Maid Sweepers

/*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
/*                     SWEEPING MAID 404                      */
/*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

//SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/utils/Strings.sol";
import "./Ownable.sol";
import "./Structs.sol";

abstract contract ERC721Receiver {
  function onERC721Received(address, address, uint256, bytes calldata) external virtual returns (bytes4) {
    return ERC721Receiver.onERC721Received.selector;
  }
}

contract MaidSweepers is Ownable {
  /// NFT Metadata
  string public baseTokenURI = "ipfs://QmXBFjXX3s3aCZKPYZsKMCvGjCHx2WBE5wEg7sNjCp8YbQ/";
  uint256 public erc721totalSupply = 10000;
  uint256[] public tokenIdPool;
  uint256 public maxMintedId;

  // Metadata
  string public name = "MaidSweepers";
  string public symbol =  "SWPRS";
  uint8 public immutable decimals = 18;
  uint256 public immutable totalSupply = erc721totalSupply * (10 ** decimals);

  // Mappings
  /// @dev Mapping to check if id is assigned
  mapping(uint256 => bool) private idAssigned;
  /// @dev Balance of user in fractional representation
  mapping(address => uint256) public balanceOf;
  /// @dev Allowance of user in fractional representation
  mapping(address => mapping(address => uint256)) public allowance;
  /// @dev Approval in native representaion
  mapping(uint256 => address) public getApproved;
  /// @dev Approval for all in native representation
  mapping(address => mapping(address => bool)) public isApprovedForAll;
  /// @dev Owner of id in native representation
  mapping(uint256 => address) internal _ownerOf;
  /// @dev Array of owned ids in native representation
  mapping(address => uint256[]) internal _owned;
  /// @dev Tracks indices for the _owned mapping
  mapping(uint256 => uint256) internal _ownedIndex;
  /// @dev Addresses whitelisted from minting / burning for gas savings (pairs, routers, etc)
  mapping(address => bool) public whitelist;

  // Constructor
  constructor(address _owner) Ownable(_owner) {
    whitelist[_owner] = true;
    balanceOf[_owner] = totalSupply;
  }

  /// @notice Initialization function to set pairs / etc saving gas by avoiding mint / burn on unnecessary targets
  function setWhitelist(address target, bool state) public onlyOwner {
    if (balanceOf[target] > 0) revert SharedStructs.InvalidSetWhitelistCondition();
    whitelist[target] = state;
  }

  /// @notice Function to find owner of a given native token
  function ownerOf(uint256 id) public view returns (address owner) {
    owner = _ownerOf[id];
    if (owner == address(0)) revert SharedStructs.NotFound();
  }

  function tokenURI(uint256 id) public view returns (string memory) {
    if (id >= totalSupply || id <= 0) revert SharedStructs.InvalidId();
    return string.concat(baseTokenURI, Strings.toString(id));
  }

  /// @notice Function for token approvals
  /// @dev This function assumes id / native if amount less than or equal to current max id
  function approve(address spender, uint256 amountOrId) public returns (bool) {
    if (amountOrId <= maxMintedId && amountOrId > 0) {
      address owner = _ownerOf[amountOrId];
      if (msg.sender != owner && !isApprovedForAll[owner][msg.sender]) revert Unauthorized();
      getApproved[amountOrId] = spender;
      emit SharedStructs.Approval(owner, spender, amountOrId);
    } else {
      allowance[msg.sender][spender] = amountOrId;
      emit SharedStructs.Approval(msg.sender, spender, amountOrId);
    }

    return true;
  }

  /// @notice Function native approvals
  function setApprovalForAll(address operator, bool approved) public {
    isApprovedForAll[msg.sender][operator] = approved;
    emit SharedStructs.ApprovalForAll(msg.sender, operator, approved);
  }

  /// @notice Function for mixed transfers
  /// @dev This function assumes id / native if amount less than or equal to current max id
  function transferFrom(address from, address to, uint256 amountOrId) public {
    if (amountOrId <= erc721totalSupply) {
      if (from != _ownerOf[amountOrId]) revert SharedStructs.InvalidSender();
      if (to == address(0)) revert SharedStructs.InvalidRecipient();
      if (
        msg.sender != from &&
        !isApprovedForAll[from][msg.sender] &&
        msg.sender != getApproved[amountOrId]
      ) {
        revert Unauthorized();
      }

      balanceOf[from] -= _getUnit();
      unchecked {
        balanceOf[to] += _getUnit();
      }

      _ownerOf[amountOrId] = to;
      delete getApproved[amountOrId];

      // update _owned for sender
      uint256 updatedId = _owned[from][_owned[from].length - 1];
      _owned[from][_ownedIndex[amountOrId]] = updatedId;
      // pop
      _owned[from].pop();
      // update index for the moved id
      _ownedIndex[updatedId] = _ownedIndex[amountOrId];
      // push token to to owned
      _owned[to].push(amountOrId);
      // update index for to owned
      _ownedIndex[amountOrId] = _owned[to].length - 1;

      emit SharedStructs.Transfer(from, to, amountOrId);
      emit SharedStructs.ERC20Transfer(from, to, _getUnit());
    } else {
      uint256 allowed = allowance[from][msg.sender];
      if (allowed != type(uint256).max) {
        allowance[from][msg.sender] = allowed - amountOrId;
      }
      _transfer(from, to, amountOrId);
    }
  }

  /// @notice Function for fractional transfers
  function transfer(address to, uint256 amount) public returns (bool) {
    return _transfer(msg.sender, to, amount);
  }

  /// @notice Function for native transfers with contract support
  function safeTransferFrom(address from, address to, uint256 id) public {
    transferFrom(from, to, id);
    if (
      to.code.length != 0 &&
      ERC721Receiver(to).onERC721Received(msg.sender, from, id, "") !=
      ERC721Receiver.onERC721Received.selector
    ) {
      revert SharedStructs.UnsafeRecipient();
    }
  }

  /// @notice Function for native transfers with contract support and callback data
  function safeTransferFrom(address from, address to, uint256 id, bytes calldata data) public {
    transferFrom(from, to, id);
    if (
      to.code.length != 0 &&
      ERC721Receiver(to).onERC721Received(msg.sender, from, id, data) !=
      ERC721Receiver.onERC721Received.selector
    ) {
      revert SharedStructs.UnsafeRecipient();
    }
  }

  /// @notice Internal function for fractional transfers
  function _transfer(address from, address to, uint256 amount) internal returns (bool) {
    uint256 unit = _getUnit();
    uint256 balanceBeforeSender = balanceOf[from];
    uint256 balanceBeforeReceiver = balanceOf[to];

    balanceOf[from] -= amount;
    unchecked {
      balanceOf[to] += amount;
    }

    // Skip burn for certain addresses to save gas
    if (!whitelist[from]) {
      uint256 tokens_to_burn = (balanceBeforeSender / unit) - (balanceOf[from] / unit);
      for (uint256 i = 0; i < tokens_to_burn; i++) {
        _burn(from);
      }
    }

    // Skip minting for certain addresses to save gas
    if (!whitelist[to]) {
      uint256 tokens_to_mint = (balanceOf[to] / unit) - (balanceBeforeReceiver / unit);
      for (uint256 i = 0; i < tokens_to_mint; i++) {
        _mint(to);
      }
    }

    emit SharedStructs.ERC20Transfer(from, to, amount);
    return true;
  }

  // Internal utility logic
  function _getUnit() internal view returns (uint256) {
    return 10 ** decimals;
  }

  function _randomIdFromPool() private returns (uint256) {
    if (tokenIdPool.length == 0) revert SharedStructs.PoolIsEmpty();
    uint256 randomIndex = uint256(
      keccak256(abi.encodePacked(block.timestamp, msg.sender,tokenIdPool.length))
    ) % tokenIdPool.length;
    uint256 id = tokenIdPool[randomIndex];
    tokenIdPool[randomIndex] = tokenIdPool[tokenIdPool.length - 1];
    tokenIdPool.pop();
    idAssigned[id] = true;
    return id;
  }

  function _returnIdToPool(uint256 id) private {
    if (!idAssigned[id]) revert SharedStructs.IdNotAssigned();
    tokenIdPool.push(id);
    idAssigned[id] = false;
  }

  function _mint(address to) internal {
    if (to == address(0)) revert SharedStructs.InvalidRecipient();
    uint256 id;
    if (maxMintedId < erc721totalSupply) {
      maxMintedId++;
      id = maxMintedId;
      idAssigned[id] = true;
    } else if (tokenIdPool.length > 0) {
      id = _randomIdFromPool();
    } else {
      revert SharedStructs.PoolIsEmpty();
    }
    _ownerOf[id] = to;
    _owned[to].push(id);
    _ownedIndex[id] = _owned[to].length - 1;
    emit SharedStructs.Transfer(address(0), to, id);
  }

  function _burn(address from) internal {
    if (from == address(0)) revert SharedStructs.InvalidSender();
    uint256 id = _owned[from][_owned[from].length - 1];
    _returnIdToPool(id);
    _owned[from].pop();
    delete _ownedIndex[id];
    delete _ownerOf[id];
    delete getApproved[id];
    emit SharedStructs.Transfer(from, address(0), id);
  }

  function getTokenIdPool() public view returns (uint256[] memory) {
    return tokenIdPool;
  }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator,
        Rounding rounding
    ) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10**64) {
                value /= 10**64;
                result += 64;
            }
            if (value >= 10**32) {
                value /= 10**32;
                result += 32;
            }
            if (value >= 10**16) {
                value /= 10**16;
                result += 16;
            }
            if (value >= 10**8) {
                value /= 10**8;
                result += 8;
            }
            if (value >= 10**4) {
                value /= 10**4;
                result += 4;
            }
            if (value >= 10**2) {
                value /= 10**2;
                result += 2;
            }
            if (value >= 10**1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
        }
    }
}

//SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.20;

abstract contract Ownable {
    event OwnershipTransferred(address indexed user, address indexed newOwner);

    error Unauthorized();
    error InvalidOwner();

    address public owner;

    modifier onlyOwner() virtual {
        if (msg.sender != owner) revert Unauthorized();

        _;
    }

    constructor(address _owner) {
        if (_owner == address(0)) revert InvalidOwner();

        owner = _owner;

        emit OwnershipTransferred(address(0), _owner);
    }

    function transferOwnership(address _owner) public virtual onlyOwner {
        if (_owner == address(0)) revert InvalidOwner();

        owner = _owner;

        emit OwnershipTransferred(msg.sender, _owner);
    }

    function revokeOwnership() public virtual onlyOwner {
        owner = address(0);

        emit OwnershipTransferred(msg.sender, address(0));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

import "./math/Math.sol";

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

library SharedStructs {
  // Events
  event ERC20Transfer(
    address indexed from,
    address indexed to,
    uint256 amount
  );
  event Approval(
    address indexed owner,
    address indexed spender,
    uint256 amount
  );
  event Transfer(
    address indexed from,
    address indexed to,
    uint256 indexed id
  );
  event ERC721Approval(
    address indexed owner,
    address indexed spender,
    uint256 indexed id
  );
  event ApprovalForAll(
    address indexed owner,
    address indexed operator,
    bool approved
  );

  // Errors
  error NotFound();
  error AlreadyExists();
  error InvalidRecipient();
  error InvalidSender();
  error UnsafeRecipient();
  error InvalidId();
  error IdNotAssigned();
  error PoolIsEmpty();
  error InvalidSetWhitelistCondition();
}

{
  "compilationTarget": {
    "src/MaidSweepers.sol": "MaidSweepers"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": [
    ":@openzeppelin/contracts/=lib/openzeppelin-contracts/contracts/",
    ":ds-test/=lib/forge-std/lib/ds-test/src/",
    ":forge-std/=lib/forge-std/src/",
    ":openzeppelin-contracts/=lib/openzeppelin-contracts/"
  ]
}