1 files changed, 146 insertions, 0 deletions
diff --git a/packages/website/ts/web3_wrapper.ts b/packages/website/ts/web3_wrapper.ts
new file mode 100644
index 000000000..24279f5d2
--- /dev/null
+++ b/packages/website/ts/web3_wrapper.ts
@@ -0,0 +1,146 @@
+import * as _ from 'lodash';
+import Web3 = require('web3');
+import BigNumber from 'bignumber.js';
+import promisify = require('es6-promisify');
+import {Dispatcher} from 'ts/redux/dispatcher';
+
+export class Web3Wrapper {
+    private dispatcher: Dispatcher;
+    private web3: Web3;
+    private prevNetworkId: number;
+    private shouldPollUserAddress: boolean;
+    private watchNetworkAndBalanceIntervalId: number;
+    private prevUserEtherBalanceInEth: BigNumber;
+    private prevUserAddress: string;
+    constructor(dispatcher: Dispatcher, provider: Web3.Provider, networkIdIfExists: number,
+                shouldPollUserAddress: boolean) {
+        this.dispatcher = dispatcher;
+        this.prevNetworkId = networkIdIfExists;
+        this.shouldPollUserAddress = shouldPollUserAddress;
+
+        this.web3 = new Web3();
+        this.web3.setProvider(provider);
+
+        this.startEmittingNetworkConnectionAndUserBalanceStateAsync();
+    }
+    public isAddress(address: string) {
+        return this.web3.isAddress(address);
+    }
+    public async getAccountsAsync(): Promise<string[]> {
+        const addresses = await promisify(this.web3.eth.getAccounts)();
+        return addresses;
+    }
+    public async getFirstAccountIfExistsAsync() {
+        const addresses = await this.getAccountsAsync();
+        if (_.isEmpty(addresses)) {
+            return '';
+        }
+        return (addresses as string[])[0];
+    }
+    public async getNodeVersionAsync() {
+        const nodeVersion = await promisify(this.web3.version.getNode)();
+        return nodeVersion;
+    }
+    public getProviderObj() {
+        return this.web3.currentProvider;
+    }
+    public async getNetworkIdIfExists() {
+        try {
+            const networkId = await this.getNetworkAsync();
+            return Number(networkId);
+        } catch (err) {
+            return undefined;
+        }
+    }
+    public async getBalanceInEthAsync(owner: string): Promise<BigNumber> {
+        const balanceInWei: BigNumber = await promisify(this.web3.eth.getBalance)(owner);
+        const balanceEthOldBigNumber = this.web3.fromWei(balanceInWei, 'ether');
+        const balanceEth = new BigNumber(balanceEthOldBigNumber);
+        return balanceEth;
+    }
+    public async doesContractExistAtAddressAsync(address: string): Promise<boolean> {
+        const code = await promisify(this.web3.eth.getCode)(address);
+        // Regex matches 0x0, 0x00, 0x in order to accomodate poorly implemented clients
+        const zeroHexAddressRegex = /^0[xX][0]*$/;
+        const didFindCode = _.isNull(code.match(zeroHexAddressRegex));
+        return didFindCode;
+    }
+    public async signTransactionAsync(address: string, message: string): Promise<string> {
+        const signData = await promisify(this.web3.eth.sign)(address, message);
+        return signData;
+    }
+    public async getBlockTimestampAsync(blockHash: string): Promise<number> {
+        const {timestamp} = await promisify(this.web3.eth.getBlock)(blockHash);
+        return timestamp;
+    }
+    public destroy() {
+        this.stopEmittingNetworkConnectionAndUserBalanceStateAsync();
+        // HACK: stop() is only available on providerEngine instances
+        const provider = this.web3.currentProvider;
+        if (!_.isUndefined((provider as any).stop)) {
+            (provider as any).stop();
+        }
+    }
+    // This should only be called from the LedgerConfigDialog
+    public updatePrevUserAddress(userAddress: string) {
+        this.prevUserAddress = userAddress;
+    }
+    private async getNetworkAsync() {
+        const networkId = await promisify(this.web3.version.getNetwork)();
+        return networkId;
+    }
+    private async startEmittingNetworkConnectionAndUserBalanceStateAsync() {
+        if (!_.isUndefined(this.watchNetworkAndBalanceIntervalId)) {
+            return; // we are already emitting the state
+        }
+
+        let prevNodeVersion: string;
+        this.prevUserEtherBalanceInEth = new BigNumber(0);
+        this.dispatcher.updateNetworkId(this.prevNetworkId);
+        this.watchNetworkAndBalanceIntervalId = window.setInterval(async () => {
+            // Check for network state changes
+            const currentNetworkId = await this.getNetworkIdIfExists();
+            if (currentNetworkId !== this.prevNetworkId) {
+                this.prevNetworkId = currentNetworkId;
+                this.dispatcher.updateNetworkId(currentNetworkId);
+            }
+
+            // Check for node version changes
+            const currentNodeVersion = await this.getNodeVersionAsync();
+            if (currentNodeVersion !== prevNodeVersion) {
+                prevNodeVersion = currentNodeVersion;
+                this.dispatcher.updateNodeVersion(currentNodeVersion);
+            }
+
+            if (this.shouldPollUserAddress) {
+                const userAddressIfExists = await this.getFirstAccountIfExistsAsync();
+                // Update makerAddress on network change
+                if (this.prevUserAddress !== userAddressIfExists) {
+                    this.prevUserAddress = userAddressIfExists;
+                    this.dispatcher.updateUserAddress(userAddressIfExists);
+                }
+
+                // Check for user ether balance changes
+                if (userAddressIfExists !== '') {
+                    await this.updateUserEtherBalanceAsync(userAddressIfExists);
+                }
+            } else {
+                // This logic is primarily for the Ledger, since we don't regularly poll for the address
+                // we simply update the balance for the last fetched address.
+                if (!_.isEmpty(this.prevUserAddress)) {
+                    await this.updateUserEtherBalanceAsync(this.prevUserAddress);
+                }
+            }
+        }, 5000);
+    }
+    private async updateUserEtherBalanceAsync(userAddress: string) {
+        const balance = await this.getBalanceInEthAsync(userAddress);
+        if (!balance.eq(this.prevUserEtherBalanceInEth)) {
+            this.prevUserEtherBalanceInEth = balance;
+            this.dispatcher.updateUserEtherBalance(balance);
+        }
+    }
+    private stopEmittingNetworkConnectionAndUserBalanceStateAsync() {
+        clearInterval(this.watchNetworkAndBalanceIntervalId);
+    }
+}