// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library AddressUtils {
  function toString (address account) internal pure returns (string memory) {
    bytes32 value = bytes32(uint256(uint160(account)));
    bytes memory alphabet = '0123456789abcdef';
    bytes memory chars = new bytes(42);

    chars[0] = '0';
    chars[1] = 'x';

    for (uint256 i = 0; i < 20; i++) {
      chars[2 + i * 2] = alphabet[uint8(value[i + 12] >> 4)];
      chars[3 + i * 2] = alphabet[uint8(value[i + 12] & 0x0f)];
    }

    return string(chars);
  }

  function isContract (address account) internal view returns (bool) {
    uint size;
    assembly { size := extcodesize(account) }
    return size > 0;
  }

  function sendValue (address payable account, uint amount) internal {
    (bool success, ) = account.call{ value: amount }('');
    require(success, 'AddressUtils: failed to send value');
  }

  function functionCall (address target, bytes memory data) internal returns (bytes memory) {
    return functionCall(target, data, 'AddressUtils: failed low-level call');
  }

  function functionCall (address target, bytes memory data, string memory error) internal returns (bytes memory) {
    return _functionCallWithValue(target, data, 0, error);
  }

  function functionCallWithValue (address target, bytes memory data, uint value) internal returns (bytes memory) {
    return functionCallWithValue(target, data, value, 'AddressUtils: failed low-level call with value');
  }

  function functionCallWithValue (address target, bytes memory data, uint value, string memory error) internal returns (bytes memory) {
    require(address(this).balance >= value, 'AddressUtils: insufficient balance for call');
    return _functionCallWithValue(target, data, value, error);
  }

  function _functionCallWithValue (address target, bytes memory data, uint value, string memory error) private returns (bytes memory) {
    require(isContract(target), 'AddressUtils: function call to non-contract');

    (bool success, bytes memory returnData) = target.call{ value: value }(data);

    if (success) {
      return returnData;
    } else if (returnData.length > 0) {
      assembly {
        let returnData_size := mload(returnData)
        revert(add(32, returnData), returnData_size)
      }
    } else {
      revert(error);
    }
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {SafeOwnable, OwnableStorage, Ownable} from '../../access/SafeOwnable.sol';
import {IERC173} from '../../access/IERC173.sol';
import {ERC165, IERC165, ERC165Storage} from '../../introspection/ERC165.sol';
import {DiamondBase, DiamondBaseStorage} from './DiamondBase.sol';
import {DiamondCuttable, IDiamondCuttable} from './DiamondCuttable.sol';
import {DiamondLoupe, IDiamondLoupe} from './DiamondLoupe.sol';

/**
 * @notice SolidState "Diamond" proxy reference implementation
 */
abstract contract Diamond is DiamondBase, DiamondCuttable, DiamondLoupe, SafeOwnable, ERC165 {
  using DiamondBaseStorage for DiamondBaseStorage.Layout;
  using ERC165Storage for ERC165Storage.Layout;
  using OwnableStorage for OwnableStorage.Layout;

  constructor () {
    ERC165Storage.Layout storage erc165 = ERC165Storage.layout();
    bytes4[] memory selectors = new bytes4[](12);

    // register DiamondCuttable

    selectors[0] = IDiamondCuttable.diamondCut.selector;

    erc165.setSupportedInterface(type(IDiamondCuttable).interfaceId, true);

    // register DiamondLoupe

    selectors[1] = IDiamondLoupe.facets.selector;
    selectors[2] = IDiamondLoupe.facetFunctionSelectors.selector;
    selectors[3] = IDiamondLoupe.facetAddresses.selector;
    selectors[4] = IDiamondLoupe.facetAddress.selector;

    erc165.setSupportedInterface(type(IDiamondLoupe).interfaceId, true);

    // register ERC165

    selectors[5] = IERC165.supportsInterface.selector;

    erc165.setSupportedInterface(type(IERC165).interfaceId, true);

    // register SafeOwnable

    selectors[6] = Ownable.owner.selector;
    selectors[7] = SafeOwnable.nomineeOwner.selector;
    selectors[8] = SafeOwnable.transferOwnership.selector;
    selectors[9] = SafeOwnable.acceptOwnership.selector;

    erc165.setSupportedInterface(type(IERC173).interfaceId, true);

    // register Diamond

    selectors[10] = Diamond.getFallbackAddress.selector;
    selectors[11] = Diamond.setFallbackAddress.selector;

    // diamond cut

    FacetCut[] memory facetCuts = new FacetCut[](1);

    facetCuts[0] = FacetCut({
      target: address(this),
      action: IDiamondCuttable.FacetCutAction.ADD,
      selectors: selectors
    });

    DiamondBaseStorage.layout().diamondCut(facetCuts, address(0), '');

    // set owner

    OwnableStorage.layout().setOwner(msg.sender);
  }

  receive () external payable {}

  /**
   * @notice get the address of the fallback contract
   * @return fallback address
   */
  function getFallbackAddress () external view returns (address) {
    return DiamondBaseStorage.layout().fallbackAddress;
  }

  /**
   * @notice set the address of the fallback contract
   * @param fallbackAddress fallback address
   */
  function setFallbackAddress (
    address fallbackAddress
  ) external onlyOwner {
    DiamondBaseStorage.layout().fallbackAddress = fallbackAddress;
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {Proxy} from '../Proxy.sol';
import {DiamondBaseStorage} from './DiamondBaseStorage.sol';
import {IDiamondLoupe} from './IDiamondLoupe.sol';
import {IDiamondCuttable} from './IDiamondCuttable.sol';

/**
 * @title EIP-2535 "Diamond" proxy base contract
 * @dev see https://eips.ethereum.org/EIPS/eip-2535
 */
abstract contract DiamondBase is Proxy {
  /**
   * @inheritdoc Proxy
   */
  function _getImplementation () override internal view returns (address) {
    // inline storage layout retrieval uses less gas
    DiamondBaseStorage.Layout storage l;
    bytes32 slot = DiamondBaseStorage.STORAGE_SLOT;
    assembly { l.slot := slot }

    address implementation = address(bytes20(l.facets[msg.sig]));

    if (implementation == address(0)) {
      implementation = l.fallbackAddress;
      require(
        implementation != address(0),
        'DiamondBase: no facet found for function signature'
      );
    }

    return implementation;
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {AddressUtils} from '../../utils/AddressUtils.sol';
import {IDiamondCuttable} from './IDiamondCuttable.sol';

/**
 * @dev derived from https://github.com/mudgen/diamond-2 (MIT license)
 */
library DiamondBaseStorage {
  using AddressUtils for address;
  using DiamondBaseStorage for DiamondBaseStorage.Layout;

  struct Layout {
    // function selector => (facet address, selector slot position)
    mapping (bytes4 => bytes32) facets;
    // total number of selectors registered
    uint16 selectorCount;
    // array of selector slots with 8 selectors per slot
    mapping (uint256 => bytes32) selectorSlots;

    address fallbackAddress;
  }

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

  bytes32 internal constant STORAGE_SLOT = keccak256(
    'solidstate.contracts.storage.DiamondBase'
  );

  event DiamondCut (IDiamondCuttable.FacetCut[] facetCuts, address target, bytes data);

  function layout () internal pure returns (Layout storage l) {
    bytes32 slot = STORAGE_SLOT;
    assembly { l.slot := slot }
  }

  /**
   * @notice update functions callable on Diamond proxy
   * @param l storage layout
   * @param facetCuts array of structured Diamond facet update data
   * @param target optional recipient of initialization delegatecall
   * @param data optional initialization call data
   */
  function diamondCut(
    Layout storage l,
    IDiamondCuttable.FacetCut[] memory facetCuts,
    address target,
    bytes memory data
  ) internal {
    unchecked {
      uint256 originalSelectorCount = l.selectorCount;
      uint256 selectorCount = originalSelectorCount;
      bytes32 selectorSlot;

      // Check if last selector slot is not full
      if (selectorCount & 7 > 0) {
        // get last selectorSlot
        selectorSlot = l.selectorSlots[selectorCount >> 3];
      }

      for (uint256 i; i < facetCuts.length; i++) {
        IDiamondCuttable.FacetCut memory facetCut = facetCuts[i];
        IDiamondCuttable.FacetCutAction action = facetCut.action;

        require(
          facetCut.selectors.length > 0,
          'DiamondBase: no selectors specified'
        );

        if (action == IDiamondCuttable.FacetCutAction.ADD) {
          (selectorCount, selectorSlot) = l.addFacetSelectors(
            selectorCount,
            selectorSlot,
            facetCut
          );
        } else if (action == IDiamondCuttable.FacetCutAction.REMOVE) {
          (selectorCount, selectorSlot) = l.removeFacetSelectors(
            selectorCount,
            selectorSlot,
            facetCut
          );
        } else if (action == IDiamondCuttable.FacetCutAction.REPLACE) {
          l.replaceFacetSelectors(facetCut);
        }
      }

      if (selectorCount != originalSelectorCount) {
        l.selectorCount = uint16(selectorCount);
      }

      // If last selector slot is not full
      if (selectorCount & 7 > 0) {
        l.selectorSlots[selectorCount >> 3] = selectorSlot;
      }

      emit DiamondCut(facetCuts, target, data);
      initialize(target, data);
    }
  }

  function addFacetSelectors (
    Layout storage l,
    uint256 selectorCount,
    bytes32 selectorSlot,
    IDiamondCuttable.FacetCut memory facetCut
  ) internal returns (uint256, bytes32) {
    unchecked {
      require(
        facetCut.target == address(this) || facetCut.target.isContract(),
        'DiamondBase: ADD target has no code'
      );

      for (uint256 i; i < facetCut.selectors.length; i++) {
        bytes4 selector = facetCut.selectors[i];
        bytes32 oldFacet = l.facets[selector];

        require(
          address(bytes20(oldFacet)) == address(0),
          'DiamondBase: selector already added'
        );

        // add facet for selector
        l.facets[selector] = bytes20(facetCut.target) | bytes32(selectorCount);
        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) {
          l.selectorSlots[selectorCount >> 3] = selectorSlot;
          selectorSlot = 0;
        }

        selectorCount++;
      }

      return (selectorCount, selectorSlot);
    }
  }

  function removeFacetSelectors (
    Layout storage l,
    uint256 selectorCount,
    bytes32 selectorSlot,
    IDiamondCuttable.FacetCut memory facetCut
  ) internal returns (uint256, bytes32) {
    unchecked {
      require(
        facetCut.target == address(0),
        'DiamondBase: REMOVE target must be zero address'
      );

      uint256 selectorSlotCount = selectorCount >> 3;
      uint256 selectorInSlotIndex = selectorCount & 7;

      for (uint256 i; i < facetCut.selectors.length; i++) {
        bytes4 selector = facetCut.selectors[i];
        bytes32 oldFacet = l.facets[selector];

        require(
          address(bytes20(oldFacet)) != address(0),
          'DiamondBase: selector not found'
        );

        require(
          address(bytes20(oldFacet)) != address(this),
          'DiamondBase: selector is immutable'
        );

        if (selectorSlot == 0) {
          selectorSlotCount--;
          selectorSlot = l.selectorSlots[selectorSlotCount];
          selectorInSlotIndex = 7;
        } else {
          selectorInSlotIndex--;
        }

        bytes4 lastSelector;
        uint256 oldSelectorsSlotCount;
        uint256 oldSelectorInSlotPosition;

        // adding a block here prevents stack too deep error
        {
          // replace selector with last selector in l.facets
          lastSelector = bytes4(selectorSlot << (selectorInSlotIndex << 5));

          if (lastSelector != selector) {
            // update last selector slot position info
            l.facets[lastSelector] = (
              oldFacet & CLEAR_ADDRESS_MASK
            ) | bytes20(l.facets[lastSelector]);
          }

          delete l.facets[selector];
          uint256 oldSelectorCount = uint16(uint256(oldFacet));
          oldSelectorsSlotCount = oldSelectorCount >> 3;
          oldSelectorInSlotPosition = (oldSelectorCount & 7) << 5;
        }

        if (oldSelectorsSlotCount != selectorSlotCount) {
          bytes32 oldSelectorSlot = l.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
          l.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 l.selectorSlots[selectorSlotCount];
          selectorSlot = 0;
        }
      }

      selectorCount = (selectorSlotCount << 3) | selectorInSlotIndex;

      return (selectorCount, selectorSlot);
    }
  }

  function replaceFacetSelectors (
    Layout storage l,
    IDiamondCuttable.FacetCut memory facetCut
  ) internal {
    unchecked {
      require(
        facetCut.target.isContract(),
        'DiamondBase: REPLACE target has no code'
      );

      for (uint256 i; i < facetCut.selectors.length; i++) {
        bytes4 selector = facetCut.selectors[i];
        bytes32 oldFacet = l.facets[selector];
        address oldFacetAddress = address(bytes20(oldFacet));

        require(
          oldFacetAddress != address(0),
          'DiamondBase: selector not found'
        );

        require(
          oldFacetAddress != address(this),
          'DiamondBase: selector is immutable'
        );

        require(
          oldFacetAddress != facetCut.target,
          'DiamondBase: REPLACE target is identical'
        );

        // replace old facet address
        l.facets[selector] = (oldFacet & CLEAR_ADDRESS_MASK) | bytes20(facetCut.target);
      }
    }
  }

  function initialize (
    address target,
    bytes memory data
  ) private {
    require(
      (target == address(0)) == (data.length == 0),
      'DiamondBase: invalid initialization parameters'
    );

    if (target != address(0)) {
      if (target != address(this)) {
        require(
          target.isContract(),
          'DiamondBase: initialization target has no code'
        );
      }

      (bool success, ) = target.delegatecall(data);

      if (!success) {
        assembly {
          returndatacopy(0, 0, returndatasize())
          revert(0, returndatasize())
        }
      }
    }
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {OwnableInternal} from '../../access/OwnableInternal.sol';
import {IDiamondCuttable} from './IDiamondCuttable.sol';
import {DiamondBaseStorage} from './DiamondBaseStorage.sol';

/**
 * @title EIP-2535 "Diamond" proxy update contract
 */
abstract contract DiamondCuttable is IDiamondCuttable, OwnableInternal {
  using DiamondBaseStorage for DiamondBaseStorage.Layout;

  /**
   * @notice update functions callable on Diamond proxy
   * @param facetCuts array of structured Diamond facet update data
   * @param target optional recipient of initialization delegatecall
   * @param data optional initialization call data
   */
  function diamondCut (
    FacetCut[] calldata facetCuts,
    address target,
    bytes calldata data
  ) external override onlyOwner {
    DiamondBaseStorage.layout().diamondCut(facetCuts, target, data);
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {DiamondBaseStorage} from './DiamondBaseStorage.sol';
import {IDiamondLoupe} from './IDiamondLoupe.sol';

/**
 * @title EIP-2535 "Diamond" proxy introspection contract
 * @dev derived from https://github.com/mudgen/diamond-2 (MIT license)
 */
abstract contract DiamondLoupe is IDiamondLoupe {
  /**
   * @inheritdoc IDiamondLoupe
   */
  function facets () external override view returns (Facet[] memory diamondFacets) {
    DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout();

    diamondFacets = new Facet[](l.selectorCount);

    uint8[] memory numFacetSelectors = new uint8[](l.selectorCount);
    uint256 numFacets;
    uint256 selectorIndex;

    // loop through function selectors
    for (uint256 slotIndex; selectorIndex < l.selectorCount; slotIndex++) {
      bytes32 slot = l.selectorSlots[slotIndex];

      for (uint256 selectorSlotIndex; selectorSlotIndex < 8; selectorSlotIndex++) {
        selectorIndex++;

        if (selectorIndex > l.selectorCount) {
          break;
        }

        bytes4 selector = bytes4(slot << (selectorSlotIndex << 5));
        address facet = address(bytes20(l.facets[selector]));

        bool continueLoop;

        for (uint256 facetIndex; facetIndex < numFacets; facetIndex++) {
          if (diamondFacets[facetIndex].target == facet) {
            diamondFacets[facetIndex].selectors[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;
        }

        diamondFacets[numFacets].target = facet;
        diamondFacets[numFacets].selectors = new bytes4[](l.selectorCount);
        diamondFacets[numFacets].selectors[0] = selector;
        numFacetSelectors[numFacets] = 1;
        numFacets++;
      }
    }

    for (uint256 facetIndex; facetIndex < numFacets; facetIndex++) {
      uint256 numSelectors = numFacetSelectors[facetIndex];
      bytes4[] memory selectors = diamondFacets[facetIndex].selectors;

      // setting the number of selectors
      assembly { mstore(selectors, numSelectors) }
    }

    // setting the number of facets
    assembly { mstore(diamondFacets, numFacets) }
  }

  /**
   * @inheritdoc IDiamondLoupe
   */
  function facetFunctionSelectors (
    address facet
  ) external override view returns (bytes4[] memory selectors) {
    DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout();

    selectors = new bytes4[](l.selectorCount);

    uint256 numSelectors;
    uint256 selectorIndex;

    // loop through function selectors
    for (uint256 slotIndex; selectorIndex < l.selectorCount; slotIndex++) {
      bytes32 slot = l.selectorSlots[slotIndex];

      for (uint256 selectorSlotIndex; selectorSlotIndex < 8; selectorSlotIndex++) {
        selectorIndex++;

        if (selectorIndex > l.selectorCount) {
          break;
        }

        bytes4 selector = bytes4(slot << (selectorSlotIndex << 5));

        if (facet == address(bytes20(l.facets[selector]))) {
          selectors[numSelectors] = selector;
          numSelectors++;
        }
      }
    }

    // set the number of selectors in the array
    assembly { mstore(selectors, numSelectors) }
  }

  /**
   * @inheritdoc IDiamondLoupe
   */
  function facetAddresses () external override view returns (address[] memory addresses) {
    DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout();

    addresses = new address[](l.selectorCount);
    uint256 numFacets;
    uint256 selectorIndex;

    for (uint256 slotIndex; selectorIndex < l.selectorCount; slotIndex++) {
      bytes32 slot = l.selectorSlots[slotIndex];

      for (uint256 selectorSlotIndex; selectorSlotIndex < 8; selectorSlotIndex++) {
        selectorIndex++;

        if (selectorIndex > l.selectorCount) {
          break;
        }

        bytes4 selector = bytes4(slot << (selectorSlotIndex << 5));
        address facet = address(bytes20(l.facets[selector]));

        bool continueLoop;

        for (uint256 facetIndex; facetIndex < numFacets; facetIndex++) {
          if (facet == addresses[facetIndex]) {
            continueLoop = true;
            break;
          }
        }

        if (continueLoop) {
          continue;
        }

        addresses[numFacets] = facet;
        numFacets++;
      }
    }

    // set the number of facet addresses in the array
    assembly { mstore(addresses, numFacets) }
  }

  /**
   * @inheritdoc IDiamondLoupe
   */
  function facetAddress (
    bytes4 selector
  ) external override view returns (address facet) {
    facet = address(bytes20(
      DiamondBaseStorage.layout().facets[selector]
    ));
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {IERC165} from './IERC165.sol';
import {ERC165Storage} from './ERC165Storage.sol';

/**
 * @title ERC165 implementation
 */
abstract contract ERC165 is IERC165 {
  using ERC165Storage for ERC165Storage.Layout;

  /**
   * @inheritdoc IERC165
   */
  function supportsInterface (bytes4 interfaceId) override public view returns (bool) {
    return ERC165Storage.layout().isSupportedInterface(interfaceId);
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library ERC165Storage {
  struct Layout {
    // TODO: use EnumerableSet to allow post-diamond-cut auditing
    mapping (bytes4 => bool) supportedInterfaces;
  }

  bytes32 internal constant STORAGE_SLOT = keccak256(
    'solidstate.contracts.storage.ERC165'
  );

  function layout () internal pure returns (Layout storage l) {
    bytes32 slot = STORAGE_SLOT;
    assembly { l.slot := slot }
  }

  function isSupportedInterface (
    Layout storage l,
    bytes4 interfaceId
  ) internal view returns (bool) {
    return l.supportedInterfaces[interfaceId];
  }

  function setSupportedInterface (
    Layout storage l,
    bytes4 interfaceId,
    bool status
  ) internal {
    require(interfaceId != 0xffffffff, 'ERC165: invalid interface id');
    l.supportedInterfaces[interfaceId] = status;
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library ERC20MetadataStorage {
  struct Layout {
    string name;
    string symbol;
    uint8 decimals;
  }

  bytes32 internal constant STORAGE_SLOT = keccak256(
    'solidstate.contracts.storage.ERC20Metadata'
  );

  function layout () internal pure returns (Layout storage l) {
    bytes32 slot = STORAGE_SLOT;
    assembly { l.slot := slot }
  }

  function setName (
    Layout storage l,
    string memory name
  ) internal {
    l.name = name;
  }

  function setSymbol (
    Layout storage l,
    string memory symbol
  ) internal {
    l.symbol = symbol;
  }

  function setDecimals (
    Layout storage l,
    uint8 decimals
  ) internal {
    l.decimals = decimals;
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @title Diamond proxy upgrade interface
 * @dev see https://eips.ethereum.org/EIPS/eip-2535
 */
interface IDiamondCuttable {
  enum FacetCutAction { ADD, REPLACE, REMOVE }

  event DiamondCut (FacetCut[] facetCuts, address target, bytes data);

  struct FacetCut {
    address target;
    FacetCutAction action;
    bytes4[] selectors;
  }

  /**
   * @notice update diamond facets and optionally execute arbitrary initialization function
   * @param facetCuts facet addresses, actions, and function selectors
   * @param target initialization function target
   * @param data initialization function call data
   */
  function diamondCut (
    FacetCut[] calldata facetCuts,
    address target,
    bytes calldata data
  ) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @title Diamond proxy introspection interface
 * @dev see https://eips.ethereum.org/EIPS/eip-2535
 */
interface IDiamondLoupe {
  struct Facet {
    address target;
    bytes4[] selectors;
  }

  /**
   * @notice get all facets and their selectors
   * @return diamondFacets array of structured facet data
   */
  function facets () external view returns (Facet[] memory diamondFacets);

  /**
   * @notice get all selectors for given facet address
   * @param facet address of facet to query
   * @return selectors array of function selectors
   */
  function facetFunctionSelectors (
    address facet
  ) external view returns (bytes4[] memory selectors);

  /**
   * @notice get addresses of all facets used by diamond
   * @return addresses array of facet addresses
   */
  function facetAddresses () external view returns (address[] memory addresses);

  /**
   * @notice get the address of the facet associated with given selector
   * @param selector function selector to query
   * @return facet facet address (zero address if not found)
   */
  function facetAddress (
    bytes4 selector
  ) external view returns (address facet);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @title ERC165 interface registration interface
 * @dev see https://eips.ethereum.org/EIPS/eip-165
 */
interface IERC165 {
  /**
   * @notice query whether contract has registered support for given interface
   * @param interfaceId interface id
   * @return bool whether interface is supported
   */
  function supportsInterface (
    bytes4 interfaceId
  ) external view returns (bool);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @title Contract ownership standard interface
 * @dev see https://eips.ethereum.org/EIPS/eip-173
 */
interface IERC173 {
  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
   * @notice get the ERC173 contract owner
   * @return conract owner
   */
  function owner () external view returns (address);

  /**
   * @notice transfer contract ownership to new account
   * @param account address of new owner
   */
  function transferOwnership (address account) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import '@solidstate/contracts/proxy/diamond/Diamond.sol';
import '@solidstate/contracts/token/ERC20/metadata/ERC20MetadataStorage.sol';

contract MagicProxy is Diamond {
    constructor() {
        ERC20MetadataStorage.Layout storage l = ERC20MetadataStorage.layout();
        l.name = 'MAGIC';
        l.symbol = 'MAGIC';
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {IERC173} from './IERC173.sol';
import {OwnableInternal} from './OwnableInternal.sol';
import {OwnableStorage} from './OwnableStorage.sol';

/**
 * @title Ownership access control based on ERC173
 */
abstract contract Ownable is IERC173, OwnableInternal {
  using OwnableStorage for OwnableStorage.Layout;

  /**
   * @inheritdoc IERC173
   */
  function owner () virtual override public view returns (address) {
    return OwnableStorage.layout().owner;
  }

  /**
   * @inheritdoc IERC173
   */
  function transferOwnership (
    address account
  ) virtual override public onlyOwner {
    OwnableStorage.layout().setOwner(account);
    emit OwnershipTransferred(msg.sender, account);
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {OwnableStorage} from './OwnableStorage.sol';

abstract contract OwnableInternal {
  using OwnableStorage for OwnableStorage.Layout;

  modifier onlyOwner {
    require(
      msg.sender == OwnableStorage.layout().owner,
      'Ownable: sender must be owner'
    );
    _;
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library OwnableStorage {
  struct Layout {
    address owner;
  }

  bytes32 internal constant STORAGE_SLOT = keccak256(
    'solidstate.contracts.storage.Ownable'
  );

  function layout () internal pure returns (Layout storage l) {
    bytes32 slot = STORAGE_SLOT;
    assembly { l.slot := slot }
  }

  function setOwner (
    Layout storage l,
    address owner
  ) internal {
    l.owner = owner;
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {AddressUtils} from '../utils/AddressUtils.sol';

/**
 * @title Base proxy contract
 */
abstract contract Proxy {
  using AddressUtils for address;

  /**
   * @notice delegate all calls to implementation contract
   * @dev reverts if implementation address contains no code, for compatibility with metamorphic contracts
   * @dev memory location in use by assembly may be unsafe in other contexts
   */
  fallback () virtual external payable {
    address implementation = _getImplementation();

    require(
      implementation.isContract(),
      'Proxy: implementation must be contract'
    );

    assembly {
      calldatacopy(0, 0, calldatasize())
      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
      returndatacopy(0, 0, returndatasize())

      switch result
      case 0 { revert(0, returndatasize()) }
      default { return (0, returndatasize()) }
    }
  }

  /**
   * @notice get logic implementation address
   * @return implementation address
   */
  function _getImplementation () virtual internal returns (address);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {Ownable, OwnableStorage} from './Ownable.sol';
import {SafeOwnableInternal} from './SafeOwnableInternal.sol';
import {SafeOwnableStorage} from './SafeOwnableStorage.sol';

/**
 * @title Ownership access control based on ERC173 with ownership transfer safety check
 */
abstract contract SafeOwnable is Ownable, SafeOwnableInternal {
  using OwnableStorage for OwnableStorage.Layout;
  using SafeOwnableStorage for SafeOwnableStorage.Layout;

  function nomineeOwner () virtual public view returns (address) {
    return SafeOwnableStorage.layout().nomineeOwner;
  }

  /**
   * @inheritdoc Ownable
   * @dev ownership transfer must be accepted by beneficiary before transfer is complete
   */
  function transferOwnership (
    address account
  ) virtual override public onlyOwner {
    SafeOwnableStorage.layout().setNomineeOwner(account);
  }

  /**
   * @notice accept transfer of contract ownership
   */
  function acceptOwnership () virtual public onlyNomineeOwner {
    OwnableStorage.Layout storage l = OwnableStorage.layout();
    emit OwnershipTransferred(l.owner, msg.sender);
    l.setOwner(msg.sender);
    SafeOwnableStorage.layout().setNomineeOwner(address(0));
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import {SafeOwnableStorage} from './SafeOwnableStorage.sol';

abstract contract SafeOwnableInternal {
  using SafeOwnableStorage for SafeOwnableStorage.Layout;

  modifier onlyNomineeOwner () {
    require(
      msg.sender == SafeOwnableStorage.layout().nomineeOwner,
      'SafeOwnable: sender must be nominee owner'
    );
    _;
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library SafeOwnableStorage {
  struct Layout {
    address nomineeOwner;
  }

  bytes32 internal constant STORAGE_SLOT = keccak256(
    'solidstate.contracts.storage.SafeOwnable'
  );

  function layout () internal pure returns (Layout storage l) {
    bytes32 slot = STORAGE_SLOT;
    assembly { l.slot := slot }
  }

  function setNomineeOwner (
    Layout storage l,
    address nomineeOwner
  ) internal {
    l.nomineeOwner = nomineeOwner;
  }
}

{
  "compilationTarget": {
    "contracts/token/MagicProxy.sol": "MagicProxy"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}