import { assetProxyUtils } from '@0xproject/order-utils'; import { AssetProxyId, SignedOrder } from '@0xproject/types'; import { BigNumber } from '@0xproject/utils'; import { Web3Wrapper } from '@0xproject/web3-wrapper'; import { Provider, TransactionReceiptWithDecodedLogs, TxDataPayable } from 'ethereum-types'; import * as _ from 'lodash'; import { ForwarderContract } from '../../generated_contract_wrappers/forwarder'; import { constants } from './constants'; import { formatters } from './formatters'; import { LogDecoder } from './log_decoder'; import { MarketSellOrders } from './types'; const DEFAULT_FEE_PROPORTION = 0; const PERCENTAGE_DENOMINATOR = 10000; const ZERO_AMOUNT = new BigNumber(0); const INSUFFICENT_ORDERS_FOR_MAKER_AMOUNT = 'Unable to satisfy makerAssetFillAmount with provided orders'; export class ForwarderWrapper { private readonly _web3Wrapper: Web3Wrapper; private readonly _forwarderContract: ForwarderContract; private readonly _logDecoder: LogDecoder; private readonly _zrxAddress: string; private static _createOptimizedSellOrders(signedOrders: SignedOrder[]): MarketSellOrders { const marketSellOrders = formatters.createMarketSellOrders(signedOrders, ZERO_AMOUNT); const assetDataId = assetProxyUtils.decodeAssetDataId(signedOrders[0].makerAssetData); // Contract will fill this in for us as all of the assetData is assumed to be the same for (let i = 0; i < signedOrders.length; i++) { if (i !== 0 && assetDataId === AssetProxyId.ERC20) { // Forwarding contract will fill this in from the first order marketSellOrders.orders[i].makerAssetData = constants.NULL_BYTES; } marketSellOrders.orders[i].takerAssetData = constants.NULL_BYTES; } return marketSellOrders; } private static _createOptimizedZRXSellOrders(signedOrders: SignedOrder[]): MarketSellOrders { const marketSellOrders = formatters.createMarketSellOrders(signedOrders, ZERO_AMOUNT); // Contract will fill this in for us as all of the assetData is assumed to be the same for (let i = 0; i < signedOrders.length; i++) { marketSellOrders.orders[i].makerAssetData = constants.NULL_BYTES; marketSellOrders.orders[i].takerAssetData = constants.NULL_BYTES; } return marketSellOrders; } private static _calculateAdditionalFeeProportionAmount(feeProportion: number, fillAmountWei: BigNumber): BigNumber { if (feeProportion > 0) { // Add to the total ETH transaction to ensure all NFTs can be filled after fees // 150 = 1.5% = 0.015 const denominator = new BigNumber(1).minus(new BigNumber(feeProportion).dividedBy(PERCENTAGE_DENOMINATOR)); return fillAmountWei.dividedBy(denominator).round(0, BigNumber.ROUND_FLOOR); } return fillAmountWei; } constructor(contractInstance: ForwarderContract, provider: Provider, zrxAddress: string) { this._forwarderContract = contractInstance; this._web3Wrapper = new Web3Wrapper(provider); this._logDecoder = new LogDecoder(this._web3Wrapper, this._forwarderContract.address); // this._web3Wrapper.abiDecoder.addABI(contractInstance.abi); this._zrxAddress = zrxAddress; } public async marketBuyTokensWithEthAsync( orders: SignedOrder[], feeOrders: SignedOrder[], makerTokenBuyAmount: BigNumber, txData: TxDataPayable, opts: { feeProportion?: number; feeRecipient?: string } = {}, ): Promise { const params = ForwarderWrapper._createOptimizedSellOrders(orders); const feeParams = ForwarderWrapper._createOptimizedZRXSellOrders(feeOrders); const feeProportion = _.isUndefined(opts.feeProportion) ? DEFAULT_FEE_PROPORTION : opts.feeProportion; const feeRecipient = _.isUndefined(opts.feeRecipient) ? constants.NULL_ADDRESS : opts.feeRecipient; const txHash: string = await this._forwarderContract.marketBuyTokensWithEth.sendTransactionAsync( params.orders, params.signatures, feeParams.orders, feeParams.signatures, makerTokenBuyAmount, feeProportion, feeRecipient, txData, ); const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash); return tx; } public async marketSellEthForERC20Async( orders: SignedOrder[], feeOrders: SignedOrder[], txData: TxDataPayable, opts: { feeProportion?: number; feeRecipient?: string } = {}, ): Promise { const assetDataId = assetProxyUtils.decodeAssetDataId(orders[0].makerAssetData); if (assetDataId !== AssetProxyId.ERC20) { throw new Error('Asset type not supported by marketSellEthForERC20'); } const params = ForwarderWrapper._createOptimizedSellOrders(orders); const feeParams = ForwarderWrapper._createOptimizedZRXSellOrders(feeOrders); const feeProportion = _.isUndefined(opts.feeProportion) ? DEFAULT_FEE_PROPORTION : opts.feeProportion; const feeRecipient = _.isUndefined(opts.feeRecipient) ? constants.NULL_ADDRESS : opts.feeRecipient; const txHash: string = await this._forwarderContract.marketSellEthForERC20.sendTransactionAsync( params.orders, params.signatures, feeParams.orders, feeParams.signatures, feeProportion, feeRecipient, txData, ); const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash); return tx; } public async calculateMarketBuyFillAmountWeiAsync( orders: SignedOrder[], feeOrders: SignedOrder[], feeProportion: number, makerAssetFillAmount: BigNumber, ): Promise { const assetProxyId = assetProxyUtils.decodeAssetDataId(orders[0].makerAssetData); switch (assetProxyId) { case AssetProxyId.ERC20: { const fillAmountWei = this._calculateMarketBuyERC20FillAmountAsync( orders, feeOrders, feeProportion, makerAssetFillAmount, ); return fillAmountWei; } case AssetProxyId.ERC721: { const fillAmountWei = await this._calculateMarketBuyERC721FillAmountAsync( orders, feeOrders, feeProportion, ); return fillAmountWei; } default: throw new Error(`Invalid Asset Proxy Id: ${assetProxyId}`); } } private async _calculateMarketBuyERC20FillAmountAsync( orders: SignedOrder[], feeOrders: SignedOrder[], feeProportion: number, makerAssetFillAmount: BigNumber, ): Promise { const makerAssetData = assetProxyUtils.decodeAssetData(orders[0].makerAssetData); const makerAssetToken = makerAssetData.tokenAddress; const params = formatters.createMarketBuyOrders(orders, makerAssetFillAmount); let fillAmountWei; if (makerAssetToken === this._zrxAddress) { // If buying ZRX we buy the tokens and fees from the ZRX order in one step const expectedBuyFeeTokensFillResults = await this._forwarderContract.calculateMarketBuyZrxResults.callAsync( params.orders, makerAssetFillAmount, ); if (expectedBuyFeeTokensFillResults.makerAssetFilledAmount.lessThan(makerAssetFillAmount)) { throw new Error(INSUFFICENT_ORDERS_FOR_MAKER_AMOUNT); } fillAmountWei = expectedBuyFeeTokensFillResults.takerAssetFilledAmount; } else { const expectedMarketBuyFillResults = await this._forwarderContract.calculateMarketBuyResults.callAsync( params.orders, makerAssetFillAmount, ); if (expectedMarketBuyFillResults.makerAssetFilledAmount.lessThan(makerAssetFillAmount)) { throw new Error(INSUFFICENT_ORDERS_FOR_MAKER_AMOUNT); } fillAmountWei = expectedMarketBuyFillResults.takerAssetFilledAmount; const expectedFeeAmount = expectedMarketBuyFillResults.takerFeePaid; if (expectedFeeAmount.greaterThan(ZERO_AMOUNT)) { const expectedFeeFillFillAmountWei = await this._calculateMarketBuyERC20FillAmountAsync( feeOrders, [], DEFAULT_FEE_PROPORTION, expectedFeeAmount, ); fillAmountWei = fillAmountWei.plus(expectedFeeFillFillAmountWei); } } fillAmountWei = ForwarderWrapper._calculateAdditionalFeeProportionAmount(feeProportion, fillAmountWei); return fillAmountWei; } private async _calculateMarketBuyERC721FillAmountAsync( orders: SignedOrder[], feeOrders: SignedOrder[], feeProportion: number, ): Promise { // Total cost when buying ERC721 is the total cost of all ERC721 orders + any fee abstraction let fillAmountWei = _.reduce( orders, (totalAmount: BigNumber, order: SignedOrder) => { return totalAmount.plus(order.takerAssetAmount); }, ZERO_AMOUNT, ); const totalFees = _.reduce( orders, (totalAmount: BigNumber, order: SignedOrder) => { return totalAmount.plus(order.takerFee); }, ZERO_AMOUNT, ); if (totalFees.greaterThan(ZERO_AMOUNT)) { // Calculate the ZRX fee abstraction cost const emptyFeeOrders: SignedOrder[] = []; const expectedFeeAmountWei = await this._calculateMarketBuyERC20FillAmountAsync( feeOrders, emptyFeeOrders, DEFAULT_FEE_PROPORTION, totalFees, ); fillAmountWei = fillAmountWei.plus(expectedFeeAmountWei); } fillAmountWei = ForwarderWrapper._calculateAdditionalFeeProportionAmount(feeProportion, fillAmountWei); return fillAmountWei; } }