// File: contracts/CitizenAlpha.sol



//SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import { Base64 } from "base64-sol/base64.sol";
import { Strings } from "@openzeppelin/contracts/utils/Strings.sol";
import { AccessControl } from "@openzeppelin/contracts/access/AccessControl.sol";
import { ERC721 } from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import { CitizenAlphaMetadata } from "./CitizenAlphaMetadata.sol";

/**
 _    _      _      _____   _____ _ _   _               
| |  | |    | |    |____ | /  __ (_) | (_)              
| |  | | ___| |__      / / | /  \/_| |_ _ _______ _ __  
| |/\| |/ _ \ '_ \     \ \ | |   | | __| |_  / _ \ '_ \ 
\  /\  /  __/ |_) |.___/ / | \__/\ | |_| |/ /  __/ | | |
 \/  \/ \___|_.__/ \____/   \____/_|\__|_/___\___|_| |_|

🗺️ Overview:
CitizenAlpha (Beta) is an experiment for bootstrapping a Decentralized Society.
Combining on-chain permissions and off-chain data (ENS text fields i.e. DIDs, pointers, etc...)
CitizenAlpha is an attempt to better understand Web3 of Trust mechanics.
Simple in nature, the contract is only responsible for issuing/revoking of soulbounds. 
Metadata is generated via an external contract: allowing on-going updates during the Beta.

🏗️ Architecture:
Citizens:
  - Issue Citizenship
Founders:
  - Issue Citizenship
  - Revoke Citizenship
  Admin:
  - Issue Citizenship
  - Revoke Citizenship
  - Add Founder
  - Remover Founder
*/

/**
 * @title CitizenAlpha
 * @author Kames Geraghty
 * @notice CitizenAlpha is a Web3 of Trust experiment.
           Combining Soulbounds and Decentralized Identifiers to bootstrap a Decentralized Society.
 */
contract CitizenAlpha is ERC721, AccessControl {
  using Strings for uint256;
  using Strings for address;

  /// @notice Total citizenships issued
  uint256 private _idCounter;

  /// @notice CitizenAlphaMetadata instance used to generate token metadata
  CitizenAlphaMetadata private metadata;

  /// @notice Reverse lookup of a tokenId using the owner address
  mapping(address => uint256) private _tokens;

  /// @notice Lookup address of Citizenship issuer
  mapping(address => address) private _citizenLinks;

  /// @notice Founder Role to enforce access controls
  bytes32 public constant FOUNDER = keccak256("FOUNDER");

  /**
   * @notice Emit when Citizenship is issued.
   * @param id Citizen ID
   * @param citizen Address of new Citizen
   * @param link Address of  Citizen issuing new Citizenship
   */
  event Issued(uint256 id, address indexed citizen, address indexed link);

  /**
   * @notice Emit when Citizenship is revoked.
   * @param id Citizen ID
   * @param citizen Address of new Citizen
   * @param link Address of Founder revoking Citizenship
   */
  event Revoked(uint256 id, address indexed citizen, address indexed link);

  /**
   * @notice GaugeController Construction
   * @param _metadata CitizenAlphaMetadata instance (manage token metadata)
   * @param _founders Array of Founding Citizens
   */
  constructor(CitizenAlphaMetadata _metadata, address[] memory _founders) ERC721("Citizen", "CIZ") {
    metadata = _metadata;
    for (uint256 i = 0; i < _founders.length; i++) {
      _issue(_founders[i], 0x0000000000000000000000000000000000000000);
      _setupRole(DEFAULT_ADMIN_ROLE, _founders[i]);
      _setupRole(FOUNDER, _founders[i]);
    }
  }

  modifier isAuthorizedCitizen(address _citizen) {
    require(balanceOf(_citizen) == 1, "CitizenAlpha:unauthorized-access");
    _;
  }

  /* ===================================================================================== */
  /* External Functions                                                                    */
  /* ===================================================================================== */

  /**
   * @notice Read totalCitizens (_idCounter)
   * @return totalCitizens uint256
   */
  function totalCitizens() external view returns (uint256) {
    return _idCounter;
  }

  /**
   * @notice Check Citizenship status
   * @param citizen Address of potential Citizen
   * @return status bool
   */
  function isCitizen(address citizen) external view returns (bool status) {
    return balanceOf(citizen) == 1 ? true : false;
  }

  /**
   * @notice Check Citizenship ID
   * @param citizen address
   * @return id uint256
   */
  function getId(address citizen) external view returns (uint256) {
    require(_isCitizen(citizen), "CitizenAlpha:not-active-citizen");
    return _tokens[citizen];
  }

  /**
   * @notice Lookup the issuer of Citizenship
   * @param citizen address
   * @return issuer address
   */
  function getLink(address citizen) external view returns (address issuer) {
    return _citizenLinks[citizen];
  }

  /**
   * @notice Issue a new Citizenship
   * @param to address
   */
  function issue(address to) external isAuthorizedCitizen(msg.sender) {
    require(!_isCitizen(to), "CitizenAlpha:active-citizenship");
    require(!_isPreviouslyIssued(to), "CitizenAlpha:revoked-citizenship");
    _issue(to, msg.sender);
  }

  /**
   * @notice Revoke an existing Citizenship
   * @param from address
   */
  function revoke(address from) external onlyRole(FOUNDER) isAuthorizedCitizen(msg.sender) {
    require(_isCitizen(from), "CitizenAlpha:not-active-citizen");
    uint256 tokenId = _tokens[from];
    _burn(tokenId);
    emit Revoked(tokenId, from, msg.sender);
  }

  /**
   * @notice Add Founder access
   * @param citizen address
   */
  function addFounder(address citizen) external onlyRole(DEFAULT_ADMIN_ROLE) {
    require(_isCitizen(citizen), "CitizenAlpha:not-active-citizen");
    grantRole(FOUNDER, citizen);
  }

  /**
   * @notice Remove Founder access
   * @param citizen address
   */
  function removeFounder(address citizen) external onlyRole(DEFAULT_ADMIN_ROLE) {
    revokeRole(FOUNDER, citizen);
  }

  /**
   * @notice Check Founder status
   * @param founder address
   * @return status bool
   */
  function isFounder(address founder) external view returns (bool status) {
    return hasRole(FOUNDER, founder);
  }

  /**
   * @notice Override transferFrom to make non-transferable
   */
  function transferFrom(
    address,
    address,
    uint256
  ) public virtual override {
    require(false, "CitizenAlpha: Soulbound");
  }

  /**
   * @notice Generate token URI
   * @param tokenId uint256
   * @return metadata string
   */
  function tokenURI(uint256 tokenId) public view override returns (string memory) {
    return metadata.tokenURI(tokenId);
  }

  function supportsInterface(bytes4 interfaceId)
    public
    view
    virtual
    override(ERC721, AccessControl)
    returns (bool)
  {
    return super.supportsInterface(interfaceId);
  }

  /* ===================================================================================== */
  /* Internal Functions                                                                    */
  /* ===================================================================================== */

  function _isCitizen(address citizen) internal view returns (bool) {
    return balanceOf(citizen) == 1 ? true : false;
  }

  /**
   * @dev First Founder can be issued<>revoked<>issued.
   *      All other address can only be issued<>revoked.
   */
  function _isPreviouslyIssued(address citizen) internal view returns (bool) {
    return _tokens[citizen] != 0 ? true : false;
  }

  function _issue(address to, address link) internal {
    uint256 __idCounter = _idCounter++;
    _citizenLinks[to] = link;
    _tokens[to] = __idCounter;
    _mint(to, __idCounter);
    emit Issued(__idCounter, to, msg.sender);
  }
}

// File: base64-sol/base64.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0;

/// @title Base64
/// @author Brecht Devos - <brecht@loopring.org>
/// @notice Provides functions for encoding/decoding base64
library Base64 {
    string internal constant TABLE_ENCODE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
    bytes  internal constant TABLE_DECODE = hex"0000000000000000000000000000000000000000000000000000000000000000"
                                            hex"00000000000000000000003e0000003f3435363738393a3b3c3d000000000000"
                                            hex"00000102030405060708090a0b0c0d0e0f101112131415161718190000000000"
                                            hex"001a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132330000000000";

    function encode(bytes memory data) internal pure returns (string memory) {
        if (data.length == 0) return '';

        // load the table into memory
        string memory table = TABLE_ENCODE;

        // multiply by 4/3 rounded up
        uint256 encodedLen = 4 * ((data.length + 2) / 3);

        // add some extra buffer at the end required for the writing
        string memory result = new string(encodedLen + 32);

        assembly {
            // set the actual output length
            mstore(result, encodedLen)

            // prepare the lookup table
            let tablePtr := add(table, 1)

            // input ptr
            let dataPtr := data
            let endPtr := add(dataPtr, mload(data))

            // result ptr, jump over length
            let resultPtr := add(result, 32)

            // run over the input, 3 bytes at a time
            for {} lt(dataPtr, endPtr) {}
            {
                // read 3 bytes
                dataPtr := add(dataPtr, 3)
                let input := mload(dataPtr)

                // write 4 characters
                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(shr( 6, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(        input,  0x3F))))
                resultPtr := add(resultPtr, 1)
            }

            // padding with '='
            switch mod(mload(data), 3)
            case 1 { mstore(sub(resultPtr, 2), shl(240, 0x3d3d)) }
            case 2 { mstore(sub(resultPtr, 1), shl(248, 0x3d)) }
        }

        return result;
    }

    function decode(string memory _data) internal pure returns (bytes memory) {
        bytes memory data = bytes(_data);

        if (data.length == 0) return new bytes(0);
        require(data.length % 4 == 0, "invalid base64 decoder input");

        // load the table into memory
        bytes memory table = TABLE_DECODE;

        // every 4 characters represent 3 bytes
        uint256 decodedLen = (data.length / 4) * 3;

        // add some extra buffer at the end required for the writing
        bytes memory result = new bytes(decodedLen + 32);

        assembly {
            // padding with '='
            let lastBytes := mload(add(data, mload(data)))
            if eq(and(lastBytes, 0xFF), 0x3d) {
                decodedLen := sub(decodedLen, 1)
                if eq(and(lastBytes, 0xFFFF), 0x3d3d) {
                    decodedLen := sub(decodedLen, 1)
                }
            }

            // set the actual output length
            mstore(result, decodedLen)

            // prepare the lookup table
            let tablePtr := add(table, 1)

            // input ptr
            let dataPtr := data
            let endPtr := add(dataPtr, mload(data))

            // result ptr, jump over length
            let resultPtr := add(result, 32)

            // run over the input, 4 characters at a time
            for {} lt(dataPtr, endPtr) {}
            {
               // read 4 characters
               dataPtr := add(dataPtr, 4)
               let input := mload(dataPtr)

               // write 3 bytes
               let output := add(
                   add(
                       shl(18, and(mload(add(tablePtr, and(shr(24, input), 0xFF))), 0xFF)),
                       shl(12, and(mload(add(tablePtr, and(shr(16, input), 0xFF))), 0xFF))),
                   add(
                       shl( 6, and(mload(add(tablePtr, and(shr( 8, input), 0xFF))), 0xFF)),
                               and(mload(add(tablePtr, and(        input , 0xFF))), 0xFF)
                    )
                )
                mstore(resultPtr, shl(232, output))
                resultPtr := add(resultPtr, 3)
            }
        }

        return result;
    }
}

// File: @openzeppelin/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

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

// File: @openzeppelin/contracts/access/AccessControl.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (access/AccessControl.sol)

pragma solidity ^0.8.0;

import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role);
        _;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        Strings.toHexString(uint160(account), 20),
                        " is missing role ",
                        Strings.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}

// File: @openzeppelin/contracts/token/ERC721/ERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: balance query for the zero address");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: owner query for nonexistent token");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not owner nor approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), "ERC721: approved query for nonexistent token");

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _safeTransfer(from, to, tokenId, _data);
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `_data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, _data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);

        _afterTokenTransfer(address(0), to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);

        _afterTokenTransfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId);

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);

        _afterTokenTransfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits a {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: contracts/CitizenAlphaMetadata.sol



// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.6;

import { Base64 } from "base64-sol/base64.sol";
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { Strings } from "@openzeppelin/contracts/utils/Strings.sol";
import { IERC721 } from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import { svg } from "./lib/SVG.sol";
import { svgUtils } from "./lib/SVGUtils.sol";
import { SVGColor } from "./lib/SVGColor.sol";
import { CitizenAlpha } from "./CitizenAlpha.sol";
import { ENS } from "./interfaces/ENS.sol";
import { NameEncoder } from "./lib/NameEncoder.sol";
import { IReverseRegistrar } from "./interfaces/IReverseRegistrar.sol";
import { ITextResolver } from "./interfaces/ITextResolver.sol";
import { IDefaultReverseResolver } from "./interfaces/IDefaultReverseResolver.sol";

contract CitizenAlphaMetadata is Ownable {
  using NameEncoder for string;
  using Strings for address;
  using Strings for uint256;
  using Strings for uint8;

  CitizenAlpha private token;
  SVGColor public svgColor;
  address private ens = 0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e;
  address private resolver = 0x4976fb03C32e5B8cfe2b6cCB31c09Ba78EBaBa41;
  address private reverseRegistrar = 0x084b1c3C81545d370f3634392De611CaaBFf8148;
  address private defaultReverseResolver = 0xA2C122BE93b0074270ebeE7f6b7292C7deB45047;

  string[] private traitKeys;

  constructor(SVGColor _svgColor) public {
    svgColor = _svgColor;
    traitKeys.push("avatar");
    traitKeys.push("url");
    traitKeys.push("description");
    traitKeys.push("com.github");
    traitKeys.push("com.twitter");
    traitKeys.push("org.telegram");
    traitKeys.push("did");
  }

  /* ===================================================================================== */
  /* External Functions                                                                    */
  /* ===================================================================================== */

  function tokenURI(uint256 tokenId) external view returns (string memory) {
    return _constructTokenURI(tokenId);
  }

  function setToken(CitizenAlpha _token) external onlyOwner {
    token = _token;
  }

  function pushTraitField(string calldata _key) external onlyOwner {
    traitKeys.push(_key);
  }

  function setTraitField(uint256 _index, string calldata _key) external onlyOwner {
    traitKeys[_index] = _key;
  }

  /* ===================================================================================== */
  /* Internal Functions                                                                    */
  /* ===================================================================================== */

  function _constructTokenURI(uint256 _tokenId) internal view returns (string memory) {
    address citizen_ = token.ownerOf(_tokenId);
    (string memory alias_, bytes32 node_, ITextResolver res_) = _resolveOwner(citizen_);
    string memory name_ = string(abi.encodePacked("Citizen #", _tokenId.toString()));
    string memory description_ = bytes(alias_).length > 0
      ? alias_
      : Strings.toHexString(uint256(uint160(citizen_)), 20);
    string memory avatar_ = _generateImage(res_.text(node_, "avatar"), _tokenId, alias_);
    (string[] memory keys_, string[] memory values_) = _fetchNodeTextFields(traitKeys, node_, res_);
    address link_ = token.getLink(citizen_);
    bool isFounder_ = token.isFounder(citizen_);
    string memory traits_ = _generateTraits(keys_, values_);

    return
      string(
        abi.encodePacked(
          "data:application/json;base64,",
          Base64.encode(
            bytes(
              string.concat(
                '{"name":',
                '"',
                name_,
                '",',
                '"description":',
                '"',
                description_,
                '",',
                '"image":',
                '"',
                avatar_,
                '",',
                '"attributes": [',
                string.concat(
                  traits_,
                  _generateTrait("isFounder", isFounder_ ? "true" : "false"),
                  ",",
                  _generateTrait("link", Strings.toHexString(uint256(uint160(link_)), 20))
                ),
                "]",
                "}"
              )
            )
          )
        )
      );
  }

  function _appendTrait(string memory _traits, string memory _traitAppending)
    internal
    view
    returns (string memory)
  {
    return string.concat(_traits, bytes(_traits).length > 0 ? "," : "", _traitAppending);
  }

  function _generateImage(
    string memory _avatar,
    uint256 tokenId,
    string memory alias_
  ) internal view returns (string memory) {
    if (bytes(_avatar).length == 0) {
      return
        string(
          abi.encodePacked(
            "data:image/svg+xml;base64,",
            Base64.encode(bytes(_generate(tokenId, alias_)))
          )
        );
    }
    return _avatar;
  }

  function _generateTrait(string memory _key, string memory _value)
    internal
    view
    returns (string memory __traits)
  {
    return string.concat('{"trait_type":' '"', _key, '",', '"value":', '"', _value, '"}');
  }

  function _generateTraits(string[] memory _keys, string[] memory _values)
    internal
    view
    returns (string memory __traits)
  {
    string memory _traits = "";
    for (uint256 i = 0; i < _keys.length; i++) {
      if (bytes(_values[i]).length > 0) {
        _traits = string.concat(_traits, _generateTrait(_keys[i], _values[i]), ",");
      }
    }
    return _traits;
  }

  function _resolveOwner(address owner_)
    internal
    view
    returns (
      string memory,
      bytes32,
      ITextResolver
    )
  {
    bytes32 node_ = IReverseRegistrar(reverseRegistrar).node(owner_);
    string memory _name = IDefaultReverseResolver(defaultReverseResolver).name(node_);
    (, bytes32 _node) = _name.dnsEncodeName();
    ITextResolver _resolver = ITextResolver(resolver);
    return (_name, _node, _resolver);
  }

  function _fetchNodeTextFields(
    string[] memory _traits,
    bytes32 _node,
    ITextResolver _resolver
  ) internal view returns (string[] memory keys_, string[] memory values_) {
    string[] memory __keys = new string[](_traits.length);
    string[] memory __values = new string[](_traits.length);
    for (uint256 i = 0; i < _traits.length; i++) {
      __keys[i] = _traits[i];
      __values[i] = _resolver.text(_node, _traits[i]);
    }
    return (__keys, __values);
  }

  function _generate(uint256 _tokenId, string memory _alias) internal view returns (string memory) {
    string memory _bgDef = svgUtils.getDefURL("charcoal");

    return
      string(
        abi.encodePacked(
          svg.start(),
          _getDefs(),
          svg.rect(
            string.concat(
              svg.prop("fill", _bgDef),
              svg.prop("x", "0"),
              svg.prop("y", "0"),
              svg.prop("width", "100%"),
              svg.prop("height", "100%")
            ),
            svgUtils.NULL
          ),
          svg.text(
            string.concat(
              svg.prop("x", "50%"),
              svg.prop("y", "50%"),
              svg.prop("dominant-baseline", "middle"),
              svg.prop("text-anchor", "middle"),
              svg.prop("font-size", "48px"),
              svg.prop("fill", "white")
            ),
            string.concat("CIV #", _tokenId.toString())
          ),
          svg.text(
            string.concat(
              svg.prop("x", "50%"),
              svg.prop("y", "60%"),
              svg.prop("dominant-baseline", "middle"),
              svg.prop("text-anchor", "middle"),
              svg.prop("font-size", "22px"),
              svg.prop("fill", "white")
            ),
            _alias
          ),
          svg.end()
        )
      );
  }

  function _getDefs() internal view returns (string memory) {
    return
      svg.defs(
        string.concat(
          svg.linearGradient(
            string.concat(svg.prop("id", "charcoal"), svg.prop("gradientTransform", "rotate(140)")),
            string.concat(
              svg.stop(
                string.concat(
                  svg.prop("offset", "0%"),
                  svg.prop("stop-color", svgColor.getRgba("Dark1"))
                )
              ),
              svg.stop(
                string.concat(
                  svg.prop("offset", "70%"),
                  svg.prop("stop-color", svgColor.getRgba("Dark2"))
                )
              )
            )
          )
        )
      );
  }
}

// File: @openzeppelin/contracts/access/IAccessControl.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: contracts/lib/SVG.sol



//SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;
import "@openzeppelin/contracts/utils/Strings.sol";
import "./SVGUtils.sol";

/**
 * @title svg
 * @author Kames Geraghty
 * @notice SVG construction library using web-like API.
 * @dev Original code from w1nt3r-eth/hot-chain-svg (https://github.com/w1nt3r-eth/hot-chain-svg)
 */
library svg {
  using Strings for uint256;
  using Strings for uint8;

  function g(string memory _props, string memory _children) internal pure returns (string memory) {
    return el("g", _props, _children);
  }

  function path(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("path", _props, _children);
  }

  function text(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("text", _props, _children);
  }

  function line(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("line", _props, _children);
  }

  function circle(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("circle", _props, _children);
  }

  function circle(string memory _props) internal pure returns (string memory) {
    return el("circle", _props);
  }

  function rect(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("rect", _props, _children);
  }

  function rect(string memory _props) internal pure returns (string memory) {
    return el("rect", _props);
  }

  function stop(string memory _props) internal pure returns (string memory) {
    return el("stop", _props);
  }

  function filter(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("filter", _props, _children);
  }

  function defs(string memory _children) internal pure returns (string memory) {
    return el("defs", "", _children);
  }

  function cdata(string memory _content) internal pure returns (string memory) {
    return string.concat("<![CDATA[", _content, "]]>");
  }

  /* GRADIENTS */
  function radialGradient(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("radialGradient", _props, _children);
  }

  function linearGradient(string memory _props, string memory _children)
    internal
    pure
    returns (string memory)
  {
    return el("linearGradient", _props, _children);
  }

  function gradientStop(
    uint256 offset,
    string memory stopColor,
    string memory _props
  ) internal pure returns (string memory) {
    return
      el(
        "stop",
        string.concat(
          prop("stop-color", stopColor),
          " ",
          prop("offset", string.concat(svgUtils.uint2str(offset), "%")),
          " ",
          _props
        )
      );
  }

  function animateTransform(string memory _props) internal pure returns (string memory) {
    return el("animateTransform", _props);
  }

  function image(string memory _href, string memory _props) internal pure returns (string memory) {
    return el("image", string.concat(prop("href", _href), " ", _props));
  }

  function start() internal pure returns (string memory) {
    return
      string.concat(
        '<svg width="400" height="400" style="background:#541563" ',
        'viewBox="0 0 400 400" ',
        'xmlns="http://www.w3.org/2000/svg" ',
        ">"
      );
  }

  function end() internal pure returns (bytes memory) {
    return ("</svg>");
  }

  /* COMMON */
  // A generic element, can be used to construct any SVG (or HTML) element
  function el(
    string memory _tag,
    string memory _props,
    string memory _children
  ) internal pure returns (string memory) {
    return string.concat("<", _tag, " ", _props, ">", _children, "</", _tag, ">");
  }

  // A generic element, can be used to construct any SVG (or HTML) element without children
  function el(string memory _tag, string memory _props) internal pure returns (string memory) {
    return string.concat("<", _tag, " ", _props, "/>");
  }

  // an SVG attribute
  function prop(string memory _key, string memory _val) internal pure returns (string memory) {
    return string.concat(_key, "=", '"', _val, '" ');
  }

  function stringifyIntSet(
    bytes memory _data,
    uint256 _offset,
    uint256 _len
  ) public pure returns (bytes memory) {
    bytes memory res;
    require(_data.length >= _offset + _len, "Out of range");
    for (uint256 i = _offset; i < _offset + _len; i++) {
      res = abi.encodePacked(res, byte2uint8(_data, i).toString(), " ");
    }
    return res;
  }

  function byte2uint8(bytes memory _data, uint256 _offset) public pure returns (uint8) {
    require(_data.length > _offset, "Out of range");
    return uint8(_data[_offset]);
  }
}

// File: contracts/lib/SVGUtils.sol



//SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;
import "@openzeppelin/contracts/utils/Strings.sol";
/**
  * @title  SVG Utilities
  * @author Kames Geraghty
  * @notice The SVG Utilities Library provides functions for constructing SVG; format CSS and numbers.
  * @dev Original code from w1nt3r-eth/hot-chain-svg (https://github.com/w1nt3r-eth/hot-chain-svg)
*/
library svgUtils {
    using Strings for uint256;
    using Strings for uint8;
    
    /// @notice Empty SVG element
    string internal constant NULL = "";

    /**
     * @notice Formats a CSS variable line. Includes a semicolon for formatting.
     * @param _key User for which to calculate prize amount.
     * @param _val User for which to calculate prize amount.
     * @return string Generated CSS variable.
    */
    function setCssVar(string memory _key, string memory _val)
        internal
        pure
        returns (string memory)
    {
        return string.concat("--", _key, ":", _val, ";");
    }

    /**
     * @notice Formats getting a css variable
     * @param _key User for which to calculate prize amount.
     * @return string Generated CSS variable.
    */
    function getCssVar(string memory _key)
        internal
        pure
        returns (string memory)
    {
        return string.concat("var(--", _key, ")");
    }

    // formats getting a def URL
    function getDefURL(string memory _id)
        internal
        pure
        returns (string memory)
    {
        return string.concat("url(#", _id, ")");
    }

    // checks if two strings are equal
    function stringsEqual(string memory _a, string memory _b)
        internal
        pure
        returns (bool)
    {
        return
            keccak256(abi.encodePacked(_a)) == keccak256(abi.encodePacked(_b));
    }

    // returns the length of a string in characters
    function utfStringLength(string memory _str)
        internal
        pure
        returns (uint256 length)
    {
        uint256 i = 0;
        bytes memory string_rep = bytes(_str);

        while (i < string_rep.length) {
            if (string_rep[i] >> 7 == 0) i += 1;
            else if (string_rep[i] >> 5 == bytes1(uint8(0x6))) i += 2;
            else if (string_rep[i] >> 4 == bytes1(uint8(0xE))) i += 3;
            else if (string_rep[i] >> 3 == bytes1(uint8(0x1E)))
                i += 4;
                //For safety
            else i += 1;

            length++;
        }
    }

    function round2Txt(
        uint256 _value,
        uint8 _decimals,
        uint8 _prec
    ) internal pure returns (bytes memory) {
        return abi.encodePacked(
            (_value / 10 ** _decimals).toString(), 
            ".",
            ( _value / 10 ** (_decimals - _prec) -
                _value / 10 ** (_decimals ) * 10 ** _prec
            ).toString()
        );
    }

     // converts an unsigned integer to a string
     function uint2str(uint256 _i)
     internal
     pure
     returns (string memory _uintAsString)
 {
     if (_i == 0) {
         return "0";
     }
     uint256 j = _i;
     uint256 len;
     while (j != 0) {
         len++;
         j /= 10;
     }
     bytes memory bstr = new bytes(len);
     uint256 k = len;
     while (_i != 0) {
         k = k - 1;
         uint8 temp = (48 + uint8(_i - (_i / 10) * 10));
         bytes1 b1 = bytes1(temp);
         bstr[k] = b1;
         _i /= 10;
     }
     return string(bstr);
 }
}

// File: contracts/lib/SVGColor.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;
import "@openzeppelin/contracts/utils/Strings.sol";

contract SVGColor {
  using Strings for uint256;
  using Strings for uint8;

  mapping(string => bytes) public colors;

  constructor() {
    colors["Black"] = hex"000000";
    colors["White"] = hex"FFFFFF";
    colors["Dark1"] = hex"232323";
    colors["Dark2"] = hex"464646";
  }

  function getColor(string memory _colorName) public view returns (bytes memory) {
    require(colors[_colorName].length == 3, "Unknown color");
    return abi.encodePacked(colors[_colorName], hex"64");
  }

  function getColor(string memory _colorName, uint8 _alpha) public view returns (bytes memory) {
    require(colors[_colorName].length == 3, "Unknown color");
    return abi.encodePacked(colors[_colorName], _alpha);
  }

  function getRgba(string memory _colorName) public view returns (string memory) {
    return string(toRgba(getColor(_colorName), 0));
  }

  // Input: array of colors (without alpha)
  // Ouputs a linearGradient
  function autoLinearGradient(
    bytes memory _colors,
    bytes memory _id,
    bytes memory _customAttributes
  ) public view returns (bytes memory) {
    return this.autoLinearGradient("", _colors, _id, _customAttributes);
  }

  function autoLinearGradient(
    bytes memory _coordinates,
    bytes memory _colors,
    bytes memory _id,
    bytes memory _customAttributes
  ) external view returns (bytes memory) {
    bytes memory _b;
    if (_coordinates.length > 3) {
      _b = abi.encodePacked(uint8(128), _coordinates);
    } else {
      _b = hex"00";
    }
    // Count the number of colors passed, each on 4 byte
    uint256 colorCount = _colors.length / 4;
    uint8 i = 0;
    while (i < colorCount) {
      _b = abi.encodePacked(
        _b,
        uint8(i * (100 / (colorCount - 1))), // grad. stop %
        uint8(_colors[i * 4]),
        uint8(_colors[i * 4 + 1]),
        uint8(_colors[i * 4 + 2]),
        uint8(_colors[i * 4 + 3])
      );
      i++;
    }
    return linearGradient(_b, _id, _customAttributes);
  }

  function linearGradient(
    bytes memory _lg,
    bytes memory _id,
    bytes memory _customAttributes
  ) public pure returns (bytes memory) {
    bytes memory grdata;
    uint8 offset = 1;

    if (uint8(_lg[0]) & 128 == 128) {
      grdata = abi.encodePacked(
        'x1="',
        byte2uint8(_lg, 1).toString(),
        '%" x2="',
        byte2uint8(_lg, 2).toString(),
        '%" y1="',
        byte2uint8(_lg, 3).toString(),
        '%" y2="',
        byte2uint8(_lg, 4).toString(),
        '%"'
      );
      offset = 5;
    }
    grdata = abi.encodePacked('<linearGradient id="', _id, '" ', _customAttributes, grdata, ">");
    for (uint256 i = offset; i < _lg.length; i += 5) {
      grdata = abi.encodePacked(
        grdata,
        '<stop offset="',
        byte2uint8(_lg, i).toString(),
        '%" stop-color="',
        toRgba(_lg, i + 1),
        '" id="',
        _id,
        byte2uint8(_lg, i).toString(),
        '"/>'
      );
    }
    return abi.encodePacked(grdata, "</linearGradient>");
  }

  function toRgba(bytes memory _rgba, uint256 offset) public pure returns (bytes memory) {
    return
      abi.encodePacked(
        "rgba(",
        byte2uint8(_rgba, offset).toString(),
        ",",
        byte2uint8(_rgba, offset + 1).toString(),
        ",",
        byte2uint8(_rgba, offset + 2).toString(),
        ",",
        byte2uint8(_rgba, offset + 3).toString(),
        "%)"
      );
  }

  function byte2uint8(bytes memory _data, uint256 _offset) public pure returns (uint8) {
    require(_data.length > _offset, "Out of range");
    return uint8(_data[_offset]);
  }

  // formats rgba white with a specified opacity / alpha
  function white_a(uint256 _a) internal pure returns (string memory) {
    return rgba(255, 255, 255, _a);
  }

  // formats rgba black with a specified opacity / alpha
  function black_a(uint256 _a) internal pure returns (string memory) {
    return rgba(0, 0, 0, _a);
  }

  // formats generic rgba color in css
  function rgba(
    uint256 _r,
    uint256 _g,
    uint256 _b,
    uint256 _a
  ) internal pure returns (string memory) {
    string memory formattedA = _a < 100 ? string.concat("0.", uint2str(_a)) : "1";
    return
      string.concat(
        "rgba(",
        uint2str(_r),
        ",",
        uint2str(_g),
        ",",
        uint2str(_b),
        ",",
        formattedA,
        ")"
      );
  }

  function uint2str(uint256 _i) internal pure returns (string memory _uintAsString) {
    if (_i == 0) {
      return "0";
    }
    uint256 j = _i;
    uint256 len;
    while (j != 0) {
      len++;
      j /= 10;
    }
    bytes memory bstr = new bytes(len);
    uint256 k = len;
    while (_i != 0) {
      k = k - 1;
      uint8 temp = (48 + uint8(_i - (_i / 10) * 10));
      bytes1 b1 = bytes1(temp);
      bstr[k] = b1;
      _i /= 10;
    }
    return string(bstr);
  }
}

// File: contracts/interfaces/ENS.sol



pragma solidity >=0.8.4;

interface ENS {
    // Logged when the owner of a node assigns a new owner to a subnode.
    event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

    // Logged when the owner of a node transfers ownership to a new account.
    event Transfer(bytes32 indexed node, address owner);

    // Logged when the resolver for a node changes.
    event NewResolver(bytes32 indexed node, address resolver);

    // Logged when the TTL of a node changes
    event NewTTL(bytes32 indexed node, uint64 ttl);

    // Logged when an operator is added or removed.
    event ApprovalForAll(
        address indexed owner,
        address indexed operator,
        bool approved
    );

    function setRecord(
        bytes32 node,
        address owner,
        address resolver,
        uint64 ttl
    ) external;

    function setSubnodeRecord(
        bytes32 node,
        bytes32 label,
        address owner,
        address resolver,
        uint64 ttl
    ) external;

    function setSubnodeOwner(
        bytes32 node,
        bytes32 label,
        address owner
    ) external returns (bytes32);

    function setResolver(bytes32 node, address resolver) external;

    function setOwner(bytes32 node, address owner) external;

    function setTTL(bytes32 node, uint64 ttl) external;

    function setApprovalForAll(address operator, bool approved) external;

    function owner(bytes32 node) external view returns (address);

    function resolver(bytes32 node) external view returns (address);

    function ttl(bytes32 node) external view returns (uint64);

    function recordExists(bytes32 node) external view returns (bool);

    function isApprovedForAll(address owner, address operator)
        external
        view
        returns (bool);
}

// File: contracts/lib/NameEncoder.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import "./BytesUtils.sol";

library NameEncoder {
  using BytesUtils for bytes;

  function dnsEncodeName(string memory name)
    internal
    pure
    returns (bytes memory dnsName, bytes32 node)
  {
    uint8 labelLength = 0;
    bytes memory bytesName = bytes(name);
    uint256 length = bytesName.length;
    dnsName = new bytes(length + 2);
    node = 0;
    if (length == 0) {
      dnsName[0] = 0;
      return (dnsName, node);
    }

    // use unchecked to save gas since we check for an underflow
    // and we check for the length before the loop
    unchecked {
      for (uint256 i = length - 1; i >= 0; i--) {
        if (bytesName[i] == ".") {
          dnsName[i + 1] = bytes1(labelLength);
          node = keccak256(abi.encodePacked(node, bytesName.keccak(i + 1, labelLength)));
          labelLength = 0;
        } else {
          labelLength += 1;
          dnsName[i + 1] = bytesName[i];
        }
        if (i == 0) {
          break;
        }
      }
    }

    node = keccak256(abi.encodePacked(node, bytesName.keccak(0, labelLength)));

    dnsName[0] = bytes1(labelLength);
    return (dnsName, node);
  }
}

// File: contracts/interfaces/IReverseRegistrar.sol



pragma solidity >=0.8.4;

interface IReverseRegistrar {
  function setDefaultResolver(address resolver) external;

  function claim(address owner) external returns (bytes32);

  function claimForAddr(
    address addr,
    address owner,
    address resolver
  ) external returns (bytes32);

  function claimWithResolver(address owner, address resolver) external returns (bytes32);

  function setName(string memory name) external returns (bytes32);

  function setNameForAddr(
    address addr,
    address owner,
    address resolver,
    string memory name
  ) external returns (bytes32);

  function node(address addr) external pure returns (bytes32);
}

// File: contracts/interfaces/ITextResolver.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

interface ITextResolver {
  event TextChanged(bytes32 indexed node, string indexed indexedKey, string key);

  /**
   * Returns the text data associated with an ENS node and key.
   * @param node The ENS node to query.
   * @param key The text data key to query.
   * @return The associated text data.
   */
  function text(bytes32 node, string calldata key) external view returns (string memory);
}

// File: contracts/interfaces/IDefaultReverseResolver.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

interface IDefaultReverseResolver {
  function name(bytes32 input) external view returns (string calldata);
}

// File: contracts/lib/BytesUtils.sol



//SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;

library BytesUtils {
  /*
   * @dev Returns the keccak-256 hash of a byte range.
   * @param self The byte string to hash.
   * @param offset The position to start hashing at.
   * @param len The number of bytes to hash.
   * @return The hash of the byte range.
   */
  function keccak(
    bytes memory self,
    uint256 offset,
    uint256 len
  ) internal pure returns (bytes32 ret) {
    require(offset + len <= self.length);
    assembly {
      ret := keccak256(add(add(self, 32), offset), len)
    }
  }

  /**
   * @dev Returns the ENS namehash of a DNS-encoded name.
   * @param self The DNS-encoded name to hash.
   * @param offset The offset at which to start hashing.
   * @return The namehash of the name.
   */
  function namehash(bytes memory self, uint256 offset) internal pure returns (bytes32) {
    (bytes32 labelhash, uint256 newOffset) = readLabel(self, offset);
    if (labelhash == bytes32(0)) {
      require(offset == self.length - 1, "namehash: Junk at end of name");
      return bytes32(0);
    }
    return keccak256(abi.encodePacked(namehash(self, newOffset), labelhash));
  }

  /**
   * @dev Returns the keccak-256 hash of a DNS-encoded label, and the offset to the start of the next label.
   * @param self The byte string to read a label from.
   * @param idx The index to read a label at.
   * @return labelhash The hash of the label at the specified index, or 0 if it is the last label.
   * @return newIdx The index of the start of the next label.
   */
  function readLabel(bytes memory self, uint256 idx)
    internal
    pure
    returns (bytes32 labelhash, uint256 newIdx)
  {
    require(idx < self.length, "readLabel: Index out of bounds");
    uint256 len = uint256(uint8(self[idx]));
    if (len > 0) {
      labelhash = keccak(self, idx + 1, len);
    } else {
      labelhash = bytes32(0);
    }
    newIdx = idx + len + 1;
  }
}