feat: New UniswapV2LockstakeCallee (#43)

.gitmodules

@@ -22,3 +22,6 @@
 [submodule "lib/dss-crop-join"]
 	path = lib/dss-crop-join
 	url = https://github.com/makerdao/dss-crop-join
+[submodule "lib/lockstake"]
+	path = lib/lockstake
+	url = https://github.com/makerdao/lockstake

scripts/test.sh

@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
 
 if [[ $# -eq 0 ]] ; then
-    forge test --use solc:0.6.12 --fork-url "$ETH_RPC_URL"
+    forge test --fork-url "$ETH_RPC_URL"
 else
-    forge test --use solc:0.6.12 --fork-url "$ETH_RPC_URL" -vvv --match-test ${1}
+    forge test --fork-url "$ETH_RPC_URL" -vvv --match-test ${1}
 fi
 

src/OasisDexCallee.sol

@@ -14,7 +14,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 
 interface VatLike {
     function hope(address) external;

src/OneInchCallee.sol

@@ -14,7 +14,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 pragma experimental ABIEncoderV2;
 
 interface GemJoinLike {

src/PSMCallee.sol

@@ -14,7 +14,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 pragma experimental ABIEncoderV2;
 
 interface GemJoinLike {

src/UniswapV2Callee.sol

@@ -15,7 +15,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 
 interface VatLike {
     function hope(address) external;

src/UniswapV2LockstakeCallee.sol

@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (C) 2020 Maker Ecosystem Growth Holdings, INC.
+// Copyright (C) 2024 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 TokenLike {
+    function approve(address, uint256) external;
+    function transfer(address, uint256) external;
+    function balanceOf(address) external view returns (uint256);
+}
+
+interface UniswapV2Router02Like {
+    function swapExactTokensForTokens(uint256, uint256, address[] calldata, address, uint256) external returns (uint256[] memory);
+}
+
+interface DaiJoinLike {
+    function dai() external view returns (address);
+    function join(address, uint256) external;
+}
+
+interface NstJoinLike {
+    function nst() external view returns (address);
+    function join(address, uint256) external;
+}
+
+interface MkrNgt {
+    function mkr() external view returns (address);
+    function ngt() external view returns (address);
+    function rate() external view returns (uint256);
+    function mkrToNgt(address, uint256) external;
+}
+
+contract UniswapV2LockstakeCallee {
+    UniswapV2Router02Like   public immutable uniRouter02;
+    DaiJoinLike             public immutable daiJoin;
+    TokenLike               public immutable dai;
+    NstJoinLike             public immutable nstJoin;
+    TokenLike               public immutable nst;
+    MkrNgt                  public immutable mkrNgt;
+    TokenLike               public immutable mkr;
+    TokenLike               public immutable ngt;
+    uint256                 public constant RAY = 10 ** 27;
+
+    constructor(address uniRouter02_, address daiJoin_, address nstJoin_, address mkrNgt_) {
+        uniRouter02 = UniswapV2Router02Like(uniRouter02_);
+
+        daiJoin = DaiJoinLike(daiJoin_);
+        dai = TokenLike(daiJoin.dai());
+        dai.approve(daiJoin_, type(uint256).max);
+
+        nstJoin = NstJoinLike(nstJoin_);
+        nst = TokenLike(nstJoin.nst());
+        nst.approve(nstJoin_, type(uint256).max);
+
+        mkrNgt = MkrNgt(mkrNgt_);
+        mkr = TokenLike(mkrNgt.mkr());
+        ngt = TokenLike(mkrNgt.ngt());
+    }
+
+    function divup(uint256 x, uint256 y) internal pure returns (uint256 z) {
+        z = x != 0 ? ((x - 1) / y) + 1 : 0;
+    }
+
+    function clipperCall(
+        address sender,     // Clipper Caller and DAI/NST delivery address
+        uint256 dstAmt,     // DAI/NST amount to payback [rad]
+        uint256 gemAmt,     // Gem amount received [wad]
+        bytes calldata data // Extra data needed
+    ) external {
+        (
+            address to,           // Address to send remaining DAI/NST to
+            uint256 minProfit,    // Minimum profit in DAI/NST to make [wad]
+            address[] memory path // Uniswap pool path
+        ) = abi.decode(data, (address, uint256, address[]));
+
+        // Support NGT
+        TokenLike gem = mkr;
+        if (path[0] == address(ngt)) {
+            gem = ngt;
+            mkr.approve(address(mkrNgt), gemAmt);
+            mkrNgt.mkrToNgt(address(this), gemAmt);
+            gemAmt = gemAmt * mkrNgt.rate();
+        }
+
+        // Approve uniRouter02 to take gem
+        gem.approve(address(uniRouter02), gemAmt);
+
+        // Calculate amount of tokens to Join (as erc20 WAD value)
+        uint256 amtToJoin = divup(dstAmt, RAY);
+
+        // Exchange tokens based on the path (checking the profit is achieved)
+        uniRouter02.swapExactTokensForTokens(
+            gemAmt,
+            amtToJoin + minProfit,
+            path,
+            address(this),
+            block.timestamp
+        );
+
+        // Although Uniswap will accept all gems, this check is a sanity check, just in case
+        if (gem.balanceOf(address(this)) > 0) {
+            // Transfer any lingering gem to specified address
+            gem.transfer(to, gem.balanceOf(address(this)));
+        }
+
+        // Determine destination token
+        TokenLike dst = TokenLike(path[path.length - 1]);
+
+        // Convert tokens bought to internal vat value of the msg.sender of Clipper.take
+        if (address(dst) == address(dai)) {
+            daiJoin.join(sender, amtToJoin);
+        } else if (address(dst) == address(nst)) {
+            nstJoin.join(sender, amtToJoin);
+        }
+
+        // Transfer remaining tokens to specified address
+        dst.transfer(to, dst.balanceOf(address(this)));
+    }
+}
+

src/UniswapV2LpTokenCallee.sol

@@ -15,7 +15,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 
 interface VatLike {
     function hope(address) external;

src/UniswapV3Callee.sol

@@ -14,7 +14,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 pragma experimental ABIEncoderV2;
 
 interface GemJoinLike {

src/UniswapV3SplitRouteCallee.sol

@@ -14,7 +14,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 pragma experimental ABIEncoderV2;
 
 interface GemJoinLike {

src/WstETHCurveUniv3Callee.sol

@@ -14,7 +14,7 @@
 // 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 >=0.6.12;
+pragma solidity 0.6.12;
 pragma experimental ABIEncoderV2;
 
 interface GemJoinLike {