// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
*
* Implementation of a diamond.
/******************************************************************************/

import { LibDiamond } from "./libraries/LibDiamond.sol";
import { IDiamondCut } from "./interfaces/IDiamondCut.sol";

contract Diamond {    

    constructor(address _contractOwner, address _diamondCutFacet) payable {        
        LibDiamond.setContractOwner(_contractOwner);

        // Add the diamondCut external function from the diamondCutFacet
        IDiamondCut.FacetCut[] memory cut = new IDiamondCut.FacetCut[](1);
        bytes4[] memory functionSelectors = new bytes4[](1);
        functionSelectors[0] = IDiamondCut.diamondCut.selector;
        cut[0] = IDiamondCut.FacetCut({
            facetAddress: _diamondCutFacet, 
            action: IDiamondCut.FacetCutAction.Add, 
            functionSelectors: functionSelectors
        });
        LibDiamond.diamondCut(cut, address(0), "");        
    }

    // Find facet for function that is called and execute the
    // function if a facet is found and return any value.
    fallback() external payable {
        LibDiamond.DiamondStorage storage ds;
        bytes32 position = LibDiamond.DIAMOND_STORAGE_POSITION;
        // get diamond storage
        assembly {
            ds.slot := position
        }
        // get facet from function selector
        address facet = address(bytes20(ds.facets[msg.sig]));
        require(facet != address(0), "Diamond: Function does not exist");
        // Execute external function from facet using delegatecall and return any value.
        assembly {
            // copy function selector and any arguments
            calldatacopy(0, 0, calldatasize())
            // execute function call using the facet
            let result := delegatecall(gas(), facet, 0, calldatasize(), 0, 0)
            // get any return value
            returndatacopy(0, 0, returndatasize())
            // return any return value or error back to the caller
            switch result
                case 0 {
                    revert(0, returndatasize())
                }
                default {
                    return(0, returndatasize())
                }
        }
    }

    receive() external payable {}
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/

import { IDiamondCut } from "../interfaces/IDiamondCut.sol";
import { LibDiamond } from "../libraries/LibDiamond.sol";

// Remember to add the loupe functions from DiamondLoupeFacet to the diamond.
// The loupe functions are required by the EIP2535 Diamonds standard

contract DiamondCutFacet is IDiamondCut {
    /// @notice Add/replace/remove any number of functions and optionally execute
    ///         a function with delegatecall
    /// @param _diamondCut Contains the facet addresses and function selectors
    /// @param _init The address of the contract or facet to execute _calldata
    /// @param _calldata A function call, including function selector and arguments
    ///                  _calldata is executed with delegatecall on _init
    function diamondCut(
        FacetCut[] calldata _diamondCut,
        address _init,
        bytes calldata _calldata
    ) external override {
        LibDiamond.enforceIsContractOwner();
        LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
        uint256 originalSelectorCount = ds.selectorCount;
        uint256 selectorCount = originalSelectorCount;
        bytes32 selectorSlot;
        // Check if last selector slot is not full
        // "selectorCount & 7" is a gas efficient modulo by eight "selectorCount % 8" 
        if (selectorCount & 7 > 0) {
            // get last selectorSlot
            // "selectorCount >> 3" is a gas efficient division by 8 "selectorCount / 8"
            selectorSlot = ds.selectorSlots[selectorCount >> 3];
        }
        // loop through diamond cut
        for (uint256 facetIndex; facetIndex < _diamondCut.length; ) {
            (selectorCount, selectorSlot) = LibDiamond.addReplaceRemoveFacetSelectors(
                selectorCount,
                selectorSlot,
                _diamondCut[facetIndex].facetAddress,
                _diamondCut[facetIndex].action,
                _diamondCut[facetIndex].functionSelectors
            );

            unchecked {
                facetIndex++;
            }
        }
        if (selectorCount != originalSelectorCount) {
            ds.selectorCount = uint16(selectorCount);
        }
        // If last selector slot is not full
        // "selectorCount & 7" is a gas efficient modulo by eight "selectorCount % 8" 
        if (selectorCount & 7 > 0) {
            // "selectorCount >> 3" is a gas efficient division by 8 "selectorCount / 8"
            ds.selectorSlots[selectorCount >> 3] = selectorSlot;
        }
        emit DiamondCut(_diamondCut, _init, _calldata);
        LibDiamond.initializeDiamondCut(_init, _calldata);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/

import { LibDiamond } from  "../libraries/LibDiamond.sol";
import { IDiamondLoupe } from "../interfaces/IDiamondLoupe.sol";
import { IERC165 } from "../interfaces/IERC165.sol";

// The functions in DiamondLoupeFacet MUST be added to a diamond.
// The EIP-2535 Diamond standard requires these functions

contract DiamondLoupeFacet is IDiamondLoupe, IERC165 {
    // Diamond Loupe Functions
    ////////////////////////////////////////////////////////////////////
    /// These functions are expected to be called frequently by tools.
    //
    // struct Facet {
    //     address facetAddress;
    //     bytes4[] functionSelectors;
    // }
    /// @notice Gets all facets and their selectors.
    /// @return facets_ Facet
    function facets() external override view returns (Facet[] memory facets_) {
        LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
        facets_ = new Facet[](ds.selectorCount);
        uint16[] memory numFacetSelectors = new uint16[](ds.selectorCount);
        uint256 numFacets;
        uint256 selectorIndex;
        // loop through function selectors
        for (uint256 slotIndex; selectorIndex < ds.selectorCount; slotIndex++) {
            bytes32 slot = ds.selectorSlots[slotIndex];
            for (uint256 selectorSlotIndex; selectorSlotIndex < 8; selectorSlotIndex++) {
                selectorIndex++;
                if (selectorIndex > ds.selectorCount) {
                    break;
                }
                // " << 5 is the same as multiplying by 32 ( * 32)
                bytes4 selector = bytes4(slot << (selectorSlotIndex << 5));
                address facetAddress_ = address(bytes20(ds.facets[selector]));
                bool continueLoop;
                for (uint256 facetIndex; facetIndex < numFacets; facetIndex++) {
                    if (facets_[facetIndex].facetAddress == facetAddress_) {
                        facets_[facetIndex].functionSelectors[numFacetSelectors[facetIndex]] = selector;
                        // probably will never have more than 256 functions from one facet contract
                        require(numFacetSelectors[facetIndex] < 255);
                        numFacetSelectors[facetIndex]++;
                        continueLoop = true;
                        break;
                    }
                }
                if (continueLoop) {
                    continue;
                }
                facets_[numFacets].facetAddress = facetAddress_;
                facets_[numFacets].functionSelectors = new bytes4[](ds.selectorCount);
                facets_[numFacets].functionSelectors[0] = selector;
                numFacetSelectors[numFacets] = 1;
                numFacets++;
            }
        }
        for (uint256 facetIndex; facetIndex < numFacets; facetIndex++) {
            uint256 numSelectors = numFacetSelectors[facetIndex];
            bytes4[] memory selectors = facets_[facetIndex].functionSelectors;
            // setting the number of selectors
            assembly {
                mstore(selectors, numSelectors)
            }
        }
        // setting the number of facets
        assembly {
            mstore(facets_, numFacets)
        }
    }

    /// @notice Gets all the function selectors supported by a specific facet.
    /// @param _facet The facet address.
    /// @return _facetFunctionSelectors The selectors associated with a facet address.
    function facetFunctionSelectors(address _facet) external override view returns (bytes4[] memory _facetFunctionSelectors) {
        LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
        uint256 numSelectors;
        _facetFunctionSelectors = new bytes4[](ds.selectorCount);
        uint256 selectorIndex;
        // loop through function selectors
        for (uint256 slotIndex; selectorIndex < ds.selectorCount; slotIndex++) {
            bytes32 slot = ds.selectorSlots[slotIndex];
            for (uint256 selectorSlotIndex; selectorSlotIndex < 8; selectorSlotIndex++) {
                selectorIndex++;
                if (selectorIndex > ds.selectorCount) {
                    break;
                }
                // " << 5 is the same as multiplying by 32 ( * 32)
                bytes4 selector = bytes4(slot << (selectorSlotIndex << 5));
                address facet = address(bytes20(ds.facets[selector]));
                if (_facet == facet) {
                    _facetFunctionSelectors[numSelectors] = selector;
                    numSelectors++;
                }
            }
        }
        // Set the number of selectors in the array
        assembly {
            mstore(_facetFunctionSelectors, numSelectors)
        }
    }

    /// @notice Get all the facet addresses used by a diamond.
    /// @return facetAddresses_
    function facetAddresses() external override view returns (address[] memory facetAddresses_) {
        LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
        facetAddresses_ = new address[](ds.selectorCount);
        uint256 numFacets;
        uint256 selectorIndex;
        // loop through function selectors
        for (uint256 slotIndex; selectorIndex < ds.selectorCount; slotIndex++) {
            bytes32 slot = ds.selectorSlots[slotIndex];
            for (uint256 selectorSlotIndex; selectorSlotIndex < 8; selectorSlotIndex++) {
                selectorIndex++;
                if (selectorIndex > ds.selectorCount) {
                    break;
                }
                // " << 5 is the same as multiplying by 32 ( * 32)
                bytes4 selector = bytes4(slot << (selectorSlotIndex << 5));
                address facetAddress_ = address(bytes20(ds.facets[selector]));
                bool continueLoop;
                for (uint256 facetIndex; facetIndex < numFacets; facetIndex++) {
                    if (facetAddress_ == facetAddresses_[facetIndex]) {
                        continueLoop = true;
                        break;
                    }
                }
                if (continueLoop) {                    
                    continue;
                }
                facetAddresses_[numFacets] = facetAddress_;
                numFacets++;
            }
        }
        // Set the number of facet addresses in the array
        assembly {
            mstore(facetAddresses_, numFacets)
        }
    }

    /// @notice Gets the facet that supports the given selector.
    /// @dev If facet is not found return address(0).
    /// @param _functionSelector The function selector.
    /// @return facetAddress_ The facet address.
    function facetAddress(bytes4 _functionSelector) external override view returns (address facetAddress_) {
        LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
        facetAddress_ = address(bytes20(ds.facets[_functionSelector]));
    }

    // This implements ERC-165.
    function supportsInterface(bytes4 _interfaceId) external override view returns (bool) {
        LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
        return ds.supportedInterfaces[_interfaceId];
    }
}

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.20;

/// ------------------------------------------------------------------------------------------------------------
///
/// NOTE: This file is auto-generated by Gemforge.
///
/// ------------------------------------------------------------------------------------------------------------

import { Diamond } from 'lib/diamond-2-hardhat/contracts/Diamond.sol';
import { LibDiamond } from 'lib/diamond-2-hardhat/contracts/libraries/LibDiamond.sol';
import { DiamondCutFacet } from 'lib/diamond-2-hardhat/contracts/facets/DiamondCutFacet.sol';
import { DiamondLoupeFacet } from 'lib/diamond-2-hardhat/contracts/facets/DiamondLoupeFacet.sol';
import { OwnershipFacet } from 'lib/diamond-2-hardhat/contracts/facets/OwnershipFacet.sol';
import { IDiamondCut } from 'lib/diamond-2-hardhat/contracts/interfaces/IDiamondCut.sol';
import { IDiamondLoupe } from 'lib/diamond-2-hardhat/contracts/interfaces/IDiamondLoupe.sol';
import { IERC165 } from 'lib/diamond-2-hardhat/contracts/interfaces/IERC165.sol';
import { IERC173 } from 'lib/diamond-2-hardhat/contracts/interfaces/IERC173.sol';

contract DiamondProxy is Diamond {
  constructor(address _contractOwner) payable Diamond(_contractOwner, address(new DiamondCutFacet())) {
    // add core facets
    _initCoreFacets();

    // setup ERC165 data
    LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
    ds.supportedInterfaces[type(IERC165).interfaceId] = true;
    ds.supportedInterfaces[type(IDiamondCut).interfaceId] = true;
    ds.supportedInterfaces[type(IDiamondLoupe).interfaceId] = true;
    ds.supportedInterfaces[type(IERC173).interfaceId] = true;
  }

  // Internal

  function _initCoreFacets() private {
    // add basic facets
    IDiamondCut.FacetCut[] memory cut = new IDiamondCut.FacetCut[](2);

    address _diamondLoupeFacet = address(new DiamondLoupeFacet());
    bytes4[] memory f1 = new bytes4[](5);
    f1[0] = IDiamondLoupe.facets.selector;
    f1[1] = IDiamondLoupe.facetFunctionSelectors.selector;
    f1[2] = IDiamondLoupe.facetAddresses.selector;
    f1[3] = IDiamondLoupe.facetAddress.selector;
    f1[4] = IERC165.supportsInterface.selector;
    cut[0] = IDiamondCut.FacetCut({
      facetAddress: _diamondLoupeFacet,
      action: IDiamondCut.FacetCutAction.Add,
      functionSelectors: f1
    });

    address _ownershipFacet = address(new OwnershipFacet());
    bytes4[] memory f2 = new bytes4[](2);
    f2[0] = IERC173.owner.selector;
    f2[1] = IERC173.transferOwnership.selector;
    cut[1] = IDiamondCut.FacetCut({
      facetAddress: _ownershipFacet,
      action: IDiamondCut.FacetCutAction.Add,
      functionSelectors: f2
    });

    LibDiamond.diamondCut(cut, address(0), "");
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/

interface IDiamondCut {
    enum FacetCutAction {Add, Replace, Remove}
    // Add=0, Replace=1, Remove=2

    struct FacetCut {
        address facetAddress;
        FacetCutAction action;
        bytes4[] functionSelectors;
    }

    /// @notice Add/replace/remove any number of functions and optionally execute
    ///         a function with delegatecall
    /// @param _diamondCut Contains the facet addresses and function selectors
    /// @param _init The address of the contract or facet to execute _calldata
    /// @param _calldata A function call, including function selector and arguments
    ///                  _calldata is executed with delegatecall on _init
    function diamondCut(
        FacetCut[] calldata _diamondCut,
        address _init,
        bytes calldata _calldata
    ) external;

    event DiamondCut(FacetCut[] _diamondCut, address _init, bytes _calldata);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/

// A loupe is a small magnifying glass used to look at diamonds.
// These functions look at diamonds
interface IDiamondLoupe {
    /// These functions are expected to be called frequently
    /// by tools.

    struct Facet {
        address facetAddress;
        bytes4[] functionSelectors;
    }

    /// @notice Gets all facet addresses and their four byte function selectors.
    /// @return facets_ Facet
    function facets() external view returns (Facet[] memory facets_);

    /// @notice Gets all the function selectors supported by a specific facet.
    /// @param _facet The facet address.
    /// @return facetFunctionSelectors_
    function facetFunctionSelectors(address _facet) external view returns (bytes4[] memory facetFunctionSelectors_);

    /// @notice Get all the facet addresses used by a diamond.
    /// @return facetAddresses_
    function facetAddresses() external view returns (address[] memory facetAddresses_);

    /// @notice Gets the facet that supports the given selector.
    /// @dev If facet is not found return address(0).
    /// @param _functionSelector The function selector.
    /// @return facetAddress_ The facet address.
    function facetAddress(bytes4 _functionSelector) external view returns (address facetAddress_);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IERC165 {
    /// @notice Query if a contract implements an interface
    /// @param interfaceId The interface identifier, as specified in ERC-165
    /// @dev Interface identification is specified in ERC-165. This function
    ///  uses less than 30,000 gas.
    /// @return `true` if the contract implements `interfaceID` and
    ///  `interfaceID` is not 0xffffffff, `false` otherwise
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title ERC-173 Contract Ownership Standard
///  Note: the ERC-165 identifier for this interface is 0x7f5828d0
/* is ERC165 */
interface IERC173 {
    /// @dev This emits when ownership of a contract changes.
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /// @notice Get the address of the owner
    /// @return owner_ The address of the owner.
    function owner() external view returns (address owner_);

    /// @notice Set the address of the new owner of the contract
    /// @dev Set _newOwner to address(0) to renounce any ownership.
    /// @param _newOwner The address of the new owner of the contract
    function transferOwnership(address _newOwner) external;
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com> (https://twitter.com/mudgen)
* EIP-2535 Diamonds: https://eips.ethereum.org/EIPS/eip-2535
/******************************************************************************/
import { IDiamondCut } from "../interfaces/IDiamondCut.sol";

// Remember to add the loupe functions from DiamondLoupeFacet to the diamond.
// The loupe functions are required by the EIP2535 Diamonds standard

error InitializationFunctionReverted(address _initializationContractAddress, bytes _calldata);

library LibDiamond {
    bytes32 constant DIAMOND_STORAGE_POSITION = keccak256("diamond.standard.diamond.storage");

    struct DiamondStorage {
        // maps function selectors to the facets that execute the functions.
        // and maps the selectors to their position in the selectorSlots array.
        // func selector => address facet, selector position
        mapping(bytes4 => bytes32) facets;
        // array of slots of function selectors.
        // each slot holds 8 function selectors.
        mapping(uint256 => bytes32) selectorSlots;
        // The number of function selectors in selectorSlots
        uint16 selectorCount;
        // Used to query if a contract implements an interface.
        // Used to implement ERC-165.
        mapping(bytes4 => bool) supportedInterfaces;
        // owner of the contract
        address contractOwner;
    }

    function diamondStorage() internal pure returns (DiamondStorage storage ds) {
        bytes32 position = DIAMOND_STORAGE_POSITION;
        assembly {
            ds.slot := position
        }
    }

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    function setContractOwner(address _newOwner) internal {
        DiamondStorage storage ds = diamondStorage();
        address previousOwner = ds.contractOwner;
        ds.contractOwner = _newOwner;
        emit OwnershipTransferred(previousOwner, _newOwner);
    }

    function contractOwner() internal view returns (address contractOwner_) {
        contractOwner_ = diamondStorage().contractOwner;
    }

    function enforceIsContractOwner() internal view {
        require(msg.sender == diamondStorage().contractOwner, "LibDiamond: Must be contract owner");
    }

    event DiamondCut(IDiamondCut.FacetCut[] _diamondCut, address _init, bytes _calldata);

    bytes32 constant CLEAR_ADDRESS_MASK = bytes32(uint256(0xffffffffffffffffffffffff));
    bytes32 constant CLEAR_SELECTOR_MASK = bytes32(uint256(0xffffffff << 224));

    // Internal function version of diamondCut
    // This code is almost the same as the external diamondCut,
    // except it is using 'Facet[] memory _diamondCut' instead of
    // 'Facet[] calldata _diamondCut'.
    // The code is duplicated to prevent copying calldata to memory which
    // causes an error for a two dimensional array.
    function diamondCut(
        IDiamondCut.FacetCut[] memory _diamondCut,
        address _init,
        bytes memory _calldata
    ) internal {
        DiamondStorage storage ds = diamondStorage();
        uint256 originalSelectorCount = ds.selectorCount;
        uint256 selectorCount = originalSelectorCount;
        bytes32 selectorSlot;
        // Check if last selector slot is not full
        // "selectorCount & 7" is a gas efficient modulo by eight "selectorCount % 8" 
        if (selectorCount & 7 > 0) {
            // get last selectorSlot
            // "selectorSlot >> 3" is a gas efficient division by 8 "selectorSlot / 8"
            selectorSlot = ds.selectorSlots[selectorCount >> 3];
        }
        // loop through diamond cut
        for (uint256 facetIndex; facetIndex < _diamondCut.length; ) {
            (selectorCount, selectorSlot) = addReplaceRemoveFacetSelectors(
                selectorCount,
                selectorSlot,
                _diamondCut[facetIndex].facetAddress,
                _diamondCut[facetIndex].action,
                _diamondCut[facetIndex].functionSelectors
            );

            unchecked {
                facetIndex++;
            }
        }
        if (selectorCount != originalSelectorCount) {
            ds.selectorCount = uint16(selectorCount);
        }
        // If last selector slot is not full
        // "selectorCount & 7" is a gas efficient modulo by eight "selectorCount % 8" 
        if (selectorCount & 7 > 0) {
            // "selectorSlot >> 3" is a gas efficient division by 8 "selectorSlot / 8"
            ds.selectorSlots[selectorCount >> 3] = selectorSlot;
        }
        emit DiamondCut(_diamondCut, _init, _calldata);
        initializeDiamondCut(_init, _calldata);
    }

    function addReplaceRemoveFacetSelectors(
        uint256 _selectorCount,
        bytes32 _selectorSlot,
        address _newFacetAddress,
        IDiamondCut.FacetCutAction _action,
        bytes4[] memory _selectors
    ) internal returns (uint256, bytes32) {
        DiamondStorage storage ds = diamondStorage();
        require(_selectors.length > 0, "LibDiamondCut: No selectors in facet to cut");
        if (_action == IDiamondCut.FacetCutAction.Add) {
            enforceHasContractCode(_newFacetAddress, "LibDiamondCut: Add facet has no code");
            for (uint256 selectorIndex; selectorIndex < _selectors.length; ) {
                bytes4 selector = _selectors[selectorIndex];
                bytes32 oldFacet = ds.facets[selector];
                require(address(bytes20(oldFacet)) == address(0), "LibDiamondCut: Can't add function that already exists");
                // add facet for selector
                ds.facets[selector] = bytes20(_newFacetAddress) | bytes32(_selectorCount);
                // "_selectorCount & 7" is a gas efficient modulo by eight "_selectorCount % 8" 
                // " << 5 is the same as multiplying by 32 ( * 32)
                uint256 selectorInSlotPosition = (_selectorCount & 7) << 5;
                // clear selector position in slot and add selector
                _selectorSlot = (_selectorSlot & ~(CLEAR_SELECTOR_MASK >> selectorInSlotPosition)) | (bytes32(selector) >> selectorInSlotPosition);
                // if slot is full then write it to storage
                if (selectorInSlotPosition == 224) {
                    // "_selectorSlot >> 3" is a gas efficient division by 8 "_selectorSlot / 8"
                    ds.selectorSlots[_selectorCount >> 3] = _selectorSlot;
                    _selectorSlot = 0;
                }
                _selectorCount++;

                unchecked {
                    selectorIndex++;
                }
            }
        } else if (_action == IDiamondCut.FacetCutAction.Replace) {
            enforceHasContractCode(_newFacetAddress, "LibDiamondCut: Replace facet has no code");
            for (uint256 selectorIndex; selectorIndex < _selectors.length; ) {
                bytes4 selector = _selectors[selectorIndex];
                bytes32 oldFacet = ds.facets[selector];
                address oldFacetAddress = address(bytes20(oldFacet));
                // only useful if immutable functions exist
                require(oldFacetAddress != address(this), "LibDiamondCut: Can't replace immutable function");
                require(oldFacetAddress != _newFacetAddress, "LibDiamondCut: Can't replace function with same function");
                require(oldFacetAddress != address(0), "LibDiamondCut: Can't replace function that doesn't exist");
                // replace old facet address
                ds.facets[selector] = (oldFacet & CLEAR_ADDRESS_MASK) | bytes20(_newFacetAddress);

                unchecked {
                    selectorIndex++;
                }
            }
        } else if (_action == IDiamondCut.FacetCutAction.Remove) {
            require(_newFacetAddress == address(0), "LibDiamondCut: Remove facet address must be address(0)");
            // "_selectorCount >> 3" is a gas efficient division by 8 "_selectorCount / 8"
            uint256 selectorSlotCount = _selectorCount >> 3;
            // "_selectorCount & 7" is a gas efficient modulo by eight "_selectorCount % 8" 
            uint256 selectorInSlotIndex = _selectorCount & 7;
            for (uint256 selectorIndex; selectorIndex < _selectors.length; ) {
                if (_selectorSlot == 0) {
                    // get last selectorSlot
                    selectorSlotCount--;
                    _selectorSlot = ds.selectorSlots[selectorSlotCount];
                    selectorInSlotIndex = 7;
                } else {
                    selectorInSlotIndex--;
                }
                bytes4 lastSelector;
                uint256 oldSelectorsSlotCount;
                uint256 oldSelectorInSlotPosition;
                // adding a block here prevents stack too deep error
                {
                    bytes4 selector = _selectors[selectorIndex];
                    bytes32 oldFacet = ds.facets[selector];
                    require(address(bytes20(oldFacet)) != address(0), "LibDiamondCut: Can't remove function that doesn't exist");
                    // only useful if immutable functions exist
                    require(address(bytes20(oldFacet)) != address(this), "LibDiamondCut: Can't remove immutable function");
                    // replace selector with last selector in ds.facets
                    // gets the last selector
                    // " << 5 is the same as multiplying by 32 ( * 32)
                    lastSelector = bytes4(_selectorSlot << (selectorInSlotIndex << 5));
                    if (lastSelector != selector) {
                        // update last selector slot position info
                        ds.facets[lastSelector] = (oldFacet & CLEAR_ADDRESS_MASK) | bytes20(ds.facets[lastSelector]);
                    }
                    delete ds.facets[selector];
                    uint256 oldSelectorCount = uint16(uint256(oldFacet));
                    // "oldSelectorCount >> 3" is a gas efficient division by 8 "oldSelectorCount / 8"
                    oldSelectorsSlotCount = oldSelectorCount >> 3;
                    // "oldSelectorCount & 7" is a gas efficient modulo by eight "oldSelectorCount % 8" 
                    // " << 5 is the same as multiplying by 32 ( * 32)
                    oldSelectorInSlotPosition = (oldSelectorCount & 7) << 5;
                }
                if (oldSelectorsSlotCount != selectorSlotCount) {
                    bytes32 oldSelectorSlot = ds.selectorSlots[oldSelectorsSlotCount];
                    // clears the selector we are deleting and puts the last selector in its place.
                    oldSelectorSlot =
                        (oldSelectorSlot & ~(CLEAR_SELECTOR_MASK >> oldSelectorInSlotPosition)) |
                        (bytes32(lastSelector) >> oldSelectorInSlotPosition);
                    // update storage with the modified slot
                    ds.selectorSlots[oldSelectorsSlotCount] = oldSelectorSlot;
                } else {
                    // clears the selector we are deleting and puts the last selector in its place.
                    _selectorSlot =
                        (_selectorSlot & ~(CLEAR_SELECTOR_MASK >> oldSelectorInSlotPosition)) |
                        (bytes32(lastSelector) >> oldSelectorInSlotPosition);
                }
                if (selectorInSlotIndex == 0) {
                    delete ds.selectorSlots[selectorSlotCount];
                    _selectorSlot = 0;
                }

                unchecked {
                    selectorIndex++;
                }
            }
            _selectorCount = selectorSlotCount * 8 + selectorInSlotIndex;
        } else {
            revert("LibDiamondCut: Incorrect FacetCutAction");
        }
        return (_selectorCount, _selectorSlot);
    }

    function initializeDiamondCut(address _init, bytes memory _calldata) internal {
        if (_init == address(0)) {
            return;
        }
        enforceHasContractCode(_init, "LibDiamondCut: _init address has no code");        
        (bool success, bytes memory error) = _init.delegatecall(_calldata);
        if (!success) {
            if (error.length > 0) {
                // bubble up error
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(error)
                    revert(add(32, error), returndata_size)
                }
            } else {
                revert InitializationFunctionReverted(_init, _calldata);
            }
        }
    }

    function enforceHasContractCode(address _contract, string memory _errorMessage) internal view {
        uint256 contractSize;
        assembly {
            contractSize := extcodesize(_contract)
        }
        require(contractSize > 0, _errorMessage);
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { LibDiamond } from "../libraries/LibDiamond.sol";
import { IERC173 } from "../interfaces/IERC173.sol";

contract OwnershipFacet is IERC173 {
    function transferOwnership(address _newOwner) external override {
        LibDiamond.enforceIsContractOwner();
        LibDiamond.setContractOwner(_newOwner);
    }

    function owner() external override view returns (address owner_) {
        owner_ = LibDiamond.contractOwner();
    }
}

{
  "compilationTarget": {
    "src/generated/DiamondProxy.sol": "DiamondProxy"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "appendCBOR": false,
    "bytecodeHash": "none"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": [
    ":@openzeppelin/contracts/=lib/oz/contracts/",
    ":diamond-2-hardhat/=lib/diamond-2-hardhat/contracts/",
    ":ds-test/=lib/ds-test/src/",
    ":erc4626-tests/=lib/oz/lib/erc4626-tests/",
    ":forge-std/=lib/forge-std/src/",
    ":oz/=lib/oz/",
    ":solady/=lib/solady/",
    ":solidity-lib/=lib/solidity-lib/contracts/",
    ":solidity-stringutils/=lib/solidity-stringutils/",
    ":solmate/=lib/solmate/src/"
  ]
}