Add OrderValidator contract

1 files changed, 140 insertions, 0 deletions

diff --git a/packages/contracts/src/2.0.0/extensions/OrderValidator/OrderValidator.sol b/packages/contracts/src/2.0.0/extensions/OrderValidator/OrderValidator.sol
new file mode 100644
index 000000000..dcbbd7fa5
--- /dev/null
+++ b/packages/contracts/src/2.0.0/extensions/OrderValidator/OrderValidator.sol
@@ -0,0 +1,140 @@
+/*
+
+  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 "../../protocol/Exchange/interfaces/IExchange.sol";
+import "../../protocol/Exchange/libs/LibOrder.sol";
+import "../../tokens/ERC20Token/IERC20Token.sol";
+import "../../tokens/ERC721Token/IERC721Token.sol";
+import "../../utils/LibBytes/LibBytes.sol";
+
+
+contract OrderValidator {
+
+    bytes4 constant internal ERC20_DATA_ID = bytes4(keccak256("ERC20Token(address)"));
+    bytes4 constant internal ERC721_DATA_ID = bytes4(keccak256("ERC721Token(address,uint256)"));
+
+    using LibBytes for bytes;
+
+    struct TraderInfo {
+        uint256 makerBalance;    // Maker's balance of makerAsset
+        uint256 makerAllowance;  // Maker's allowance to corresponding AssetProxy
+        uint256 takerBalance;    // Taker's balance of takerAsset
+        uint256 takerAllowance;  // Taker's allowance to corresponding AssetProxy
+    }
+
+    // Exchange contract.
+    // solhint-disable-next-line var-name-mixedcase
+    IExchange internal EXCHANGE;
+
+    constructor (address _exchange)
+        public
+    {
+        EXCHANGE = IExchange(_exchange);
+    }
+
+    /// @dev Fetches information for order and maker/taker of order.
+    /// @param order The order structure.
+    /// @param takerAddress Address that will be filling the order.
+    /// @return OrderInfo and TraderInfo instances for given order.
+    function getOrderAndTraderInfo(LibOrder.Order memory order, address takerAddress)
+        public
+        view
+        returns (LibOrder.OrderInfo memory orderInfo, TraderInfo memory traderInfo)
+    {
+        orderInfo = EXCHANGE.getOrderInfo(order);
+        traderInfo = getTraderInfo(order, takerAddress);
+        return (orderInfo, traderInfo);
+    }
+
+    /// @dev Fetches information for all passed in orders and the makers/takers of each order.
+    /// @param orders Array of order specifications.
+    /// @param takerAddresses Array of taker addresses corresponding to each order.
+    /// @return Arrays of OrderInfo and TraderInfo instances that correspond to each order.
+    function getOrdersAndTradersInfo(LibOrder.Order[] memory orders, address[] memory takerAddresses)
+        public
+        view
+        returns (LibOrder.OrderInfo[] memory ordersInfo, TraderInfo[] memory tradersInfo)
+    {
+        ordersInfo = EXCHANGE.getOrdersInfo(orders);
+        tradersInfo = getTradersInfo(orders, takerAddresses);
+        return (ordersInfo, tradersInfo);
+    }
+
+    /// @dev Fetches balance and allowances for maker and taker of order.
+    /// @param order The order structure.
+    /// @param takerAddress Address that will be filling the order.
+    /// @return Balances and allowances of maker and taker of order.
+    function getTraderInfo(LibOrder.Order memory order, address takerAddress)
+        public
+        view
+        returns (TraderInfo memory traderInfo)
+    {
+        (traderInfo.makerBalance, traderInfo.makerAllowance) = getBalanceAndAllowance(order.makerAddress, order.makerAssetData);
+        (traderInfo.takerBalance, traderInfo.takerAllowance) = getBalanceAndAllowance(takerAddress, order.takerAssetData);
+        return traderInfo;
+    }
+
+    /// @dev Fetches balances and allowances of maker and taker for each provided order.
+    /// @param orders Array of order specifications.
+    /// @param takerAddresses Array of taker addresses corresponding to each order.
+    /// @return Array of balances and allowances for maker and taker of each order.
+    function getTradersInfo(LibOrder.Order[] memory orders, address[] memory takerAddresses)
+        public
+        view
+        returns (TraderInfo[] memory)
+    {
+        uint256 ordersLength = orders.length;
+        TraderInfo[] memory tradersInfo = new TraderInfo[](ordersLength);
+        for (uint256 i = 0; i != ordersLength; i++) {
+            tradersInfo[i] = getTraderInfo(orders[i], takerAddresses[i]);
+        }
+        return tradersInfo;
+    }
+
+    /// @dev Fetches token balances and allowances of an address to given assetProxy. Supports ERC20 and ERC721.
+    /// @param target Address to fetch balances and allowances of.
+    /// @param assetData Encoded data that can be decoded by a specified proxy contract when transferring asset.
+    /// @return Balance of asset and allowance set to given proxy of asset.
+    ///         For ERC721 tokens, these values will always be 1 or 0.
+    function getBalanceAndAllowance(address target, bytes memory assetData)
+        public
+        view
+        returns (uint256 balance, uint256 allowance)
+    {
+        bytes4 assetProxyId = assetData.readBytes4(0);
+        address token = assetData.readAddress(16);
+        address assetProxy = EXCHANGE.getAssetProxy(assetProxyId);
+
+        if (assetProxyId == ERC20_DATA_ID) {
+            balance = IERC20Token(token).balanceOf(target);
+            allowance = IERC20Token(token).allowance(target, assetProxy);
+        } else if (assetProxyId == ERC721_DATA_ID) {
+            uint256 tokenId = assetData.readUint256(36);
+            address owner = IERC721Token(token).ownerOf(tokenId);
+            balance = target == owner ? 1 : 0;
+            bool isApproved = IERC721Token(token).isApprovedForAll(target, assetProxy) || IERC721Token(token).getApproved(tokenId) == assetProxy;
+            allowance = isApproved ? 1 : 0;
+        } else {
+            revert("UNSUPPORTED_ASSET_PROXY");
+        }
+        return (balance, allowance);
+    }
+}