// 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;

library StablePhantomPoolUserData {
    enum JoinKindPhantom { INIT, EXACT_TOKENS_IN_FOR_BPT_OUT }
    enum ExitKindPhantom { BPT_IN_FOR_EXACT_TOKENS_OUT }

    function joinKind(bytes memory self) internal pure returns (JoinKindPhantom) {
        return abi.decode(self, (JoinKindPhantom));
    }

    function exitKind(bytes memory self) internal pure returns (ExitKindPhantom) {
        return abi.decode(self, (ExitKindPhantom));
    }

    // Joins

    function initialAmountsIn(bytes memory self) internal pure returns (uint256[] memory amountsIn) {
        (, amountsIn) = abi.decode(self, (JoinKindPhantom, uint256[]));
    }

    function exactTokensInForBptOut(bytes memory self)
        internal
        pure
        returns (uint256[] memory amountsIn, uint256 minBPTAmountOut)
    {
        (, amountsIn, minBPTAmountOut) = abi.decode(self, (JoinKindPhantom, uint256[], uint256));
    }

    // Exits

    function bptInForExactTokensOut(bytes memory self)
        internal
        pure
        returns (uint256[] memory amountsOut, uint256 maxBPTAmountIn)
    {
        (, amountsOut, maxBPTAmountIn) = abi.decode(self, (ExitKindPhantom, uint256[], uint256));
    }
}