import * as _ from 'lodash';
import * as BigNumber from 'bignumber.js';
import promisify = require('es6-promisify');
import {Web3Wrapper} from '../web3_wrapper';
import {
ECSignature,
ExchangeContract,
ExchangeContractErrCodes,
ExchangeContractErrs,
FillOrderValidationErrs,
OrderValues,
OrderAddresses,
SignedOrder,
ContractEvent,
ZeroExError,
ExchangeEvents,
SubscriptionOpts,
IndexFilterValues,
CreateContractEvent,
ContractEventObj,
EventCallback,
} from '../types';
import {assert} from '../utils/assert';
import {utils} from '../utils/utils';
import {ContractWrapper} from './contract_wrapper';
import * as ExchangeArtifacts from '../artifacts/Exchange.json';
import {ecSignatureSchema} from '../schemas/ec_signature_schema';
import {signedOrderSchema} from '../schemas/order_schemas';
import {SchemaValidator} from '../utils/schema_validator';
import {ContractResponse} from '../types';
import {constants} from '../utils/constants';
import {TokenWrapper} from './token_wrapper';
export class ExchangeWrapper extends ContractWrapper {
private exchangeContractErrCodesToMsg = {
[ExchangeContractErrCodes.ERROR_FILL_EXPIRED]: ExchangeContractErrs.ORDER_EXPIRED,
[ExchangeContractErrCodes.ERROR_CANCEL_EXPIRED]: ExchangeContractErrs.ORDER_EXPIRED,
[ExchangeContractErrCodes.ERROR_FILL_NO_VALUE]: ExchangeContractErrs.ORDER_REMAINING_FILL_AMOUNT_ZERO,
[ExchangeContractErrCodes.ERROR_CANCEL_NO_VALUE]: ExchangeContractErrs.ORDER_REMAINING_FILL_AMOUNT_ZERO,
[ExchangeContractErrCodes.ERROR_FILL_TRUNCATION]: ExchangeContractErrs.ORDER_ROUNDING_ERROR,
[ExchangeContractErrCodes.ERROR_FILL_BALANCE_ALLOWANCE]: ExchangeContractErrs.ORDER_BALANCE_ALLOWANCE_ERROR,
};
private exchangeContractIfExists?: ExchangeContract;
private exchangeLogEventObjs: ContractEventObj[];
private tokenWrapper: TokenWrapper;
constructor(web3Wrapper: Web3Wrapper, tokenWrapper: TokenWrapper) {
super(web3Wrapper);
this.tokenWrapper = tokenWrapper;
this.exchangeLogEventObjs = [];
}
public async invalidateContractInstanceAsync(): Promise<void> {
await this.stopWatchingExchangeLogEventsAsync();
delete this.exchangeContractIfExists;
}
public async isValidSignatureAsync(dataHex: string, ecSignature: ECSignature,
signerAddressHex: string): Promise<boolean> {
assert.isHexString('dataHex', dataHex);
assert.doesConformToSchema('ecSignature', ecSignature, ecSignatureSchema);
assert.isETHAddressHex('signerAddressHex', signerAddressHex);
const senderAddress = await this.web3Wrapper.getSenderAddressOrThrowAsync();
const exchangeInstance = await this.getExchangeContractAsync();
const isValidSignature = await exchangeInstance.isValidSignature.call(
signerAddressHex,
dataHex,
ecSignature.v,
ecSignature.r,
ecSignature.s,
{
from: senderAddress,
},
);
return isValidSignature;
}
/**
* Returns the unavailable takerAmount of an order. Unavailable amount is defined as the total
* amount that has been filled or cancelled. The remaining takerAmount can be calculated by
* subtracting the unavailable amount from the total order takerAmount.
*/
public async getUnavailableTakerAmountAsync(orderHashHex: string): Promise<BigNumber.BigNumber> {
assert.isValidOrderHash('orderHashHex', orderHashHex);
const exchangeContract = await this.getExchangeContractAsync();
let unavailableAmountInBaseUnits = await exchangeContract.getUnavailableValueT.call(orderHashHex);
// Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
unavailableAmountInBaseUnits = new BigNumber(unavailableAmountInBaseUnits);
return unavailableAmountInBaseUnits;
}
/**
* Retrieve the takerAmount of an order that has already been filled.
*/
public async getFilledTakerAmountAsync(orderHashHex: string): Promise<BigNumber.BigNumber> {
assert.isValidOrderHash('orderHashHex', orderHashHex);
const exchangeContract = await this.getExchangeContractAsync();
let fillAmountInBaseUnits = await exchangeContract.filled.call(orderHashHex);
// Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
fillAmountInBaseUnits = new BigNumber(fillAmountInBaseUnits);
return fillAmountInBaseUnits;
}
/**
* Retrieve the takerAmount of an order that has been cancelled.
*/
public async getCanceledTakerAmountAsync(orderHashHex: string): Promise<BigNumber.BigNumber> {
assert.isValidOrderHash('orderHashHex', orderHashHex);
const exchangeContract = await this.getExchangeContractAsync();
let cancelledAmountInBaseUnits = await exchangeContract.cancelled.call(orderHashHex);
// Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
cancelledAmountInBaseUnits = new BigNumber(cancelledAmountInBaseUnits);
return cancelledAmountInBaseUnits;
}
/**
* Fills a signed order with a fillAmount denominated in baseUnits of the taker token. The caller can
* decide whether they want the call to throw if the balance/allowance checks fail by setting
* shouldCheckTransfer to false. If set to true, the call will fail without throwing, preserving gas costs.
*/
public async fillOrderAsync(signedOrder: SignedOrder, fillTakerAmountInBaseUnits: BigNumber.BigNumber,
shouldCheckTransfer: boolean): Promise<void> {
assert.doesConformToSchema('signedOrder',
SchemaValidator.convertToJSONSchemaCompatibleObject(signedOrder as object),
signedOrderSchema);
assert.isBigNumber('fillTakerAmountInBaseUnits', fillTakerAmountInBaseUnits);
assert.isBoolean('shouldCheckTransfer', shouldCheckTransfer);
const senderAddress = await this.web3Wrapper.getSenderAddressOrThrowAsync();
await this.validateFillOrderAsync(signedOrder, fillTakerAmountInBaseUnits, senderAddress);
const exchangeInstance = await this.getExchangeContractAsync();
const orderAddresses: OrderAddresses = [
signedOrder.maker,
signedOrder.taker,
signedOrder.makerTokenAddress,
signedOrder.takerTokenAddress,
signedOrder.feeRecipient,
];
const orderValues: OrderValues = [
signedOrder.makerTokenAmount,
signedOrder.takerTokenAmount,
signedOrder.makerFee,
signedOrder.takerFee,
signedOrder.expirationUnixTimestampSec,
signedOrder.salt,
];
const gas = await exchangeInstance.fill.estimateGas(
orderAddresses,
orderValues,
fillTakerAmountInBaseUnits,
shouldCheckTransfer,
signedOrder.ecSignature.v,
signedOrder.ecSignature.r,
signedOrder.ecSignature.s,
{
from: senderAddress,
},
);
const response: ContractResponse = await exchangeInstance.fill(
orderAddresses,
orderValues,
fillTakerAmountInBaseUnits,
shouldCheckTransfer,
signedOrder.ecSignature.v,
signedOrder.ecSignature.r,
signedOrder.ecSignature.s,
{
from: senderAddress,
gas,
},
);
this.throwErrorLogsAsErrors(response.logs);
}
/**
* Subscribe to an event type emitted by the Exchange smart contract
*/
public async subscribeAsync(eventName: ExchangeEvents, subscriptionOpts: SubscriptionOpts,
indexFilterValues: IndexFilterValues, callback: EventCallback) {
const exchangeContract = await this.getExchangeContractAsync();
let createLogEvent: CreateContractEvent;
switch (eventName) {
case ExchangeEvents.LogFill:
createLogEvent = exchangeContract.LogFill;
break;
case ExchangeEvents.LogError:
createLogEvent = exchangeContract.LogError;
break;
case ExchangeEvents.LogCancel:
createLogEvent = exchangeContract.LogCancel;
break;
default:
utils.spawnSwitchErr('ExchangeEvents', eventName);
return;
}
const logEventObj: ContractEventObj = createLogEvent(indexFilterValues, subscriptionOpts);
logEventObj.watch(callback);
this.exchangeLogEventObjs.push(logEventObj);
}
private async stopWatchingExchangeLogEventsAsync() {
for (const logEventObj of this.exchangeLogEventObjs) {
await promisify(logEventObj.stopWatching, logEventObj)();
}
this.exchangeLogEventObjs = [];
}
private async validateFillOrderAsync(signedOrder: SignedOrder, fillAmount: BigNumber.BigNumber,
senderAddress: string) {
if (fillAmount.eq(0)) {
throw new Error(FillOrderValidationErrs.FILL_AMOUNT_IS_ZERO);
}
if (signedOrder.taker !== constants.NULL_ADDRESS && signedOrder.taker !== senderAddress) {
throw new Error(FillOrderValidationErrs.NOT_A_TAKER);
}
if (signedOrder.expirationUnixTimestampSec.lessThan(Date.now() / 1000)) {
throw new Error(FillOrderValidationErrs.EXPIRED);
}
const makerBalance = await this.tokenWrapper.getBalanceAsync(signedOrder.makerTokenAddress,
signedOrder.maker);
const takerBalance = await this.tokenWrapper.getBalanceAsync(signedOrder.takerTokenAddress, senderAddress);
const makerAllowance = await this.tokenWrapper.getProxyAllowanceAsync(signedOrder.makerTokenAddress,
signedOrder.maker);
const takerAllowance = await this.tokenWrapper.getProxyAllowanceAsync(signedOrder.takerTokenAddress,
senderAddress);
if (fillAmount.greaterThan(takerBalance)) {
throw new Error(FillOrderValidationErrs.NOT_ENOUGH_TAKER_BALANCE);
}
if (fillAmount.greaterThan(takerAllowance)) {
throw new Error(FillOrderValidationErrs.NOT_ENOUGH_TAKER_ALLOWANCE);
}
}
private throwErrorLogsAsErrors(logs: ContractEvent[]): void {
const errEvent = _.find(logs, {event: 'LogError'});
if (!_.isUndefined(errEvent)) {
const errCode = errEvent.args.errorId.toNumber();
const errMessage = this.exchangeContractErrCodesToMsg[errCode];
throw new Error(errMessage);
}
}
private async getExchangeContractAsync(): Promise<ExchangeContract> {
if (!_.isUndefined(this.exchangeContractIfExists)) {
return this.exchangeContractIfExists;
}
const contractInstance = await this.instantiateContractIfExistsAsync((ExchangeArtifacts as any));
this.exchangeContractIfExists = contractInstance as ExchangeContract;
return this.exchangeContractIfExists;
}
}
