feat: Flash Mint Compound

Flash mint contract for cTokens.

Author: FlattestWhite

contracts/exchangeIssuance/FlashMintWrapped.sol

@@ -0,0 +1,236 @@
+/*
+    Copyright 2022 Index Cooperative
+
+    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 { Address } from "@openzeppelin/contracts/utils/Address.sol";
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import { Math } from "@openzeppelin/contracts/math/Math.sol";
+import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
+import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
+import { ReentrancyGuard } from "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
+
+import { IController } from "../interfaces/IController.sol";
+import { IDebtIssuanceModule } from "../interfaces/IDebtIssuanceModule.sol";
+import { ISetToken } from "../interfaces/ISetToken.sol";
+import { IWETH } from "../interfaces/IWETH.sol";
+import { PreciseUnitMath } from "../lib/PreciseUnitMath.sol";
+
+/**
+ * @title FlashMintWrapped
+ *
+ * Flash issues SetTokens whose components are purely made up of wrapped tokens.
+ * In particular, for issuance, the contract needs to:
+ * 1. For all components in a SetToken, swap input token into matching unwrapped component
+ * 2. For each unwrapped component, execute the wrapping function
+ * 3. Call on issuanceModule to issue tokens
+ */
+contract FlashMintWrapped is ReentrancyGuard {
+
+    using Address for address payable;
+    using SafeMath for uint256;
+    using PreciseUnitMath for uint256;
+    using SafeERC20 for IERC20;
+    using SafeERC20 for ISetToken;
+
+    struct WrappedCalldata {
+        address target;
+        uint256 quantity;
+        bytes callData;
+    }
+
+    /* ============ Enums ============ */
+
+    /* ============ Constants ============= */
+
+    uint256 constant private MAX_UINT96 = 2**96 - 1;
+    address constant public ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
+
+    /* ============ State Variables ============ */
+
+    IController public immutable controller;
+
+    /* ============ Events ============ */
+
+    event ExchangeIssue(
+        address indexed _recipient,     // The recipient address of the issued SetTokens
+        ISetToken indexed _setToken,    // The issued SetToken
+        IERC20 indexed _inputToken,     // The address of the input asset(ERC20/ETH) used to issue the SetTokens
+        uint256 _amountInputToken,      // The amount of input tokens used for issuance
+        uint256 _amountSetIssued        // The amount of SetTokens received by the recipient
+    );
+
+    event ExchangeRedeem(
+        address indexed _recipient,     // The recipient address which redeemed the SetTokens
+        ISetToken indexed _setToken,    // The redeemed SetToken
+        IERC20 indexed _outputToken,    // The address of output asset(ERC20/ETH) received by the recipient
+        uint256 _amountSetRedeemed,     // The amount of SetTokens redeemed for output tokens
+        uint256 _amountOutputToken      // The amount of output tokens received by the recipient
+    );
+
+    /* ============ Modifiers ============ */
+
+    modifier isSetToken(ISetToken _setToken) {
+        require(controller.isSet(address(_setToken)), "ExchangeIssuance: INVALID SET");
+        _;
+    }
+
+    modifier isValidModule(address _issuanceModule) {
+        require(controller.isModule(_issuanceModule), "ExchangeIssuance: INVALID ISSUANCE MODULE");
+        _;
+    }
+
+    /* ========== Constructor ========== */
+
+    constructor(address _controller) {
+       controller = IController(_controller);
+    }
+
+    /* ============ External Functions ============ */
+
+    /**
+     * Runs all the necessary approval functions required for a given ERC20 token.
+     * This function can be called when a new token is added to a SetToken during a
+     * rebalance.
+     *
+     * @param _token    Address of the token which needs approval
+     * @param _spender  Address of the spender which will be approved to spend token. (Must be a whitlisted issuance module)
+     */
+    function approveToken(IERC20 _token, address _spender) external isValidModule(_spender) {
+    }
+
+    /**
+     * Runs all the necessary approval functions required for a list of ERC20 tokens.
+     *
+     * @param _tokens    Addresses of the tokens which need approval
+     * @param _spender   Address of the spender which will be approved to spend token. (Must be a whitlisted issuance module)
+     */
+    function approveTokens(IERC20[] calldata _tokens, address _spender) external {
+    }
+
+    /**
+     * Runs all the necessary approval functions required before issuing
+     * or redeeming a SetToken. This function need to be called only once before the first time
+     * this smart contract is used on any particular SetToken.
+     *
+     * @param _setToken          Address of the SetToken being initialized
+     * @param _issuanceModule    Address of the issuance module which will be approved to spend component tokens.
+     */
+    function approveSetToken(ISetToken _setToken, address _issuanceModule) external {
+    }
+
+    /**
+    * Issues an exact amount of SetTokens for given amount of input ERC20 tokens.
+    * The excess amount of tokens is returned in an equivalent amount of ether.
+    *
+    * @param _setToken              Address of the SetToken to be issued
+    * @param _inputToken            Address of the input token
+    * @param _amountSetToken        Amount of SetTokens to issue
+    * @param _calldata              The calldata needed to execute all the wrapping of tokens
+    *
+    * @return totalInputTokenSold   Amount of input token spent for issuance
+    */
+    function issueExactSetFromToken(
+        ISetToken _setToken,
+        IERC20 _inputToken,
+        uint256 _amountSetToken,
+        WrappedCalldata[] memory _calldata
+    )
+    external
+    nonReentrant
+    returns (uint256)
+    {
+        return 0;
+    }
+
+
+    /**
+    * Issues an exact amount of SetTokens for given amount of ETH.
+    * The excess amount of tokens is returned in an equivalent amount of ether.
+    *
+    * @param _setToken              Address of the SetToken to be issued
+    * @param _amountSetToken        Amount of SetTokens to issue
+    * @param _componentQuotes       The encoded 0x transactions to execute
+    *
+    * @return amountEthReturn       Amount of ether returned to the caller
+    */
+    function issueExactSetFromETH(
+        ISetToken _setToken,
+        uint256 _amountSetToken
+    )
+    external
+    nonReentrant
+    payable
+    returns (uint256)
+    {
+        return 0;
+    }
+
+    /**
+     * Redeems an exact amount of SetTokens for an ERC20 token.
+     * The SetToken must be approved by the sender to this contract.
+     *
+     * @param _setToken             Address of the SetToken being redeemed
+     * @param _outputToken          Address of output token
+     * @param _amountSetToken       Amount SetTokens to redeem
+     * @param _minOutputReceive     Minimum amount of output token to receive
+     * @param _componentQuotes      The encoded 0x transactions execute (components -> WETH).
+     * @param _issuanceModule       Address of issuance Module to use
+     * @param _isDebtIssuance       Flag indicating wether given issuance module is a debt issuance module
+     *
+     * @return outputAmount         Amount of output tokens sent to the caller
+     */
+    function redeemExactSetForToken(
+        ISetToken _setToken,
+        IERC20 _outputToken,
+        uint256 _amountSetToken,
+        uint256 _minOutputReceive,
+        address _issuanceModule
+    )
+    external
+    nonReentrant
+    returns (uint256)
+    {
+        return 0;
+    }
+
+    /**
+     * Redeems an exact amount of SetTokens for ETH.
+     * The SetToken must be approved by the sender to this contract.
+     *
+     * @param _setToken             Address of the SetToken being redeemed
+     * @param _amountSetToken       Amount SetTokens to redeem
+     * @param _minEthReceive        Minimum amount of Eth to receive
+     * @param _componentQuotes      The encoded 0x transactions execute
+     * @param _issuanceModule       Address of issuance Module to use
+     * @param _isDebtIssuance       Flag indicating wether given issuance module is a debt issuance module
+     *
+     * @return outputAmount         Amount of output tokens sent to the caller
+     */
+    function redeemExactSetForETH(
+        ISetToken _setToken,
+        uint256 _amountSetToken,
+        uint256 _minEthReceive,
+        address _issuanceModule
+    )
+    external
+    nonReentrant
+    returns (uint256)
+    {
+        return 0;
+    }
+}