Add GeneralIndexModule contract

contracts/interfaces/IExchangeAdapter.sol

@@ -30,4 +30,9 @@ interface IExchangeAdapter {
         external
         view
         returns (address, uint256, bytes memory);
+    function generateDataParam(
+        address _sellComponent, 
+        address _buyComponent, 
+        bool _fixIn
+    ) external view returns (bytes memory);
 }

contracts/protocol/integration/BalancerV1ExchangeAdapter.sol

@@ -0,0 +1,133 @@
+/*
+    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";
+
+/**
+ * @title BalancerV1ExchangeAdapter
+ * @author Set Protocol
+ *
+ * A Balancer exchange adapter that returns calldata for trading.
+ */
+contract BalancerV1ExchangeAdapter {
+
+    /* ============ Constants ============ */
+
+    // Amount of pools examined when fetching quote
+    uint256 private constant BALANCER_POOL_LIMIT = 3;
+
+    /* ============ State Variables ============ */
+
+    // Address of Uniswap V2 Router02 contract
+    address public immutable balancerProxy;
+    // Balancer proxy function string for swapping exact tokens for a minimum of receive tokens
+    string internal constant EXACT_IN = "smartSwapExactIn(address,address,uint256,uint256,uint256)";
+    // Balancer proxy function string for swapping tokens for an exact amount of receive tokens
+    string internal constant EXACT_OUT = "smartSwapExactOut(address,address,uint256,uint256,uint256)";
+
+    /* ============ Constructor ============ */
+
+    /**
+     * Set state variables
+     *
+     * @param _balancerProxy       Balancer exchange proxy address
+     */
+    constructor(address _balancerProxy) public {
+        balancerProxy = _balancerProxy;
+    }
+
+    /* ============ External Getter Functions ============ */
+
+    /**
+     * Return calldata for Balancer Proxy. Bool to select trade function is encoded in the arbitrary data parameter.
+     *
+     * @param  _sourceToken              Address of source token to be sold
+     * @param  _destinationToken         Address of destination token to buy
+     * @param  _destinationAddress       Address that assets should be transferred to
+     * @param  _sourceQuantity           Fixed/Max amount of source token to sell
+     * @param  _destinationQuantity      Min/Fixed amount of destination tokens to receive
+     * @param  _data                     Arbitrary bytes containing bool to determine function string
+     *
+     * @return address                   Target contract address
+     * @return uint256                   Call value
+     * @return bytes                     Trade calldata
+     */
+    function getTradeCalldata(
+        address _sourceToken,
+        address _destinationToken,
+        address _destinationAddress,
+        uint256 _sourceQuantity,
+        uint256 _destinationQuantity,
+        bytes memory _data
+    )
+        external
+        view
+        returns (address, uint256, bytes memory)
+    {   
+        (
+            bool shouldSwapFixedInputAmount
+        ) = abi.decode(_data, (bool));
+
+        bytes memory callData = abi.encodeWithSignature(
+            shouldSwapFixedInputAmount ? EXACT_IN : EXACT_OUT,
+            _sourceToken,
+            _destinationToken,
+            shouldSwapFixedInputAmount ? _sourceQuantity : _destinationQuantity,
+            shouldSwapFixedInputAmount ? _destinationQuantity : _sourceQuantity,
+            BALANCER_POOL_LIMIT
+        );
+
+        return (balancerProxy, 0, callData);
+    }
+
+    /**
+     * Generate data parameter to be passed to `getTradeCallData`. Returns encoded bool to select trade function.
+     *
+     * @param _sellComponent        Address of the token to be sold        
+     * @param _buyComponent         Address of the token to be bought
+     * @param _fixIn                Boolean representing if input tokens amount is fixed
+     * 
+     * @return bytes                Data parameter to be passed to `getTradeCallData`          
+     */
+    function generateDataParam(address _sellComponent, address _buyComponent, bool _fixIn)
+        external
+        view
+        returns (bytes memory) 
+    {   
+        return abi.encode(_fixIn);
+    }
+
+    /**
+     * Returns the address to approve source tokens to for trading. This is the Balancer proxy address
+     *
+     * @return address             Address of the contract to approve tokens to
+     */
+    function getSpender() external view returns (address) {
+        return balancerProxy;
+    }
+
+    /**
+     * Helper that returns the encoded data of boolean indicating the Balancer swap function to use.
+     *
+     * @return bytes               Encoded data used for trading on Balancer
+     */
+    function getBalancerExchangeData(bool _shouldSwarFixeInputtAmount) external view returns (bytes memory) {
+        return abi.encode(_shouldSwarFixeInputtAmount);
+    }
+} 

contracts/protocol/integration/UniswapV2ExchangeAdapterV2.sol

@@ -23,12 +23,13 @@ pragma experimental "ABIEncoderV2";
  * @title UniswapV2ExchangeAdapterV2
  * @author Set Protocol
  *
- * A Uniswap Router02 exchange adapter that returns calldata for trading. Includes option for 2 different trade types on Uniswap
+ * A Uniswap Router02 exchange adapter that returns calldata for trading. Includes option for 2 different trade types on Uniswap.
  *
  * CHANGE LOG:
  * - Add helper that encodes path and boolean into bytes
  * - Generalized ability to choose whether to swap an exact amount of source token for a min amount of receive token or swap a max amount of source token for
  * an exact amount of receive token
+ * - Add helper to generate data parameter for `getTradeCallData`
  *
  */
 contract UniswapV2ExchangeAdapterV2 {
@@ -64,8 +65,8 @@ contract UniswapV2ExchangeAdapterV2 {
      * @param  _sourceToken              Address of source token to be sold
      * @param  _destinationToken         Address of destination token to buy
      * @param  _destinationAddress       Address that assets should be transferred to
-     * @param  _sourceQuantity           Amount of source token to sell
-     * @param  _minDestinationQuantity   Min amount of destination token to buy
+     * @param  _sourceQuantity           Fixed/Max amount of source token to sell
+     * @param  _destinationQuantity      Min/Fixed amount of destination token to buy
      * @param  _data                     Arbitrary bytes containing trade path and bool to determine function string
      *
      * @return address                   Target contract address
@@ -77,7 +78,7 @@ contract UniswapV2ExchangeAdapterV2 {
         address _destinationToken,
         address _destinationAddress,
         uint256 _sourceQuantity,
-        uint256 _minDestinationQuantity,
+        uint256 _destinationQuantity,
         bytes memory _data
     )
         external
@@ -86,22 +87,40 @@ contract UniswapV2ExchangeAdapterV2 {
     {   
         (
             address[] memory path,
-            bool shouldSwapTokensForExactTokens
+            bool shouldSwapExactTokensForTokens
         ) = abi.decode(_data, (address[],bool));
 
-        // If shouldSwapTokensForExactTokens, use appropriate function string and flip source and destination quantities to conform with Uniswap interface
         bytes memory callData = abi.encodeWithSignature(
-            shouldSwapTokensForExactTokens ? SWAP_TOKENS_FOR_EXACT_TOKENS : SWAP_EXACT_TOKENS_FOR_TOKENS,
-            shouldSwapTokensForExactTokens ? _minDestinationQuantity : _sourceQuantity,
-            shouldSwapTokensForExactTokens ? _sourceQuantity : _minDestinationQuantity,
+            shouldSwapExactTokensForTokens ? SWAP_EXACT_TOKENS_FOR_TOKENS : SWAP_TOKENS_FOR_EXACT_TOKENS,
+            shouldSwapExactTokensForTokens ? _sourceQuantity : _destinationQuantity,
+            shouldSwapExactTokensForTokens ? _destinationQuantity : _sourceQuantity,
             path,
             _destinationAddress,
             block.timestamp
         );
-
         return (router, 0, callData);
     }
 
+    /**
+     * Generate data parameter to be passed to `getTradeCallData`. Returns encoded trade paths and bool to select trade function.
+     *
+     * @param _sellComponent        Address of the token to be sold        
+     * @param _buyComponent         Address of the token to be bought
+     * @param _fixIn                Boolean representing if input tokens amount is fixed
+     * 
+     * @return bytes                Data parameter to be passed to `getTradeCallData`          
+     */
+    function generateDataParam(address _sellComponent, address _buyComponent, bool _fixIn)
+        external
+        view
+        returns (bytes memory) 
+    {
+        address[] memory path = new address[](2);
+        path[0] = _sellComponent;
+        path[1] = _buyComponent;
+        return abi.encode(path, _fixIn);
+    }
+
     /**
      * Returns the address to approve source tokens to for trading. This is the Uniswap router address
      *
@@ -116,7 +135,7 @@ contract UniswapV2ExchangeAdapterV2 {
      *
      * @return bytes               Encoded data used for trading on Uniswap
      */
-    function getUniswapExchangeData(address[] memory _path, bool _shouldSwapTokensForExactTokens) external view returns (bytes memory) {
-        return abi.encode(_path, _shouldSwapTokensForExactTokens);
+    function getUniswapExchangeData(address[] memory _path, bool _shouldSwapExactTokensForTokens) external view returns (bytes memory) {
+        return abi.encode(_path, _shouldSwapExactTokensForTokens);
     }
 }