Markov's Dream: Orb (lite)

// SPDX-License-Identifier: MIT

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
pragma solidity ^0.8.13;

/// @title Base64
/// @author Brecht Devos - <brecht@loopring.org>
/// @notice Provides a function for encoding some bytes in base64
library Base64 {
    string internal constant TABLE =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

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

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

        // 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) {

            } {
                dataPtr := add(dataPtr, 3)

                // read 3 bytes
                let input := mload(dataPtr)

                // write 4 characters
                mstore(
                    resultPtr,
                    shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                )
                resultPtr := add(resultPtr, 1)
                mstore(
                    resultPtr,
                    shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                )
                resultPtr := add(resultPtr, 1)
                mstore(
                    resultPtr,
                    shl(248, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                )
                resultPtr := add(resultPtr, 1)
                mstore(
                    resultPtr,
                    shl(248, 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;
    }
}

// SPDX-License-Identifier: MIT

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

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

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 {
        require(operator != _msgSender(), "ERC721: approve to caller");

        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_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 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

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;

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

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

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
pragma solidity ^0.8.13;

import './SVG.sol';
import './Utils.sol';
import '@openzeppelin/contracts/access/Ownable.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/token/ERC721/ERC721.sol';
import './Base64.sol';

struct Coord {
  uint256 x;
  uint256 y;
}

struct Size {
  uint256 width;
  uint256 height;
}

struct SquirclePoints {
  Coord a;
  Coord b;
  Coord c;
  Coord d;
  uint256 pull;
}

contract Orb is ERC721, Ownable {
  uint16 private _tokenTokenIdMax = 769;
  uint256 private _price = 0.0 ether;
  bool private _paused = true;
  bool private _enableListMintPaused = true;
  address payable private adminWallet =
    payable(0x9011Eb570D1bE09eA4d10f38c119DCDF29725c41);

  uint16 private constant CANVAS_SIZE = 1200;
  mapping(address => uint8) private _enableList;
  string constant JSON_PROTOCOL_URI = 'data:application/json;base64,';
  string constant SVG_PROTOCOL_URI = 'data:image/svg+xml;base64,';
  uint256 private _lastMintedTokenId = 0;

  mapping(uint256 => uint256) public seeds;

  constructor() ERC721("Markov's Dream: Orb (lite)", 'MDO') {}

  function getMaxRings(uint256 seed) private pure returns (uint8) {
    return 10 + utils.randomUint8(seed + 0xff0ff) / 24;
  }

  function getMargin(uint256 seed) private pure returns (uint8) {
    return uint8(CANVAS_SIZE / 2 / getMaxRings(seed));
  }

  function squircle(
    Coord memory position,
    Size memory size,
    uint8 inst,
    uint256 seed
  ) private pure returns (string memory) {
    if (inst > getMaxRings(seed)) return '';
    SquirclePoints memory points = calculatePoints(size.width, seed);

    return
      string.concat(
        svg.el(
          'path',
          string.concat(
            svg.prop(
              'fill',
              string.concat(
                'url("#p',
                utils.uint2str((inst - 1) % getPaletteSize(seed)),
                '")'
              )
            ),
            svg.prop(
              'd',
              string.concat(
                'M',
                coordString(points.a.x + position.x, points.a.y + position.y),
                _squircleC(position, points),
                _squircleS(position, points)
              )
            )
          )
        ),
        nestedSquircle(size.width, inst, inst == 1 ? 0 : getMargin(seed), seed)
      );
  }

  function getPaletteSize(uint256 seed) public pure returns (uint8) {
    uint8 count = utils.randomUint8(seed + 666) / 8 + 1;
    if (count > getMaxRings(seed)) return getMaxRings(seed);
    return count;
  }

  function nestedSquircle(
    uint256 size,
    uint8 inst,
    uint256 margin,
    uint256 seed
  ) private pure returns (string memory) {
    uint256 newSize = size - getMargin(seed) * 2;
    return
      svg.el(
        'svg',
        string.concat(
          svg.prop('x', utils.uint2str(margin)),
          svg.prop('y', utils.uint2str(margin))
        ),
        svg.el(
          'g',
          '',
          string.concat(
            animateTransform(newSize, seed, inst),
            squircle(
              Coord({x: getMargin(seed), y: getMargin(seed)}),
              Size({width: newSize, height: newSize}),
              inst + 1,
              seed
            )
          )
        )
      );
  }

  function animateTransform(
    uint256 width,
    uint256 seed,
    uint8 inst
  ) private pure returns (string memory) {
    uint256 center = (width + getMargin(seed) * 2) / 2;
    string memory centerString = utils.uint2str(center);
    uint8 duration = utils.randomUint8(seed / inst) / 4 + 8;

    return
      string.concat(
        '<animateTransform attributeName="transform" type="rotate" from="0 ',
        centerString,
        ' ',
        centerString,
        '" to="',
        utils.randomUint8(seed + 1001 + inst) > 128 ? '-' : '',
        '360 ',
        centerString,
        ' ',
        centerString,
        '" dur="',
        utils.uint2str(duration),
        's" repeatCount="indefinite"/>'
      );
  }

  function _squircleC(Coord memory position, SquirclePoints memory points)
    private
    pure
    returns (string memory)
  {
    return
      string.concat(
        'C',
        coordString(points.a.x + position.x, points.pull + position.y),
        coordString(points.pull + position.x, points.b.y + position.y),
        coordString(points.b.x + position.x, points.b.y + position.y)
      );
  }

  function _squircleS(Coord memory position, SquirclePoints memory points)
    private
    pure
    returns (string memory)
  {
    return
      string.concat(
        'S',
        coordString(points.c.x + position.x, points.pull + position.y),
        coordString(points.c.x + position.x, points.c.y + position.y),
        coordString(
          points.c.x - points.pull + position.x,
          points.d.y + position.y
        ),
        coordString(points.d.x + position.x, points.d.y + position.y),
        coordString(
          points.a.x + position.x,
          points.d.y - points.pull + position.y
        ),
        coordString(points.a.x + position.x, points.a.y + position.y)
      );
  }

  function getPullDiv(uint256 seed) private pure returns (uint8) {
    if (utils.randomUint8(seed + 0x8f0ff) > 220) {
      return 4;
    }
    uint8 rings = getMaxRings(seed);
    if (rings > 20) {
      return 5;
    }
    if (rings > 13) {
      return 6;
    }
    return 7;
  }

  function curveString(uint256 seed) private pure returns (string memory) {
    uint8 curve = getPullDiv(seed);
    if (curve == 4) {
      return 'light';
    }
    if (curve == 5) {
      return 'mild';
    }
    if (curve == 6) {
      return 'strong';
    }
    return 'extreme';
  }

  function calculatePoints(uint256 size, uint256 seed)
    private
    pure
    returns (SquirclePoints memory)
  {
    return
      SquirclePoints({
        a: Coord({x: 0, y: size / 2}),
        b: Coord({x: size / 2, y: 0}),
        c: Coord({x: size, y: size / 2}),
        d: Coord({x: size / 2, y: size}),
        pull: size / getPullDiv(seed)
      });
  }

  function coordString(uint256 x, uint256 y)
    private
    pure
    returns (string memory)
  {
    return string.concat(utils.uint2str(x), ',', utils.uint2str(y), ' ');
  }

  function defs(uint256 seed) private pure returns (string memory) {
    return svg.el('defs', '', linearGradientRefs(seed));
  }

  function linearGradientRefs(uint256 seed)
    private
    pure
    returns (string memory)
  {
    string memory result = '';
    uint8[3] memory bias = getBias(seed);
    for (uint8 i = 0; i < getMaxRings(seed); i++) {
      result = string.concat(result, linearGradientRef(i, seed, bias));
    }
    return result;
  }

  function getBias(uint256 seed) private pure returns (uint8[3] memory) {
    uint8 bias = utils.randomUint8(seed + 11);
    if (bias > 191) return [10, 20, 16]; // warm
    if (bias > 127) return [13, 13, 10]; // cold
    if (bias > 64) return [10, 10, 10]; // unbiased
    return [10, 13, 12]; // reddish
  }

  function getBiasString(uint256 seed) public pure returns (string memory) {
    uint8 bias = utils.randomUint8(seed + 11);
    if (bias > 191) return 'horny';
    if (bias > 127) return 'deep';
    if (bias > 64) return 'innocent';
    return 'vivid';
  }

  function randomColor(uint256 seed, uint8[3] memory bias)
    private
    pure
    returns (string memory)
  {
    return
      string.concat(
        'rgba(',
        utils.uint2str((utils.randomUint8(seed) / bias[0]) * 10),
        ',',
        utils.uint2str((utils.randomUint8(seed + 10) / bias[1]) * 10),
        ',',
        utils.uint2str((utils.randomUint8(seed + 20) / bias[2]) * 10),
        ',0.',
        utils.uint2str(utils.randomUint8(seed + 30)),
        ')'
      );
  }

  function linearGradientRef(
    uint8 id,
    uint256 seed,
    uint8[3] memory bias
  ) private pure returns (string memory) {
    return
      svg.el(
        'linearGradient',
        string.concat(
          svg.prop('id', string.concat('p', utils.uint2str(id))),
          svg.prop('x2', '0'),
          svg.prop('y2', '1')
        ),
        string.concat(
          svg.el(
            'stop',
            string.concat(
              svg.prop('stop-color', randomColor(seed + 100 + id, bias)),
              svg.prop('offset', '0')
            )
          ),
          svg.el(
            'stop',
            string.concat(
              svg.prop('stop-color', randomColor(seed + 200 + id, bias)),
              svg.prop('offset', '1')
            )
          )
        )
      );
  }

  function render(uint256 seed) public pure returns (string memory) {
    return
      string.concat(
        '<svg xmlns="http://www.w3.org/2000/svg" width="1200" height="1200" viewBox="0 0 1200 1200">',
        defs(seed),
        squircle(
          Coord({x: 0, y: 0}),
          Size({width: CANVAS_SIZE, height: CANVAS_SIZE}),
          1,
          seed
        ),
        '</svg>'
      );
  }

  function getSVG(uint256 seed) public pure returns (string memory) {
    return Base64.encode(abi.encodePacked(render(seed)));
  }

  function example() external pure returns (string memory) {
    return
      render(
        12092617800810096820759526468342665250412819988344321001321974471951203194760
      );
  }

  function tokenURI(uint256 tokenId)
    public
    view
    virtual
    override
    returns (string memory)
  {
    require(
      _exists(tokenId),
      'ERC721Metadata: URI query for nonexistent token'
    );

    bytes memory image = abi.encodePacked(
      SVG_PROTOCOL_URI,
      getSVG(seeds[tokenId])
    );

    bytes memory json = abi.encodePacked(
      '{"name":"',
      'Orb (lite) #',
      utils.uint2str(tokenId),
      '",',
      '"description":"On-chain rotating nested squircles by Harm van den Dorpel, 2022",',
      '"image":"',
      image,
      traitsString(seeds[tokenId]),
      '"}]}'
    );
    return string(abi.encodePacked(JSON_PROTOCOL_URI, Base64.encode(json)));
  }

  function traitsString(uint256 seed) private pure returns (bytes memory) {
    return
      abi.encodePacked(
        '","attributes":[{"trait_type":"Colours","value":"',
        utils.uint2str(getPaletteSize(seed)),
        '"},{"trait_type": "Temperament", "value": "',
        getBiasString(seed),
        '"},{"trait_type":"Rings","value":"',
        utils.uint2str(getMaxRings(seed)),
        '"},{"trait_type":"Curve","value":"',
        curveString(seed)
      );
  }

  function mint(address recipient) external payable {
    require(!_paused, 'not activated yet');
    require(msg.value >= _price, 'send more ether');
    
    _mint(recipient);
    adminWallet.transfer(msg.value);
  }

  function _mint(address recipient) private {
    require(_lastMintedTokenId < _tokenTokenIdMax, 'all minted');
    _lastMintedTokenId = _lastMintedTokenId + 1;
    uint256 sender = uint256(uint160(address(msg.sender)));
    seeds[_lastMintedTokenId] =
      uint256(blockhash(block.number - 1)) +
      sender +
      _lastMintedTokenId;
    _safeMint(recipient, _lastMintedTokenId);
  }

  function setTokenIdMax(uint16 newTokenIdMax) external onlyOwner {
    _tokenTokenIdMax = newTokenIdMax;
  }

  function setPaused(bool newPaused) external onlyOwner {
    _paused = newPaused;
  }

  function setEnableListPaused(bool newPaused) external onlyOwner {
    _enableListMintPaused = newPaused;
  }

  function adminMint(address recipient) external onlyOwner {
    _mint(recipient);
  }

  function updateAdminWallet(address payable _adminWallet) external onlyOwner {
    adminWallet = _adminWallet;
  }

  function setPrice(uint256 newPrice) external onlyOwner {
    _price = newPrice;
  }

  function getPrice() public view returns (uint256) {
    return _price;
  }

  function totalSupply() public view returns (uint256) {
    return _lastMintedTokenId;
  }

  function setEnableListMultiple(address[] memory recipients, uint8 count)
    external
    onlyOwner
  {
    for (uint256 i = 0; i < recipients.length; i++) {
      _enableList[recipients[i]] = count;
    }
  }

  function setEnableList(address recipient, uint8 count) external onlyOwner {
    _enableList[recipient] = count;
  }

  function getEnableList(address recipient) external view returns (uint8) {
    return _enableList[recipient];
  }

  function mintFromEnableList(address recipient) external payable {
    require(!_enableListMintPaused, 'enableList paused');
    require(_enableList[recipient] > 0, 'no credits on enablelist');
    require(msg.value >= _price, 'send more ether');

    _mint(recipient);
    _enableList[recipient] -= 1;
    adminWallet.transfer(msg.value);
  }
}

// SPDX-License-Identifier: MIT

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() {
        _setOwner(_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 {
        _setOwner(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");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

//SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;
import './Utils.sol';

// Core SVG utilitiy library which helps us construct
// onchain SVG's with a simple, web-like API.
library svg {
    /* MAIN ELEMENTS */
    function g(string memory _props, string memory _children)
        internal
        pure
        returns (string memory)
    {
        return el('g', _props, _children);
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT

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
pragma solidity ^0.8.13;

// Core utils used extensively to format CSS and numbers.
library utils {
    // used to simulate empty strings
    string internal constant NULL = '';

    // formats a CSS variable line. includes a semicolon for formatting.
    function setCssVar(string memory _key, string memory _val)
        internal
        pure
        returns (string memory)
    {
        return string.concat('--', _key, ':', _val, ';');
    }

    // formats getting a css variable
    function getCssVar(string memory _key)
        internal
        pure
        returns (string memory)
    {
        return string.concat('var(--', _key, ')');
    }

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

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

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

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

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

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

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

            length++;
        }
    }

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

    function randomUint8(uint256 seed) internal pure returns (uint8) {
        return uint8(uint256(keccak256(abi.encodePacked(seed))));
    }
}

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