// File: src/ConclusionRenderer.sol



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

import "openzeppelin/access/Ownable.sol";

import {Base64} from "solady/utils/Base64.sol";
import {SSTORE2} from "solady/utils/SSTORE2.sol";
import {LibString} from "solady/utils/LibString.sol";

import "./ISpaceFont.sol";

/// @title On-chain renderer for POW NFT
/// @author @0x_beans
contract ConclusionRenderer is Ownable {
    // index of where the gradient image is tored
    uint256 public constant GRADIENT = 0;

    // mapping of where we'll store the gradient image
    mapping(uint256 => address) public files;

    // our on-chain font for rendering
    address public spaceFont;

    // we pass in tokenID even though we're not using it
    // in case our new renderer needs it
    function tokenURI(
        uint256 tokenId,
        uint256 blockNumber,
        uint256 blockDifficulty
    ) external view returns (string memory svgString) {
        return
            string(
                abi.encodePacked(
                    "data:application/json;base64,",
                    Base64.encode(
                        abi.encodePacked(
                            "{"
                            '"name": "Sunset",',
                            '"description": "An attempt to be the last on-chain NFT to be minted on POW",'
                            '"image": "data:image/svg+xml;base64,',
                            Base64.encode(bytes(getSVG(blockNumber))),
                            '",'
                            '"attributes": [{"trait_type": "block number", "value":"',
                            LibString.toString(blockNumber),
                            '"},',
                            '{"trait_type": "block difficulty", "value":"',
                            LibString.toString(blockDifficulty),
                            '"}]}'
                        )
                    )
                )
            );
    }

    // construct the image
    function getSVG(uint256 blockNumber)
        internal
        view
        returns (string memory svgString)
    {
        svgString = string(
            abi.encodePacked(
                "<svg xmlns='http://www.w3.org/2000/svg' width='256' height='256' viewBox='0 0 256 256' preserveAspectRatio='none'>"
                "<image height='256' width='256' href='",
                string(SSTORE2.read(files[GRADIENT])),
                "'/>"
                "<text x='50%' y='40%' dominant-baseline='middle' text-anchor='middle' class='title'>"
                "MINTED"
                "</text>"
                "<text x='50%' y='50%' dominant-baseline='middle' text-anchor='middle' class='title'>"
                "AT"
                "</text>"
                "<text x='50%' y='60%' dominant-baseline='middle' text-anchor='middle' class='title'> #",
                LibString.toString(blockNumber),
                "</text>"
                "<style type='text/css'>"
                "@font-face {"
                "font-family: 'Space-Grotesk';"
                "font-style: normal;"
                "src:url(",
                ISpaceFont(spaceFont).getFont(),
                ");}"
                ".title {"
                "font-family: 'Space-Grotesk';"
                "letter-spacing: 0.025em;"
                "font-size: 23px;"
                "fill: white;"
                "}"
                "</style>"
                "</svg>"
            )
        );
    }

    function setFontContract(address font) external onlyOwner {
        spaceFont = font;
    }

    // save gradient on chain
    function saveFile(uint256 index, string calldata fileContent)
        public
        onlyOwner
    {
        files[index] = SSTORE2.write(bytes(fileContent));
    }
}

// File: lib/openzeppelin-contracts/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: lib/solady/src/utils/Base64.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/// @notice Library to encode strings in Base64.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/Base64.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/Base64.sol)
/// @author Modified from (https://github.com/Brechtpd/base64/blob/main/base64.sol) by Brecht Devos - <brecht@loopring.org>.
library Base64 {
    function encode(bytes memory data) internal pure returns (string memory result) {
        assembly {
            let dataLength := mload(data)

            if dataLength {
                // Multiply by 4/3 rounded up.
                // The `shl(2, ...)` is equivalent to multiplying by 4.
                let encodedLength := shl(2, div(add(dataLength, 2), 3))

                // Set `result` to point to the start of the free memory.
                result := mload(0x40)

                // Write the length of the string.
                mstore(result, encodedLength)

                // Store the table into the scratch space.
                // Offsetted by -1 byte so that the `mload` will load the character.
                // We will rewrite the free memory pointer at `0x40` later with
                // the allocated size.
                mstore(0x1f, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef")
                mstore(0x3f, "ghijklmnopqrstuvwxyz0123456789+/")

                // Skip the first slot, which stores the length.
                let ptr := add(result, 0x20)
                let end := add(ptr, encodedLength)

                // Run over the input, 3 bytes at a time.
                // prettier-ignore
                for {} 1 {} {
                    data := add(data, 3) // Advance 3 bytes.
                    let input := mload(data)

                    // Write 4 bytes. Optimized for fewer stack operations.
                    mstore8(    ptr    , mload(and(shr(18, input), 0x3F)))
                    mstore8(add(ptr, 1), mload(and(shr(12, input), 0x3F)))
                    mstore8(add(ptr, 2), mload(and(shr( 6, input), 0x3F)))
                    mstore8(add(ptr, 3), mload(and(        input , 0x3F)))
                    
                    ptr := add(ptr, 4) // Advance 4 bytes.
                    // prettier-ignore
                    if iszero(lt(ptr, end)) { break }
                }

                // Offset `ptr` and pad with '='. We can simply write over the end.
                let r := mod(dataLength, 3)
                mstore8(sub(ptr, iszero(iszero(r))), 0x3d) // Pad at `ptr - 1` if `r > 0`.
                mstore8(sub(ptr, shl(1, eq(r, 1))), 0x3d) // Pad at `ptr - 2` if `r == 1`.

                // Allocate the memory for the string.
                // Add 31 and mask with `not(31)` to round the
                // free memory pointer up the next multiple of 32.
                mstore(0x40, and(add(end, 31), not(31)))
            }
        }
    }

    function decode(string memory data) internal pure returns (bytes memory result) {
        assembly {
            let dataLength := mload(data)

            if dataLength {
                let decodedLength := mul(shr(2, dataLength), 3)

                switch and(dataLength, 3)
                case 0 {
                    // If padded.
                    let lastBytes := mload(add(data, mload(data)))
                    decodedLength := sub(
                        decodedLength,
                        add(eq(and(lastBytes, 0xFF), 0x3d), eq(and(lastBytes, 0xFFFF), 0x3d3d))
                    )
                }
                default {
                    // If non-padded.
                    decodedLength := add(decodedLength, sub(and(dataLength, 3), 1))
                }

                result := mload(0x40)

                // Write the length of the string.
                mstore(result, decodedLength)

                // Skip the first slot, which stores the length.
                let ptr := add(result, 0x20)

                // Cache the slot.
                let m0x80 := mload(0x80)

                // Load the table into the scratch space.
                mstore(0x40, 0x000000000000000000003e0000003f3435363738393a3b3c3d00000000000000)
                mstore(0x60, 0x000102030405060708090a0b0c0d0e0f10111213141516171819000000000000)
                mstore(0x80, 0x1a1b1c1d1e1f202122232425262728292a2b2c2d2e2f30313233000000000000)

                let end := add(data, dataLength)
                // prettier-ignore
                for {} 1 {} {
                    // Read 4 bytes.
                    data := add(data, 4)
                    let input := mload(data)

                    // Write 3 bytes.
                    mstore(ptr, shl(232, or(
                        or(
                            shl(18, and(mload(byte(28, input)), 0xFF)),
                            shl(12, and(mload(byte(29, input)), 0xFF))),
                        or(
                            shl( 6, and(mload(byte(30, input)), 0xFF)),
                                    and(mload(byte(31, input)), 0xFF)
                        )
                    )))

                    ptr := add(ptr, 3)
                    
                    // prettier-ignore
                    if iszero(lt(data, end)) { break }
                }

                // Allocate the memory for the string.
                // Add 32 + 31 and mask with `not(31)` to round the
                // free memory pointer up the next multiple of 32.
                mstore(0x40, and(add(add(result, decodedLength), 63), not(31)))

                // Restore the slots.
                mstore(0x60, 0)
                mstore(0x80, m0x80)
            }
        }
    }
}

// File: lib/solady/src/utils/SSTORE2.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/// @notice Read and write to persistent storage at a fraction of the cost.
/// @author Solady (https://github.com/vectorized/solmady/blob/main/src/utils/SSTORE2.sol)
/// @author Saw-mon-and-Natalie (https://github.com/Saw-mon-and-Natalie)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/SSTORE2.sol)
/// @author Modified from 0xSequence (https://github.com/0xSequence/sstore2/blob/master/contracts/SSTORE2.sol)
library SSTORE2 {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                        CUSTOM ERRORS                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    error DeploymentFailed();

    error InvalidPointer();

    error ReadOutOfBounds();

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                         WRITE LOGIC                        */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    function write(bytes memory data) internal returns (address pointer) {
        // Note: The assembly block below does not expand the memory.
        assembly {
            let originalDataLength := mload(data)

            // Add 1 to data size since we are prefixing it with a STOP opcode.
            let dataSize := add(originalDataLength, 1)

            /**
             * ------------------------------------------------------------------------------+
             * Opcode      | Mnemonic        | Stack                   | Memory              |
             * ------------------------------------------------------------------------------|
             * 61 codeSize | PUSH2 codeSize  | codeSize                |                     |
             * 80          | DUP1            | codeSize codeSize       |                     |
             * 60 0xa      | PUSH1 0xa       | 0xa codeSize codeSize   |                     |
             * 3D          | RETURNDATASIZE  | 0 0xa codeSize codeSize |                     |
             * 39          | CODECOPY        | codeSize                | [0..codeSize): code |
             * 3D          | RETURNDATASZIE  | 0 codeSize              | [0..codeSize): code |
             * F3          | RETURN          |                         | [0..codeSize): code |
             * 00          | STOP            |                         |                     |
             * ------------------------------------------------------------------------------+
             * @dev Prefix the bytecode with a STOP opcode to ensure it cannot be called.
             * Also PUSH2 is used since max contract size cap is 24,576 bytes which is less than 2 ** 16.
             */
            mstore(
                data,
                or(
                    0x61000080600a3d393df300,
                    // Left shift `dataSize` by 64 so that it lines up with the 0000 after PUSH2.
                    shl(0x40, dataSize)
                )
            )

            // Deploy a new contract with the generated creation code.
            pointer := create(0, add(data, 0x15), add(dataSize, 0xa))

            // If `pointer` is zero, revert.
            if iszero(pointer) {
                // Store the function selector of `DeploymentFailed()`.
                mstore(0x00, 0x30116425)
                // Revert with (offset, size).
                revert(0x1c, 0x04)
            }

            // Restore original length of the variable size `data`.
            mstore(data, originalDataLength)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                         READ LOGIC                         */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    function read(address pointer) internal view returns (bytes memory data) {
        assembly {
            let pointerCodesize := extcodesize(pointer)
            if iszero(pointerCodesize) {
                // Store the function selector of `InvalidPointer()`.
                mstore(0x00, 0x11052bb4)
                // Revert with (offset, size).
                revert(0x1c, 0x04)
            }
            // Offset all indices by 1 to skip the STOP opcode.
            let size := sub(pointerCodesize, 1)

            // Get the pointer to the free memory and allocate
            // enough 32-byte words for the data and the length of the data,
            // then copy the code to the allocated memory.
            // Masking with 0xffe0 will suffice, since contract size is less than 16 bits.
            data := mload(0x40)
            mstore(0x40, add(data, and(add(size, 0x3f), 0xffe0)))
            mstore(data, size)
            extcodecopy(pointer, add(data, 0x20), 1, size)
        }
    }

    function read(address pointer, uint256 start) internal view returns (bytes memory data) {
        assembly {
            let pointerCodesize := extcodesize(pointer)
            if iszero(pointerCodesize) {
                // Store the function selector of `InvalidPointer()`.
                mstore(0x00, 0x11052bb4)
                // Revert with (offset, size).
                revert(0x1c, 0x04)
            }

            // If `!(pointer.code.size > start)`, reverts.
            // This also handles the case where `start + 1` overflows.
            if iszero(gt(pointerCodesize, start)) {
                // Store the function selector of `ReadOutOfBounds()`.
                mstore(0x00, 0x84eb0dd1)
                // Revert with (offset, size).
                revert(0x1c, 0x04)
            }
            let size := sub(pointerCodesize, add(start, 1))

            // Get the pointer to the free memory and allocate
            // enough 32-byte words for the data and the length of the data,
            // then copy the code to the allocated memory.
            // Masking with 0xffe0 will suffice, since contract size is less than 16 bits.
            data := mload(0x40)
            mstore(0x40, add(data, and(add(size, 0x3f), 0xffe0)))
            mstore(data, size)
            extcodecopy(pointer, add(data, 0x20), add(start, 1), size)
        }
    }

    function read(
        address pointer,
        uint256 start,
        uint256 end
    ) internal view returns (bytes memory data) {
        assembly {
            let pointerCodesize := extcodesize(pointer)
            if iszero(pointerCodesize) {
                // Store the function selector of `InvalidPointer()`.
                mstore(0x00, 0x11052bb4)
                // Revert with (offset, size).
                revert(0x1c, 0x04)
            }

            // If `!(pointer.code.size > end) || (start > end)`, revert.
            // This also handles the cases where `end + 1` or `start + 1` overflow.
            if iszero(
                and(
                    gt(pointerCodesize, end), // Within bounds.
                    iszero(gt(start, end)) // Valid range.
                )
            ) {
                // Store the function selector of `ReadOutOfBounds()`.
                mstore(0x00, 0x84eb0dd1)
                // Revert with (offset, size).
                revert(0x1c, 0x04)
            }
            let size := sub(end, start)

            // Get the pointer to the free memory and allocate
            // enough 32-byte words for the data and the length of the data,
            // then copy the code to the allocated memory.
            // Masking with 0xffe0 will suffice, since contract size is less than 16 bits.
            data := mload(0x40)
            mstore(0x40, add(data, and(add(size, 0x3f), 0xffe0)))
            mstore(data, size)
            extcodecopy(pointer, add(data, 0x20), add(start, 1), size)
        }
    }
}

// File: lib/solady/src/utils/LibString.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/// @notice Library for converting numbers into strings and other string operations.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/LibString.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/LibString.sol)
library LibString {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                        CUSTOM ERRORS                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    error HexLengthInsufficient();

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                     DECIMAL OPERATIONS                     */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    function toString(uint256 value) internal pure returns (string memory str) {
        assembly {
            // The maximum value of a uint256 contains 78 digits (1 byte per digit), but
            // we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.
            // We will need 1 word for the trailing zeros padding, 1 word for the length,
            // and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.
            let m := add(mload(0x40), 0xa0)
            // Update the free memory pointer to allocate.
            mstore(0x40, m)
            // Assign the `str` to the end.
            str := sub(m, 0x20)
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end of the memory to calculate the length later.
            let end := str

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 1)
                // Write the character to the pointer.
                // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
                // prettier-ignore
                if iszero(temp) { break }
            }

            let length := sub(end, str)
            // Move the pointer 32 bytes leftwards to make room for the length.
            str := sub(str, 0x20)
            // Store the length.
            mstore(str, length)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   HEXADECIMAL OPERATIONS                   */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    function toHexString(uint256 value, uint256 length) internal pure returns (string memory str) {
        assembly {
            let start := mload(0x40)
            // We need 0x20 bytes for the trailing zeros padding, `length * 2` bytes
            // for the digits, 0x02 bytes for the prefix, and 0x20 bytes for the length.
            // We add 0x20 to the total and round down to a multiple of 0x20.
            // (0x20 + 0x20 + 0x02 + 0x20) = 0x62.
            let m := add(start, and(add(shl(1, length), 0x62), not(0x1f)))
            // Allocate the memory.
            mstore(0x40, m)
            // Assign the `str` to the end.
            str := sub(m, 0x20)
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end to calculate the length later.
            let end := str
            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            let temp := value
            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for {} 1 {} {
                str := sub(str, 2)
                mstore8(add(str, 1), mload(and(temp, 15)))
                mstore8(str, mload(and(shr(4, temp), 15)))
                temp := shr(8, temp)
                length := sub(length, 1)
                // prettier-ignore
                if iszero(length) { break }
            }

            if temp {
                // Store the function selector of `HexLengthInsufficient()`.
                mstore(0x00, 0x2194895a)
                // Revert with (offset, size).
                revert(0x1c, 0x04)
            }

            // Compute the string's length.
            let strLength := add(sub(end, str), 2)
            // Move the pointer and write the "0x" prefix.
            str := sub(str, 0x20)
            mstore(str, 0x3078)
            // Move the pointer and write the length.
            str := sub(str, 2)
            mstore(str, strLength)
        }
    }

    function toHexString(uint256 value) internal pure returns (string memory str) {
        assembly {
            let start := mload(0x40)
            // We need 0x20 bytes for the trailing zeros padding, 0x20 bytes for the length,
            // 0x02 bytes for the prefix, and 0x40 bytes for the digits.
            // The next multiple of 0x20 above (0x20 + 0x20 + 0x02 + 0x40) is 0xa0.
            let m := add(start, 0xa0)
            // Allocate the memory.
            mstore(0x40, m)
            // Assign the `str` to the end.
            str := sub(m, 0x20)
            // Zeroize the slot after the string.
            mstore(str, 0)

            // Cache the end to calculate the length later.
            let end := str
            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 2)
                mstore8(add(str, 1), mload(and(temp, 15)))
                mstore8(str, mload(and(shr(4, temp), 15)))
                temp := shr(8, temp)
                // prettier-ignore
                if iszero(temp) { break }
            }

            // Compute the string's length.
            let strLength := add(sub(end, str), 2)
            // Move the pointer and write the "0x" prefix.
            str := sub(str, 0x20)
            mstore(str, 0x3078)
            // Move the pointer and write the length.
            str := sub(str, 2)
            mstore(str, strLength)
        }
    }

    function toHexString(address value) internal pure returns (string memory str) {
        assembly {
            let start := mload(0x40)
            // We need 0x20 bytes for the length, 0x02 bytes for the prefix,
            // and 0x28 bytes for the digits.
            // The next multiple of 0x20 above (0x20 + 0x02 + 0x28) is 0x60.
            str := add(start, 0x60)

            // Allocate the memory.
            mstore(0x40, str)
            // Store "0123456789abcdef" in scratch space.
            mstore(0x0f, 0x30313233343536373839616263646566)

            let length := 20
            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 2)
                mstore8(add(str, 1), mload(and(temp, 15)))
                mstore8(str, mload(and(shr(4, temp), 15)))
                temp := shr(8, temp)
                length := sub(length, 1)
                // prettier-ignore
                if iszero(length) { break }
            }

            // Move the pointer and write the "0x" prefix.
            str := sub(str, 32)
            mstore(str, 0x3078)
            // Move the pointer and write the length.
            str := sub(str, 2)
            mstore(str, 42)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                   OTHER STRING OPERATIONS                  */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    function replace(
        string memory subject,
        string memory search,
        string memory replacement
    ) internal pure returns (string memory result) {
        assembly {
            let subjectLength := mload(subject)
            let searchLength := mload(search)
            let replacementLength := mload(replacement)

            subject := add(subject, 0x20)
            search := add(search, 0x20)
            replacement := add(replacement, 0x20)
            result := add(mload(0x40), 0x20)

            let subjectEnd := add(subject, subjectLength)
            if iszero(gt(searchLength, subjectLength)) {
                let subjectSearchEnd := add(sub(subjectEnd, searchLength), 1)
                let h := 0
                if iszero(lt(searchLength, 32)) {
                    h := keccak256(search, searchLength)
                }
                let m := shl(3, sub(32, and(searchLength, 31)))
                let s := mload(search)
                // prettier-ignore
                for {} 1 {} {
                    let t := mload(subject)
                    // Whether the first `searchLength % 32` bytes of 
                    // `subject` and `search` matches.
                    if iszero(shr(m, xor(t, s))) {
                        if h {
                            if iszero(eq(keccak256(subject, searchLength), h)) {
                                mstore(result, t)
                                result := add(result, 1)
                                subject := add(subject, 1)
                                // prettier-ignore
                                if iszero(lt(subject, subjectSearchEnd)) { break }
                                continue
                            }
                        }
                        // Copy the `replacement` one word at a time.
                        // prettier-ignore
                        for { let o := 0 } 1 {} {
                            mstore(add(result, o), mload(add(replacement, o)))
                            o := add(o, 0x20)
                            // prettier-ignore
                            if iszero(lt(o, replacementLength)) { break }
                        }
                        result := add(result, replacementLength)
                        subject := add(subject, searchLength)    
                        if iszero(searchLength) {
                            mstore(result, t)
                            result := add(result, 1)
                            subject := add(subject, 1)
                        }
                        // prettier-ignore
                        if iszero(lt(subject, subjectSearchEnd)) { break }
                        continue
                    }
                    mstore(result, t)
                    result := add(result, 1)
                    subject := add(subject, 1)
                    // prettier-ignore
                    if iszero(lt(subject, subjectSearchEnd)) { break }
                }
            }

            let resultRemainder := result
            result := add(mload(0x40), 0x20)
            let k := add(sub(resultRemainder, result), sub(subjectEnd, subject))
            // Copy the rest of the string one word at a time.
            // prettier-ignore
            for {} lt(subject, subjectEnd) {} {
                mstore(resultRemainder, mload(subject))
                resultRemainder := add(resultRemainder, 0x20)
                subject := add(subject, 0x20)
            }
            // Allocate memory for the length and the bytes,
            // rounded up to a multiple of 32.
            mstore(0x40, add(result, and(add(k, 0x40), not(0x1f))))
            result := sub(result, 0x20)
            mstore(result, k)
        }
    }
}

// File: src/ISpaceFont.sol



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

interface ISpaceFont {
    function getFont() external view returns (string memory);
}

// File: lib/openzeppelin-contracts/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;
    }
}