[ERC7527] ERC20/ETHをERC721（NFT）にラップ/アンラップする仕組みを理解しよう！

pragma solidity ^0.8.20;

/**
 * @dev The settings of the agency.
 * @param currency The address of the currency. If `currency` is 0, the currency is Ether.
 * @param premium The base premium of the currency.
 * @param feeRecipient The address of the fee recipient.
 * @param mintFeePercent The fee of minting.
 * @param burnFeePercent The fee of burning.
 */
struct Asset {
    address currency;
    uint256 premium;
    address feeRecipient;
    uint16 mintFeePercent;
    uint16 burnFeePercent;
}

interface IERC7527Agency {
    /**
     * @dev Allows the account to receive Ether
     *
     * Accounts MUST implement a `receive` function.
     *
     * Accounts MAY perform arbitrary logic to restrict conditions
     * under which Ether can be received.
     */
    receive() external payable;

    /**
     * @dev Emitted when `tokenId` token is wrapped.
     * @param to The address of the recipient of the newly created non-fungible token.
     * @param tokenId The identifier of the newly created non-fungible token.
     * @param price The price of wrapping.
     * @param fee The fee of wrapping.
     */
    event Wrap(address indexed to, uint256 indexed tokenId, uint256 price, uint256 fee);

    /**
     * @dev Emitted when `tokenId` token is unwrapped.
     * @param to The address of the recipient of the currency.
     * @param tokenId The identifier of the non-fungible token to unwrap.
     * @param price The price of unwrapping.
     * @param fee The fee of unwrapping.
     */
    event Unwrap(address indexed to, uint256 indexed tokenId, uint256 price, uint256 fee);

    /**
     * @dev Wrap currency premium into a non-fungible token.
     * @param to The address of the recipient of the newly created non-fungible token.
     * @param data The data to encode into ifself and the newly created non-fungible token.
     * @return The identifier of the newly created non-fungible token.
     */
    function wrap(address to, bytes calldata data) external payable returns (uint256);

    /**
     * @dev Unwrap a non-fungible token into currency premium.
     * @param to The address of the recipient of the currency.
     * @param tokenId The identifier of the non-fungible token to unwrap.
     * @param data The data to encode into ifself and the non-fungible token with identifier `tokenId`.
     */
    function unwrap(address to, uint256 tokenId, bytes calldata data) external payable;

    /**
     * @dev Returns the strategy of the agency.
     * @return app The address of the app.
     * @return asset The asset of the agency.
     * @return attributeData The attributeData of the agency.
     */
    function getStrategy() external view returns (address app, Asset memory asset, bytes memory attributeData);

    /**
     * @dev Returns the price and fee of unwrapping.
     * @param data The data to encode to calculate the price and fee of unwrapping.
     * @return price The price of wrapping.
     * @return fee The fee of wrapping.
     */
    function getUnwrapOracle(bytes memory data) external view returns (uint256 price, uint256 fee);

    /**
     * @dev Returns the price and fee of wrapping.
     * @param data The data to encode to calculate the price and fee of wrapping.
     * @return price The price of wrapping.
     * @return fee The fee of wrapping.
     */
    function getWrapOracle(bytes memory data) external view returns (uint256 price, uint256 fee);
}

event Wrap(address indexed to, uint256 indexed tokenId, uint256 price, uint256 fee);

event Unwrap(address indexed to, uint256 indexed tokenId, uint256 price, uint256 fee);

function wrap(address to, bytes calldata data) external payable returns (uint256);

function unwrap(address to, uint256 tokenId, bytes calldata data) external payable;

function getStrategy() external view returns (address app, Asset memory asset, bytes memory attributeData);

function getUnwrapOracle(bytes memory data) external view returns (uint256 price, uint256 fee);

function getWrapOracle(bytes memory data) external view returns (uint256 price, uint256 fee);

pragma solidity ^0.8.20;

interface IERC7527App {
    /**
     * @dev Returns the maximum supply of the non-fungible token.
     */
    function getMaxSupply() external view returns (uint256);

    /**
     * @dev Returns the name of the non-fungible token with identifier `id`.
     * @param id The identifier of the non-fungible token.
     */
    function getName(uint256 id) external view returns (string memory);

    /**
     * @dev Returns the agency of the non-fungible token.
     */
    function getAgency() external view returns (address payable);

    /**
     * @dev Sets the agency of the non-fungible token.
     * @param agency The agency of the non-fungible token.
     */
    function setAgency(address payable agency) external;

    /**
     * @dev Mints a non-fungible token to `to`.
     * @param to The address of the recipient of the newly created non-fungible token.
     * @param data The data to encode into the newly created non-fungible token.
     */
    function mint(address to, bytes calldata data) external returns (uint256);

    /**
     * @dev Burns a non-fungible token with identifier `tokenId`.
     * @param tokenId The identifier of the non-fungible token to burn.
     * @param data The data to encode into the non-fungible token with identifier `tokenId`.
     */
    function burn(uint256 tokenId, bytes calldata data) external;
}

function getMaxSupply() external view returns (uint256);

function getName(uint256 id) external view returns (string memory);

function getAgency() external view returns (address payable);

function setAgency(address payable agency) external;

function mint(address to, bytes calldata data) external returns (uint256);

function burn(uint256 tokenId, bytes calldata data) external;

pragma solidity ^0.8.20;

import {Asset} from "./IERC7527Agency.sol";

/**
 * @dev The settings of the agency.
 * @param implementation The address of the agency implementation.
 * @param asset The parameter of asset of the agency.
 * @param immutableData The immutable data are stored in the code region of the created proxy contract of agencyImplementation.
 * @param initData If init data is not empty, calls proxy contract of agencyImplementation with this data.
 */
struct AgencySettings {
    address payable implementation;
    Asset asset;
    bytes immutableData;
    bytes initData;
}

/**
 * @dev The settings of the app.
 * @param implementation The address of the app implementation.
 * @param immutableData The immutable data are stored in the code region of the created proxy contract of appImplementation.
 * @param initData If init data is not empty, calls proxy contract of appImplementation with this data.
 */
struct AppSettings {
    address implementation;
    bytes immutableData;
    bytes initData;
}

interface IERC7527Factory {
    /**
     * @dev Deploys a new agency and app clone and initializes both.
     * @param agencySettings The settings of the agency.
     * @param appSettings The settings of the app.
     * @param data The data is additional data, it has no specified format and it is sent in call to `factory`.
     * @return appInstance The address of the created proxy contract of appImplementation.
     * @return agencyInstance The address of the created proxy contract of agencyImplementation.
     */
    function deployWrap(AgencySettings calldata agencySettings, AppSettings calldata appSettings, bytes calldata data)
        external
        returns (address, address);
}

struct AgencySettings {
    address payable implementation;
    Asset asset;
    bytes immutableData;
    bytes initData;
}

struct AppSettings {
    address implementation;
    bytes immutableData;
    bytes initData;
}

function deployWrap(AgencySettings calldata agencySettings, AppSettings calldata appSettings, bytes calldata data)
        external
        returns (address, address);

pragma solidity ^0.8.20;

import {
    ERC721Enumerable,
    ERC721,
    IERC721Enumerable
} from "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {Address} from "@openzeppelin/contracts/utils/Address.sol";
import {ClonesWithImmutableArgs} from "clones-with-immutable-args/ClonesWithImmutableArgs.sol";
import {IERC7527App} from "./interfaces/IERC7527App.sol";
import {IERC7527Agency, Asset} from "./interfaces/IERC7527Agency.sol";
import {IERC7527Factory, AgencySettings, AppSettings} from "./interfaces/IERC7527Factory.sol";

contract ERC7527Agency is IERC7527Agency {
    using Address for address payable;

    receive() external payable {}

    function unwrap(address to, uint256 tokenId, bytes calldata data) external payable override {
        (address _app, Asset memory _asset,) = getStrategy();
        require(_isApprovedOrOwner(_app, msg.sender, tokenId), "LnModule: not owner");
        IERC7527App(_app).burn(tokenId, data);
        uint256 _sold = IERC721Enumerable(_app).totalSupply();
        (uint256 premium, uint256 burnFee) = getUnwrapOracle(abi.encode(_sold));
        _transfer(address(0), payable(to), premium - burnFee);
        _transfer(address(0), _asset.feeRecipient, burnFee);
        emit Unwrap(to, tokenId, premium, burnFee);
    }

    function wrap(address to, bytes calldata data) external payable override returns (uint256) {
        (address _app, Asset memory _asset,) = getStrategy();
        uint256 _sold = IERC721Enumerable(_app).totalSupply();
        (uint256 premium, uint256 mintFee) = getWrapOracle(abi.encode(_sold));
        require(msg.value >= premium + mintFee, "ERC7527Agency: insufficient funds");
        _transfer(address(0), _asset.feeRecipient, mintFee);
        if (msg.value > premium + mintFee) {
            _transfer(address(0), payable(msg.sender), msg.value - premium - mintFee);
        }
        uint256 id_ = IERC7527App(_app).mint(to, data);
        require(_sold + 1 == IERC721Enumerable(_app).totalSupply(), "ERC7527Agency: Reentrancy");
        emit Wrap(to, id_, premium, mintFee);
        return id_;
    }

    function getStrategy() public pure override returns (address app, Asset memory asset, bytes memory attributeData) {
        uint256 offset = _getImmutableArgsOffset();
        address currency;
        uint256 premium;
        address payable awardFeeRecipient;
        uint16 mintFeePercent;
        uint16 burnFeePercent;
        assembly {
            app := shr(0x60, calldataload(add(offset, 0)))
            currency := shr(0x60, calldataload(add(offset, 20)))
            premium := calldataload(add(offset, 40))
            awardFeeRecipient := shr(0x60, calldataload(add(offset, 72)))
            mintFeePercent := shr(0xf0, calldataload(add(offset, 92)))
            burnFeePercent := shr(0xf0, calldataload(add(offset, 94)))
        }
        asset = Asset(currency, premium, awardFeeRecipient, mintFeePercent, burnFeePercent);
        attributeData = "";
    }

    function getUnwrapOracle(bytes memory data) public pure override returns (uint256 premium, uint256 fee) {
        uint256 input = abi.decode(data, (uint256));
        (, Asset memory _asset,) = getStrategy();
        premium = _asset.premium + input * _asset.premium / 100;
        fee = premium * _asset.burnFeePercent / 10000;
    }

    function getWrapOracle(bytes memory data) public pure override returns (uint256 premium, uint256 fee) {
        uint256 input = abi.decode(data, (uint256));
        (, Asset memory _asset,) = getStrategy();
        premium = _asset.premium + input * _asset.premium / 100;
        fee = premium * _asset.mintFeePercent / 10000;
    }

    function _transfer(address currency, address recipient, uint256 premium) internal {
        if (currency == address(0)) {
            payable(recipient).sendValue(premium);
        } else {
            IERC20(currency).transfer(recipient, premium);
        }
    }

    function _isApprovedOrOwner(address app, address spender, uint256 tokenId) internal view virtual returns (bool) {
        IERC721Enumerable _app = IERC721Enumerable(app);
        address _owner = _app.ownerOf(tokenId);
        return (spender == _owner || _app.isApprovedForAll(_owner, spender) || _app.getApproved(tokenId) == spender);
    }
    /// @return offset The offset of the packed immutable args in calldata

    function _getImmutableArgsOffset() internal pure returns (uint256 offset) {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            offset := sub(calldatasize(), add(shr(240, calldataload(sub(calldatasize(), 2))), 2))
        }
    }
}

contract ERC7527App is ERC721Enumerable, IERC7527App {
    constructor() ERC721("ERC7527App", "EA") {}

    address payable private _oracle;

    modifier onlyAgency() {
        require(msg.sender == _getAgency(), "only agency");
        _;
    }

    function getName(uint256) external pure returns (string memory) {
        return "App";
    }

    function getMaxSupply() public pure override returns (uint256) {
        return 100;
    }

    function getAgency() external view override returns (address payable) {
        return _getAgency();
    }

    function setAgency(address payable oracle) external override {
        require(_getAgency() == address(0), "already set");
        _oracle = oracle;
    }

    function mint(address to, bytes calldata data) external override onlyAgency returns (uint256 tokenId) {
        require(totalSupply() < getMaxSupply(), "max supply reached");
        tokenId = abi.decode(data, (uint256));
        _mint(to, tokenId);
    }

    function burn(uint256 tokenId, bytes calldata) external override onlyAgency {
        _burn(tokenId);
    }

    function _getAgency() internal view returns (address payable) {
        return _oracle;
    }
}

contract ERC7527Factory is IERC7527Factory {
    using ClonesWithImmutableArgs for address;

    function deployWrap(AgencySettings calldata agencySettings, AppSettings calldata appSettings, bytes calldata)
        external
        override
        returns (address appInstance, address agencyInstance)
    {
        appInstance = appSettings.implementation.clone(appSettings.immutableData);
        {
            agencyInstance = address(agencySettings.implementation).clone(
                abi.encodePacked(
                    appInstance,
                    agencySettings.asset.currency,
                    agencySettings.asset.premium,
                    agencySettings.asset.feeRecipient,
                    agencySettings.asset.mintFeePercent,
                    agencySettings.asset.burnFeePercent,
                    agencySettings.immutableData
                )
            );
        }

        IERC7527App(appInstance).setAgency(payable(agencyInstance));
        if (agencySettings.initData.length != 0) {
            (bool success, bytes memory result) = agencyInstance.call(agencySettings.initData);

            if (!success) {
                assembly {
                    revert(add(result, 32), mload(result))
                }
            }
        }

        if (appSettings.initData.length != 0) {
            (bool success, bytes memory result) = appInstance.call(appSettings.initData);

            if (!success) {
                assembly {
                    revert(add(result, 32), mload(result))
                }
            }
        }
    }
}