feat: nft yield

.gitmodules

@@ -2,3 +2,9 @@
 	path = lib/forge-std
 	url = https://github.com/foundry-rs/forge-std
 	branch = v1
+[submodule "lib/common"]
+	path = lib/common
+	url = git@github.com:MZero-Labs/common.git
+[submodule "lib/openzeppelin-contracts"]
+	path = lib/openzeppelin-contracts
+	url = git@github.com:OpenZeppelin/openzeppelin-contracts.git

.prettierrc

@@ -1,16 +1,17 @@
 {
-  "plugins": ["prettier-plugin-solidity"],
+  "plugins": [
+    "prettier-plugin-solidity"
+  ],
   "overrides": [
     {
       "files": "*.sol",
       "options": {
         "bracketSpacing": true,
-        "compiler": "0.8.25",
+        "compiler": "0.8.23",
         "parser": "solidity-parse",
         "printWidth": 120,
         "tabWidth": 4,
       }
     }
   ]
 }
-

.solhint.json

@@ -1,10 +1,20 @@
 {
-  "extends": ["solhint:recommended"],
-  "plugins": ["prettier"],
+  "extends": [
+    "solhint:recommended"
+  ],
+  "plugins": [
+    "prettier"
+  ],
   "rules": {
     "prettier/prettier": "error",
-    "code-complexity": ["warn", 10],
-    "compiler-version": ["error", "0.8.25"],
+    "code-complexity": [
+      "warn",
+      10
+    ],
+    "compiler-version": [
+      "error",
+      "0.8.23"
+    ],
     "comprehensive-interface": "off",
     "const-name-snakecase": "off",
     "func-name-mixedcase": "off",
@@ -14,10 +24,16 @@
         "ignoreConstructors": true
       }
     ],
-    "function-max-lines": ["warn", 100],
+    "function-max-lines": [
+      "warn",
+      100
+    ],
     "immutable-vars-naming": "off",
     "imports-on-top": "error",
-    "max-line-length": ["warn", 120],
+    "max-line-length": [
+      "warn",
+      120
+    ],
     "no-empty-blocks": "off",
     "no-inline-assembly": "off",
     "not-rely-on-time": "off",

foundry.toml

@@ -3,7 +3,7 @@ gas_reports = ["*"]
 gas_reports_ignore = []
 ignored_error_codes = []
 optimizer = false
-solc_version = "0.8.25"
+solc_version = "0.8.23"
 verbosity = 3
 
 [profile.production]

src/MTokenYield.sol

@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.23;
+
+import { UIntMath } from "../lib/common/src/libs/UIntMath.sol";
+
+import { ERC721 } from "../lib/openzeppelin-contracts/contracts/token/ERC721/ERC721.sol";
+
+import { IMTokenLike } from "./interfaces/IMTokenLike.sol";
+import { IMTokenYield } from "./interfaces/IMTokenYield.sol";
+import { IWrappedM } from "./interfaces/IWrappedM.sol";
+
+contract MTokenYield is IMTokenYield, ERC721 {
+    // TODO: Might be a way to make this a uint112 and uint128 for one slot.
+    struct YieldBase {
+        uint240 amount;
+        uint128 index;
+    }
+
+    /* ============ Variables ============ */
+
+    uint56 internal constant _EXP_SCALED_ONE = 1e12;
+
+    address public immutable mToken;
+    address public immutable wrappedM;
+
+    uint256 internal _tokenCount;
+
+    mapping(uint256 tokenId => YieldBase yieldBase) internal _yieldBases;
+
+    /* ============ Modifiers ============ */
+
+    modifier onlyWrappedM() {
+        if (msg.sender != wrappedM) revert NotWrappedM();
+
+        _;
+    }
+
+    /* ============ Constructor ============ */
+
+    constructor(address mToken_, address wrappedM_) ERC721("MYield by M^0", "ysM") {
+        mToken = mToken_;
+        wrappedM = wrappedM_;
+    }
+
+    /* ============ Interactive Functions ============ */
+
+    function mint(address account_, uint256 amount_) external onlyWrappedM returns (uint256 tokenId_) {
+        tokenId_ = ++_tokenCount;
+
+        _yieldBases[tokenId_] = YieldBase({
+            amount: UIntMath.safe240(amount_),
+            index: IMTokenLike(mToken).currentIndex()
+        });
+
+        _mint(account_, tokenId_);
+    }
+
+    function burn(
+        address account_,
+        uint256 tokenId_
+    ) external onlyWrappedM returns (uint256 baseAmount_, uint256 yield_) {
+        if (ownerOf(tokenId_) != account_) revert NotOwner();
+
+        _burn(tokenId_);
+
+        YieldBase storage yieldBase_ = _yieldBases[tokenId_];
+
+        baseAmount_ = yieldBase_.amount;
+
+        yield_ = _multiplyDown(yieldBase_.amount, yieldBase_.index - IMTokenLike(mToken).currentIndex());
+
+        delete _yieldBases[tokenId_];
+    }
+
+    function claim(address account_, uint256 tokenId_) external returns (uint256 yield_) {
+        if (ownerOf(tokenId_) != msg.sender) revert NotOwner();
+
+        YieldBase storage yieldBase_ = _yieldBases[tokenId_];
+
+        uint128 currentIndex_ = IMTokenLike(mToken).currentIndex();
+
+        yield_ = _multiplyDown(yieldBase_.amount, yieldBase_.index - currentIndex_);
+
+        yieldBase_.index = currentIndex_;
+
+        IWrappedM(wrappedM).extract(account_, yield_);
+    }
+
+    function reshape(
+        address account_,
+        uint256[] calldata tokenIds_,
+        uint256[] calldata amounts_
+    ) external returns (uint256[] memory newTokenIds_, uint256 yield_) {
+        if (tokenIds_.length != amounts_.length) revert LengthMismatch();
+
+        uint128 currentIndex_ = IMTokenLike(mToken).currentIndex();
+
+        uint240 total_;
+
+        for (uint256 index_; index_ < tokenIds_.length; ++index_) {
+            uint256 tokenId_ = tokenIds_[index_];
+
+            if (ownerOf(tokenId_) != msg.sender) revert NotOwner();
+
+            _burn(tokenId_);
+
+            YieldBase storage yieldBase_ = _yieldBases[tokenId_];
+
+            total_ += yieldBase_.amount;
+            yield_ += _multiplyDown(yieldBase_.amount, yieldBase_.index - currentIndex_);
+
+            delete _yieldBases[tokenId_];
+        }
+
+        newTokenIds_ = new uint256[](tokenIds_.length);
+
+        for (uint256 index_; index_ < newTokenIds_.length; ++index_) {
+            uint256 tokenId_ = newTokenIds_[index_] = ++_tokenCount;
+            uint240 amount_ = UIntMath.safe240(amounts_[index_]);
+
+            _yieldBases[tokenId_] = YieldBase({
+                amount: amount_,
+                index: currentIndex_
+            });
+
+            total_ -= amount_;
+
+            _mint(account_, tokenId_);
+        }
+
+        if (total_ > 0) revert ExcessAmount();
+
+        IWrappedM(wrappedM).extract(account_, yield_);
+    }
+
+    /* ============ View/Pure Functions ============ */
+
+    function getYieldBase(uint256 tokenId_) external view returns (uint240 amount_, uint128 index_) {
+        YieldBase storage yieldBase_ = _yieldBases[tokenId_];
+
+        amount_ = yieldBase_.amount;
+        index_ = yieldBase_.index;
+    }
+
+    /* ============ Internal Interactive Functions ============ */
+
+    /* ============ Internal View/Pure Functions ============ */
+
+    function _multiplyDown(uint240 x_, uint128 index_) internal pure returns (uint240) {
+        unchecked {
+            return uint240((uint256(x_) * index_) / _EXP_SCALED_ONE);
+        }
+    }
+}

src/WrappedM.sol

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.23;
+
+import { UIntMath } from "../lib/common/src/libs/UIntMath.sol";
+
+import { IERC20 } from "../lib/common/src/interfaces/IERC20.sol";
+
+import { ERC20Extended } from "../lib/common/src/ERC20Extended.sol";
+
+import { IMTokenLike } from "./interfaces/IMTokenLike.sol";
+import { IMTokenYield } from "./interfaces/IMTokenYield.sol";
+import { IWrappedM } from "./interfaces/IWrappedM.sol";
+
+contract WrappedM is IWrappedM, ERC20Extended {
+    /* ============ Variables ============ */
+
+    address public immutable mToken;
+    address public immutable mYield;
+
+    uint256 public totalSupply;
+
+    mapping(address account => uint256 balance) public balanceOf;
+
+    /* ============ Modifiers ============ */
+
+    modifier onlyEarner() {
+        if (!IMTokenLike(mToken).isEarning(msg.sender)) revert NotEarner();
+
+        _;
+    }
+
+    modifier onlyMYield() {
+        if (msg.sender != mYield) revert NotMYield();
+
+        _;
+    }
+
+    /* ============ Constructor ============ */
+
+    constructor(address mToken_, address mYield_) ERC20Extended("WrappedM by M^0", "wM", 6) {
+        mToken = mToken_;
+        mYield = mYield_;
+    }
+
+    /* ============ Interactive Functions ============ */
+
+    function deposit(address account_, uint256 amount_) external onlyEarner returns (uint256 mYieldTokenId_) {
+        emit Transfer(address(0), account_, amount_);
+
+        balanceOf[account_] += amount_;
+        totalSupply += amount_;
+
+        mYieldTokenId_ = IMTokenYield(mYield).mint(account_, amount_);
+
+        IERC20(mToken).transferFrom(msg.sender, address(this), amount_);
+    }
+
+    function withdraw(address account_, uint256 mYieldTokenId_) external returns (uint256 baseAmount_, uint256 yield_) {
+        (baseAmount_, yield_) = IMTokenYield(mYield).burn(msg.sender, mYieldTokenId_);
+
+        balanceOf[account_] -= baseAmount_;
+        totalSupply -= baseAmount_;
+
+        IERC20(mToken).transfer(account_, baseAmount_ + yield_);
+    }
+
+    function extract(address account_, uint256 amount_) external onlyMYield {
+        IERC20(mToken).transfer(account_, amount_);
+    }
+
+    /* ============ View/Pure Functions ============ */
+
+    /* ============ Internal Interactive Functions ============ */
+
+    function _transfer(address sender_, address recipient_, uint256 amount_) internal override {
+        emit Transfer(sender_, recipient_, amount_);
+
+        balanceOf[sender_] -= amount_;
+        balanceOf[recipient_] += amount_;
+    }
+
+    /* ============ Internal View/Pure Functions ============ */
+}

src/interfaces/IMTokenLike.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.23;
+
+interface IMTokenLike {
+    /* ============ View/Pure Functions ============ */
+
+    function currentIndex() external view returns (uint128);
+
+    function isEarning(address account) external view returns (bool);
+}