1 files changed, 213 insertions, 0 deletions
diff --git a/packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol b/packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol
new file mode 100644
index 000000000..42cec4d36
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+++ b/packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol
@@ -0,0 +1,213 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "./libs/LibConstants.sol";
+import "./mixins/MWeth.sol";
+import "./mixins/MAssets.sol";
+import "./mixins/MExchangeWrapper.sol";
+import "./interfaces/IForwarderCore.sol";
+import "../../utils/LibBytes/LibBytes.sol";
+import "../../protocol/Exchange/libs/LibOrder.sol";
+import "../../protocol/Exchange/libs/LibFillResults.sol";
+import "../../protocol/Exchange/libs/LibMath.sol";
+
+
+contract MixinForwarderCore is
+    LibFillResults,
+    LibMath,
+    LibConstants,
+    MWeth,
+    MAssets,
+    MExchangeWrapper,
+    IForwarderCore
+{
+
+    using LibBytes for bytes;
+
+    /// @dev Constructor approves ERC20 proxy to transfer ZRX and WETH on this contract's behalf.
+    constructor ()
+        public
+    {
+        address proxyAddress = EXCHANGE.getAssetProxy(ERC20_DATA_ID);
+        if (proxyAddress != address(0)) {
+            ETHER_TOKEN.approve(proxyAddress, MAX_UINT);
+            ZRX_TOKEN.approve(proxyAddress, MAX_UINT);
+        }
+    }
+
+    /// @dev Purchases as much of orders' makerAssets as possible by selling up to 95% of transaction's ETH value.
+    ///      Any ZRX required to pay fees for primary orders will automatically be purchased by this contract.
+    ///      5% of ETH value is reserved for paying fees to order feeRecipients (in ZRX) and forwarding contract feeRecipient (in ETH).
+    ///      Any ETH not spent will be refunded to sender.
+    /// @param orders Array of order specifications used containing desired makerAsset and WETH as takerAsset. 
+    /// @param signatures Proofs that orders have been created by makers.
+    /// @param feeOrders Array of order specifications containing ZRX as makerAsset and WETH as takerAsset. Used to purchase ZRX for primary order fees.
+    /// @param feeSignatures Proofs that feeOrders have been created by makers.
+    /// @param feePercentage Percentage of WETH sold that will payed as fee to forwarding contract feeRecipient.
+    /// @param feeRecipient Address that will receive ETH when orders are filled.
+    /// @return Amounts filled and fees paid by maker and taker for both sets of orders.
+    function marketSellOrdersWithEth(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint256  feePercentage,
+        address feeRecipient
+    )
+        public
+        payable
+        returns (
+            FillResults memory orderFillResults,
+            FillResults memory feeOrderFillResults
+        )
+    {
+        // Convert ETH to WETH.
+        convertEthToWeth();
+
+        uint256 wethSellAmount;
+        uint256 zrxBuyAmount;
+        uint256 makerAssetAmountPurchased;
+        if (orders[0].makerAssetData.equals(ZRX_ASSET_DATA)) {
+            // Calculate amount of WETH that won't be spent on ETH fees.
+            wethSellAmount = getPartialAmount(
+                PERCENTAGE_DENOMINATOR,
+                safeAdd(PERCENTAGE_DENOMINATOR, feePercentage),
+                msg.value
+            );
+            // Market sell available WETH.
+            // ZRX fees are paid with this contract's balance.
+            orderFillResults = marketSellWeth(
+                orders,
+                wethSellAmount,
+                signatures
+            );
+            // The fee amount must be deducted from the amount transfered back to sender.
+            makerAssetAmountPurchased = safeSub(orderFillResults.makerAssetFilledAmount, orderFillResults.takerFeePaid);
+        } else {
+            // 5% of WETH is reserved for filling feeOrders and paying feeRecipient.
+            wethSellAmount = getPartialAmount(
+                MAX_WETH_FILL_PERCENTAGE,
+                PERCENTAGE_DENOMINATOR,
+                msg.value
+            );
+            // Market sell 95% of WETH.
+            // ZRX fees are payed with this contract's balance.
+            orderFillResults = marketSellWeth(
+                orders,
+                wethSellAmount,
+                signatures
+            );
+            // Buy back all ZRX spent on fees.
+            zrxBuyAmount = orderFillResults.takerFeePaid;
+            feeOrderFillResults = marketBuyExactZrxWithWeth(
+                feeOrders,
+                zrxBuyAmount,
+                feeSignatures
+            );
+            makerAssetAmountPurchased = orderFillResults.makerAssetFilledAmount;
+        }
+
+        // Transfer feePercentage of total ETH spent on primary orders to feeRecipient.
+        // Refund remaining ETH to msg.sender.
+        transferEthFeeAndRefund(
+            orderFillResults.takerAssetFilledAmount,
+            feeOrderFillResults.takerAssetFilledAmount,
+            feePercentage,
+            feeRecipient
+        );
+
+        // Transfer purchased assets to msg.sender.
+        transferAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased);
+    }
+
+    /// @dev Attempt to purchase makerAssetFillAmount of makerAsset by selling ETH provided with transaction.
+    ///      Any ZRX required to pay fees for primary orders will automatically be purchased by this contract.
+    ///      Any ETH not spent will be refunded to sender.
+    /// @param orders Array of order specifications used containing desired makerAsset and WETH as takerAsset. 
+    /// @param makerAssetFillAmount Desired amount of makerAsset to purchase.
+    /// @param signatures Proofs that orders have been created by makers.
+    /// @param feeOrders Array of order specifications containing ZRX as makerAsset and WETH as takerAsset. Used to purchase ZRX for primary order fees.
+    /// @param feeSignatures Proofs that feeOrders have been created by makers.
+    /// @param feePercentage Percentage of WETH sold that will payed as fee to forwarding contract feeRecipient.
+    /// @param feeRecipient Address that will receive ETH when orders are filled.
+    /// @return Amounts filled and fees paid by maker and taker for both sets of orders.
+    function marketBuyOrdersWithEth(
+        LibOrder.Order[] memory orders,
+        uint256 makerAssetFillAmount,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint256  feePercentage,
+        address feeRecipient
+    )
+        public
+        payable
+        returns (
+            FillResults memory orderFillResults,
+            FillResults memory feeOrderFillResults
+        )
+    {
+        // Convert ETH to WETH.
+        convertEthToWeth();
+
+        uint256 zrxBuyAmount;
+        uint256 makerAssetAmountPurchased;
+        if (orders[0].makerAssetData.equals(ZRX_ASSET_DATA)) {
+            // If the makerAsset is ZRX, it is not necessary to pay fees out of this
+            // contracts's ZRX balance because fees are factored into the price of the order.
+            orderFillResults = marketBuyExactZrxWithWeth(
+                orders,
+                makerAssetFillAmount,
+                signatures
+            );
+            // The fee amount must be deducted from the amount transfered back to sender.
+            makerAssetAmountPurchased = safeSub(orderFillResults.makerAssetFilledAmount, orderFillResults.takerFeePaid);
+        } else {
+            // Attemp to purchase desired amount of makerAsset.
+            // ZRX fees are payed with this contract's balance.
+            orderFillResults = marketBuyExactAmountWithWeth(
+                orders,
+                makerAssetFillAmount,
+                signatures
+            );
+            // Buy back all ZRX spent on fees.
+            zrxBuyAmount = orderFillResults.takerFeePaid;
+            feeOrderFillResults = marketBuyExactZrxWithWeth(
+                feeOrders,
+                zrxBuyAmount,
+                feeSignatures
+            );
+            makerAssetAmountPurchased = orderFillResults.makerAssetFilledAmount;
+        }
+
+        // Transfer feePercentage of total ETH spent on primary orders to feeRecipient.
+        // Refund remaining ETH to msg.sender.
+        transferEthFeeAndRefund(
+            orderFillResults.takerAssetFilledAmount,
+            feeOrderFillResults.takerAssetFilledAmount,
+            feePercentage,
+            feeRecipient
+        );
+
+        // Transfer purchased assets to msg.sender.
+        transferAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased);
+    }
+}