// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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 Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        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);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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: address zero is not a valid owner");
        return _balances[owner];
    }
    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _ownerOf(tokenId);
        require(owner != address(0), "ERC721: invalid token ID");
        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) {
        _requireMinted(tokenId);
        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 token owner or approved for all"
        );
        _approve(to, tokenId);
    }
    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        _requireMinted(tokenId);
        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: caller is not token owner or 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: caller is not token owner or 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 the owner of the `tokenId`. Does NOT revert if token doesn't exist
     */
    function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
        return _owners[tokenId];
    }
    /**
     * @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 _ownerOf(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) {
        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, 1);
        // Check that tokenId was not minted by `_beforeTokenTransfer` hook
        require(!_exists(tokenId), "ERC721: token already minted");
        unchecked {
            // Will not overflow unless all 2**256 token ids are minted to the same owner.
            // Given that tokens are minted one by one, it is impossible in practice that
            // this ever happens. Might change if we allow batch minting.
            // The ERC fails to describe this case.
            _balances[to] += 1;
        }
        _owners[tokenId] = to;
        emit Transfer(address(0), to, tokenId);
        _afterTokenTransfer(address(0), to, tokenId, 1);
    }
    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     * This is an internal function that does not check if the sender is authorized to operate on the token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);
        _beforeTokenTransfer(owner, address(0), tokenId, 1);
        // Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook
        owner = ERC721.ownerOf(tokenId);
        // Clear approvals
        delete _tokenApprovals[tokenId];
        unchecked {
            // Cannot overflow, as that would require more tokens to be burned/transferred
            // out than the owner initially received through minting and transferring in.
            _balances[owner] -= 1;
        }
        delete _owners[tokenId];
        emit Transfer(owner, address(0), tokenId);
        _afterTokenTransfer(owner, address(0), tokenId, 1);
    }
    /**
     * @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, 1);
        // Check that tokenId was not transferred by `_beforeTokenTransfer` hook
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
        // Clear approvals from the previous owner
        delete _tokenApprovals[tokenId];
        unchecked {
            // `_balances[from]` cannot overflow for the same reason as described in `_burn`:
            // `from`'s balance is the number of token held, which is at least one before the current
            // transfer.
            // `_balances[to]` could overflow in the conditions described in `_mint`. That would require
            // all 2**256 token ids to be minted, which in practice is impossible.
            _balances[from] -= 1;
            _balances[to] += 1;
        }
        _owners[tokenId] = to;
        emit Transfer(from, to, tokenId);
        _afterTokenTransfer(from, to, tokenId, 1);
    }
    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {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 an {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 Reverts if the `tokenId` has not been minted yet.
     */
    function _requireMinted(uint256 tokenId) internal view virtual {
        require(_exists(tokenId), "ERC721: invalid token ID");
    }
    /**
     * @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 {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }
    /**
     * @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`.
     * - When `from` is zero, the tokens will be minted for `to`.
     * - When `to` is zero, ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256, /* firstTokenId */
        uint256 batchSize
    ) internal virtual {
        if (batchSize > 1) {
            if (from != address(0)) {
                _balances[from] -= batchSize;
            }
            if (to != address(0)) {
                _balances[to] += batchSize;
            }
        }
    }
    /**
     * @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`.
     * - When `from` is zero, the tokens were minted for `to`.
     * - When `to` is zero, ``from``'s tokens were burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize
    ) internal virtual {}
}
// 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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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 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: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
     * understand this adds an external call which potentially creates a reentrancy vulnerability.
     *
     * 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);
}
// 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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }
    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or 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 {
            _revert(returndata, errorMessage);
        }
    }
    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}
// 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;
    }
}
// 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;
    }
}
// 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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }
    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }
    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }
    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }
    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }
            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                return prod0 / denominator;
            }
            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);
            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////
            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)
                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }
            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.
            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)
                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)
                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }
            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;
            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;
            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256
            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }
    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator,
        Rounding rounding
    ) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }
    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);
        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }
    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }
    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }
    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }
    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10**64) {
                value /= 10**64;
                result += 64;
            }
            if (value >= 10**32) {
                value /= 10**32;
                result += 32;
            }
            if (value >= 10**16) {
                value /= 10**16;
                result += 16;
            }
            if (value >= 10**8) {
                value /= 10**8;
                result += 8;
            }
            if (value >= 10**4) {
                value /= 10**4;
                result += 4;
            }
            if (value >= 10**2) {
                value /= 10**2;
                result += 2;
            }
            if (value >= 10**1) {
                result += 1;
            }
        }
        return result;
    }
    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
        }
    }
    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }
    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;
    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }
    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }
    /**
     * @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] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0;
/// @title Base64
/// @author Brecht Devos - <[email protected]>
/// @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;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12; 
import "@openzeppelin/contracts/utils/Strings.sol";
import "base64-sol/base64.sol";
struct tokenData {
        uint tokenId;
        uint level;
        uint xCoordinate;
        uint yCoordinate;
        int elevation;
        int structureSpaceX;
        int structureSpaceY;
        int structureSpaceZ;
        string zoneName;
        string[10] zoneColors;
        string[9] characterSet;
    }
interface ITerraforms {
    function tokenHeightmapIndices(uint) external view returns(uint256[32][32] memory);
    function tokenSupplementalData(uint) external view returns(tokenData memory);  
    function tokenToPlacement(uint) external view returns(uint256);
\tfunction ownerOf(uint) external view returns(address);
}
interface ITerraformsData {
\tfunction characterSet(uint256, uint256) external view returns(string[9] memory, uint256, uint256, uint256);
}
interface ITerraformsChars {
\tfunction font(uint256) external view returns(string memory);
}
interface IFileStore {
\tfunction readFile(address, string memory) external view returns(string memory);
}
contract AutomataData {
\taddress immutable public terraformsAddress;
\taddress immutable public terraformsDataAddress;
\taddress immutable public terraformsCharsAddress;
\taddress immutable public fileStoreAddress;
\tconstructor(address _terraformsAddress, address _terraformsDataAddress, address _terraformsCharsAddress, address _fileStoreAddress) {
\t\tterraformsAddress = _terraformsAddress;
\t\tterraformsDataAddress = _terraformsDataAddress;
\t\tterraformsCharsAddress = _terraformsCharsAddress;
\t\tfileStoreAddress = _fileStoreAddress;
\t}
   \tfunction getPlacement(uint tokenId) internal view virtual returns(uint256) {
\t\treturn ITerraforms(terraformsAddress).tokenToPlacement(tokenId);
\t}
\tfunction getCharacterSet(uint256 placement, uint256 seed) internal view virtual returns(string[9] memory, uint256, uint256, uint256) {
\t\treturn ITerraformsData(terraformsDataAddress).characterSet(placement, seed);
\t}
\tfunction getFontData(uint256 id) internal view virtual returns(string memory) {
\t\treturn ITerraformsChars(terraformsCharsAddress).font(id);
\t}
\t
\tfunction getFont(uint tokenId) internal view virtual returns(string memory, uint256) {
\t\tuint256 placement = getPlacement(tokenId);
\t\t(,uint256 font,uint256 fontSize,) = getCharacterSet(placement, 10196);
\t\treturn (getFontData(font),fontSize);
    }
    function getTokenHeightmapIndices(uint tokenId) internal view virtual returns(uint256[32][32] memory) {
    \treturn ITerraforms(terraformsAddress).tokenHeightmapIndices(tokenId);
    }
    function getTokenSupplementalData(uint tokenId) internal view virtual returns(tokenData memory) {
    \treturn ITerraforms(terraformsAddress).tokenSupplementalData(tokenId);
    }
\tfunction heightToString(uint256[32][32] memory height) internal view virtual returns(string memory) {
\t\tstring memory combinedString = "[";
\t\tfor (uint256 i = 0; i < 32; i++) {
  \t\t\tfor (uint256 j = 0; j < 32; j++) {
\t\t\t\tcombinedString = string.concat(combinedString,Strings.toString(height[i][j]),",");
  \t\t\t}
\t\t}
\t\tcombinedString = string.concat(combinedString,"]");
\t\treturn combinedString;
\t}
\tfunction getTerraformOwner(uint tokenId) internal view virtual returns(address) {
\t\treturn ITerraforms(terraformsAddress).ownerOf(tokenId);
\t}
\tfunction getLibraries(address addi, string memory lib) internal view virtual returns(string memory) {
\t\treturn IFileStore(fileStoreAddress).readFile(addi, lib);
\t}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12; 
/*          TERRAFORM AUTOMATA
            \\(")/
\t\t\t-( )-
\t\t\t/(_)\\
*/
import "./AutomataData.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
/// @title Terraform Automata, onchain cellular automata using Terraforms as a canvas.
/// @author mozrt
contract TerraformAutomata is ERC721, Ownable, AutomataData {
\tstring public previewURL;
\taddress public immutable EthFS;
    constructor (
\t\taddress _terraformsAddress,
\t\taddress _terraformsDataAddress,
\t\taddress _terraformsCharsAddress,
\t\taddress _fileStoreAddress,
\t\taddress _ethFS,
\t\tstring memory _previewURL
\t) ERC721 (
\t\t"Terraform Automata", "TA"
\t) AutomataData (
\t\t_terraformsAddress, 
\t\t_terraformsDataAddress, 
\t\t_terraformsCharsAddress, 
\t\t_fileStoreAddress
\t) {
\t\tEthFS = _ethFS;
\t\tpreviewURL = _previewURL;
    }
    mapping(uint256 => string) public scripts;
\tfunction firstHtml() internal view virtual returns(string memory) {
        string memory startURL = "<html> <head> <meta charset='UTF-8'> <script type='text/javascript+gzip' src='data:text/javascript;base64,";
        string memory interURL = "'></script> <script src='data:text/javascript;base64,";
        string memory lib = getLibraries(EthFS,"p5-v1.5.0.min.js.gz");
\t\tstring memory compression = getLibraries(EthFS,"gunzipScripts-0.0.1.js");
        return string.concat(startURL,lib,interURL,compression);
    }
\tfunction getVars(uint tokenId) internal view virtual returns(string memory) {
\t\tuint256[32][32] memory heightmap = getTokenHeightmapIndices(tokenId);
\t\tstring[10] memory zone = getTokenSupplementalData(tokenId).zoneColors;
\t\tstring[9] memory biome = getTokenSupplementalData(tokenId).characterSet;
\t\t(string memory font, uint256 fontSize) = getFont(tokenId);
\t\tstring memory zoneString = string(abi.encodePacked("; const zone = ['", zone[0], "','", zone[1], "','", zone[2], "','", zone[3], "','", zone[4], "','", zone[5], "','", zone[6], "','", zone[7], "','", zone[8], "','", zone[9], "']"));
\t\tstring memory biomeString = string(abi.encodePacked("; const biome = ['", biome[0], "','", biome[1], "','", biome[2], "','", biome[3], "','", biome[4], "','", biome[5], "','", biome[6], "','", biome[7], "','", biome[8], "']"));
\t\tstring memory vars = string(abi.encodePacked("const heightmap = ", heightToString(heightmap), zoneString, biomeString, "; const fontSize = ", Strings.toString(fontSize),"; const font = 'data:application/font-woff2;charset=utf-8;base64,", font, "';"));
\t\treturn vars;
\t}
    function tokenHTML(uint tokenId) public view returns(string memory) {
\t\tstring memory encoded = "data:text/html;base64,";
\t\tstring memory midURL = "'></script> </head> <body> <script>";
\t\tstring memory endURL = "</script> </body> </html>";    
\t\tstring memory secondHtml = string(abi.encodePacked(midURL, getVars(tokenId), checkScript(tokenId), endURL));
\t\tstring memory htmlRaw = string(abi.encodePacked(firstHtml(), secondHtml));
\t\tstring memory html = string(abi.encodePacked(encoded, Base64.encode(bytes(htmlRaw))));
\t\treturn html;
    }
\tfunction tokenURI (uint tokenId) public view override returns (string memory) {
        string memory baseURL = "data:application/json;base64,";
\t\tstring memory URI = Base64.encode(bytes(abi.encodePacked("{\\"description\\": \\"Terraform Automata are onchain cellular automata using Terraforms as a canvas.\\", \\"external_url\\": \\"https://www.terraformautomata.xyz/inventory/", Strings.toString(tokenId),"\\", \\"image\\":\\"", previewURL, Strings.toString(tokenId), "\\", \\"animation_url\\": \\"", tokenHTML(tokenId), "\\", \\"name\\": \\"Automaton ", Strings.toString(tokenId), "\\"}")));\t
\t\treturn string(abi.encodePacked(baseURL, URI));
\t}
\tfunction updateScript(uint[] memory tokenIds, string memory _script) public {
\t\tfor (uint i = 0; i < tokenIds.length; i++) {
\t\t\trequire(msg.sender == ownerOf(tokenIds[i]), "Only the token owner can update the script");
\t\t\tscripts[tokenIds[i]] = _script;
        }
    }
    function getScript(uint256 _tokenId) public view returns (string memory) {
        return scripts[_tokenId];
    }
\tfunction checkScript(uint tokenId) internal view virtual returns(string memory) {
\t\tstring memory script; 
\t\tif (bytes(getScript(tokenId)).length == 0) {
\t\t\tscript = getLibraries(EthFS,"automata.js");
\t\t} else {
\t\t\tscript = getLibraries(EthFS,getScript(tokenId));
\t\t}
        script = string(Base64.decode(script));
\t\treturn script;
\t}
\tfunction updatePreview(string memory newPreviewURL) public returns (string memory) {
\t\trequire(msg.sender == owner(), "Only the contract owner can update the preview URL.");
\t\tpreviewURL = newPreviewURL; 
\t\treturn previewURL;
\t}
\tfunction mint(address holder, uint[] memory tokenIds) public payable {
        uint256 cost = 10000000000000000; 
        uint256 total = cost * tokenIds.length;
        require(msg.value >= total, "Insufficient ETH to mint tokens submitted.");
        for (uint i = 0; i < tokenIds.length; i++) {
            require(getTerraformOwner(tokenIds[i]) == holder, "Terraform owned by another address.");
            require(!_exists(tokenIds[i]), "Token already minted.");
            _safeMint(holder, tokenIds[i]);
        }
    }
    function withdraw(uint256 amount) public {
        require(msg.sender == owner(), "Only the contract owner can withdraw funds.");
        require(address(this).balance >= amount, "Not enough funds in the contract to withdraw.");
        payable(owner()).transfer(amount);
    }\t
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    constructor() {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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 overriden 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 || getApproved(tokenId) == spender || isApprovedForAll(owner, 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);
    }
    /**
     * @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);
    }
    /**
     * @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 of token that is not own");
        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);
    }
    /**
     * @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 {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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`, 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 Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);
    /**
     * @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 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);
    /**
     * @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;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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 `IERC721.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (token/ERC721/extensions/ERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../ERC721.sol";
import "./IERC721Enumerable.sol";
/**
 * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
 * enumerability of all the token ids in the contract as well as all token ids owned by each
 * account.
 */
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
    // Mapping from owner to list of owned token IDs
    mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
    // Mapping from token ID to index of the owner tokens list
    mapping(uint256 => uint256) private _ownedTokensIndex;
    // Array with all token ids, used for enumeration
    uint256[] private _allTokens;
    // Mapping from token id to position in the allTokens array
    mapping(uint256 => uint256) private _allTokensIndex;
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
        return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
        return _ownedTokens[owner][index];
    }
    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _allTokens.length;
    }
    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
        return _allTokens[index];
    }
    /**
     * @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` cannot be the zero address.
     * - `to` cannot be the zero address.
     *
     * 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 override {
        super._beforeTokenTransfer(from, to, tokenId);
        if (from == address(0)) {
            _addTokenToAllTokensEnumeration(tokenId);
        } else if (from != to) {
            _removeTokenFromOwnerEnumeration(from, tokenId);
        }
        if (to == address(0)) {
            _removeTokenFromAllTokensEnumeration(tokenId);
        } else if (to != from) {
            _addTokenToOwnerEnumeration(to, tokenId);
        }
    }
    /**
     * @dev Private function to add a token to this extension's ownership-tracking data structures.
     * @param to address representing the new owner of the given token ID
     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
     */
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        uint256 length = ERC721.balanceOf(to);
        _ownedTokens[to][length] = tokenId;
        _ownedTokensIndex[tokenId] = length;
    }
    /**
     * @dev Private function to add a token to this extension's token tracking data structures.
     * @param tokenId uint256 ID of the token to be added to the tokens list
     */
    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }
    /**
     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
     * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
     * This has O(1) time complexity, but alters the order of the _ownedTokens array.
     * @param from address representing the previous owner of the given token ID
     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
     */
    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).
        uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
        uint256 tokenIndex = _ownedTokensIndex[tokenId];
        // When the token to delete is the last token, the swap operation is unnecessary
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
        }
        // This also deletes the contents at the last position of the array
        delete _ownedTokensIndex[tokenId];
        delete _ownedTokens[from][lastTokenIndex];
    }
    /**
     * @dev Private function to remove a token from this extension's token tracking data structures.
     * This has O(1) time complexity, but alters the order of the _allTokens array.
     * @param tokenId uint256 ID of the token to be removed from the tokens list
     */
    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).
        uint256 lastTokenIndex = _allTokens.length - 1;
        uint256 tokenIndex = _allTokensIndex[tokenId];
        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
        uint256 lastTokenId = _allTokens[lastTokenIndex];
        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
        // This also deletes the contents at the last position of the array
        delete _allTokensIndex[tokenId];
        _allTokens.pop();
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (token/ERC721/extensions/IERC721Enumerable.sol)
pragma solidity ^0.8.0;
import "../IERC721.sol";
/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (utils/Address.sol)
pragma solidity ^0.8.0;
/**
 * @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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.0 (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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
interface ITerraformsData {
    function tokenURI(uint, uint, uint, uint, uint, uint[] memory) 
        external 
        view 
        returns (string memory);
    function tokenHTML(uint, uint, uint, uint, uint[] memory) 
        external 
        view 
        returns (string memory);
    function tokenSVG(uint, uint, uint, uint, uint[] memory) 
        external 
        view 
        returns (string memory);
    function tokenTerrain(uint, uint, uint) 
        external 
        view 
        returns (int[32][32] memory);
    function tokenCharacters(uint, uint, uint, uint, uint[] memory) 
        external 
        view 
        returns (string[32][32] memory);
    function tokenHeightmapIndices(uint, uint, uint, uint, uint[] memory) 
        external 
        view 
        returns (uint[32][32] memory);
    function tokenZone(uint, uint) 
        external 
        view 
        returns (string[10] memory, string memory);
    function characterSet(uint, uint) 
        external 
        view 
        returns (string[9] memory, uint, uint, uint);
    
    function levelAndTile(uint, uint) external view returns (uint, uint);
    
    function tileOrigin(uint, uint, uint, uint, uint) 
        external 
        view 
        returns (int, int, int);
   
    function levelDimensions(uint) external view returns (uint);
    function tokenElevation(uint, uint, uint) external view returns (int);
    function prerevealURI(uint) external view returns (string memory);
}// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/*                                 TERRAFORMS
            . . # # - _ _ > _ _ - - # # # # . + + ^ + . . # - _ } ~ 
            . . # - - _ > } } _ _ _ - - - - # . + + + + . # - _ ~ ~ 
            # # # - _ _ } ~ ~ ~ } > _ _ _ - # . + ^ ^ + . # - _ } ~ 
            # - - - _ > } ~ ~ ~ ~ ~ ~ ~ } _ - . + ^ ^ ^ + . # - > ~ 
            - - _ _ _ > ~ ~ ~ ~ ~ ~ ~ ~ ~ _ - . + ^ ^ ^ ^ + . - _ } 
            _ _ _ _ _ > } ~ ~ ~ ~ ~ ~ ~ ~ _ # . ^ ^ ^ ^ ^ + . # - _ 
            _ > > _ _ _ _ } ~ ~ ~ ~ ~ ~ > - # + ^ ^ ^ ^ ^ + . # - - 
            _ > _ _ - - - _ } ~ ~ ~ } _ _ # . ^ ^ ^ ^ ^ ^ + . # # - 
            _ _ _ - - # # - _ _ > > _ - # . ^ ^ ^ ^ ^ ^ + . # # # # 
            _ _ - # # . # # - - _ _ - # . + ^ ^ ^ ^ ^ + . # # - - # 
            - - # # . . . . # - - - # . . ^ ^ ^ ^ ^ ^ . # - - - - # 
            # # # . + ^ + + . # # # . . + ^ ^ ^ ^ ^ + . # - _ _ - - 
            # # . + ^ ^ ^ ^ + . . . . + ^ ^ ^ ^ ^ ^ . # - - _ _ - # 
            # . . ^ ^ ^ ^ ^ ^ ^ + + + ^ ^ ^ ^ ^ ^ + . # - - - - - # 
            - . . ^ ^ ^ ^ ^ ^ ^ ^ + + ^ ^ ^ ^ + + . # # # - - # # # 
            - # . + ^ ^ ^ ^ ^ ^ ^ ^ + + + + . . # # # # # # # . . . 
            _ - # . + ^ ^ ^ ^ ^ ^ ^ + . . # # - - - # # . . . + + + 
            > - # . + ^ ^ ^ ^ ^ ^ + . . # - _ _ _ _ - # . . + ^ ^ + 
            } _ - # . + ^ ^ ^ ^ ^ + . # - _ > } } _ - # . . + ^ ^ + 
            } _ - # . + ^ ^ ^ ^ ^ + . # - _ } ~ ~ } _ - # . + + ^ + 
            } _ - # . + ^ ^ ^ ^ ^ + . # - _ } ~ ~ ~ } _ - # . + + + 
            > _ - # . + ^ ^ ^ ^ ^ + . # - _ } ~ ~ ~ ~ _ - - # . + + 
            _ _ - # . + ^ ^ ^ ^ ^ + . . # - > ~ ~ ~ ~ > _ - # . + + 
            - - - # # . + ^ ^ ^ ^ ^ + . # - _ } ~ ~ } _ - - # . + ^ 
            - - # # # . . + ^ ^ ^ ^ ^ + . # - _ > } _ _ - # . + ^ ^ 
            # # # # # # # . + ^ ^ ^ ^ ^ + . # - _ _ _ - # . . + ^ ^ 
            . . # # - - - # . + + ^ ^ ^ + . # # - - - # # . + ^ ^ ^ 
            + . # # - - - - # . . + + + + . . # - - - # . + + ^ ^ ^ 
*/
import "./ITerraformsData.sol";
import "./TerraformsPlacements.sol";
/// @title  Land parcels in an onchain 3D megastructure
/// @author xaltgeist, with code direction and consultation from 0x113d
contract Terraforms is TerraformsPlacements {
    
    /// @notice Tokens are pieces of an onchain 3D megastructure. Represents a
    ///         level of the structure
    struct StructureLevel {
        uint levelNumber;
        uint tokensOnLevel;
        int structureSpaceX;
        int structureSpaceY;
        int structureSpaceZ;  
    }
    /// @notice Supplemental token data, including spatial information
    struct TokenData {
        uint tokenId;
        uint level;
        uint xCoordinate;
        uint yCoordinate;
        int elevation;
        int structureSpaceX;
        int structureSpaceY;
        int structureSpaceZ;
        string zoneName;
        string[10] zoneColors;
        string[9] characterSet;
    }
    /// @notice Address of contract managing augmentations
    address public immutable terraformsAugmentationsAddress;
    /// @notice This constant is the length of a token in 3D space
    int public constant TOKEN_SCALE = 6619 * 32;
    /// @notice An append-only list of optional (opt-in) tokenURI upgrades
    address[] public tokenURIAddresses;
    // The array index of the tokenURIAddress for each token
    mapping(uint => uint) tokenToURIAddressIndex;
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * CONSTRUCTOR, FALLBACKS
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    constructor(
        address _terraformsDataAddress, 
        address _terraformsAugmentationsAddress
    ) 
        ERC721("Terraforms", "TERRAFORMS")
        Ownable()
    {
        tokenURIAddresses.push(_terraformsDataAddress);
        terraformsAugmentationsAddress = _terraformsAugmentationsAddress;
    }
 
    receive() external payable {}
    fallback() external payable {}
    
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * FUNCTION MODIFIERS
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    modifier publicMint (uint numTokens) {
        require(numTokens <= 10, "Max 10");
        require(
            tokenCounter <= (SUPPLY - numTokens) &&
            msg.value >= numTokens * PRICE
        );
        _;
    }
    modifier postReveal (uint tokenId) {
        require(seed != 0 && _exists(tokenId));
        _;
    }
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * PUBLIC: MINTING
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    /// @notice Mint tokens
    /// @param numTokens The amount of tokens
    function mint(uint numTokens) 
        public 
        payable 
        nonReentrant 
        publicMint(numTokens)
    {
        require(!mintingPaused, "Paused");
        _mintTokens(msg.sender, numTokens);
    }
    /// @notice Mints tokens if you hold Loot or a mintpass
    /// @dev Queries the Loot contract to check if minter is a holder
    /// @param numTokens The amount of tokens
    function earlyMint(uint numTokens) 
        public 
        payable 
        nonReentrant 
        publicMint(numTokens)
    {
        require(earlyMintActive, "Inactive");
        require(
            balanceOf(msg.sender) <= 100 && // Early wallet limit of 100
            (
                IERC721(
                    0xFF9C1b15B16263C61d017ee9F65C50e4AE0113D7
                ).balanceOf(msg.sender) > 0 || // Check if sender has Loot
                addressToMintpass[msg.sender] != Mintpass.None // Or a mintpass
            )
        );
        _mintTokens(msg.sender, numTokens);
    }
    /// @notice Redeems a mintpass for a dreaming token
    function redeemMintpass() public nonReentrant {
        require(addressToMintpass[msg.sender] == Mintpass.Unused);
        addressToMintpass[msg.sender] = Mintpass.Used;
        _mintTokens(msg.sender, 1);
        dreamers += 1;
        tokenToDreamBlock[tokenCounter] = block.number;
        tokenToStatus[tokenCounter] = Status.OriginDaydream;
        emit Daydreaming(tokenCounter);
    }
    /// @notice Allows owners to claim an allotment of tokens
    /// @param to The recipient address
    /// @param numTokens The amount of tokens
    function ownerClaim(address to, uint numTokens) public onlyOwner {
        require(
            tokenCounter >= SUPPLY && 
            tokenCounter <= (MAX_SUPPLY - numTokens)
        );
        _mintTokens(to, numTokens);
    }
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * PUBLIC: TOKEN DATA
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    /// @notice Returns the token URI
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @dev Token owners can specify which tokenURI address to use
    ///      on a per-token basis using setTokenURIAddress
    /// @return result A base64 encoded JSON string
    function tokenURI(uint256 tokenId) 
        public 
        view
        override
        returns (string memory result) 
    {
        if (seed == 0){ // If tokens aren't revealed yet, return a placeholder
            result = ITerraformsData(tokenURIAddresses[0]).prerevealURI(tokenId);
        } else { // Otherwise, call the token's specified tokenURI address
            result = ITerraformsData(
                tokenURIAddresses[tokenToURIAddressIndex[tokenId]]
            ).tokenURI(
                tokenId,
                uint(tokenToStatus[tokenId]),
                tokenToPlacement[tokenId],
                seed,
                _yearsOfDecay(block.timestamp),
                tokenToCanvasData[tokenId]
            );
        }
    }
    /// @notice Returns HTML containing the token SVG
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @return result A plaintext HTML string with a plaintext token SVG
    function tokenHTML(uint tokenId) 
        public 
        view
        postReveal(tokenId)
        returns (string memory result)
    {
        result = ITerraformsData( // Call the token's specified tokenURI address
            tokenURIAddresses[tokenToURIAddressIndex[tokenId]]
        ).tokenHTML(
            uint(tokenToStatus[tokenId]),
            tokenToPlacement[tokenId],
            seed,
            _yearsOfDecay(block.timestamp),
            tokenToCanvasData[tokenId]
        );
    }
    /// @notice Returns an SVG of the token
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @return A plaintext SVG
    function tokenSVG(uint tokenId) 
        public 
        view 
        postReveal(tokenId)
        returns (string memory) 
    {
        return ITerraformsData( // Call the token's specified tokenURI address
            tokenURIAddresses[tokenToURIAddressIndex[tokenId]]
        ).tokenSVG(
            uint(tokenToStatus[tokenId]),
            tokenToPlacement[tokenId],
            seed,
            _yearsOfDecay(block.timestamp),
            tokenToCanvasData[tokenId]
        );
    }
    /// @notice Returns the characters composing the token image
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @return A 2D array of strings
    function tokenCharacters(uint tokenId) 
        public 
        view
        postReveal(tokenId)
        returns (string[32][32] memory) 
    {
        return ITerraformsData( // Call the token's specified tokenURI address
            tokenURIAddresses[tokenToURIAddressIndex[tokenId]]
        ).tokenCharacters(
            uint(tokenToStatus[tokenId]),
            tokenToPlacement[tokenId],
            seed,
            _yearsOfDecay(block.timestamp),
            tokenToCanvasData[tokenId]
        );
    }
    /// @notice Returns the integer values that determine the token's topography
    /// @dev Values are 16-bit signed ints (i.e., +/- 65536)
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @return A 2D array of signed integers
    function tokenTerrainValues(uint tokenId) 
        public 
        view
        postReveal(tokenId)
        returns (int[32][32] memory) 
    {
        return ITerraformsData( // Call the token's specified tokenURI address
            tokenURIAddresses[tokenToURIAddressIndex[tokenId]]
        ).tokenTerrain(
            tokenToPlacement[tokenId], 
            seed, 
            _yearsOfDecay(block.timestamp)
        );
    }
    /// @notice Returns the stepwise height values visually represented on token
    /// @dev Values range from 0 (highest) to 8 (lowest). 9 indicates empty 
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @return A 2D array of unsigned integers
    function tokenHeightmapIndices(uint tokenId)
        public 
        view
        postReveal(tokenId)
        returns (uint[32][32] memory)
    {
        return ITerraformsData( // Call the token's specified tokenURI address
            tokenURIAddresses[tokenToURIAddressIndex[tokenId]]
        ).tokenHeightmapIndices(
            uint(tokenToStatus[tokenId]),
            tokenToPlacement[tokenId], 
            seed, 
            _yearsOfDecay(block.timestamp),
            tokenToCanvasData[tokenId]
        );
    }
    /// @notice Spatial information about the token structure at a given time
    /// @dev Spatial values used to generate visuals are offset by
    ///      (seed * TOKEN_SCALE). Return values remove that offset
    /// @param timestamp The point in time to visualize the structure
    /// @return structure An array of StructureLevel structs
    function structureData(uint timestamp) 
        public 
        view 
        returns (StructureLevel[20] memory structure)
    {
        ITerraformsData terraformsData = ITerraformsData(tokenURIAddresses[0]);
        uint decay = _yearsOfDecay(timestamp);
        // Structure is offset into 3D space by the seed * the size of a tile
        // That offset is removed for ease of use
        int xyzNormalization = int(seed) * TOKEN_SCALE;
        
        // Temporary variables for loop
        int x;
        int y;
        int z;
        
        for (uint i; i < 20; i++){ 
            // Get XYZ origin for 0,0 tile on each level
            (x, y, z) = terraformsData.tileOrigin(i, 0, seed, decay, timestamp);
            
            // Add level to result array
            structure[i] = StructureLevel(
                i + 1, // Adjust level from zero-index
                terraformsData.levelDimensions(i) ** 2, // n Tokens == edge^2
                x - xyzNormalization,
                y - xyzNormalization,
                z - xyzNormalization                
            );
        }
        return structure;
    }
    /// @notice Data re: a token's visual composition and location on structure
    /// @dev Spatial values used to generate visuals are offset by
    ///      (seed * TOKEN_SCALE). Return values remove that offset
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @return result A TokenData struct
    function tokenSupplementalData(uint tokenId) 
        public 
        view
        postReveal(tokenId)
        returns (TokenData memory result) 
    {
        ITerraformsData terraformsData = ITerraformsData(
            tokenURIAddresses[tokenToURIAddressIndex[tokenId]]
        );
        // Structure is offset into 3D space by the seed * the size of a tile
        // That offset is removed for ease of use
        int xyzNormalization = int(seed) * TOKEN_SCALE;   
        (uint level, uint tile) = terraformsData.levelAndTile(
            tokenToPlacement[tokenId], 
            seed
        );
        uint dimensions = terraformsData.levelDimensions(level);
        
        result.elevation = terraformsData.tokenElevation(level, tile, seed);
        (
            result.structureSpaceX, 
            result.structureSpaceY, 
            result.structureSpaceZ
        ) = terraformsData.tileOrigin(
            level, 
            tile, 
            seed, 
            _yearsOfDecay(block.timestamp),
            block.timestamp
        );
        (result.zoneColors, result.zoneName) = terraformsData.tokenZone(
            tokenToPlacement[tokenId], 
            seed
        );
        (result.characterSet, , , ) = terraformsData.characterSet(
            tokenToPlacement[tokenId], seed
        );
        result.level = level + 1; // Adjust from zero-index
        result.xCoordinate = tile % dimensions;
        result.yCoordinate = tile / dimensions;
        result.structureSpaceX -= xyzNormalization;
        result.structureSpaceY -= xyzNormalization;
        result.structureSpaceZ -= xyzNormalization;
        return result;
        
    }
    /// @notice Token owner can set tokenURI address for an array of tokens
    /// @param tokens The tokens to set to the new URI address
    /// @param index The index of the new tokenURIAddress in tokenURIAddresses
    function setTokenURIAddress(uint[] memory tokens, uint index) public {
        require(index < tokenURIAddresses.length);
        for(uint i; i < tokens.length; i++){
            require(msg.sender == ownerOf(tokens[i]));
            tokenToURIAddressIndex[tokens[i]] = index;
        }
    }
    /// @notice Owner can add new opt-in tokenURI address
    /// @param newAddress The new tokenURI address
    function addTokenURIAddress(address newAddress) public onlyOwner {
        tokenURIAddresses.push(newAddress);
    }
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * INTERNAL: MINTING
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    /// @notice Internal function for minting tokens
    /// @param to The recipient address
    /// @param numTokens The amount of tokens
    function _mintTokens(address to, uint numTokens) internal {
        uint base = tokenCounter;
        while (tokenCounter < base + numTokens) {
            _shufflePlacements();
            tokenCounter += 1;
            _safeMint(to, tokenCounter);
        }
    }
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * INTERNAL: TOKEN DATA
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    /// @notice Returns the amount of decay to apply to the token structure
    /// @dev Decay begins unless there are enough dreamers
    /// @param timestamp The point in time for determining decay
    /// @return The years of decay affecting the tokens
    function _yearsOfDecay(uint timestamp) internal view returns (uint) {
        uint decayBegins = REVEAL_TIMESTAMP + dreamers * 3_650 days;
        if (dreamers >= 500 || timestamp <= decayBegins) {
            return 0;
        } else {
            return (timestamp - decayBegins) / 365 days;
        }
    }
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * LICENSES
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
FOR UPDATES AND ADDITIONAL INFO ABOUT THE LICENSE RELATING TO THIS PROJECT,
SEE WWW.MATHCASTLES.XYZ
AS OF DEPLOY TIME, THE FOLLOWING LICENSE APPLIES TO THIS PROJECT'S ARTWORK
(EXCLUDING ITS FONTS, WHICH ARE COVERED BY THE LICENSE BELOW THIS LICENSE):
# License - Terraforms by Mathcastles
## 1. Purpose
This license (this “**License**”) was created by Mathcastles LLC 
("**Mathcastles**") to promote the interests of and to foster the innovations 
and creativity of NFT collectors and developers. This License seeks to maximize 
the rights of owners to enjoy and profit from the NFTs they own while preserving 
their value for future owners.
## 2. Summary
### 2.A. Owners of Terraforms NFTs can:
1. Display, reproduce and commercialize the Art (defined below) while they own 
the NFTs, with optional attribution.
2. Develop and commercialize derivative works of the Art, both physical and 
virtual (including, for example, fractionalizations) while they own the 
corresponding NFTs, with optional attribution.
3. Continue to commercialize derivative works of the Art of NFTs they previously 
owned if the derivative works were developed and released while they owned the 
NFTs.
4. Use the Art for personal, non-commercial use.
5. Display the Art on marketplaces for buying and selling their NFTs.
6. Use their NFTs to interact with websites and apps, including decentralized 
apps (dapps).
### 2.B. Owners of Terraforms NFTs cannot:
1. Transfer the rights granted by this license to anyone, or to the public.
2. Commercialize the Art of NFTs they do not currently own, or develop or 
release derivative works of the Art of NFTs they do not currently own.
3. Register or attempt to enforce any intellectual property rights in any 
derivative work of the Art, in a manner that would limit a past, present or 
future owner from commercializing the Art or creating derivative works in 
accordance with this license.
### 2.C. Additional Terms for Commercial Enterprises:
If an owner, together with its direct and indirect affiliates, operates an 
enterprise that has ten (10) or more employees or US$5,000,000 or more per year 
in gross receipts, then the owner cannot make more than US$500,000 in total 
annual revenue from commercializing its NFTs or derivatives without separate 
written permission from Mathcastles.
## 3. Terms
### 3.A. Definitions
“**Art**” means any art, design, and related underlying data that may be 
associated with an NFT that you Own.
"**Commercial Enterprise**" means any natural person, incorporated entity, or 
other commercial venture, together with its direct and indirect owners and 
affiliates, which during any of the last three calendar years had, in the 
aggregate, (i) ten (10) or more employees or (ii) the equivalent of 
US$5,000,000 or more per year in gross receipts.
"**Creator**" means Mathcastles LLC.
“**Derivatives**” means extensions or derivative works created by you of 
Purchased NFTs that include, or contain or are derived from the Art.
"**NFT**" means an Ethereum blockchain-tracked non-fungible token created from
this contract.
“**Own**” means, with respect to an NFT, an NFT that you have purchased or 
otherwise rightfully acquired, where proof of such purchase is recorded on the 
relevant blockchain, and that you continue to possess.
“**Purchased NFT**” means an NFT that you Own.
“**Third Party IP**” means any third party patent rights (including, without 
limitation, patent applications and disclosures), copyrights, trade secrets, 
trademarks, know-how or any other intellectual property rights recognized in any 
country or jurisdiction in the world.
### 3.B. Ownership
You acknowledge and agree that Creator (or, as applicable, its licensors) owns 
all legal right, title and interest in and to the Art, and all intellectual 
property rights therein. The rights that you have in and to the Art are limited 
to those described in this License. Creator reserves all rights in and to the 
Art not expressly granted to you in this License.
### 3.C. License
#### 3.C.1. General Use
Subject to your continued compliance with the terms of this License, Creator 
grants you a worldwide, non-exclusive, non-transferable, royalty-free license to 
use, copy, and display the Art for your Purchased NFTs, along with any 
Derivatives that you choose to create or use, solely for the following purposes:
1. for your own personal, non-commercial use;
2. as part of a marketplace that permits the purchase and sale of your NFTs; or
3. as part of a third party website or application that permits the inclusion, 
involvement, or participation of your NFTs.
#### 3.C.2. Commercial and Derivative Use
Creator grants you a limited, worldwide, non-exclusive, non-transferable license 
to use, copy, and display the Art for your Purchased NFTs for the purpose of 
commercializing your own physical or virtual merchandise that includes, 
contains, or consists of the Art for your Purchased NFTs (“**Commercial Use**”) 
and to commercialize Derivatives of your Purchased NFTs ("**Derivative Use**"), 
provided that if you are a Commercial Enterprise, such Commercial Use and 
Derivative Use do not in the aggregate result in you earning more than Five 
Hundred Thousand U.S. Dollars (US$500,000) in gross revenue in any year. For 
the sake of clarity, nothing in this Section 3.C.2. will be deemed to restrict 
you from:
1. owning or operating a marketplace that permits the use and sale of NFTs 
generally;
2. owning or operating a third party website or application that permits the 
inclusion, involvement, or participation of NFTs generally; or
3. earning revenue from any of the foregoing, even where such revenue is in 
excess of US$500,000 per year.
### 3.D. Restrictions
#### 3.D.1. No Additional IP Rights
You may not attempt to trademark, copyright, or otherwise acquire additional 
intellectual property rights in the Art, nor permit any third party to do or 
attempt to do any of the foregoing, without Creator’s express prior written 
consent; _provided_, that this section does not prohibit an owner from acquiring 
intellectual property rights in a derivative work.
#### 3.D.2. No License Granted as to Third Party IP
To the extent that Art associated with your Purchased NFTs contains Third Party 
IP (for example, licensed intellectual property from a third party artist, 
company, or public figure), you understand and agree as follows:
1. that the inclusion of any Third Party IP in the Art does not grant you any 
rights to use such Third Party IP except as it is incorporated in the Art;
2. that, depending on the nature of the license granted from the owner of the 
Third Party IP, Creator may need to pass through additional restrictions on your 
ability to use the Art; and
3. to the extent that Creator informs you of such additional restrictions in 
writing (including by email), you will be responsible for complying with all 
such restrictions from the date that you receive the notice, and that failure 
to do so will be deemed a breach of this license.
The restrictions in this Section 3.D. will survive the expiration or termination 
of this License.
### 3.E. Limitations of License
Except for the right to Derivative Use described in Section 3.C.2., the license 
granted in this Section 3 applies only to the extent that you continue to Own 
the applicable Purchased NFT. If at any time you sell, trade, donate, give away, 
transfer, or otherwise dispose of your Purchased NFT for any reason, the license 
granted in Section 3 (except for the right to Derivative Use described in 
Section 3.C.2.) will immediately expire with respect to those NFTs without the 
requirement of notice, and you will have no further rights in or to the Art for 
those NFTs. The right to Derivative Use described in Section 3.C.2. shall 
continue indefinitely for so long as you comply with this License.
If you are a Commercial Enterprise and you exceed the US$500,000 limitation on 
annual gross revenue set forth in Section 3.C.2. above, you will be in breach of 
this License, and must send an email to Creator at [email protected] 
within fifteen (15) days, with the phrase “NFT License - Commercial Use” in the 
subject line, requesting a discussion with Creator regarding entering into a 
broader license agreement or obtaining an exemption (which may be granted or 
withheld in Creator’s sole and absolute discretion).
If you exceed the scope of the license grant in this Section 3 without entering 
into a broader license agreement with or obtaining an exemption from Creator, 
you acknowledge and agree that:
1. you are in breach of this License;
2. in addition to any remedies that may be available to Creator at law or in 
equity, the Creator may immediately terminate this License, without the 
requirement of notice; and
3. you will be responsible to reimburse Creator for any costs and expenses 
incurred by Creator during the course of enforcing the terms of this License 
against you.
********************************************************************************
THE FOLLOWING LICENSE APPLIES TO THE FONTS USED IN THIS PROJECT
Copyright 2018 The Noto Project Authors (github.com/googlei18n/noto-fonts)
This Font Software is licensed under the SIL Open Font License,
Version 1.1.
This license is copied below, and is also available with a FAQ at:
http://scripts.sil.org/OFL
-----------------------------------------------------------
SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
-----------------------------------------------------------
PREAMBLE
The goals of the Open Font License (OFL) are to stimulate worldwide
development of collaborative font projects, to support the font
creation efforts of academic and linguistic communities, and to
provide a free and open framework in which fonts may be shared and
improved in partnership with others.
The OFL allows the licensed fonts to be used, studied, modified and
redistributed freely as long as they are not sold by themselves. The
fonts, including any derivative works, can be bundled, embedded,
redistributed and/or sold with any software provided that any reserved
names are not used by derivative works. The fonts and derivatives,
however, cannot be released under any other type of license. The
requirement for fonts to remain under this license does not apply to
any document created using the fonts or their derivatives.
DEFINITIONS
"Font Software" refers to the set of files released by the Copyright
Holder(s) under this license and clearly marked as such. This may
include source files, build scripts and documentation.
"Reserved Font Name" refers to any names specified as such after the
copyright statement(s).
"Original Version" refers to the collection of Font Software
components as distributed by the Copyright Holder(s).
"Modified Version" refers to any derivative made by adding to,
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components of the Original Version, by changing formats or by porting
the Font Software to a new environment.
"Author" refers to any designer, engineer, programmer, technical
writer or other person who contributed to the Font Software.
PERMISSION & CONDITIONS
Permission is hereby granted, free of charge, to any person obtaining
a copy of the Font Software, to use, study, copy, merge, embed,
modify, redistribute, and sell modified and unmodified copies of the
Font Software, subject to the following conditions:
1) Neither the Font Software nor any of its individual components, in
Original or Modified Versions, may be sold by itself.
2) Original or Modified Versions of the Font Software may be bundled,
redistributed and/or sold with any software, provided that each copy
contains the above copyright notice and this license. These can be
included either as stand-alone text files, human-readable headers or
in the appropriate machine-readable metadata fields within text or
binary files as long as those fields can be easily viewed by the user.
3) No Modified Version of the Font Software may use the Reserved Font
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4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
Software shall not be used to promote, endorse or advertise any
Modified Version, except to acknowledge the contribution(s) of the
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5) The Font Software, modified or unmodified, in part or in whole,
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remain under this license does not apply to any document created using
the Font Software.
TERMINATION
This license becomes null and void if any of the above conditions are
not met.
DISCLAIMER
THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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OTHER DEALINGS IN THE FONT SOFTWARE.
*/// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
/// @title Admin functions and access control for the Terraforms contract
/// @author xaltgeist
abstract contract TerraformsAdmin is ERC721Enumerable, ReentrancyGuard, Ownable{
    
    enum Mintpass {None, Unused, Used}
    
    /// @notice Sale information
    uint public constant PRICE = 0.16 ether; 
    uint public constant MAX_SUPPLY = 11_104;
    uint public constant OWNER_ALLOTMENT = 1_200;
    uint public constant SUPPLY = MAX_SUPPLY - OWNER_ALLOTMENT;
    uint public tokenCounter;
    bool public earlyMintActive;
    bool public mintingPaused = true;
    mapping(address => Mintpass) addressToMintpass;
    
    /// @notice Toggles whether claimers can mint (other than through early)
    function togglePause() public onlyOwner {
        mintingPaused = !mintingPaused;
    }
    /// @notice Toggles whether Loot and mintpass holders can mint early
    function toggleEarly() public onlyOwner {
        earlyMintActive = !earlyMintActive;
    }
    /// @notice Sets the addresses of mintpass holders
    function setMintpassHolders(address[] memory mintpassHolders) 
        public
        onlyOwner 
    {
        for (uint i; i < mintpassHolders.length; i ++){
            addressToMintpass[mintpassHolders[i]] = Mintpass.Unused;
        }
    }
    /// @notice Transfers the contract balance to the owner
    function withdraw() public onlyOwner {
        (bool success, ) = owner().call{value: address(this).balance}("");
        require(success);
    }
}// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./TerraformsAdmin.sol";
/// @author xaltgeist
/// @title Tokens can be transformed to painter apps or terraformed
abstract contract TerraformsDreaming is TerraformsAdmin {
    
    /// Tokens can have one of five statuses:
    /// 0. Terrain:       The default visual presentation
    /// 1. Daydream:      A blank token that users can paint on
    /// 2. Terraformed:   A terraformed token with user-supplied visuals
    /// 3. OriginDaydream:    A daydream token that was dreaming on mint
    /// 4. OriginTerraformed: A terraformed OriginDaydream token
    enum Status {
        Terrain, 
        Daydream, 
        Terraformed, 
        OriginDaydream, 
        OriginTerraformed
    }
    
    uint public dreamers; // Number of dreaming tokens
    mapping(uint => uint) public tokenToDreamBlock;
    mapping(uint => Status) public tokenToStatus;
    mapping(uint => uint[]) public tokenToCanvasData;
    mapping(uint => address) public tokenToDreamer;
    mapping(uint => address) public tokenToAuthorizedDreamer;
    event Daydreaming(uint tokenId);
    event Terraformed(uint tokenId, address terraformer);
    /// @notice *PERMANENTLY* sets a token to dreaming, changing its attributes
    /// @dev A minimum amount must be dreaming to prevent collapse
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    function enterDream(uint tokenId) public {
        require(msg.sender == ownerOf(tokenId));
        tokenToDreamBlock[tokenId] = block.number;
        if (tokenToStatus[tokenId] == Status.Terrain){
            dreamers += 1;
        }
        if (uint(tokenToStatus[tokenId]) > 2){
            tokenToStatus[tokenId] = Status.OriginDaydream;
        } else {
            tokenToStatus[tokenId] = Status.Daydream;   
        }
        emit Daydreaming(tokenId);
    }
    /// @notice Authorizes an address to commit canvas data to a dreaming token
    /// @dev To revoke, call authorizeDreamer with address(0).
    /// NOTE Authorization is automatically revoked on transfer.
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @param authorizedDreamer The address authorized to commit canvas data
    function authorizeDreamer(uint tokenId, address authorizedDreamer) public {
        require(msg.sender == ownerOf(tokenId));
        tokenToAuthorizedDreamer[tokenId] = authorizedDreamer;
    }
    /// @notice Sets a dreaming token's canvas to a user-supplied drawing
    /// @dev The drawing data is encoded as 16 uints. The 64 least significant
    ///      digits of each uint represent values from 0-9 at successive x,y
    ///      positions on the token, beginning in the top left corner. Each 
    ///      value will be obtained from left to right by taking the current 
    ///      uint mod 10, and then advancing to the next digit until all uints 
    ///      are exhausted. 
    /// @param tokenId The tokenId, from 1 to tokenCounter (max MAX_SUPPLY)
    /// @param dream An array of 16 uints, each representing the heightmap 
    ///              indices of two rows
    function commitDreamToCanvas(uint tokenId, uint[16] memory dream) public {
        require(
            (
                msg.sender == ownerOf(tokenId) ||
                msg.sender == tokenToAuthorizedDreamer[tokenId]
            ) &&
            uint(tokenToStatus[tokenId]) % 2 == 1
        );
        tokenToDreamer[tokenId] = msg.sender;
        tokenToStatus[tokenId] = Status(uint(tokenToStatus[tokenId]) + 1);
        tokenToCanvasData[tokenId] = dream;
        emit Terraformed(tokenId, msg.sender);
    }
    /// @notice On transfer, revokes authorization to commit dreaming token
    function _beforeTokenTransfer(address from, address to, uint256 tokenId)
        internal 
        virtual 
        override
    {
        super._beforeTokenTransfer(from, to, tokenId);
        tokenToAuthorizedDreamer[tokenId] = address(0);
    }
}// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./TerraformsDreaming.sol";
/// @author xaltgeist
/// @title Pseudorandom token placements
abstract contract TerraformsPlacements is TerraformsDreaming {
    
    uint public seed; // Seed derived from blockhash, used to rotate placements
    mapping(uint => uint) public tokenToPlacement; // Pseudorandom placements
    uint public immutable REVEAL_TIMESTAMP; // Token reveal (if not minted out)
    uint[MAX_SUPPLY] placementShuffler; // Used for pseudorandom placements
    event TokensRevealed(uint timestamp, uint seed);
    constructor (){
        REVEAL_TIMESTAMP = block.timestamp + 7 days;
    }
    /// @notice Finalizes the seed used to randomize token placement
    /// @dev Requires that seed isn't set, and that either the supply is minted
    ///      or a week has elapsed since deploy
    function setSeed() public {
        require(
            seed == 0 && 
            (tokenCounter >= SUPPLY || block.timestamp >= REVEAL_TIMESTAMP)
        );
        seed = uint(blockhash(block.number - 1)) % MAX_SUPPLY;
        if (seed == 0) { // Don't allow seed to be 0
            seed = 1;
        }
        emit TokensRevealed(block.timestamp, seed);
    }
    /// @notice Creates initial placements to determine a token's level/tile
    /// @dev Initial pseudorandom placements will be rotated by the seed
    function _shufflePlacements() internal {
        uint max = MAX_SUPPLY - tokenCounter;
        uint result;
        uint next = uint(
            keccak256(
                abi.encodePacked(
                    tokenCounter, 
                    blockhash(block.number - 1), 
                    block.difficulty
                )
            )
        ) % max;
        
        if (placementShuffler[next] == 0) {
            result = next;
        } else {
            result = placementShuffler[next];
        }
        if (placementShuffler[max - 1] != 0) {
            placementShuffler[next] = placementShuffler[max - 1];            
        } else {
            placementShuffler[next] = max - 1;
        }
        
        tokenToPlacement[tokenCounter + 1] = result;
    }
}