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GenericMage/Contracts...MFP-ListingTemplate_flattened.sol

Created March 26, 2025 10:51
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  1. GenericMage created this gist Mar 26, 2025.
    694 changes: 694 additions & 0 deletions Contracts...MFP-ListingTemplate_flattened.sol
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    // File: Contracts/imports/IERC20.sol


    pragma solidity ^0.8.1;

    interface IERC20 {
    function decimals() external view returns (uint8);
    function transfer(address to, uint256 amount) external returns (bool);
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
    function approve(address spender, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    }
    // File: Contracts/imports/IERC20Permit.sol


    // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

    pragma solidity ^0.8.0;

    /**
    * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
    * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
    *
    * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
    * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
    * need to send a transaction, and thus is not required to hold Ether at all.
    */
    interface IERC20Permit {
    /**
    * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
    * given ``owner``'s signed approval.
    *
    * IMPORTANT: The same issues {IERC20-approve} has related to transaction
    * ordering also apply here.
    *
    * Emits an {Approval} event.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    * - `deadline` must be a timestamp in the future.
    * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
    * over the EIP712-formatted function arguments.
    * - the signature must use ``owner``'s current nonce (see {nonces}).
    *
    * For more information on the signature format, see the
    * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
    * section].
    */
    function permit(
    address owner,
    address spender,
    uint256 value,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
    ) external;

    /**
    * @dev Returns the current nonce for `owner`. This value must be
    * included whenever a signature is generated for {permit}.
    *
    * Every successful call to {permit} increases ``owner``'s nonce by one. This
    * prevents a signature from being used multiple times.
    */
    function nonces(address owner) external view returns (uint256);

    /**
    * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
    */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
    }

    // File: Contracts/imports/Address.sol


    // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)

    pragma solidity ^0.8.1;

    /**
    * @dev Collection of functions related to the address type
    */
    library Address {
    /**
    * @dev Returns true if `account` is a contract.
    *
    * [IMPORTANT]
    * ====
    * It is unsafe to assume that an address for which this function returns
    * false is an externally-owned account (EOA) and not a contract.
    *
    * Among others, `isContract` will return false for the following
    * types of addresses:
    *
    * - an externally-owned account
    * - a contract in construction
    * - an address where a contract will be created
    * - an address where a contract lived, but was destroyed
    *
    * Furthermore, `isContract` will also return true if the target contract within
    * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
    * which only has an effect at the end of a transaction.
    * ====
    *
    * [IMPORTANT]
    * ====
    * You shouldn't rely on `isContract` to protect against flash loan attacks!
    *
    * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
    * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
    * constructor.
    * ====
    */
    function isContract(address account) internal view returns (bool) {
    // This method relies on extcodesize/address.code.length, which returns 0
    // for contracts in construction, since the code is only stored at the end
    // of the constructor execution.

    return account.code.length > 0;
    }

    /**
    * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
    * `recipient`, forwarding all available gas and reverting on errors.
    *
    * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
    * of certain opcodes, possibly making contracts go over the 2300 gas limit
    * imposed by `transfer`, making them unable to receive funds via
    * `transfer`. {sendValue} removes this limitation.
    *
    * https://consensys.net/diligence/blog/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/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
    */
    function sendValue(address payable recipient, uint256 amount) internal {
    require(address(this).balance >= amount, "Address: insufficient balance");

    (bool success, ) = recipient.call{value: amount}("");
    require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
    * @dev Performs a Solidity function call using a low level `call`. A
    * plain `call` is an unsafe replacement for a function call: use this
    * function instead.
    *
    * If `target` reverts with a revert reason, it is bubbled up by this
    * function (like regular Solidity function calls).
    *
    * Returns the raw returned data. To convert to the expected return value,
    * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
    *
    * Requirements:
    *
    * - `target` must be a contract.
    * - calling `target` with `data` must not revert.
    *
    * _Available since v3.1._
    */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
    return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
    * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
    * `errorMessage` as a fallback revert reason when `target` reverts.
    *
    * _Available since v3.1._
    */
    function functionCall(
    address target,
    bytes memory data,
    string memory errorMessage
    ) internal returns (bytes memory) {
    return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
    * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
    * but also transferring `value` wei to `target`.
    *
    * Requirements:
    *
    * - the calling contract must have an ETH balance of at least `value`.
    * - the called Solidity function must be `payable`.
    *
    * _Available since v3.1._
    */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
    return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
    * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
    * with `errorMessage` as a fallback revert reason when `target` reverts.
    *
    * _Available since v3.1._
    */
    function functionCallWithValue(
    address target,
    bytes memory data,
    uint256 value,
    string memory errorMessage
    ) internal returns (bytes memory) {
    require(address(this).balance >= value, "Address: insufficient balance for call");
    (bool success, bytes memory returndata) = target.call{value: value}(data);
    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
    * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
    * but performing a static call.
    *
    * _Available since v3.3._
    */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
    return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
    * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
    * but performing a static call.
    *
    * _Available since v3.3._
    */
    function functionStaticCall(
    address target,
    bytes memory data,
    string memory errorMessage
    ) internal view returns (bytes memory) {
    (bool success, bytes memory returndata) = target.staticcall(data);
    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
    * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
    * but performing a delegate call.
    *
    * _Available since v3.4._
    */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
    return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
    * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
    * but performing a delegate call.
    *
    * _Available since v3.4._
    */
    function functionDelegateCall(
    address target,
    bytes memory data,
    string memory errorMessage
    ) internal returns (bytes memory) {
    (bool success, bytes memory returndata) = target.delegatecall(data);
    return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
    * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
    * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
    *
    * _Available since v4.8._
    */
    function verifyCallResultFromTarget(
    address target,
    bool success,
    bytes memory returndata,
    string memory errorMessage
    ) internal view returns (bytes memory) {
    if (success) {
    if (returndata.length == 0) {
    // only check isContract if the call was successful and the return data is empty
    // otherwise we already know that it was a contract
    require(isContract(target), "Address: call to non-contract");
    }
    return returndata;
    } else {
    _revert(returndata, errorMessage);
    }
    }

    /**
    * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
    * revert reason or using the provided one.
    *
    * _Available since v4.3._
    */
    function verifyCallResult(
    bool success,
    bytes memory returndata,
    string memory errorMessage
    ) internal pure returns (bytes memory) {
    if (success) {
    return returndata;
    } else {
    _revert(returndata, errorMessage);
    }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
    // Look for revert reason and bubble it up if present
    if (returndata.length > 0) {
    // The easiest way to bubble the revert reason is using memory via assembly
    /// @solidity memory-safe-assembly
    assembly {
    let returndata_size := mload(returndata)
    revert(add(32, returndata), returndata_size)
    }
    } else {
    revert(errorMessage);
    }
    }
    }

    // File: Contracts/imports/SafeERC20.sol


    // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)

    pragma solidity ^0.8.0;




    /**
    * @title SafeERC20
    * @dev Wrappers around ERC20 operations that throw on failure (when the token
    * contract returns false). Tokens that return no value (and instead revert or
    * throw on failure) are also supported, non-reverting calls are assumed to be
    * successful.
    * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
    * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
    */
    library SafeERC20 {
    using Address for address;

    /**
    * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
    * non-reverting calls are assumed to be successful.
    */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
    _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
    * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
    * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
    */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
    _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
    * @dev Deprecated. This function has issues similar to the ones found in
    * {IERC20-approve}, and its usage is discouraged.
    *
    * Whenever possible, use {safeIncreaseAllowance} and
    * {safeDecreaseAllowance} instead.
    */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
    // safeApprove should only be called when setting an initial allowance,
    // or when resetting it to zero. To increase and decrease it, use
    // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
    require(
    (value == 0) || (token.allowance(address(this), spender) == 0),
    "SafeERC20: approve from non-zero to non-zero allowance"
    );
    _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    /**
    * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
    * non-reverting calls are assumed to be successful.
    */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
    uint256 oldAllowance = token.allowance(address(this), spender);
    _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
    * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
    * non-reverting calls are assumed to be successful.
    */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
    unchecked {
    uint256 oldAllowance = token.allowance(address(this), spender);
    require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
    _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
    }
    }

    /**
    * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
    * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
    * 0 before setting it to a non-zero value.
    */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
    bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

    if (!_callOptionalReturnBool(token, approvalCall)) {
    _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
    _callOptionalReturn(token, approvalCall);
    }
    }

    /**
    * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
    * Revert on invalid signature.
    */
    function safePermit(
    IERC20Permit token,
    address owner,
    address spender,
    uint256 value,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
    ) internal {
    uint256 nonceBefore = token.nonces(owner);
    token.permit(owner, spender, value, deadline, v, r, s);
    uint256 nonceAfter = token.nonces(owner);
    require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
    * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
    * on the return value: the return value is optional (but if data is returned, it must not be false).
    * @param token The token targeted by the call.
    * @param data The call data (encoded using abi.encode or one of its variants).
    */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
    // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
    // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
    // the target address contains contract code and also asserts for success in the low-level call.

    bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
    require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
    }

    /**
    * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
    * on the return value: the return value is optional (but if data is returned, it must not be false).
    * @param token The token targeted by the call.
    * @param data The call data (encoded using abi.encode or one of its variants).
    *
    * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
    */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
    // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
    // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
    // and not revert is the subcall reverts.

    (bool success, bytes memory returndata) = address(token).call(data);
    return
    success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
    }
    }

    // File: Contracts/MFP-ListingTemplate.sol


    pragma solidity ^0.8.1;

    // Version: 0.0.5


    contract MFPListingTemplate {
    using SafeERC20 for IERC20;

    address public routerAddress;
    address public tokenA;
    address public tokenB;

    struct UpdateType { // Added locally, identical to MFPRouter.sol
    uint8 updateType; // 0 = balance, 1 = buy order, 2 = sell order
    uint256 index; // orderId or slot index
    uint256 value; // principal or amount (normalized)
    address addr; // makerAddress
    address recipient;// recipientAddress
    uint256 maxPrice; // for buy orders
    uint256 minPrice; // for sell orders
    }

    struct VolumeBalance {
    uint256 xBalance;
    uint256 yBalance;
    uint256 xVolume;
    uint256 yVolume;
    }
    struct BuyOrder {
    address makerAddress;
    address recipientAddress;
    uint256 maxPrice;
    uint256 minPrice;
    uint256 pending;
    uint256 filled;
    uint256 timestamp;
    uint256 blockNumber;
    uint8 status; // 0 = cancelled, 1 = pending, 2 = partially filled, 3 = filled
    }
    struct SellOrder {
    address makerAddress;
    address recipientAddress;
    uint256 maxPrice;
    uint256 minPrice;
    uint256 pending;
    uint256 filled;
    uint256 timestamp;
    uint256 blockNumber;
    uint8 status;
    }

    mapping(uint256 => VolumeBalance) public volumeBalances;
    mapping(uint256 => address) public liquidityAddresses;
    mapping(uint256 => uint256) public prices;
    mapping(uint256 => BuyOrder) public buyOrders;
    mapping(uint256 => SellOrder) public sellOrders;
    mapping(uint256 => uint256[]) public pendingBuyOrders;
    mapping(uint256 => uint256[]) public pendingSellOrders;
    mapping(address => uint256[]) public makerPendingOrders;

    event OrderUpdated(uint256 listingId, uint256 orderId, bool isBuy, uint8 status);
    event BalancesUpdated(uint256 listingId, uint256 xBalance, uint256 yBalance);

    function setRouter(address _routerAddress) external {
    require(routerAddress == address(0), "Router already set");
    routerAddress = _routerAddress;
    }

    function setLiquidityAddress(uint256 listingId, address _liquidityAddress) external {
    require(msg.sender == routerAddress, "Router only");
    require(liquidityAddresses[listingId] == address(0), "Liquidity already set");
    liquidityAddresses[listingId] = _liquidityAddress;
    }

    function setTokens(address _tokenA, address _tokenB) external {
    require(msg.sender == routerAddress, "Router only");
    require(tokenA == address(0) && tokenB == address(0), "Tokens already set");
    require(_tokenA != _tokenB, "Tokens must be different");
    tokenA = _tokenA;
    tokenB = _tokenB;
    }

    function update(uint256 listingId, UpdateType[] memory updates) external { // Updated signature
    require(msg.sender == routerAddress, "Router only");
    VolumeBalance storage balances = volumeBalances[listingId];

    for (uint256 i = 0; i < updates.length; i++) {
    UpdateType memory u = updates[i];
    if (u.updateType == 0) { // Balance update
    if (u.index == 0) {
    balances.xBalance = u.value;
    } else if (u.index == 1) {
    balances.yBalance = u.value;
    }
    } else if (u.updateType == 1) { // Buy order update
    BuyOrder storage order = buyOrders[u.index];
    if (order.makerAddress == address(0)) { // New order
    order.makerAddress = u.addr;
    order.recipientAddress = u.recipient;
    order.maxPrice = u.maxPrice;
    order.minPrice = u.minPrice;
    order.pending = u.value;
    order.timestamp = block.timestamp;
    order.blockNumber = block.number;
    order.status = 1;
    pendingBuyOrders[listingId].push(u.index);
    makerPendingOrders[u.addr].push(u.index);
    emit OrderUpdated(listingId, u.index, true, 1);
    } else if (u.value == 0) { // Cancel order
    order.status = 0;
    removePendingOrder(pendingBuyOrders[listingId], u.index);
    removePendingOrder(makerPendingOrders[u.addr], u.index);
    emit OrderUpdated(listingId, u.index, true, 0);
    } else if (order.status == 1) { // Fill order
    require(order.pending >= u.value, "Insufficient pending");
    order.pending -= u.value;
    order.filled += u.value;
    balances.xBalance -= u.value;
    order.status = order.pending == 0 ? 3 : 2;
    if (order.pending == 0) {
    removePendingOrder(pendingBuyOrders[listingId], u.index);
    removePendingOrder(makerPendingOrders[order.makerAddress], u.index);
    }
    emit OrderUpdated(listingId, u.index, true, order.status);
    }
    } else if (u.updateType == 2) { // Sell order update
    SellOrder storage order = sellOrders[u.index];
    if (order.makerAddress == address(0)) { // New order
    order.makerAddress = u.addr;
    order.recipientAddress = u.recipient;
    order.maxPrice = u.maxPrice;
    order.minPrice = u.minPrice;
    order.pending = u.value;
    order.timestamp = block.timestamp;
    order.blockNumber = block.number;
    order.status = 1;
    pendingSellOrders[listingId].push(u.index);
    makerPendingOrders[u.addr].push(u.index);
    emit OrderUpdated(listingId, u.index, false, 1);
    } else if (u.value == 0) { // Cancel order
    order.status = 0;
    removePendingOrder(pendingSellOrders[listingId], u.index);
    removePendingOrder(makerPendingOrders[u.addr], u.index);
    emit OrderUpdated(listingId, u.index, false, 0);
    } else if (order.status == 1) { // Fill order
    require(order.pending >= u.value, "Insufficient pending");
    order.pending -= u.value;
    order.filled += u.value;
    balances.yBalance -= u.value;
    order.status = order.pending == 0 ? 3 : 2;
    if (order.pending == 0) {
    removePendingOrder(pendingSellOrders[listingId], u.index);
    removePendingOrder(makerPendingOrders[order.makerAddress], u.index);
    }
    emit OrderUpdated(listingId, u.index, false, order.status);
    }
    }
    }

    if (balances.xBalance > 0 && balances.yBalance > 0) {
    prices[listingId] = (balances.xBalance * 1e18) / balances.yBalance;
    }
    emit BalancesUpdated(listingId, balances.xBalance, balances.yBalance);
    }

    function transact(uint256 listingId, address token, uint256 amount, address recipient) external {
    require(msg.sender == routerAddress, "Router only");
    VolumeBalance storage balances = volumeBalances[listingId];
    uint8 decimals = token == address(0) ? 18 : IERC20(token).decimals();
    uint256 normalizedAmount = normalize(amount, decimals);

    if (token == tokenA) {
    require(balances.xBalance >= normalizedAmount, "Insufficient xBalance");
    balances.xBalance -= normalizedAmount;
    balances.xVolume += normalizedAmount;
    if (token == address(0)) {
    (bool success, ) = recipient.call{value: amount}("");
    require(success, "ETH transfer failed");
    } else {
    IERC20(token).safeTransfer(recipient, amount);
    }
    } else if (token == tokenB) {
    require(balances.yBalance >= normalizedAmount, "Insufficient yBalance");
    balances.yBalance -= normalizedAmount;
    balances.yVolume += normalizedAmount;
    if (token == address(0)) {
    (bool success, ) = recipient.call{value: amount}("");
    require(success, "ETH transfer failed");
    } else {
    IERC20(token).safeTransfer(recipient, amount);
    }
    } else {
    revert("Invalid token");
    }
    if (balances.xBalance > 0 && balances.yBalance > 0) {
    prices[listingId] = (balances.xBalance * 1e18) / balances.yBalance;
    }
    emit BalancesUpdated(listingId, balances.xBalance, balances.yBalance);
    }

    function normalize(uint256 amount, uint8 decimals) internal pure returns (uint256) {
    if (decimals == 18) return amount;
    else if (decimals < 18) return amount * 10**(18 - decimals);
    else return amount / 10**(decimals - 18);
    }

    function denormalize(uint256 amount, uint8 decimals) internal pure returns (uint256) {
    if (decimals == 18) return amount;
    else if (decimals < 18) return amount / 10**(18 - decimals);
    else return amount * 10**(decimals - 18);
    }

    function removePendingOrder(uint256[] storage orders, uint256 orderId) internal {
    for (uint256 i = 0; i < orders.length; i++) {
    if (orders[i] == orderId) {
    orders[i] = orders[orders.length - 1];
    orders.pop();
    break;
    }
    }
    }
    }