feat: custom provider that only acts as relayer on low balance and calling specific functions (#300)

* feat: hide token offers if you don't have ETH in your wallet
* fix: code review
* feat: hidde other assets from profile
* fix: code review
* feat: custom provider
* fix: code review
* fix: code revew / reversing condition

contracts/teller-network/Escrow.sol

@@ -43,7 +43,7 @@ contract Escrow is Pausable, MessageSigned, Fees, Arbitrable, RelayRecipient {
     }
 
     function setRelayHubAddress(address _relayHub) public onlyOwner {
-        init_relay_hub(RelayHub(_relayHub));
+        set_relay_hub(RelayHub(_relayHub));
     }
 
     Arbitration arbitration;

embarkConfig/contracts.js

@@ -260,6 +260,46 @@ module.exports = {
     dappConnection: ["$WEB3"]
   },
 
+  ropsten: {
+    tracking: 'shared.ropsten.chains.json',
+    contracts: {
+      Escrow: {
+        args: ["$License", "$Arbitration", "$MetadataStore", "$SNT", BURN_ADDRESS, FEE_AMOUNT],
+        deps: ['RelayHub'],
+        onDeploy: [
+          "Arbitration.methods.setEscrowAddress('$Escrow').send()",
+          "MetadataStore.methods.setEscrowAddress('$Escrow').send()",
+          "Escrow.methods.setRelayHubAddress('$RelayHub').send()",
+          "RelayHub.methods.depositFor('$Escrow').send({value: 300000000000000000})"
+        ]
+      },
+      SNT: {
+        address: "0xc55cf4b03948d7ebc8b9e8bad92643703811d162"
+      },
+      "RLPReader": {
+        deploy: false
+      },
+      "RelayHub": {
+        address: "0x1349584869A1C7b8dc8AE0e93D8c15F5BB3B4B87"
+      }
+    },
+    deployment: {
+      accounts: [
+        {
+          mnemonic: secret.mnemonic,
+          hdpath: secret.hdpath || "m/44'/60'/0'/0/",
+          numAddresses: "10"
+        }
+      ],
+      host: `ropsten.infura.io/${secret.infuraKey}`,
+      port: false,
+      protocol: 'https',
+      type: "rpc"
+    },
+    afterDeploy: dataMigration.bind(null, LICENSE_PRICE, ARB_LICENSE_PRICE, FEE_AMOUNT),
+    dappConnection: ["$WEB3"]
+  },
+
   // merges with the settings in default
   // used with "embark run livenet"
   livenet: {

shared.ropsten.chains.json

@@ -0,0 +1,46 @@
+{
+  "0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d": {
+    "contracts": {
+      "0x3043b04ad856d169c8f0b0509c0bc63192dc7edd92d6933c58708298a0e381be": {
+        "name": "ENSRegistry",
+        "address": "0x112234455c3a32fd11230c42e7bccd4a84e02010"
+      },
+      "0x4f96b534860cd72e9388b7373c14f4d9bdc201a81bdccdc1b2922865de029497": {
+        "name": "RelayHub",
+        "address": "0x1349584869A1C7b8dc8AE0e93D8c15F5BB3B4B87"
+      },
+      "0x573ce922ef30ea27239add0fb9f2af8d008314dc4a0b3eaefa0adaf8963e44fa": {
+        "name": "StandardToken",
+        "address": "0xEAFb5d3c2c79B48896589ec1dfd1E95ed24D6f93"
+      },
+      "0x5cd70a563902729e50887cf8436b89ccf72107e0acf1a98fd78d1b68c0a8edcc": {
+        "name": "MiniMeTokenFactory",
+        "address": "0x1B3748Bdc4aF6f6BE159DDDEA0154fa3717cB516"
+      },
+      "0x90633e0d0e44dedf48012ba2f1f863ad09468d7fb9793830f6e1a8adbeaaf2e7": {
+        "name": "SNT",
+        "address": "0xc55cf4b03948d7ebc8b9e8bad92643703811d162"
+      },
+      "0x823f81eb5239fd857afd6bb050d2d628acddcaf2394ef641cd91cf0b8ff874b9": {
+        "name": "ERC20Receiver",
+        "address": "0xB59B23736D852b854aE0eE6687c2b90B01A02AB4"
+      },
+      "0x2677020cbbcaa18ce69dd8bb8df64aa0e52a0223b292a7a9abb9a9bdef750dd3": {
+        "name": "License",
+        "address": "0x0c7e44b251861a8D4E5E1C81E100CAAd4DCD1DEc"
+      },
+      "0x744d8dd8d4284e8cdebc5adaf2047826cb846f723c7ec842d12ad5b52678a73a": {
+        "name": "Arbitration",
+        "address": "0xaCd119C6049D3cDAe874d73b944a25592233Dd14"
+      },
+      "0xf0e3441440660cc814b11ddb03e1e1f801b6208fe8d821643596e92ac3af2450": {
+        "name": "MetadataStore",
+        "address": "0x72296A3Bd9bdcdE4bCa5fa63920D40388D84cafB"
+      },
+      "0x6736899f25ec619bbd3b81360f73a21009700e238aa3d743aaa8f9456e4ea5d3": {
+        "name": "Escrow",
+        "address": "0xe515E50DeB4280a3C4f57509CCA9310B0D75b501"
+      }
+    }
+  }
+}

src/js/pages/OffersList/index.jsx

@@ -19,7 +19,7 @@ import {sortByDate, sortByRating} from '../../utils/sorters';
 import './index.scss';
 import {withNamespaces} from "react-i18next";
 import {addressCompare} from "../../utils/address";
-import {checkEnoughETH, filterValidGaslessOffers} from "../../utils/transaction";
+import {checkNotEnoughETH, filterValidGaslessOffers} from "../../utils/transaction";
 
 class OffersList extends Component {
   constructor(props) {
@@ -89,7 +89,7 @@ class OffersList extends Component {
   };
 
   render() {
-    const notEnoughETH = checkEnoughETH(this.props.gasPrice, this.props.ethBalance);
+    const notEnoughETH = checkNotEnoughETH(this.props.gasPrice, this.props.ethBalance);
     let filteredOffers = filterValidGaslessOffers(this.props.offers, notEnoughETH);
 
     if (this.state.locationCoords) {

src/js/pages/Profile/index.jsx

@@ -14,7 +14,7 @@ import newBuy from "../../features/newBuy";
 import network from "../../features/network";
 
 import {addressCompare} from "../../utils/address";
-import {checkEnoughETH, filterValidGaslessOffers} from "../../utils/transaction";
+import {checkNotEnoughETH, filterValidGaslessOffers} from "../../utils/transaction";
 
 import './index.scss';
 import Loading from "../../components/Loading";
@@ -39,7 +39,7 @@ class Profile extends Component {
     const {profile, prices, address} = this.props;
     if(!profile || !prices) return <Loading page={true} />;
 
-    const notEnoughETH = checkEnoughETH(this.props.gasPrice, this.props.ethBalance);
+    const notEnoughETH = checkNotEnoughETH(this.props.gasPrice, this.props.ethBalance);
     const filteredOffers = filterValidGaslessOffers(profile.offers, notEnoughETH);
 
     return (

src/js/provider.js

@@ -0,0 +1,56 @@
+/* global web3 */
+import Escrow from '../embarkArtifacts/contracts/Escrow';
+import {checkNotEnoughETH} from './utils/transaction';
+import {addressCompare} from './utils/address';
+
+const VALID_OPERATIONS = {
+  "cancel(uint256)": "40e58ee5",
+  "create(address,uint256,uint256,uint8,uint256,bytes,string,string)": "a63c5162",
+  "openCase(uint256,string)": "58b67904",
+  "pay(uint256)": "c290d691"
+};
+
+class Provider {
+    constructor(origProvider, relayProvider) {
+        this.origProvider = origProvider;
+        this.relayProvider = relayProvider;
+        this.origProviderSend = (this.origProvider['sendAsync'] || this.origProvider['send']).bind(this.origProvider);
+        this.relayProviderSend = (this.relayProvider['sendAsync'] || this.relayProvider['send']).bind(this.relayProvider);
+    }
+
+    send(payload, callback) {
+      const params = payload.params[0];
+
+      if(!(params && params.to && addressCompare(params.to, Escrow.options.address.toLowerCase()) && 
+           payload.method === "eth_sendTransaction" && 
+           Object.values(VALID_OPERATIONS).includes(params.data.substring(2, 10)))){
+        this.origProviderSend(payload, callback);
+        return;
+      }
+
+      (async () => {
+        const balance = await web3.eth.getBalance(web3.eth.defaultAccount);
+        const gasPrice = await web3.eth.getGasPrice();
+        if(checkNotEnoughETH(gasPrice, balance)){
+          // Increase 120%. 
+          // Normally we would use gaspriceFactorPercent on tabookey.RelayProvider
+          // but this version of web3 does a getPrice before send() if the gas price is null
+          // to set this gas price as a parameter. Tabookey will then use this value directly
+          // without applying the factor percent
+          const useGasPrice = web3.utils.toBN(gasPrice).mul(web3.utils.toBN("120")).div(web3.utils.toBN("100"));
+          payload.params[0].gasPrice = web3.utils.toHex(useGasPrice);
+          this.relayProviderSend(payload, function (error, result) {
+            callback(error, result);
+          });
+        } else {
+          this.origProviderSend(payload, callback);
+        }
+      })();
+    }
+
+    sendAsync(payload, callback) {
+        return this.send(payload, callback);
+    }
+}
+
+export default Provider;

src/js/services/embarkjs.js

@@ -1,6 +1,8 @@
 /*global web3*/
 import EmbarkJS from '../../embarkArtifacts/embarkjs';
 import {contactCodeRegExp} from '../utils/address';
+import TellerProvider from '../provider';
+import tabookey from 'tabookey-gasless';
 
 export function onReady() {
   return new Promise((resolve, reject) => {
@@ -9,6 +11,12 @@ export function onReady() {
         return reject(err);
       }
 
+      // A relay gets compensated whenever it relays a transaction: whatever the gas usage it pays, 
+      // it gets back the same plus the "txFee" precent - that is, it gets back ( (txFee+100)*gasUsed ) / 100
+      const relayProvider = new tabookey.RelayProvider(web3.currentProvider, { txfee: 12 });
+      const customProvider = new TellerProvider(web3.currentProvider, relayProvider);
+      web3.setProvider(customProvider);
+
       resolve();
     });
   });

src/js/utils/transaction.js

@@ -13,7 +13,7 @@ export const calculateEscrowPrice = (escrow, prices) => {
 
 const toBN = web3.utils.toBN;
 
-export const checkEnoughETH = (gasPrice, ethBalance) => {
+export const checkNotEnoughETH = (gasPrice, ethBalance) => {
   const relayGasPrice = toBN(gasPrice || '0').mul(toBN(120)).div(toBN(100)); // 120%. toBN doesnt like decimals?
   return toBN(web3.utils.toWei(ethBalance || '0', 'ether')).lt(toBN(500000).mul(relayGasPrice)); // only allow ETH if less than 500000*gasPrice
 };