// File: @ensdomains/ens-contracts/contracts/registry/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 virtual;
    function setSubnodeRecord(bytes32 node, bytes32 label, address owner, address resolver, uint64 ttl) external virtual;
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) external virtual returns(bytes32);
    function setResolver(bytes32 node, address resolver) external virtual;
    function setOwner(bytes32 node, address owner) external virtual;
    function setTTL(bytes32 node, uint64 ttl) external virtual;
    function setApprovalForAll(address operator, bool approved) external virtual;
    function owner(bytes32 node) external virtual view returns (address);
    function resolver(bytes32 node) external virtual view returns (address);
    function ttl(bytes32 node) external virtual view returns (uint64);
    function recordExists(bytes32 node) external virtual view returns (bool);
    function isApprovedForAll(address owner, address operator) external virtual view returns (bool);
}

// File: @ensdomains/ens-contracts/contracts/registry/ENSRegistry.sol



pragma solidity >=0.8.4;

import "./ENS.sol";

/**
 * The ENS registry contract.
 */
contract ENSRegistry is ENS {

    struct Record {
        address owner;
        address resolver;
        uint64 ttl;
    }

    mapping (bytes32 => Record) records;
    mapping (address => mapping(address => bool)) operators;

    // Permits modifications only by the owner of the specified node.
    modifier authorised(bytes32 node) {
        address owner = records[node].owner;
        require(owner == msg.sender || operators[owner][msg.sender]);
        _;
    }

    /**
     * @dev Constructs a new ENS registrar.
     */
    constructor() public {
        records[0x0].owner = msg.sender;
    }

    /**
     * @dev Sets the record for a node.
     * @param node The node to update.
     * @param owner The address of the new owner.
     * @param resolver The address of the resolver.
     * @param ttl The TTL in seconds.
     */
    function setRecord(bytes32 node, address owner, address resolver, uint64 ttl) external virtual override {
        setOwner(node, owner);
        _setResolverAndTTL(node, resolver, ttl);
    }

    /**
     * @dev Sets the record for a subnode.
     * @param node The parent node.
     * @param label The hash of the label specifying the subnode.
     * @param owner The address of the new owner.
     * @param resolver The address of the resolver.
     * @param ttl The TTL in seconds.
     */
    function setSubnodeRecord(bytes32 node, bytes32 label, address owner, address resolver, uint64 ttl) external virtual override {
        bytes32 subnode = setSubnodeOwner(node, label, owner);
        _setResolverAndTTL(subnode, resolver, ttl);
    }

    /**
     * @dev Transfers ownership of a node to a new address. May only be called by the current owner of the node.
     * @param node The node to transfer ownership of.
     * @param owner The address of the new owner.
     */
    function setOwner(bytes32 node, address owner) public virtual override authorised(node) {
        _setOwner(node, owner);
        emit Transfer(node, owner);
    }

    /**
     * @dev Transfers ownership of a subnode keccak256(node, label) to a new address. May only be called by the owner of the parent node.
     * @param node The parent node.
     * @param label The hash of the label specifying the subnode.
     * @param owner The address of the new owner.
     */
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) public virtual override authorised(node) returns(bytes32) {
        bytes32 subnode = keccak256(abi.encodePacked(node, label));
        _setOwner(subnode, owner);
        emit NewOwner(node, label, owner);
        return subnode;
    }

    /**
     * @dev Sets the resolver address for the specified node.
     * @param node The node to update.
     * @param resolver The address of the resolver.
     */
    function setResolver(bytes32 node, address resolver) public virtual override authorised(node) {
        emit NewResolver(node, resolver);
        records[node].resolver = resolver;
    }

    /**
     * @dev Sets the TTL for the specified node.
     * @param node The node to update.
     * @param ttl The TTL in seconds.
     */
    function setTTL(bytes32 node, uint64 ttl) public virtual override authorised(node) {
        emit NewTTL(node, ttl);
        records[node].ttl = ttl;
    }

    /**
     * @dev Enable or disable approval for a third party ("operator") to manage
     *  all of `msg.sender`'s ENS records. Emits the ApprovalForAll event.
     * @param operator Address to add to the set of authorized operators.
     * @param approved True if the operator is approved, false to revoke approval.
     */
    function setApprovalForAll(address operator, bool approved) external virtual override {
        operators[msg.sender][operator] = approved;
        emit ApprovalForAll(msg.sender, operator, approved);
    }

    /**
     * @dev Returns the address that owns the specified node.
     * @param node The specified node.
     * @return address of the owner.
     */
    function owner(bytes32 node) public virtual override view returns (address) {
        address addr = records[node].owner;
        if (addr == address(this)) {
            return address(0x0);
        }

        return addr;
    }

    /**
     * @dev Returns the address of the resolver for the specified node.
     * @param node The specified node.
     * @return address of the resolver.
     */
    function resolver(bytes32 node) public virtual override view returns (address) {
        return records[node].resolver;
    }

    /**
     * @dev Returns the TTL of a node, and any records associated with it.
     * @param node The specified node.
     * @return ttl of the node.
     */
    function ttl(bytes32 node) public virtual override view returns (uint64) {
        return records[node].ttl;
    }

    /**
     * @dev Returns whether a record has been imported to the registry.
     * @param node The specified node.
     * @return Bool if record exists
     */
    function recordExists(bytes32 node) public virtual override view returns (bool) {
        return records[node].owner != address(0x0);
    }

    /**
     * @dev Query if an address is an authorized operator for another address.
     * @param owner The address that owns the records.
     * @param operator The address that acts on behalf of the owner.
     * @return True if `operator` is an approved operator for `owner`, false otherwise.
     */
    function isApprovedForAll(address owner, address operator) external virtual override view returns (bool) {
        return operators[owner][operator];
    }

    function _setOwner(bytes32 node, address owner) internal virtual {
        records[node].owner = owner;
    }

    function _setResolverAndTTL(bytes32 node, address resolver, uint64 ttl) internal {
        if(resolver != records[node].resolver) {
            records[node].resolver = resolver;
            emit NewResolver(node, resolver);
        }

        if(ttl != records[node].ttl) {
            records[node].ttl = ttl;
            emit NewTTL(node, ttl);
        }
    }
}

// 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: @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: @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/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/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/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: src/common/IPriceOracle.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.8.4;

interface IPriceOracle {
    /**
     * @dev Returns the price to register or renew a name.
     * @param name The name being registered or renewed.
     * @param expires When the name presently expires (0 if this is a new registration).
     * @param duration How long the name is being registered or extended for, in seconds.
     * @return The price of this renewal or registration, in wei.
     */
    function price(string calldata name, uint expires, uint duration) external view returns(uint);
}

// File: src/common/PremiumPriceOracle.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "./SafeMath.sol";
import "./StringUtils.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./StablePriceOracle.sol";
import "../universal/UniversalRegistrar.sol";
import "./SLDPriceOracle.sol";
import "../universal_v2/Access.sol";

// PremiumPriceOracle a price oracle with support for setting different prices for premium names.
contract PremiumPriceOracle is Ownable, Access {
    using SafeMath for *;
    using StringUtils for *;

    AggregatorInterface public immutable usdOracle;
    SLDPriceOracle public sldPriceOracle;

    // Rent in base price units by length. Element 0 is for 1-length names, and so on.
    uint256[] public defaultPrices;
    mapping(bytes32 => uint256[]) public rentPrices;
    mapping(bytes32 => uint256) public rentPricesUpdated;

    mapping(uint256 => mapping(bytes32 => mapping(bytes32 => uint256))) public premiumPrices;
    mapping(bytes32 => uint256) public premiumPricesVersion;

    event NamePremium(bytes32 indexed node, string name, uint256 price);
    event PremiumsCleared(bytes32 indexed node);
    event RentPriceChanged(bytes32 node, uint256[] prices);
    event DefaultRentPriceChanged(uint256[] prices);

    bytes4 private constant INTERFACE_META_ID =
    bytes4(keccak256("supportsInterface(bytes4)"));

    bytes4 private constant ORACLE_ID =
    bytes4(keccak256("price(bytes32,string,uint256,uint256)"));

    constructor(SLDPriceOracle _sldPriceOracle, uint256[] memory _defaultPrices) Access(_sldPriceOracle.registrar()) {
        usdOracle = _sldPriceOracle.usdOracle();
        sldPriceOracle = _sldPriceOracle;
        _setDefaultPrices(_defaultPrices);
    }

    function price(bytes32 node, string calldata name, uint256 expires, uint256 duration) external view returns (uint256) {
        bytes32 label = keccak256(bytes(name));

        // if a premium price exists, return it
        if (premiumPrices[premiumPricesVersion[node]][node][label] != 0) {
            uint256 basePremium = premiumPrices[premiumPricesVersion[node]][node][label];
            return attoUSDToWei(basePremium.mul(duration));
        }

        // fallback to SLDPriceOracle if no prices set
        if (rentPricesUpdated[node] == 0) {
            return sldPriceOracle.price(node, name, expires, duration);
        }

        uint256 len = name.strlen();
        uint256[] memory prices = rentPrices[node].length > 0 ? rentPrices[node] : defaultPrices;

        if (len > prices.length) {
            len = prices.length;
        }
        require(len > 0);

        uint256 basePrice = prices[len - 1].mul(duration);
        return attoUSDToWei(basePrice);
    }

    function attoUSDToWei(uint256 amount) internal view returns (uint256) {
        uint256 ethPrice = uint256(usdOracle.latestAnswer()); //2
        return amount.mul(1e8).div(ethPrice);
    }

    function weiToAttoUSD(uint256 amount) internal view returns (uint256) {
        uint256 ethPrice = uint256(usdOracle.latestAnswer());
        return amount.mul(ethPrice).div(1e8);
    }

    function premium(bytes32 node, bytes32 label) external view returns (uint256) {
        return premiumPrices[premiumPricesVersion[node]][node][label];
    }

    /**
     * @dev Sets the rent price for a specific name.
     * @param node The node to set the rent price for.
     * @param name The name to set the rent price for.
     * @param _price The rent price. Values are in base
     * price units, equal to one attodollar (1e-18 dollar)
     * each (zero values will clear the price premium).
     */
    function setPremium(bytes32 node, string calldata name, uint256 _price) external nodeOperator(node) {
        bytes32 label = keccak256(bytes(name));
        premiumPrices[premiumPricesVersion[node]][node][label] = _price;
        emit NamePremium(node, name, _price);
    }

    function setPremiums(bytes32 node, string[] calldata names, uint256[] calldata prices) external nodeOperator(node) {
        require(names.length == prices.length, "names and prices must have the same length");
        for (uint i = 0; i < names.length; i++) {
            bytes32 label = keccak256(bytes(names[i]));
            premiumPrices[premiumPricesVersion[node]][node][label] = prices[i];
            emit NamePremium(node, names[i], prices[i]);
        }
    }

    function clearPremiums(bytes32 node) external nodeOperator(node) {
        premiumPricesVersion[node]++;
        emit PremiumsCleared(node);
    }

    /**
     * @dev Sets rent prices for the specified node (can only be called by the node owner)
     * @param _rentPrices The price array. Each element corresponds to a specific
     *                    name length; names longer than the length of the array
     *                    default to the price of the last element. Values are
     *                    in base price units, equal to one attodollar (1e-18
     *                    dollar) each.
     */
    function setPrices(bytes32 node, uint256[] memory _rentPrices) public nodeOperator(node) {
        require(block.timestamp - rentPricesUpdated[node] > 5 minutes);

        rentPrices[node] = _rentPrices;
        rentPricesUpdated[node] = block.timestamp;
        emit RentPriceChanged(node, _rentPrices);
    }

    /**
     * @dev Sets default rent prices to be used by nodes that don't have pricing set.
     * @param _defaultPrices The price array. Each element corresponds to a specific
     *                    name length; names longer than the length of the array
     *                    default to the price of the last element. Values are
     *                    in base price units, equal to one attodollar (1e-18
     *                    dollar) each.
     */
    function setDefaultPrices(uint256[] memory _defaultPrices) public onlyOwner {
        _setDefaultPrices(_defaultPrices);
    }

    function _setDefaultPrices(uint256[] memory _defaultPrices) internal {
        defaultPrices = _defaultPrices;
        emit DefaultRentPriceChanged(_defaultPrices);
    }

    function supportsInterface(bytes4 interfaceID) public view virtual returns (bool)
    {
        return interfaceID == INTERFACE_META_ID || interfaceID == ORACLE_ID;
    }
}

// File: src/common/SLDPriceOracle.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "./SafeMath.sol";
import "./StringUtils.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./StablePriceOracle.sol";
import "../universal/UniversalRegistrar.sol";

// SLDPriceOracle sets a price in USD, based on an oracle for each node.
// The registry can set and change default prices. However, if the node owner
// sets their own price, they will override the default.
contract SLDPriceOracle is Ownable {
    using SafeMath for *;
    using StringUtils for *;

    // Rent in base price units by length. Element 0 is for 1-length names, and so on.
    mapping(bytes32 => uint256[]) public rentPrices;
    uint256[] public defaultPrices;

    // Oracle address
    AggregatorInterface public immutable usdOracle;
    // Registrar address
    UniversalRegistrar public registrar;

    /**
     * @dev Throws if called by any account other than the node owner.
     */
    modifier onlyNodeOwner(bytes32 node) {
        require(registrar.ownerOfNode(node) == _msgSender(), "caller is not the node owner");
        _;
    }

    event OracleChanged(address oracle);

    event RentPriceChanged(bytes32 node, uint256[] prices);
    event DefaultRentPriceChanged(uint256[] prices);

    bytes4 private constant INTERFACE_META_ID =
    bytes4(keccak256("supportsInterface(bytes4)"));

    bytes4 private constant ORACLE_ID =
    bytes4(keccak256("price(bytes32,string,uint256,uint256)"));

    constructor(UniversalRegistrar _registrar, AggregatorInterface _usdOracle, uint256[] memory _defaultPrices) {
        registrar = _registrar;
        usdOracle = _usdOracle;
        defaultPrices = _defaultPrices;
    }

    function price(bytes32 node, string calldata name, uint256 expires, uint256 duration) external view returns (uint256) {
        uint256 len = name.strlen();
        uint256[] memory prices = rentPrices[node].length > 0 ? rentPrices[node] : defaultPrices;

        if (len > prices.length) {
            len = prices.length;
        }
        require(len > 0);

        uint256 basePrice = prices[len - 1].mul(duration);
        return attoUSDToWei(basePrice);
    }

    /**
     * @dev Sets rent prices for the specified node (can only be called by the node owner)
     * @param _rentPrices The price array. Each element corresponds to a specific
     *                    name length; names longer than the length of the array
     *                    default to the price of the last element. Values are
     *                    in base price units, equal to one attodollar (1e-18
     *                    dollar) each.
     */
    function setPrices(bytes32 node, uint256[] memory _rentPrices) public onlyNodeOwner(node) {
        rentPrices[node] = _rentPrices;
        emit RentPriceChanged(node, _rentPrices);
    }

    /**
     * @dev Sets default rent prices to be used by nodes that don't have pricing set.
     * @param _defaultPrices The price array. Each element corresponds to a specific
     *                    name length; names longer than the length of the array
     *                    default to the price of the last element. Values are
     *                    in base price units, equal to one attodollar (1e-18
     *                    dollar) each.
     */
    function setDefaultPrices(uint256[] memory _defaultPrices) public onlyOwner {
        defaultPrices = _defaultPrices;
        emit DefaultRentPriceChanged(_defaultPrices);
    }

    function attoUSDToWei(uint256 amount) internal view returns (uint256) {
        uint256 ethPrice = uint256(usdOracle.latestAnswer()); //2
        return amount.mul(1e8).div(ethPrice);
    }

    function weiToAttoUSD(uint256 amount) internal view returns (uint256) {
        uint256 ethPrice = uint256(usdOracle.latestAnswer());
        return amount.mul(ethPrice).div(1e8);
    }

    function supportsInterface(bytes4 interfaceID) public view virtual returns (bool)
    {
        return interfaceID == INTERFACE_META_ID || interfaceID == ORACLE_ID;
    }
}

// File: src/common/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.8.4;

/**
 * @title SafeMath
 * @dev Unsigned math operations with safety checks that revert on error
 */
library SafeMath {
    /**
    * @dev Multiplies two unsigned integers, reverts on overflow.
    */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b);

        return c;
    }

    /**
    * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
    */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
    * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

    /**
    * @dev Adds two unsigned integers, reverts on overflow.
    */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a);

        return c;
    }

    /**
    * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
    * reverts when dividing by zero.
    */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }
}

// File: src/common/StablePriceOracle.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "./IPriceOracle.sol";
import "./SafeMath.sol";
import "./StringUtils.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

interface AggregatorInterface {
    function latestAnswer() external view returns (int256);
}

// StablePriceOracle sets a price in USD, based on an oracle.
contract StablePriceOracle is Ownable, IPriceOracle {
    using SafeMath for *;
    using StringUtils for *;

    // Rent in base price units by length. Element 0 is for 1-length names, and so on.
    uint256[] public rentPrices;

    // Oracle address
    AggregatorInterface public immutable usdOracle;

    event OracleChanged(address oracle);

    event RentPriceChanged(uint256[] prices);

    bytes4 private constant INTERFACE_META_ID =
    bytes4(keccak256("supportsInterface(bytes4)"));
    bytes4 private constant ORACLE_ID =
    bytes4(
        keccak256("price(string,uint256,uint256)") ^
        keccak256("premium(string,uint256,uint256)")
    );

    constructor(AggregatorInterface _usdOracle, uint256[] memory _rentPrices) {
        usdOracle = _usdOracle;
        setPrices(_rentPrices);
    }

    function price(string calldata name, uint256 expires, uint256 duration) external view override returns (uint256) {
        uint256 len = name.strlen();
        if (len > rentPrices.length) {
            len = rentPrices.length;
        }
        require(len > 0);

        uint256 basePrice = rentPrices[len - 1].mul(duration);
        basePrice = basePrice.add(_premium(name, expires, duration));

        return attoUSDToWei(basePrice);
    }

    /**
     * @dev Sets rent prices.
     * @param _rentPrices The price array. Each element corresponds to a specific
     *                    name length; names longer than the length of the array
     *                    default to the price of the last element. Values are
     *                    in base price units, equal to one attodollar (1e-18
     *                    dollar) each.
     */
    function setPrices(uint256[] memory _rentPrices) public onlyOwner {
        rentPrices = _rentPrices;
        emit RentPriceChanged(_rentPrices);
    }

    /**
     * @dev Returns the pricing premium in wei.
     */
    function premium(
        string calldata name,
        uint256 expires,
        uint256 duration
    ) external view returns (uint256) {
        uint256 weiPrice = attoUSDToWei(_premium(name, expires, duration));
        return weiPrice;
    }

    /**
     * @dev Returns the pricing premium in internal base units.
     */
    function _premium(
        string memory name,
        uint256 expires,
        uint256 duration
    ) internal view virtual returns (uint256) {
        return 0;
    }

    function attoUSDToWei(uint256 amount) internal view returns (uint256) {
        uint256 ethPrice = uint256(usdOracle.latestAnswer()); //2
        return amount.mul(1e8).div(ethPrice);
    }

    function weiToAttoUSD(uint256 amount) internal view returns (uint256) {
        uint256 ethPrice = uint256(usdOracle.latestAnswer());
        return amount.mul(ethPrice).div(1e8);
    }

    function supportsInterface(bytes4 interfaceID) public view virtual returns (bool)
    {
        return interfaceID == INTERFACE_META_ID || interfaceID == ORACLE_ID;
    }
}

// File: src/common/StringUtils.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.8.4;

library StringUtils {
    /**
     * @dev Returns the length of a given string
     *
     * @param s The string to measure the length of
     * @return The length of the input string
     */
    function strlen(string memory s) internal pure returns (uint) {
        uint len;
        uint i = 0;
        uint bytelength = bytes(s).length;
        for(len = 0; i < bytelength; len++) {
            bytes1 b = bytes(s)[i];
            if(b < 0x80) {
                i += 1;
            } else if (b < 0xE0) {
                i += 2;
            } else if (b < 0xF0) {
                i += 3;
            } else if (b < 0xF8) {
                i += 4;
            } else if (b < 0xFC) {
                i += 5;
            } else {
                i += 6;
            }
        }
        return len;
    }
}

// File: src/root/Controllable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "@openzeppelin/contracts/access/Ownable.sol";

contract Controllable is Ownable {
    mapping(address => bool) public controllers;

    event ControllerChanged(address indexed controller, bool enabled);

    modifier onlyController {
        require(
            controllers[msg.sender],
            "Controllable: Caller is not a controller"
        );
        _;
    }

    function setController(address controller, bool enabled) public onlyOwner {
        controllers[controller] = enabled;
        emit ControllerChanged(controller, enabled);
    }
}

// File: src/root/Root.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "@ensdomains/ens-contracts/contracts/registry/ENS.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./Controllable.sol";

contract Root is Ownable, Controllable {
    bytes32 private constant ROOT_NODE = bytes32(0);

    bytes4 private constant INTERFACE_META_ID =
    bytes4(keccak256("supportsInterface(bytes4)"));

    event TLDLocked(bytes32 indexed label);

    ENS public ens;
    mapping(bytes32 => bool) public locked;

    constructor(ENS _ens) {
        ens = _ens;
    }

    function setSubnodeOwner(bytes32 label, address owner) external onlyController
    {
        require(!locked[label], "name locked");
        ens.setSubnodeOwner(ROOT_NODE, label, owner);
    }

    function setResolver(address resolver) external onlyController {
        ens.setResolver(ROOT_NODE, resolver);
    }

    function lock(bytes32 label) external onlyController {
        emit TLDLocked(label);
        locked[label] = true;
    }

    function supportsInterface(bytes4 interfaceID) external pure returns (bool) {
        return interfaceID == INTERFACE_META_ID;
    }
}

// File: src/universal/IUniversalRegistrar.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "@openzeppelin/contracts/token/ERC721/IERC721.sol";

interface IUniversalRegistrar is IERC721 {
    event ControllerAdded(bytes32 node, address indexed controller);
    event ControllerRemoved(bytes32 node, address indexed controller);

    event NameRegistered(
        bytes32 node,
        bytes32 indexed label,
        address indexed owner,
        uint256 expires
    );
    event NameRenewed(bytes32 node, bytes32 indexed label, uint256 expires);

    // Authorises a controller, who can register and renew domains.
    function addController(bytes32 node, address controller) external;

    // Revoke controller permission for an address.
    function removeController(bytes32 node, address controller) external;

    // Set the resolver for the TLD this registrar manages.
    function setResolver(bytes32 node, address resolver) external;

    // Returns the expiration timestamp of the specified label hash.
    function nameExpires(uint256 id) external view returns (uint256);

    // Returns true iff the specified name is available for registration.
    function available(uint256 id) external view returns (bool);

    /**
     * @dev Register a name.
     */
    function register(
        bytes32 node,
        bytes32 label,
        address owner,
        uint256 duration
    ) external returns (uint256);

    function renew(bytes32 node, bytes32 label, uint256 duration) external returns (uint256);

    /**
     * @dev Reclaim ownership of a name in ENS, if you own it in the registrar.
     */
    function reclaim(bytes32 node, bytes32 label, address owner) external;
}

// File: src/universal/RegistrarAccess.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "../root/Root.sol";

contract RegistrarAccess {
    event NodeOwnerChanged(bytes32 node, address indexed oldOwner, address indexed newOwner);
    event RegistryControllersChanged(address indexed controller, bool approved);
    event RegistryNodeControllersChanged(bytes32 node, address indexed controller, bool approved);

    Root public root;

    constructor(Root _root) {
        root = _root;
    }

    // A map of top level domains and their authorised owner
    mapping(bytes32 => address) private nodeOwners;

    // A map specifying which controller addresses TLD owners are allowed to use.
    mapping(address => bool) private registryControllers;

    // A map specifying which controller addresses a specific TLD owner is allowed to use.
    mapping(bytes32 => mapping(address => bool)) private registryNodeControllers;

    modifier onlyNodeOwner(bytes32 node) {
        require(nodeOwners[node] == msg.sender);
        _;
    }

    modifier onlyRegistry {
        require(root.controllers(msg.sender));
        _;
    }

    modifier onlyRegistryControllers(bytes32 node, address controller) {
        require(registryNodeControllers[node][controller] ||
            registryControllers[controller], "controller not approved by registry");
        _;
    }

    // Transfers ownership of a TLD to a new owner
    // can only be called by existing node owner.
    function transferNodeOwnership(bytes32 node, address newOwner) public onlyNodeOwner(node) {
        require(newOwner != address(0));
        emit NodeOwnerChanged(node, nodeOwners[node], newOwner);
        nodeOwners[node] = newOwner;
    }

    // Gives up ownership of a TLD to a burn address. All functionality marked with onlyNodeOwner
    // will be disabled for the specified TLD. It will also affect any contracts
    // that rely on {ownerOfNode}. Use with extreme caution.
    function renounceNodeOwnership(bytes32 node) public onlyNodeOwner(node) {
        emit NodeOwnerChanged(node, nodeOwners[node], address(0));
        nodeOwners[node] = address(0);
    }

    function ownerOfNode(bytes32 node) public view returns (address) {
        return nodeOwners[node];
    }

    // Sets ownership of a name in the registrar. If the name
    // is locked, only the owner can transfer ownership by
    // calling transferNodeOwnership.
    function setSubnodeOwner(bytes32 label, address owner) public onlyRegistry returns(bytes32) {
        require(!root.locked(label), "name locked");
        bytes32 node = keccak256(abi.encodePacked(bytes32(0), label));
        emit NodeOwnerChanged(node, nodeOwners[node], owner);
        nodeOwners[node] = owner;
        return node;
    }

    // Whitelists a controller address to be used by the specified node.
    function approveControllerForNode(bytes32 node, address controller, bool approved) external onlyRegistry {
        registryNodeControllers[node][controller] = approved;
        emit RegistryNodeControllersChanged(node, controller, approved);
    }

    // Whitelists a controller address to be used by any node.
    function approveController(address controller, bool approved) external onlyRegistry {
        registryControllers[controller] = approved;
        emit RegistryControllersChanged(controller, approved);
    }
}

// File: src/universal/UniversalRegistrar.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

import "@ensdomains/ens-contracts/contracts/registry/ENS.sol";
import "@ensdomains/ens-contracts/contracts/registry/ENSRegistry.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./IUniversalRegistrar.sol";
import "./RegistrarAccess.sol";

contract UniversalRegistrar is ERC721, RegistrarAccess, IUniversalRegistrar, Ownable {
    // A map of expiry times
    mapping(uint256 => uint) expiries;
    ENS public ens;

    // ERC721 Metadata URI
    string private metadataUri;

    // A map of addresses that are authorised to register and renew
    // names for the given top level node.
    mapping(bytes32 => mapping(address => bool)) public controllers;

    uint256 public constant GRACE_PERIOD = 90 days;

    bytes4 constant private INTERFACE_META_ID = bytes4(keccak256("supportsInterface(bytes4)"));
    bytes4 constant private ERC721_ID = bytes4(
        keccak256("balanceOf(address)") ^
        keccak256("ownerOf(uint256)") ^
        keccak256("approve(address,uint256)") ^
        keccak256("getApproved(uint256)") ^
        keccak256("setApprovalForAll(address,bool)") ^
        keccak256("isApprovedForAll(address,address)") ^
        keccak256("transferFrom(address,address,uint256)") ^
        keccak256("safeTransferFrom(address,address,uint256)") ^
        keccak256("safeTransferFrom(address,address,uint256,bytes)")
    );
    bytes4 constant private RECLAIM_ID = bytes4(keccak256("reclaim(bytes32,uint256,address)"));

    /**
     * v2.1.3 version of _isApprovedOrOwner which calls ownerOf(tokenId) and takes grace period into consideration instead of ERC721.ownerOf(tokenId);
     * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v2.1.3/contracts/token/ERC721/ERC721.sol#L187
     * @dev Returns whether the given spender can transfer a given token ID
     * @param spender address of the spender to query
     * @param tokenId uint256 ID of the token to be transferred
     * @return bool whether the msg.sender is approved for the given token ID,
     *    is an operator of the owner, or is the owner of the token
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view override returns (bool) {
        address owner = ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    constructor(ENS _ens, Root _root) ERC721("Impervious Registry", "IR") RegistrarAccess(_root) {
        ens = _ens;
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`.
     */
    function _baseURI() internal view virtual override returns (string memory) {
        return metadataUri;
    }

    modifier live(bytes32 node) {
        require(ens.owner(node) == address(this));
        _;
    }

    modifier onlyController(bytes32 node) {
        require(controllers[node][msg.sender]);
        _;
    }

    /**
     * @dev Gets the owner of the specified token ID. Names become unowned
     *      when their registration expires.
     * @param tokenId uint256 ID of the token to query the owner of
     * @return address currently marked as the owner of the given token ID
     */
    function ownerOf(uint256 tokenId) public view override(IERC721, ERC721) returns (address) {
        require(expiries[tokenId] > block.timestamp);
        return super.ownerOf(tokenId);
    }

    // Change metadata uri
    function setUri(string memory _uri) external onlyOwner {
        metadataUri = _uri;
    }

    // Authorises a controller, who can register and renew domains.
    // can only be called by the node owner.
    function addController(
        bytes32 node,
        address controller
    ) external override onlyNodeOwner(node) onlyRegistryControllers(node, controller) {
        controllers[node][controller] = true;
        emit ControllerAdded(node, controller);
    }

    // Revoke controller permission for an address.
    // can only be called by the node owner.
    function removeController(bytes32 node, address controller) external override onlyNodeOwner(node) {
        controllers[node][controller] = false;
        emit ControllerRemoved(node, controller);
    }

    // Set the resolver for the TLD this registrar manages.
    // can only be called by the node owner.
    function setResolver(bytes32 node, address resolver) external override onlyNodeOwner(node) {
        ens.setResolver(node, resolver);
    }

    // Returns the expiration timestamp of the specified id.
    function nameExpires(uint256 id) external view override returns (uint) {
        return expiries[id];
    }

    // Returns true iff the specified name is available for registration.
    function available(uint256 id) public view override returns (bool) {
        // Not available if it's registered here or in its grace period.
        return expiries[id] + GRACE_PERIOD < block.timestamp;
    }

    /**
     * @dev Register a name.
     * @param node The node hash.
     * @param label The token ID (keccak256 of the label).
     * @param owner The address that should own the registration.
     * @param duration Duration in seconds for the registration.
     */
    function register(bytes32 node, bytes32 label, address owner, uint duration) external override returns (uint) {
        return _register(node, label, owner, duration, true);
    }

    /**
     * @dev Register a name, without modifying the registry.
     * @param node The node hash.
     * @param label The token ID (keccak256 of the label).
     * @param owner The address that should own the registration.
     * @param duration Duration in seconds for the registration.
     */
    function registerOnly(bytes32 node, bytes32 label, address owner, uint duration) external returns (uint) {
        return _register(node, label, owner, duration, false);
    }

    function _register(bytes32 node, bytes32 label, address owner,
        uint duration, bool updateRegistry) internal live(node) onlyController(node) returns (uint) {
        require(block.timestamp + duration + GRACE_PERIOD > block.timestamp + GRACE_PERIOD); // Prevent future overflow

        uint256 id = _tokenID(node, label);
        require(available(id));

        expiries[id] = block.timestamp + duration;
        if (_exists(id)) {
            // Name was previously owned, and expired
            _burn(id);
        }
        _mint(owner, id);
        if (updateRegistry) {
            ens.setSubnodeOwner(node, label, owner);
        }

        emit NameRegistered(node, label, owner, block.timestamp + duration);

        return block.timestamp + duration;
    }

    function renew(bytes32 node, bytes32 label, uint duration) external override live(node) onlyController(node) returns (uint) {
        uint256 id = _tokenID(node, label);
        require(expiries[id] + GRACE_PERIOD >= block.timestamp); // Name must be registered here or in grace period
        require(expiries[id] + duration + GRACE_PERIOD > duration + GRACE_PERIOD); // Prevent future overflow

        expiries[id] += duration;
        emit NameRenewed(node, label, expiries[id]);
        return expiries[id];
    }

    /**
     * @dev Reclaim ownership of a name in ENS, if you own it in the registrar.
     */
    function reclaim(bytes32 node, bytes32 label, address owner) external override live(node) {
        uint256 id = _tokenID(node, label);
        require(_isApprovedOrOwner(msg.sender, id));
        ens.setSubnodeOwner(node, label, owner);
    }

    function supportsInterface(bytes4 interfaceID) public override(ERC721, IERC165) view returns (bool) {
        return interfaceID == INTERFACE_META_ID ||
        interfaceID == ERC721_ID ||
        interfaceID == RECLAIM_ID;
    }

    function _tokenID(bytes32 node, bytes32 label) internal pure returns (uint256) {
        return uint256(keccak256(abi.encodePacked(node, label)));
    }
}

// File: src/universal_v2/Access.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.8.4;

import "../universal/UniversalRegistrar.sol";
import "./IExtensionAccess.sol";

abstract contract Access {
    UniversalRegistrar public registrar;

    constructor(UniversalRegistrar _registrar) {
        registrar = _registrar;
    }

    modifier nodeOperator(bytes32 node) {
        require(_isNodeOperator(node, msg.sender), "Caller is not a node operator");
        _;
    }

    modifier nodeApprovedOrOwner(bytes32 node) {
        require(_isNodeApprovedOrOwner(node, msg.sender), "Caller is not a node owner nor approved by owner");
        _;
    }

    function isNodeOperator(bytes32 node, address operator) public view returns (bool) {
        return _isNodeOperator(node, operator);
    }

    function isNodeApprovedOrOwner(bytes32 node, address operator) public view returns (bool) {
        return _isNodeApprovedOrOwner(node, operator);
    }

    function _isNodeOperator(bytes32 node, address addr) internal view returns (bool) {
        address owner = registrar.ownerOfNode(node);
        if (!Address.isContract(owner)) {
            return owner == addr;
        }

        try IERC165(owner).supportsInterface(type(IExtensionAccess).interfaceId) returns (bool supported) {
            if (supported) {
                return IExtensionAccess(owner).isApprovedOrOwner(addr, uint256(node)) ||
                 IExtensionAccess(owner).getOperator(uint256(node)) == addr;
            }
        } catch {}

        return owner == addr;
    }

    function _isNodeApprovedOrOwner(bytes32 node, address addr) internal view returns (bool) {
        address owner = registrar.ownerOfNode(node);
        if (!Address.isContract(owner)) {
            return owner == addr;
        }

        try IERC165(owner).supportsInterface(type(IExtensionAccess).interfaceId) returns (bool supported) {
            if (supported) {
                return IExtensionAccess(owner).isApprovedOrOwner(addr, uint256(node));
            }
        } catch {}

        return owner == addr;
    }
}

// File: src/universal_v2/IExtensionAccess.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.8.4;

interface IExtensionAccess {
    function getOperator(uint256 tokenId) external view returns (address);
    function getOwner(uint256 tokenId) external view returns (address);
    function isApprovedOrOwner(address spender, uint256 tokenId) external view returns (bool);
}