// SPDX-License-Identifier: MIT
pragma solidity 0.8.21;

abstract contract Errors {
  error AlreadyInitialized();
}

// 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 0.8.21;

/******************************************************************************\
* 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 FacetAddressAndPosition {
    address facetAddress;
    uint96 functionSelectorPosition; // position in facetFunctionSelectors.functionSelectors array
  }

  struct FacetFunctionSelectors {
    bytes4[] functionSelectors;
    uint256 facetAddressPosition; // position of facetAddress in facetAddresses array
  }

  struct DiamondStorage {
    // maps function selector to the facet address and
    // the position of the selector in the facetFunctionSelectors.selectors array
    mapping(bytes4 => FacetAddressAndPosition) selectorToFacetAndPosition;
    // maps facet addresses to function selectors
    mapping(address => FacetFunctionSelectors) facetFunctionSelectors;
    // facet addresses
    address[] facetAddresses;
    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);

  // Internal function version of diamondCut
  function diamondCut(
    IDiamondCut.FacetCut[] memory _diamondCut,
    address _init,
    bytes memory _calldata
  ) internal {
    for (uint256 facetIndex; facetIndex < _diamondCut.length; facetIndex++) {
      IDiamondCut.FacetCutAction action = _diamondCut[facetIndex].action;
      if (action == IDiamondCut.FacetCutAction.Add) {
        addFunctions(
          _diamondCut[facetIndex].facetAddress,
          _diamondCut[facetIndex].functionSelectors
        );
      } else if (action == IDiamondCut.FacetCutAction.Replace) {
        replaceFunctions(
          _diamondCut[facetIndex].facetAddress,
          _diamondCut[facetIndex].functionSelectors
        );
      } else if (action == IDiamondCut.FacetCutAction.Remove) {
        removeFunctions(
          _diamondCut[facetIndex].facetAddress,
          _diamondCut[facetIndex].functionSelectors
        );
      } else {
        revert('LibDiamondCut: Incorrect FacetCutAction');
      }
    }
    emit DiamondCut(_diamondCut, _init, _calldata);
    initializeDiamondCut(_init, _calldata);
  }

  function addFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
    require(_functionSelectors.length > 0, 'LibDiamondCut: No selectors in facet to cut');
    DiamondStorage storage ds = diamondStorage();
    require(_facetAddress != address(0), "LibDiamondCut: Add facet can't be address(0)");
    uint96 selectorPosition = uint96(
      ds.facetFunctionSelectors[_facetAddress].functionSelectors.length
    );
    // add new facet address if it does not exist
    if (selectorPosition == 0) {
      addFacet(ds, _facetAddress);
    }
    for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
      bytes4 selector = _functionSelectors[selectorIndex];
      address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
      require(
        oldFacetAddress == address(0),
        "LibDiamondCut: Can't add function that already exists"
      );
      addFunction(ds, selector, selectorPosition, _facetAddress);
      selectorPosition++;
    }
  }

  function replaceFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
    require(_functionSelectors.length > 0, 'LibDiamondCut: No selectors in facet to cut');
    DiamondStorage storage ds = diamondStorage();
    require(_facetAddress != address(0), "LibDiamondCut: Add facet can't be address(0)");
    uint96 selectorPosition = uint96(
      ds.facetFunctionSelectors[_facetAddress].functionSelectors.length
    );
    // add new facet address if it does not exist
    if (selectorPosition == 0) {
      addFacet(ds, _facetAddress);
    }
    for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
      bytes4 selector = _functionSelectors[selectorIndex];
      address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
      require(
        oldFacetAddress != _facetAddress,
        "LibDiamondCut: Can't replace function with same function"
      );
      removeFunction(ds, oldFacetAddress, selector);
      addFunction(ds, selector, selectorPosition, _facetAddress);
      selectorPosition++;
    }
  }

  function removeFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
    require(_functionSelectors.length > 0, 'LibDiamondCut: No selectors in facet to cut');
    DiamondStorage storage ds = diamondStorage();
    // if function does not exist then do nothing and return
    require(_facetAddress == address(0), 'LibDiamondCut: Remove facet address must be address(0)');
    for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
      bytes4 selector = _functionSelectors[selectorIndex];
      address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
      removeFunction(ds, oldFacetAddress, selector);
    }
  }

  function addFacet(DiamondStorage storage ds, address _facetAddress) internal {
    enforceHasContractCode(_facetAddress, 'LibDiamondCut: New facet has no code');
    ds.facetFunctionSelectors[_facetAddress].facetAddressPosition = ds.facetAddresses.length;
    ds.facetAddresses.push(_facetAddress);
  }

  function addFunction(
    DiamondStorage storage ds,
    bytes4 _selector,
    uint96 _selectorPosition,
    address _facetAddress
  ) internal {
    ds.selectorToFacetAndPosition[_selector].functionSelectorPosition = _selectorPosition;
    ds.facetFunctionSelectors[_facetAddress].functionSelectors.push(_selector);
    ds.selectorToFacetAndPosition[_selector].facetAddress = _facetAddress;
  }

  function removeFunction(
    DiamondStorage storage ds,
    address _facetAddress,
    bytes4 _selector
  ) internal {
    require(_facetAddress != address(0), "LibDiamondCut: Can't remove function that doesn't exist");
    // an immutable function is a function defined directly in a diamond
    require(_facetAddress != address(this), "LibDiamondCut: Can't remove immutable function");
    // replace selector with last selector, then delete last selector
    uint256 selectorPosition = ds.selectorToFacetAndPosition[_selector].functionSelectorPosition;
    uint256 lastSelectorPosition = ds
      .facetFunctionSelectors[_facetAddress]
      .functionSelectors
      .length - 1;
    // if not the same then replace _selector with lastSelector
    if (selectorPosition != lastSelectorPosition) {
      bytes4 lastSelector = ds.facetFunctionSelectors[_facetAddress].functionSelectors[
        lastSelectorPosition
      ];
      ds.facetFunctionSelectors[_facetAddress].functionSelectors[selectorPosition] = lastSelector;
      ds.selectorToFacetAndPosition[lastSelector].functionSelectorPosition = uint96(
        selectorPosition
      );
    }
    // delete the last selector
    ds.facetFunctionSelectors[_facetAddress].functionSelectors.pop();
    delete ds.selectorToFacetAndPosition[_selector];

    // if no more selectors for facet address then delete the facet address
    if (lastSelectorPosition == 0) {
      // replace facet address with last facet address and delete last facet address
      uint256 lastFacetAddressPosition = ds.facetAddresses.length - 1;
      uint256 facetAddressPosition = ds.facetFunctionSelectors[_facetAddress].facetAddressPosition;
      if (facetAddressPosition != lastFacetAddressPosition) {
        address lastFacetAddress = ds.facetAddresses[lastFacetAddressPosition];
        ds.facetAddresses[facetAddressPosition] = lastFacetAddress;
        ds.facetFunctionSelectors[lastFacetAddress].facetAddressPosition = facetAddressPosition;
      }
      ds.facetAddresses.pop();
      delete ds.facetFunctionSelectors[_facetAddress].facetAddressPosition;
    }
  }

  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 0.8.21;

/******************************************************************************\
* 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';
import {Errors} from './libraries/Errors.sol';
import {IDiamondLoupe} from './interfaces/IDiamondLoupe.sol';

contract SifiDiamond {
  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 = ds.selectorToFacetAndPosition[msg.sig].facetAddress;
    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 {}
}

{
  "compilationTarget": {
    "contracts/v2/SifiDiamond.sol": "SifiDiamond"
  },
  "evmVersion": "shanghai",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs",
    "useLiteralContent": true
  },
  "optimizer": {
    "enabled": true,
    "runs": 100000000
  },
  "remappings": [
    ":@openzeppelin/=@openzeppelin/",
    ":@uniswap/=@uniswap/",
    ":ds-test/=lib/forge-std/lib/ds-test/src/",
    ":forge-std/=lib/forge-std/src/",
    ":hardhat-deploy/=hardhat-deploy/",
    ":hardhat/=hardhat/",
    ":solidity-stringutils/=lib/solidity-stringutils/src/"
  ]
}