BalancerV2IndexExchangeAdapter

contracts/interfaces/external/IBVault.sol

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+pragma solidity 0.6.10;
+pragma experimental ABIEncoderV2;
+
+interface IBVault {
+
+    enum SwapKind { GIVEN_IN, GIVEN_OUT }
+
+    function swap(
+        SingleSwap memory singleSwap,
+        FundManagement memory funds,
+        uint256 limit,
+        uint256 deadline
+    ) external payable returns (uint256);
+
+    struct SingleSwap {
+        bytes32 poolId;
+        SwapKind kind;
+        address assetIn;
+        address assetOut;
+        uint256 amount;
+        bytes userData;
+    }
+
+    struct FundManagement {
+        address sender;
+        bool fromInternalBalance;
+        address payable recipient;
+        bool toInternalBalance;
+    }
+}

contracts/protocol/integration/index-exchange/BalancerV2IndexExchangeAdapter.sol

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+/*
+    Copyright 2021 Set Labs Inc.
+
+    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.
+
+    SPDX-License-Identifier: Apache License, Version 2.0
+*/
+
+pragma solidity 0.6.10;
+pragma experimental "ABIEncoderV2";
+
+import { IBVault } from "../../../interfaces/external/IBVault.sol";
+import { IIndexExchangeAdapter } from "../../../interfaces/IIndexExchangeAdapter.sol";
+
+import { console } from "hardhat/console.sol";
+
+/**
+ * @title BalancerV2IndexExchangeAdapter
+ * @author Set Protocol
+ *
+ * A Balancer V2 exchange adapter that returns calldata for trading with GeneralIndexModule, allows trading a fixed input amount or for a fixed
+ * output amount.
+ */
+contract BalancerV2IndexExchangeAdapter is IIndexExchangeAdapter {
+
+    /* ============ State Variables ============ */
+
+    // Address of Balancer V2 vault contract
+    address public immutable vault;
+
+    /* ============ Constructor ============ */
+
+    /**
+     * Set state variables
+     *
+     * @param _vault        balancer vault address
+     */
+    constructor(address _vault) public {
+        vault = _vault;
+    }
+
+    /* ============ External Getter Functions ============ */
+
+    /**
+     * Return calldata for Balancer Vault, _isSendTokenFixed indicates whether a fixed amount of token should be sold for an unfixed amount, or
+     * if an unfixed amount of token should be spent for a fixed amount.
+     *
+     * Note: When _isSendTokenFixed is false, _sourceQuantity is defined as the max token quantity you are willing to trade, and
+     * _destinationQuantity is the exact quantity of token you are receiving.
+     *
+     * @param  _sourceToken              Address of source token to be sold
+     * @param  _destinationToken         Address of destination token to buy
+     * @param  _isSendTokenFixed         Boolean indicating if the send quantity is fixed, used to determine correct trade interface
+     * @param  _sourceQuantity           Fixed/Max amount of source token to sell
+     * @param  _destinationQuantity      Min/Fixed amount of destination tokens to receive
+     *
+     * @return address                   Target contract address
+     * @return uint256                   Call value
+     * @return bytes                     Trade calldata
+     */
+    function getTradeCalldata(
+        address _sourceToken,
+        address _destinationToken,
+        address _destinationAddress,
+        bool _isSendTokenFixed,
+        uint256 _sourceQuantity,
+        uint256 _destinationQuantity,
+        bytes memory _data
+    )
+        external
+        view
+        override
+        returns (address, uint256, bytes memory)
+    {
+        bytes32 poolId = abi.decode(_data, (bytes32));
+
+        console.logBytes32(poolId);
+        console.log(_destinationAddress);
+        console.log(_sourceQuantity);
+
+        IBVault.SingleSwap memory singleSwap = IBVault.SingleSwap({
+            poolId: poolId,
+            kind: _isSendTokenFixed ? IBVault.SwapKind.GIVEN_IN : IBVault.SwapKind.GIVEN_OUT,
+            assetIn: _sourceToken,
+            assetOut: _destinationToken,
+            amount: _isSendTokenFixed ? _sourceQuantity : _destinationQuantity,
+            userData: ""
+        });
+
+        console.log("a");
+
+        IBVault.FundManagement memory funds = IBVault.FundManagement({
+            sender: _destinationAddress,
+            fromInternalBalance: false,
+            recipient: payable(_destinationAddress),
+            toInternalBalance: false
+        });
+
+        console.log("b");
+
+        bytes memory callData = abi.encodePacked(
+            IBVault.swap.selector,
+            abi.encode(
+                singleSwap,
+                funds,
+                _isSendTokenFixed ? _destinationQuantity : _sourceQuantity,
+                uint256(-1)
+            )
+        );
+
+        console.log("c");
+
+        return (vault, 0, callData);
+    }
+
+    /**
+     * Returns the address to approve source tokens to for trading. This is the Balancer V2 Vault address
+     *
+     * @return address             Address of the contract to approve tokens to
+     */
+    function getSpender() external view override returns (address) {
+        return vault;
+    }
+}