feat: add balancer v2 executor

foundry/lib/balancer-labs/v2-interfaces/contracts/standalone-utils/IEulerToken.sol

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+pragma solidity ^0.7.0;
+
+import "../solidity-utils/openzeppelin/IERC20.sol";
+
+interface IEulerToken is IERC20 {
+    /**
+     * @dev Convert an eToken balance to an underlying amount, taking into account current exchange rate
+     * @param balance eToken balance, in internal book-keeping units (18 decimals)
+     * @return Amount in underlying units, (same decimals as underlying token)
+     */
+    // https://github.com/euler-xyz/euler-contracts/blob/b1ee3265853628d5a529081d7908c38404201b4e/contracts/modules/EToken.sol#L104
+    // solhint-disable-previous-line max-line-length
+    function convertBalanceToUnderlying(uint256 balance) external view returns (uint256);
+
+    /**
+     * @dev Convert an underlying amount to an eToken balance, taking into account current exchange rate
+     * @param underlyingAmount Amount in underlying units (same decimals as underlying token)
+     * @return eToken balance, in internal book-keeping units (18 decimals)
+     */
+    // https://github.com/euler-xyz/euler-contracts/blob/b1ee3265853628d5a529081d7908c38404201b4e/contracts/modules/EToken.sol#L114
+    // solhint-disable-previous-line max-line-length
+    function convertUnderlyingToBalance(uint256 underlyingAmount) external view returns (uint256);
+
+    /**
+     * @dev Transfer underlying tokens from sender to the Euler pool, and increase account's eTokens
+     */
+    function deposit(uint256 subAccountId, uint256 amount) external;
+
+    /**
+     * @dev Transfer underlying tokens from Euler pool to sender, and decrease account's eTokens
+     */
+    function withdraw(uint256 subAccountId, uint256 amount) external;
+
+    /**
+     * @dev Address of underlying asset
+     */
+    function underlyingAsset() external view returns (address);
+}