// SPDX-License-Identifier: CC0-1.0
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com>, Twitter/Github: @mudgen
* EIP-2535 Diamonds
*
* Implementation of a diamond.
/******************************************************************************/

import { LibDiamond } from "./libraries/LibDiamond.sol";
import { IDiamondCut } from "./interfaces/IDiamondCut.sol";
import { IDiamondLoupe } from "./interfaces/IDiamondLoupe.sol";
import { IERC173 } from "./interfaces/IERC173.sol";
import { IERC165 } from "./interfaces/IERC165.sol";

// solhint-disable no-complex-fallback
// solhint-disable no-inline-assembly
// solhint-disable no-empty-blocks

// When no function exists for function called
error FunctionNotFound(bytes4 _functionSelector);

// This is used in diamond constructor
// more arguments are added to this struct
// this avoids stack too deep errors
struct DiamondArgs {
  address owner;
  address init;
  bytes initCalldata;
}

contract Diamond {
  constructor(IDiamondCut.FacetCut[] memory _diamondCut, DiamondArgs memory _args) payable {
    LibDiamond.setContractOwner(_args.owner);
    LibDiamond.diamondCut(_diamondCut, _args.init, _args.initCalldata);

    // Code can be added here to perform actions and set state variables.
  }

  // 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.facetAddressAndSelectorPosition[msg.sig].facetAddress;
    if (facet == address(0)) {
      revert FunctionNotFound(msg.sig);
    }
    // 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: CC0-1.0
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com>, Twitter/Github: @mudgen
* EIP-2535 Diamonds
/******************************************************************************/

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

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

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

// SPDX-License-Identifier: CC0-1.0
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com>, Twitter/Github: @mudgen
* EIP-2535 Diamonds
/******************************************************************************/

import { IDiamond } from "./IDiamond.sol";

interface IDiamondCut is IDiamond {
  /// @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;
}

// SPDX-License-Identifier: CC0-1.0
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com>, Twitter/Github: @mudgen
* EIP-2535 Diamonds
/******************************************************************************/

// 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: CC0-1.0
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: CC0-1.0
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: CC0-1.0
pragma solidity ^0.8.0;

/******************************************************************************\
* Author: Nick Mudge <nick@perfectabstractions.com>, Twitter/Github: @mudgen
* EIP-2535 Diamonds
/******************************************************************************/
import { IDiamond } from "../interfaces/IDiamond.sol";
import { IDiamondCut } from "../interfaces/IDiamondCut.sol";

// solhint-disable avoid-low-level-calls
// solhint-disable no-inline-assembly

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

error NoSelectorsGivenToAdd();
error NotContractOwner(address _user, address _contractOwner);
error NoSelectorsProvidedForFacetForCut(address _facetAddress);
error CannotAddSelectorsToZeroAddress(bytes4[] _selectors);
error NoBytecodeAtAddress(address _contractAddress, string _message);
error IncorrectFacetCutAction(uint8 _action);
error CannotAddFunctionToDiamondThatAlreadyExists(bytes4 _selector);
error CannotReplaceFunctionsFromFacetWithZeroAddress(bytes4[] _selectors);
error CannotReplaceImmutableFunction(bytes4 _selector);
error CannotReplaceFunctionWithTheSameFunctionFromTheSameFacet(bytes4 _selector);
error CannotReplaceFunctionThatDoesNotExists(bytes4 _selector);
error RemoveFacetAddressMustBeZeroAddress(address _facetAddress);
error CannotRemoveFunctionThatDoesNotExist(bytes4 _selector);
error CannotRemoveImmutableFunction(bytes4 _selector);
error InitializationFunctionReverted(address _initializationContractAddress, bytes _calldata);

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

  struct FacetAddressAndSelectorPosition {
    address facetAddress;
    uint16 selectorPosition;
  }

  struct DiamondStorage {
    // function selector => facet address and selector position in selectors array
    mapping(bytes4 => FacetAddressAndSelectorPosition) facetAddressAndSelectorPosition;
    bytes4[] selectors;
    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 {
    if (msg.sender != diamondStorage().contractOwner) {
      revert NotContractOwner(msg.sender, diamondStorage().contractOwner);
    }
  }

  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++) {
      bytes4[] memory functionSelectors = _diamondCut[facetIndex].functionSelectors;
      address facetAddress = _diamondCut[facetIndex].facetAddress;
      if (functionSelectors.length == 0) {
        revert NoSelectorsProvidedForFacetForCut(facetAddress);
      }
      IDiamondCut.FacetCutAction action = _diamondCut[facetIndex].action;
      if (action == IDiamond.FacetCutAction.Add) {
        addFunctions(facetAddress, functionSelectors);
      } else if (action == IDiamond.FacetCutAction.Replace) {
        replaceFunctions(facetAddress, functionSelectors);
      } else if (action == IDiamond.FacetCutAction.Remove) {
        removeFunctions(facetAddress, functionSelectors);
      } else {
        revert IncorrectFacetCutAction(uint8(action));
      }
    }
    emit DiamondCut(_diamondCut, _init, _calldata);
    initializeDiamondCut(_init, _calldata);
  }

  function addFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
    if (_facetAddress == address(0)) {
      revert CannotAddSelectorsToZeroAddress(_functionSelectors);
    }
    DiamondStorage storage ds = diamondStorage();
    uint16 selectorCount = uint16(ds.selectors.length);
    enforceHasContractCode(_facetAddress, "LibDiamondCut: Add facet has no code");
    for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
      bytes4 selector = _functionSelectors[selectorIndex];
      address oldFacetAddress = ds.facetAddressAndSelectorPosition[selector].facetAddress;
      if (oldFacetAddress != address(0)) {
        revert CannotAddFunctionToDiamondThatAlreadyExists(selector);
      }
      ds.facetAddressAndSelectorPosition[selector] = FacetAddressAndSelectorPosition(_facetAddress, selectorCount);
      ds.selectors.push(selector);
      selectorCount++;
    }
  }

  function replaceFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
    DiamondStorage storage ds = diamondStorage();
    if (_facetAddress == address(0)) {
      revert CannotReplaceFunctionsFromFacetWithZeroAddress(_functionSelectors);
    }
    enforceHasContractCode(_facetAddress, "LibDiamondCut: Replace facet has no code");
    for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
      bytes4 selector = _functionSelectors[selectorIndex];
      address oldFacetAddress = ds.facetAddressAndSelectorPosition[selector].facetAddress;
      // can't replace immutable functions -- functions defined directly in the diamond in this case
      if (oldFacetAddress == address(this)) {
        revert CannotReplaceImmutableFunction(selector);
      }
      if (oldFacetAddress == _facetAddress) {
        revert CannotReplaceFunctionWithTheSameFunctionFromTheSameFacet(selector);
      }
      if (oldFacetAddress == address(0)) {
        revert CannotReplaceFunctionThatDoesNotExists(selector);
      }
      // replace old facet address
      ds.facetAddressAndSelectorPosition[selector].facetAddress = _facetAddress;
    }
  }

  function removeFunctions(address _facetAddress, bytes4[] memory _functionSelectors) internal {
    DiamondStorage storage ds = diamondStorage();
    uint256 selectorCount = ds.selectors.length;
    if (_facetAddress != address(0)) {
      revert RemoveFacetAddressMustBeZeroAddress(_facetAddress);
    }
    for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
      bytes4 selector = _functionSelectors[selectorIndex];
      FacetAddressAndSelectorPosition memory oldFacetAddressAndSelectorPosition = ds.facetAddressAndSelectorPosition[
        selector
      ];
      if (oldFacetAddressAndSelectorPosition.facetAddress == address(0)) {
        revert CannotRemoveFunctionThatDoesNotExist(selector);
      }

      // can't remove immutable functions -- functions defined directly in the diamond
      if (oldFacetAddressAndSelectorPosition.facetAddress == address(this)) {
        revert CannotRemoveImmutableFunction(selector);
      }
      // replace selector with last selector
      selectorCount--;
      if (oldFacetAddressAndSelectorPosition.selectorPosition != selectorCount) {
        bytes4 lastSelector = ds.selectors[selectorCount];
        ds.selectors[oldFacetAddressAndSelectorPosition.selectorPosition] = lastSelector;
        ds.facetAddressAndSelectorPosition[lastSelector].selectorPosition = oldFacetAddressAndSelectorPosition
          .selectorPosition;
      }
      // delete last selector
      ds.selectors.pop();
      delete ds.facetAddressAndSelectorPosition[selector];
    }
  }

  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)
    }
    if (contractSize == 0) {
      revert NoBytecodeAtAddress(_contract, _errorMessage);
    }
  }
}

{
  "compilationTarget": {
    "contracts/common/EIP2535/Diamond.sol": "Diamond"
  },
  "evmVersion": "shanghai",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}