Implement VIPs for MakerPSM -- PRO-115

.forge-snapshots/settler_uniswapV2_DAI-WETH.snap

@@ -1 +1 @@
-136655
+136638

.forge-snapshots/settler_uniswapV2_USDC-WETH.snap

@@ -1 +1 @@
-160506
+160489

.forge-snapshots/settler_uniswapV2_USDT-WETH.snap

@@ -1 +1 @@
-153015
+142580

.forge-snapshots/settler_uniswapV2_multihop_DAI-WETH.snap

@@ -0,0 +1 @@
+189118

.forge-snapshots/settler_uniswapV2_multihop_USDC-WETH.snap

@@ -0,0 +1 @@
+212990

.forge-snapshots/settler_uniswapV2_multihop_USDT-WETH.snap

@@ -0,0 +1 @@
+195056

.forge-snapshots/settler_zeroExOtc_DAI-WETH.snap

@@ -1 +1 @@
-145780
+172912

.forge-snapshots/settler_zeroExOtc_USDC-WETH.snap

@@ -1 +1 @@
-174977
+202822

.forge-snapshots/settler_zeroExOtc_USDT-WETH.snap

@@ -1 +1 @@
-160683
+188244

.forge-snapshots/settler_zeroExOtc_partialFill_DAI-WETH.snap

@@ -0,0 +1 @@
+180742

.forge-snapshots/settler_zeroExOtc_partialFill_USDC-WETH.snap

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+212708

.forge-snapshots/settler_zeroExOtc_partialFill_USDT-WETH.snap

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+197858

README.md

@@ -74,15 +74,15 @@ Note: The following is more akin to `gasLimit` than it is `gasUsed`, this is due
 | ------- | ------- | --------- | ------ | ------ |
 | 0x V4   | 0x V4   | USDC/WETH | 112785 | 0.00%  |
 | Settler | Settler | USDC/WETH | 113732 | 0.84%  |
-| Settler | 0x V4   | USDC/WETH | 174977 | 55.14% |
+| Settler | 0x V4   | USDC/WETH | 202822 | 79.83% |
 |         |         |           |        |        |
 | 0x V4   | 0x V4   | DAI/WETH  | 93311  | 0.00%  |
 | Settler | Settler | DAI/WETH  | 94258  | 1.01%  |
-| Settler | 0x V4   | DAI/WETH  | 145780 | 56.23% |
+| Settler | 0x V4   | DAI/WETH  | 172912 | 85.31% |
 |         |         |           |        |        |
 | 0x V4   | 0x V4   | USDT/WETH | 104423 | 0.00%  |
 | Settler | Settler | USDT/WETH | 105370 | 0.91%  |
-| Settler | 0x V4   | USDT/WETH | 160683 | 53.88% |
+| Settler | 0x V4   | USDT/WETH | 188244 | 80.27% |
 |         |         |           |        |        |
 
 | Curve             | DEX   | Pair      | Gas    | %       |
@@ -501,3 +501,32 @@ TokenPermissions(address token,uint256 amount)
 ```
 
 Where `actions` is added and contains the encoded actions the to perform.
+
+## Anticipated AMM support
+
+| AMM          | support? | notes  |
+| :------------| :------: | :----- |
+| Balancer     |    ✅     | |
+| Balancer V2  |    ✅     | |
+| Bancor       |    ✅     | |
+| Bancor V3    |    ✅     | |
+| Component    |    ✅     | Shell clone |
+| CryptoCom    |    ✅     | UniV2 clone |
+| Curve        |    ✅     | |
+| Curve V2     |    ✅     | |
+| DODO         |    ❌     | Requires a helper contract in a specific direction to calculate the correct sell amount. One can only buy asset A and sell asset B |
+| DODO V2      |    ❌     | Uses a transfer + sync flow |
+| KyberDMM     |    ✅     | |
+| KyberElastic |    ✅     | |
+| Lido         |    ✅     | |
+| MakerPsm     |    ✅     | Has VIP |
+| mStable      |    ✅     | |
+| Saddle       |    ✅     | Curve clone |
+| Shell        |    ✅     | |
+| ShibaSwap    |    ✅     | UniV2 clone |
+| SushiSwap    |    ✅     | UniV2 clone |
+| Synapse      |    ✅     | Curve clone |
+| Synthetix    |    ❌     | |
+| Uniswap      |    ✅     | |
+| Uniswap V2   |    ✅     | Has VIP |
+| Uniswap V3   |    ✅     | Has VIP |

src/ISettlerActions.sol

@@ -2,7 +2,6 @@
 pragma solidity ^0.8.21;
 
 import {ISignatureTransfer} from "permit2/src/interfaces/ISignatureTransfer.sol";
-import {IZeroEx} from "./core/ZeroEx.sol";
 
 interface ISettlerActions {
     /// @dev Transfer funds from msg.sender Permit2.
@@ -62,6 +61,9 @@ interface ISettlerActions {
         bytes memory sig
     ) external;
 
+    function MAKER_PSM_SELL_GEM(address recipient, uint256 bips, address psm, address gemToken) external;
+    function MAKER_PSM_BUY_GEM(address recipient, uint256 bips, address psm, address gemToken) external;
+
     /// @dev Trades against UniswapV3 using user funds via Permit2 for funding. Metatransaction variant. Signature is over all actions.
     function METATXN_UNISWAPV3_PERMIT2_SWAP_EXACT_IN(
         address recipient,
@@ -76,12 +78,6 @@ interface ISettlerActions {
 
     function POSITIVE_SLIPPAGE(address token, address recipient, uint256 expectedAmount) external;
 
-    // @dev Fill a 0x V4 OTC order using the 0x Exchange Proxy contract
-    // Pre-req: Funded
-    // Post-req: Payout
-    function ZERO_EX_OTC(IZeroEx.OtcOrder memory order, IZeroEx.Signature memory signature, uint256 sellAmount)
-        external;
-
     /// @dev Trades against a basic AMM which follows the approval, transferFrom(msg.sender) interaction
     // Pre-req: Funded
     // Post-req: Payout

src/Settler.sol

@@ -9,7 +9,7 @@ import {Basic} from "./core/Basic.sol";
 import {OtcOrderSettlement} from "./core/OtcOrderSettlement.sol";
 import {UniswapV3} from "./core/UniswapV3.sol";
 import {UniswapV2} from "./core/UniswapV2.sol";
-import {IZeroEx, ZeroEx} from "./core/ZeroEx.sol";
+import {IPSM, MakerPSM} from "./core/MakerPSM.sol";
 
 import {SafeTransferLib} from "./utils/SafeTransferLib.sol";
 import {UnsafeMath} from "./utils/UnsafeMath.sol";
@@ -71,7 +71,7 @@ library CalldataDecoder {
     }
 }
 
-contract Settler is Permit2Payment, Basic, OtcOrderSettlement, UniswapV3, UniswapV2, ZeroEx, FreeMemory {
+contract Settler is Permit2Payment, Basic, OtcOrderSettlement, UniswapV3, UniswapV2, MakerPSM, FreeMemory {
     using SafeTransferLib for ERC20;
     using SafeTransferLib for address payable;
     using UnsafeMath for uint256;
@@ -94,13 +94,13 @@ contract Settler is Permit2Payment, Basic, OtcOrderSettlement, UniswapV3, Uniswa
 
     receive() external payable {}
 
-    constructor(address permit2, address zeroEx, address uniFactory, bytes32 poolInitCodeHash, address feeRecipient)
+    constructor(address permit2, address uniFactory, bytes32 poolInitCodeHash, address dai, address feeRecipient)
         Permit2Payment(permit2, feeRecipient)
         Basic()
         OtcOrderSettlement()
         UniswapV3(uniFactory, poolInitCodeHash)
         UniswapV2()
-        ZeroEx(zeroEx)
+        MakerPSM(dai)
     {
         assert(ACTIONS_AND_SLIPPAGE_TYPEHASH == keccak256(bytes(ACTIONS_AND_SLIPPAGE_TYPE)));
     }
@@ -339,6 +339,16 @@ contract Settler is Permit2Payment, Basic, OtcOrderSettlement, UniswapV3, Uniswa
                 abi.decode(data, (address, uint256, uint256, bytes));
 
             sellToUniswapV2(path, bips, amountOutMin, recipient);
+        } else if (action == ISettlerActions.MAKER_PSM_SELL_GEM.selector) {
+            (address recipient, uint256 bips, IPSM psm, ERC20 gemToken) =
+                abi.decode(data, (address, uint256, IPSM, ERC20));
+
+            makerPsmSellGem(recipient, bips, psm, gemToken);
+        } else if (action == ISettlerActions.MAKER_PSM_BUY_GEM.selector) {
+            (address recipient, uint256 bips, IPSM psm, ERC20 gemToken) =
+                abi.decode(data, (address, uint256, IPSM, ERC20));
+
+            makerPsmBuyGem(recipient, bips, psm, gemToken);
         } else if (action == ISettlerActions.BASIC_SELL.selector) {
             (address pool, ERC20 sellToken, uint256 proportion, uint256 offset, bytes memory _data) =
                 abi.decode(data, (address, ERC20, uint256, uint256, bytes));
@@ -361,11 +371,6 @@ contract Settler is Permit2Payment, Basic, OtcOrderSettlement, UniswapV3, Uniswa
                     }
                 }
             }
-        } else if (action == ISettlerActions.ZERO_EX_OTC.selector) {
-            (IZeroEx.OtcOrder memory order, IZeroEx.Signature memory signature, uint256 sellAmount) =
-                abi.decode(data, (IZeroEx.OtcOrder, IZeroEx.Signature, uint256));
-
-            sellTokenForTokenToZeroExOTC(order, signature, sellAmount);
         } else {
             revert ActionInvalid({i: i, action: action, data: data});
         }

src/core/MakerPSM.sol

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.21;
+
+import {ERC20} from "solmate/src/tokens/ERC20.sol";
+
+import {SafeTransferLib} from "../utils/SafeTransferLib.sol";
+import {UnsafeMath} from "../utils/UnsafeMath.sol";
+
+interface IPSM {
+    /// @dev Get the fee for selling DAI to USDC in PSM
+    /// @return tout toll out [wad]
+    function tout() external view returns (uint256);
+
+    /// @dev Get the address of the underlying vault powering PSM
+    /// @return address of gemJoin contract
+    function gemJoin() external view returns (address);
+
+    /// @dev Sell USDC for DAI
+    /// @param usr The address of the account trading USDC for DAI.
+    /// @param gemAmt The amount of USDC to sell in USDC base units
+    function sellGem(address usr, uint256 gemAmt) external;
+
+    /// @dev Buy USDC for DAI
+    /// @param usr The address of the account trading DAI for USDC
+    /// @param gemAmt The amount of USDC to buy in USDC base units
+    function buyGem(address usr, uint256 gemAmt) external;
+}
+
+abstract contract MakerPSM {
+    using UnsafeMath for uint256;
+    using SafeTransferLib for ERC20;
+
+    // Maker units https://github.com/makerdao/dss/blob/master/DEVELOPING.md
+    // wad: fixed point decimal with 18 decimals (for basic quantities, e.g. balances)
+    uint256 internal constant WAD = 10 ** 18;
+
+    ERC20 internal immutable DAI;
+
+    constructor(address dai) {
+        DAI = ERC20(dai);
+    }
+
+    function makerPsmSellGem(address recipient, uint256 bips, IPSM psm, ERC20 gemToken) internal {
+        // phantom overflow can't happen here because PSM prohibits gemToken with decimals > 18
+        uint256 sellAmount = (gemToken.balanceOf(address(this)) * bips).unsafeDiv(10_000);
+        gemToken.safeApproveIfBelow(psm.gemJoin(), sellAmount);
+        psm.sellGem(recipient, sellAmount);
+    }
+
+    function makerPsmBuyGem(address recipient, uint256 bips, IPSM psm, ERC20 gemToken) internal {
+        // phantom overflow can't happen here because DAI has decimals = 18
+        uint256 sellAmount = (DAI.balanceOf(address(this)) * bips).unsafeDiv(10_000);
+        unchecked {
+            uint256 feeDivisor = psm.tout() + WAD; // eg. 1.001 * 10 ** 18 with 0.1% fee [tout is in wad];
+            // overflow can't happen at all because DAI is reasonable and PSM prohibits gemToken with decimals > 18
+            uint256 buyAmount = (sellAmount * 10 ** uint256(gemToken.decimals())).unsafeDiv(feeDivisor);
+
+            DAI.safeApproveIfBelow(address(psm), sellAmount);
+            psm.buyGem(recipient, buyAmount);
+        }
+    }
+}