// SPDX-License-Identifier: AGPL-3.0-or-later

/// UsdsJoin.sol -- Usds adapter

// Copyright (C) 2018 Rain <rainbreak@riseup.net>
// Copyright (C) 2023 Dai Foundation
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

pragma solidity ^0.8.21;

interface UsdsLike {
    function burn(address,uint256) external;
    function mint(address,uint256) external;
}

interface VatLike {
    function move(address,address,uint256) external;
}

contract UsdsJoin {
    VatLike  public immutable vat;  // CDP Engine
    UsdsLike public immutable usds; // Stablecoin Token

    uint256 constant RAY = 10 ** 27;

    // --- Events ---
    event Join(address indexed caller, address indexed usr, uint256 wad);
    event Exit(address indexed caller, address indexed usr, uint256 wad);

    constructor(address vat_, address usds_) {
        vat  = VatLike(vat_);
        usds = UsdsLike(usds_);
    }

    function join(address usr, uint256 wad) external {
        vat.move(address(this), usr, RAY * wad);
        usds.burn(msg.sender, wad);
        emit Join(msg.sender, usr, wad);
    }

    function exit(address usr, uint256 wad) external {
        vat.move(msg.sender, address(this), RAY * wad);
        usds.mint(usr, wad);
        emit Exit(msg.sender, usr, wad);
    }

    // To fully cover daiJoin abi
    function dai() external view returns (address) {
        return address(usds);
    }
}

{
  "compilationTarget": {
    "src/UsdsJoin.sol": "UsdsJoin"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": [
    ":@openzeppelin/contracts-upgradeable/=lib/openzeppelin-contracts-upgradeable/contracts/",
    ":@openzeppelin/contracts/=lib/openzeppelin-contracts-upgradeable/lib/openzeppelin-contracts/contracts/",
    ":ds-test/=lib/openzeppelin-contracts-upgradeable/lib/forge-std/lib/ds-test/src/",
    ":dss-interfaces/=lib/token-tests/lib/dss-test/lib/dss-interfaces/src/",
    ":dss-test/=lib/token-tests/lib/dss-test/src/",
    ":erc4626-tests/=lib/openzeppelin-contracts-upgradeable/lib/erc4626-tests/",
    ":forge-std/=lib/openzeppelin-foundry-upgrades/lib/forge-std/src/",
    ":openzeppelin-contracts-upgradeable/=lib/openzeppelin-contracts-upgradeable/",
    ":openzeppelin-contracts/=lib/openzeppelin-contracts-upgradeable/lib/openzeppelin-contracts/",
    ":openzeppelin-foundry-upgrades/=lib/openzeppelin-foundry-upgrades/src/",
    ":solidity-stringutils/=lib/openzeppelin-foundry-upgrades/lib/solidity-stringutils/",
    ":token-tests/=lib/token-tests/src/"
  ]
}