// File: contracts/ASCIIGenerator.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.13;

/// @author: x0r - Michael Blau

import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/access/Ownable.sol';
import '@openzeppelin/contracts/utils/Base64.sol';
import '@openzeppelin/contracts/interfaces/IERC721.sol';

contract ASCIIGenerator is Ownable {
    using Base64 for string;
    using Strings for uint256;

    uint256[] public partOne;
    uint256[] public partTwo;

    string internal description = 'Ledger is a fully on-chain dynamic NFT that leverages smart contract composability. The ASCII image portrays a subtle x0r logo where the vertical line contains the addresses of all current owners of the NFT. Whenever this NFT transfers, the ASCII art will update and always reflect both the current owners and the last block number where an update occurred.';
    string internal SVGHeader =
        "<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 900 1090'><defs><style>.cls-1{font-size: 10px; fill: white; font-family:monospace;}</style></defs><g><rect width='900' height='1090' fill='black' />";
    string internal firstTextTagPart =
        "<text lengthAdjust='spacing' textLength='900' class='cls-1' x='0' y='";
    string internal SVGFooter = '</g></svg>';
    uint256 internal tspanLineHeight = 12;

    // =================== ASCII GENERATOR FUNCTIONS =================== //

    /**
     * @notice Generates full metadata
     */
    function generateMetadata(address _nftContract, uint256 _tokenId, uint256 _lastUpdatedBlock)
        public
        view
        returns (string memory)
    {
        string[55] memory owners = getOwners(_nftContract);

        string memory SVG = generateSVG(owners, _lastUpdatedBlock);

        string memory metadata = Base64.encode(
            bytes(
                string.concat(
                    '{"name": "Ledger #',
                    _tokenId.toString(),
                    '/55",',
                    '"description":"',
                    description,
                    '","image":"',
                    SVG,
                    '"}'
                )
            )
        );

        return string.concat('data:application/json;base64,', metadata);
    }

    /**
     * @notice Get all ERC721 owner addresses and convert them to strings
     * @param _nftContract to query NFT owners from
     */
    function getOwners(address _nftContract) internal view returns (string[55] memory) {
        IERC721 nftContract = IERC721(_nftContract);

        string[55] memory owners;

        for (uint256 i; i < owners.length; i++) {
            try nftContract.ownerOf(i + 1) returns (address nftOwner) {
                owners[i] = Strings.toHexString(uint256(uint160(nftOwner)), 20);
            } catch {
                owners[i] = Strings.toHexString(uint256(uint160(address(0))), 20);
            }
        }

        return owners;
    }

    /**
     * @notice Generates the SVG image
     */
    function generateSVG(string[55] memory _owners, uint256 _lastUpdatedBlock) public view returns (string memory) {
        string[89] memory rows = genCoreAscii(_owners);

        string memory _firstTextTagPart = firstTextTagPart;
        string memory span;
        string memory center;
        uint256 y = tspanLineHeight;

        for (uint256 i; i < rows.length; i++) {
            span = string.concat(_firstTextTagPart, y.toString(), "'>", rows[i], '</text>');
            center = string.concat(center, span);
            y += tspanLineHeight;
        }

        // add last row of ASCII that contains the last updated block number
        center = string.concat(
            center,
            _firstTextTagPart,
            y.toString(),
            "'>",
            getLastUpdatedBlockString(_lastUpdatedBlock),
            '</text>'
        );

        // base64 encode the SVG text
        string memory SVGImage = Base64.encode(bytes(string.concat(SVGHeader, center, SVGFooter)));

        return string.concat('data:image/svg+xml;base64,', SVGImage);
    }

    /**
     * @notice Generates all ASCII rows of the image
     */
    function genCoreAscii(string[55] memory _owners) public view returns (string[89] memory) {
        string[89] memory asciiRows;

        uint256 partOneEndIndex = partOne.length;
        uint256 partTwoEndIndex = partOneEndIndex + partTwo.length;

        for (uint256 i; i < asciiRows.length; i++) {
            if (i < partOneEndIndex) {
                asciiRows[i] = rowToString(partOne[i], 150);
            } else if (i >= partOneEndIndex && i < partTwoEndIndex) {
                uint256 centerIndex = i - partOneEndIndex;
                string memory rowHalf = rowToString(partTwo[centerIndex], 54);
                asciiRows[i] = string.concat(rowHalf, _owners[centerIndex], reverseValue(rowHalf));
            } else if (i >= partTwoEndIndex) {
                asciiRows[i] = asciiRows[asciiRows.length - i - 1];
            }
        }

        return asciiRows;
    }

    /**
     * @notice Generates one ASCII row as a string
     */
    function rowToString(uint256 _row, uint256 _bitsToUnpack)
        internal
        pure
        returns (string memory)
    {
        string memory rowString;
        for (uint256 i; i < _bitsToUnpack; i++) {
            if (((_row >> (1 * i)) & 1) == 0) {
                rowString = string.concat(rowString, '.');
            } else {
                rowString = string.concat(rowString, '-');
            }
        }

        return rowString;
    }

    /**
     * @notice Generates one row of ASCII that shows the last block number when the ledger was updated (i.e., the NFT was transferred)
     * @param _blockNumber when the NFT was last transferred
     */
    function getLastUpdatedBlockString(uint256 _blockNumber) public pure returns (string memory) {
        string memory blockNumberString = _blockNumber.toString();
        uint256 asciiOffset = 150 - bytes(blockNumberString).length;

        string memory asciiRow;
        for (uint256 i; i < asciiOffset; i++) {
            asciiRow = string.concat(asciiRow, '.');
        }

        return string.concat(asciiRow, blockNumberString);
    }

    /**
     * @notice reverse a string
     */
    function reverseValue(string memory _base) internal pure returns (string memory) {
        bytes memory _baseBytes = bytes(_base);
        assert(_baseBytes.length > 0);

        string memory _tempValue = new string(_baseBytes.length);
        bytes memory _newValue = bytes(_tempValue);

        for (uint256 i; i < _baseBytes.length; i++) {
            _newValue[_baseBytes.length - i - 1] = _baseBytes[i];
        }

        return string(_newValue);
    }

    // =================== STORE IMAGE DATA =================== //

    function storeImageParts(uint256[] memory _partOne, uint256[] memory _partTwo)
        external
        onlyOwner
    {
        partOne = _partOne;
        partTwo = _partTwo;
    }

    function setSVGParts(
        string calldata _SVGHeader,
        string calldata _SVGFooter,
        string calldata _firstTextTagPart,
        uint256 _tspanLineHeight
    ) external onlyOwner {
        SVGHeader = _SVGHeader;
        SVGFooter = _SVGFooter;
        firstTextTagPart = _firstTextTagPart;
        tspanLineHeight = _tspanLineHeight;
    }

    function getSVGParts()
        external
        view
        returns (
            string memory,
            string memory,
            string memory,
            uint256
        )
    {
        return (SVGHeader, SVGFooter, firstTextTagPart, tspanLineHeight);
    }

    function setDescription(string calldata _description) external onlyOwner {
        description = _description;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_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) {
        // 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);
    }

    /**
     * @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);
    }
}

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



// 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);
    }
}

// File: @openzeppelin/contracts/utils/Base64.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Base64.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides a set of functions to operate with Base64 strings.
 *
 * _Available since v4.5._
 */
library Base64 {
    /**
     * @dev Base64 Encoding/Decoding Table
     */
    string internal constant _TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    /**
     * @dev Converts a `bytes` to its Bytes64 `string` representation.
     */
    function encode(bytes memory data) internal pure returns (string memory) {
        /**
         * Inspired by Brecht Devos (Brechtpd) implementation - MIT licence
         * https://github.com/Brechtpd/base64/blob/e78d9fd951e7b0977ddca77d92dc85183770daf4/base64.sol
         */
        if (data.length == 0) return "";

        // Loads the table into memory
        string memory table = _TABLE;

        // Encoding takes 3 bytes chunks of binary data from `bytes` data parameter
        // and split into 4 numbers of 6 bits.
        // The final Base64 length should be `bytes` data length multiplied by 4/3 rounded up
        // - `data.length + 2`  -> Round up
        // - `/ 3`              -> Number of 3-bytes chunks
        // - `4 *`              -> 4 characters for each chunk
        string memory result = new string(4 * ((data.length + 2) / 3));

        /// @solidity memory-safe-assembly
        assembly {
            // Prepare the lookup table (skip the first "length" byte)
            let tablePtr := add(table, 1)

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

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

            } {
                // Advance 3 bytes
                dataPtr := add(dataPtr, 3)
                let input := mload(dataPtr)

                // To write each character, shift the 3 bytes (18 bits) chunk
                // 4 times in blocks of 6 bits for each character (18, 12, 6, 0)
                // and apply logical AND with 0x3F which is the number of
                // the previous character in the ASCII table prior to the Base64 Table
                // The result is then added to the table to get the character to write,
                // and finally write it in the result pointer but with a left shift
                // of 256 (1 byte) - 8 (1 ASCII char) = 248 bits

                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(input, 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance
            }

            // When data `bytes` is not exactly 3 bytes long
            // it is padded with `=` characters at the end
            switch mod(mload(data), 3)
            case 1 {
                mstore8(sub(resultPtr, 1), 0x3d)
                mstore8(sub(resultPtr, 2), 0x3d)
            }
            case 2 {
                mstore8(sub(resultPtr, 1), 0x3d)
            }
        }

        return result;
    }
}

// File: @openzeppelin/contracts/interfaces/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (interfaces/IERC721.sol)

pragma solidity ^0.8.0;

import "../token/ERC721/IERC721.sol";

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



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

pragma solidity ^0.8.0;

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

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

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

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

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

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

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

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



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

pragma solidity ^0.8.0;

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