams({
+        asset,
+        amount,
+        linkId,
+        verifierAddress: VERIFIER_ADDRESS,
+        verifierSignature,
+        receiverAddress,
+        receiverSignature,
+        senderAddress
+      })) === true
+    ) {
+      try {
+        const memo = `Linkdrop Id: ${linkId}`
+
+        const { success, txHash, error } = await transfer({
+          privateKey: SENDER_PRIVATE_KEY,
+          to: receiverAddress,
+          asset,
+          amount: sdk.utils.formatUnits(Number(amount)),
+          memo
+        })
+
+        if (success === true && txHash) {
+          // Save claim tx to database
+          const claimTx = new ClaimTx({
+            asset,
+            amount,
+            linkId,
+            senderAddress,
+            receiverAddress,
+            verifierAddress: VERIFIER_ADDRESS,
+            txHash
+          })
+
+          const document = await claimTx.save()
+
+          for (let key in claimTx.toObject()) {
+            if (key !== '_id' && key !== '__v') {
+              table.push([key, claimTx.toObject()[key]])
+            }
+          }
+
+          console.log('\n✅  Submitted claim transaction')
+          console.log(table.toString(), '\n')
+
+          asset,
+          amount,
+          linkId,
+          verifierSignature,
+          receiverAddress,
+          receiverSignature
+        }
+
+        res.json({
+          success,
+          txHash,
+          error
+        })
+      } catch (err) {
+        console.error(err)
+      }
+    }
+  }
+})
+
+export default { claim, isClaimed }

server/api/models/ClaimTx.js

@@ -0,0 +1,15 @@
+import { Schema, model } from 'mongoose'
+
+const claimTxSchema = new Schema({
+  asset: { type: String, required: true },
+  amount: { type: String, required: true },
+  linkId: { type: String, required: true },
+  senderAddress: { type: String, required: true },
+  receiverAddress: { type: String, required: true },
+  verifierAddress: { type: String, required: true },
+  txHash: { type: String, reqiured: true }
+})
+
+const ClaimTx = model('ClaimTx', claimTxSchema)
+
+export default ClaimTx

server/package.json

@@ -5,5 +5,30 @@
   "main": "index.js",
   "author": "Amir Jumaniyazov - <[email protected]>",
   "license": "MIT",
-  "private": true
+  "private": true,
+  "dependencies": {
+    "@binance-chain/javascript-sdk": "https://github.com/Dobrokhvalov/javascript-sdk",
+    "@hapi/boom": "^7.4.2",
+    "@linkdrop/sdk": "https://github.com/LinkdropProtocol/linkdrop-sdk",
+    "axios": "^0.19.0",
+    "cli-table": "^0.3.1",
+    "cors": "^2.8.5",
+    "csvtojson": "^2.0.8",
+    "dotenv": "^8.0.0",
+    "ethers": "^4.0.31",
+    "express": "^4.17.1",
+    "fast-csv": "^3.0.1",
+    "mongoose": "^5.6.0",
+    "morgan": "^1.9.1",
+    "pm2": "^3.5.1",
+    "query-string": "^6.8.1"
+  },
+  "devDependencies": {
+    "@babel/cli": "^7.4.4",
+    "@babel/core": "^7.4.5",
+    "@babel/node": "^7.4.5",
+    "@babel/polyfill": "^7.4.4",
+    "@babel/preset-env": "^7.4.5",
+    "@babel/register": "^7.4.4",
+  }
 }