src/BurrowMarket.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.8.26;
/*
* Bundled OpenZeppelin Contracts v5.0.2 dependencies, from
* https://github.com/OpenZeppelin/openzeppelin-contracts/tree/v5.0.2
* Kept in this file so the single-file deliverable builds without downloads.
* Only imports/pragmas are removed and top-level symbols are prefixed with
* BurrowMarket to avoid collisions with dependencies in other protocol files.
* The original library logic and documentation are retained below.
*
* The MIT License (MIT)
*
* Copyright (c) 2016-2023 zOS Global Limited and contributors
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
// OpenZeppelin v5.0.2: contracts/utils/Context.sol
// OpenZeppelin Contracts (last updated v5.0.1) (utils/BurrowMarketContext.sol)
/**
* @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 BurrowMarketContext {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
function _contextSuffixLength() internal view virtual returns (uint256) {
return 0;
}
}
// OpenZeppelin v5.0.2: contracts/access/Ownable.sol
// OpenZeppelin Contracts (last updated v5.0.0) (access/BurrowMarketOwnable.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.
*
* The initial owner is set to the address provided by the deployer. 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 BurrowMarketOwnable is BurrowMarketContext {
address private _owner;
/**
* @dev The caller account is not authorized to perform an operation.
*/
error OwnableUnauthorizedAccount(address account);
/**
* @dev The owner is not a valid owner account. (eg. `address(0)`)
*/
error OwnableInvalidOwner(address owner);
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the address provided by the deployer as the initial owner.
*/
constructor(address initialOwner) {
if (initialOwner == address(0)) {
revert OwnableInvalidOwner(address(0));
}
_transferOwnership(initialOwner);
}
/**
* @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 {
if (owner() != _msgSender()) {
revert OwnableUnauthorizedAccount(_msgSender());
}
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling 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 {
if (newOwner == address(0)) {
revert OwnableInvalidOwner(address(0));
}
_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);
}
}
// OpenZeppelin v5.0.2: contracts/access/Ownable2Step.sol
// OpenZeppelin Contracts (last updated v5.0.0) (access/BurrowMarketOwnable2Step.sol)
/**
* @dev Contract module which provides access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* The initial owner is specified at deployment time in the constructor for `BurrowMarketOwnable`. This
* can later be changed with {transferOwnership} and {acceptOwnership}.
*
* This module is used through inheritance. It will make available all functions
* from parent (BurrowMarketOwnable).
*/
abstract contract BurrowMarketOwnable2Step is BurrowMarketOwnable {
address private _pendingOwner;
event OwnershipTransferStarted(address indexed previousOwner, address indexed newOwner);
/**
* @dev Returns the address of the pending owner.
*/
function pendingOwner() public view virtual returns (address) {
return _pendingOwner;
}
/**
* @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual override onlyOwner {
_pendingOwner = newOwner;
emit OwnershipTransferStarted(owner(), newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual override {
delete _pendingOwner;
super._transferOwnership(newOwner);
}
/**
* @dev The new owner accepts the ownership transfer.
*/
function acceptOwnership() public virtual {
address sender = _msgSender();
if (pendingOwner() != sender) {
revert OwnableUnauthorizedAccount(sender);
}
_transferOwnership(sender);
}
}
// OpenZeppelin v5.0.2: contracts/utils/ReentrancyGuard.sol
// OpenZeppelin Contracts (last updated v5.0.0) (utils/BurrowMarketReentrancyGuard.sol)
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `BurrowMarketReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract BurrowMarketReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant NOT_ENTERED = 1;
uint256 private constant ENTERED = 2;
uint256 private _status;
/**
* @dev Unauthorized reentrant call.
*/
error ReentrancyGuardReentrantCall();
constructor() {
_status = NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_nonReentrantBefore();
_;
_nonReentrantAfter();
}
function _nonReentrantBefore() private {
// On the first call to nonReentrant, _status will be NOT_ENTERED
if (_status == ENTERED) {
revert ReentrancyGuardReentrantCall();
}
// Any calls to nonReentrant after this point will fail
_status = ENTERED;
}
function _nonReentrantAfter() private {
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = NOT_ENTERED;
}
/**
* @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
* `nonReentrant` function in the call stack.
*/
function _reentrancyGuardEntered() internal view returns (bool) {
return _status == ENTERED;
}
}
// OpenZeppelin v5.0.2: contracts/utils/introspection/IERC165.sol
// OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/BurrowMarketIERC165.sol)
/**
* @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 BurrowMarketIERC165 {
/**
* @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);
}
// OpenZeppelin v5.0.2: contracts/token/ERC721/IERC721Receiver.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/BurrowMarketIERC721Receiver.sol)
/**
* @title ERC721 token receiver interface
* @dev Interface for any contract that wants to support safeTransfers
* from ERC721 asset contracts.
*/
interface BurrowMarketIERC721Receiver {
/**
* @dev Whenever an {BurrowMarketIERC721} `tokenId` token is transferred to this contract via {BurrowMarketIERC721-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 `BurrowMarketIERC721Receiver.onERC721Received.selector`.
*/
function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data)
external
returns (bytes4);
}
// OpenZeppelin v5.0.2: contracts/token/ERC721/utils/ERC721Holder.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/utils/BurrowMarketERC721Holder.sol)
/**
* @dev Implementation of the {BurrowMarketIERC721Receiver} interface.
*
* Accepts all token transfers.
* Make sure the contract is able to use its token with {BurrowMarketIERC721-safeTransferFrom}, {BurrowMarketIERC721-approve} or
* {BurrowMarketIERC721-setApprovalForAll}.
*/
abstract contract BurrowMarketERC721Holder is BurrowMarketIERC721Receiver {
/**
* @dev See {BurrowMarketIERC721Receiver-onERC721Received}.
*
* Always returns `BurrowMarketIERC721Receiver.onERC721Received.selector`.
*/
function onERC721Received(address, address, uint256, bytes memory) public virtual returns (bytes4) {
return this.onERC721Received.selector;
}
}
// OpenZeppelin v5.0.2: contracts/token/ERC721/IERC721.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC721/BurrowMarketIERC721.sol)
/**
* @dev Required interface of an ERC721 compliant contract.
*/
interface BurrowMarketIERC721 is BurrowMarketIERC165 {
/**
* @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 {BurrowMarketIERC721Receiver-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 {BurrowMarketIERC721Receiver-onERC721Received}, which is called upon
* a safe transfer.
*
* Emits a {Transfer} event.
*/
function safeTransferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
* or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
* understand this adds an external call which potentially creates a reentrancy vulnerability.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 tokenId) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/
function approve(address to, uint256 tokenId) external;
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the address zero.
*
* 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);
}
// OpenZeppelin v5.0.2: contracts/token/ERC20/IERC20.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/BurrowMarketIERC20.sol)
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface BurrowMarketIERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the value of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the value of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves a `value` amount of tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 value) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets a `value` amount of tokens as the allowance of `spender` over the
* caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 value) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from `from` to `to` using the
* allowance mechanism. `value` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
// OpenZeppelin v5.0.2: contracts/token/ERC20/extensions/IERC20Permit.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/BurrowMarketIERC20Permit.sol)
/**
* @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 {BurrowMarketIERC20-allowance}) by
* presenting a message signed by the account. By not relying on {BurrowMarketIERC20-approve}, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*
* ==== Security Considerations
*
* There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
* expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
* considered as an intention to spend the allowance in any specific way. The second is that because permits have
* built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
* take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
* generally recommended is:
*
* ```solidity
* function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
* try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
* doThing(..., value);
* }
*
* function doThing(..., uint256 value) public {
* token.safeTransferFrom(msg.sender, address(this), value);
* ...
* }
* ```
*
* Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
* `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
* {BurrowMarketSafeERC20-safeTransferFrom}).
*
* Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
* contracts should have entry points that don't rely on permit.
*/
interface BurrowMarketIERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
* given ``owner``'s signed approval.
*
* IMPORTANT: The same issues {BurrowMarketIERC20-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].
*
* CAUTION: See Security Considerations above.
*/
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);
}
// OpenZeppelin v5.0.2: contracts/utils/Address.sol
// OpenZeppelin Contracts (last updated v5.0.0) (utils/BurrowMarketAddress.sol)
/**
* @dev Collection of functions related to the address type
*/
library BurrowMarketAddress {
/**
* @dev The ETH balance of the account is not enough to perform the operation.
*/
error AddressInsufficientBalance(address account);
/**
* @dev There's no code at `target` (it is not a contract).
*/
error AddressEmptyCode(address target);
/**
* @dev A call to an address target failed. The target may have reverted.
*/
error FailedInnerCall();
/**
* @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
* {BurrowMarketReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
if (address(this).balance < amount) {
revert AddressInsufficientBalance(address(this));
}
(bool success,) = recipient.call{value: amount}("");
if (!success) {
revert FailedInnerCall();
}
}
/**
* @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 or custom error, it is bubbled
* up by this function (like regular Solidity function calls). However, if
* the call reverted with no returned reason, this function reverts with a
* {FailedInnerCall} error.
*
* 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.
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0);
}
/**
* @dev Same as {xref-BurrowMarketAddress-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`.
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
if (address(this).balance < value) {
revert AddressInsufficientBalance(address(this));
}
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Same as {xref-BurrowMarketAddress-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Same as {xref-BurrowMarketAddress-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
* was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
* unsuccessful call.
*/
function verifyCallResultFromTarget(address target, bool success, bytes memory returndata)
internal
view
returns (bytes memory)
{
if (!success) {
_revert(returndata);
} else {
// only check if target is a contract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
if (returndata.length == 0 && target.code.length == 0) {
revert AddressEmptyCode(target);
}
return returndata;
}
}
/**
* @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
* revert reason or with a default {FailedInnerCall} error.
*/
function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
if (!success) {
_revert(returndata);
} else {
return returndata;
}
}
/**
* @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
*/
function _revert(bytes memory returndata) 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 FailedInnerCall();
}
}
}
// OpenZeppelin v5.0.2: contracts/token/ERC20/utils/SafeERC20.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/BurrowMarketSafeERC20.sol)
/**
* @title BurrowMarketSafeERC20
* @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 BurrowMarketSafeERC20 for BurrowMarketIERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library BurrowMarketSafeERC20 {
using BurrowMarketAddress for address;
/**
* @dev An operation with an ERC20 token failed.
*/
error SafeERC20FailedOperation(address token);
/**
* @dev Indicates a failed `decreaseAllowance` request.
*/
error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
/**
* @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(BurrowMarketIERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeCall(token.transfer, (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(BurrowMarketIERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, 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(BurrowMarketIERC20 token, address spender, uint256 value) internal {
uint256 oldAllowance = token.allowance(address(this), spender);
forceApprove(token, spender, oldAllowance + value);
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
* value, non-reverting calls are assumed to be successful.
*/
function safeDecreaseAllowance(BurrowMarketIERC20 token, address spender, uint256 requestedDecrease) internal {
unchecked {
uint256 currentAllowance = token.allowance(address(this), spender);
if (currentAllowance < requestedDecrease) {
revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
}
forceApprove(token, spender, currentAllowance - requestedDecrease);
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
* to be set to zero before setting it to a non-zero value, such as USDT.
*/
function forceApprove(BurrowMarketIERC20 token, address spender, uint256 value) internal {
bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @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(BurrowMarketIERC20 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 {BurrowMarketAddress-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);
if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
revert SafeERC20FailedOperation(address(token));
}
}
/**
* @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(BurrowMarketIERC20 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 {BurrowMarketAddress-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(token).code.length > 0;
}
}
// OpenZeppelin v5.0.2: contracts/utils/math/Math.sol
// OpenZeppelin Contracts (last updated v5.0.0) (utils/math/BurrowMarketMath.sol)
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library BurrowMarketMath {
/**
* @dev Muldiv operation overflow.
*/
error MathOverflowedMulDiv();
enum Rounding {
Floor, // Toward negative infinity
Ceil, // Toward positive infinity
Trunc, // Toward zero
Expand // Away from zero
}
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with an overflow flag.
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b > a) return (false, 0);
return (true, a - b);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a / b);
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
if (b == 0) return (false, 0);
return (true, a % b);
}
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds towards infinity instead
* of rounding towards zero.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
if (b == 0) {
// Guarantee the same behavior as in a regular Solidity division.
return a / b;
}
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
* denominator == 0.
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) with further edits by
* Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0 = x * y; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
if (denominator <= prod1) {
revert MathOverflowedMulDiv();
}
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator.
// Always >= 1. See https://cs.stackexchange.com/q/138556/92363.
uint256 twos = denominator & (0 - denominator);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also
// works in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
* towards zero.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256 of a positive value rounded towards zero.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
}
}
/**
* @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
*/
function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
return uint8(rounding) % 2 == 1;
}
}
/// @dev The only vault entry point the market needs. donate pulls SQK from its caller.
interface IBurrowMarketVault {
function donate(uint256 amount) external;
}
/// @title BurrowMarket
/// @notice SQK-denominated Squeek sales and Dutch auctions, with fees paid to BurrowVault.
/// @dev Unaudited; intended for testnet use. All amounts are raw SQK units (18 decimals).
/// Listings escrow the NFT until purchase or seller cancellation. Liquidation in the
/// vault gives the collateral to the liquidator, who may then call startAuction like
/// any other NFT owner. The market neither seizes collateral nor settles loan debt.
/// SQK, Squeek and the fee vault are immutable, constructor-supplied contracts.
contract BurrowMarket is BurrowMarketOwnable2Step, BurrowMarketERC721Holder, BurrowMarketReentrancyGuard {
using BurrowMarketSafeERC20 for BurrowMarketIERC20;
uint256 public constant BPS = 10_000;
uint256 public constant MAX_FEE_BPS = 500;
BurrowMarketIERC20 public immutable sqk;
BurrowMarketIERC721 public immutable squeek;
IBurrowMarketVault public immutable vault;
uint256 public immutable auctionDuration;
uint256 public feeBps;
struct Listing {
address seller;
uint256 price; // Fixed price, or the premium starting price of a Dutch auction.
uint256 floorPrice;
uint256 startedAt;
uint256 saleFeeBps; // Snapshotted at listing time, including for auctions.
bool isAuction;
}
mapping(uint256 tokenId => Listing) public listings;
error InvalidContract(address account);
error FeeTooHigh(uint256 requested);
error InvalidAuctionDuration();
error InvalidPrice();
error InvalidAuctionPrices(uint256 startPrice, uint256 floorPrice);
error AlreadyListed(uint256 tokenId);
error NotListed(uint256 tokenId);
error NotTokenOwner(uint256 tokenId);
error NotSeller(uint256 tokenId);
error PriceExceedsLimit(uint256 price, uint256 maxPrice);
error UnexpectedNFT();
error UnexpectedSQKTransfer();
error FeeNotCollected();
event Listed(uint256 indexed tokenId, address indexed seller, uint256 price, uint256 feeBps);
event AuctionStarted(
uint256 indexed tokenId,
address indexed seller,
uint256 startPrice,
uint256 floorPrice,
uint256 startedAt,
uint256 duration,
uint256 feeBps
);
event Cancelled(uint256 indexed tokenId, address indexed seller);
event Sold(uint256 indexed tokenId, address indexed seller, address indexed buyer, uint256 price, uint256 fee);
event FeeBpsUpdated(uint256 oldFeeBps, uint256 newFeeBps);
/// @param sqk_ The SQK ERC20 used for every payment.
/// @param squeek_ The only ERC721 collection accepted by this market.
/// @param vault_ The Burrow vault implementing donate(uint256).
/// @param initialOwner The administrator, whose sole market power is the capped fee.
/// @param initialFeeBps Sale fee in basis points, at most 500 (5%).
/// @param auctionDuration_ Immutable decay window in seconds, greater than zero.
constructor(
address sqk_,
address squeek_,
address vault_,
address initialOwner,
uint256 initialFeeBps,
uint256 auctionDuration_
) BurrowMarketOwnable(initialOwner) {
if (sqk_.code.length == 0) revert InvalidContract(sqk_);
if (squeek_.code.length == 0) revert InvalidContract(squeek_);
if (vault_.code.length == 0) revert InvalidContract(vault_);
if (initialFeeBps > MAX_FEE_BPS) revert FeeTooHigh(initialFeeBps);
if (auctionDuration_ == 0) revert InvalidAuctionDuration();
sqk = BurrowMarketIERC20(sqk_);
squeek = BurrowMarketIERC721(squeek_);
vault = IBurrowMarketVault(vault_);
auctionDuration = auctionDuration_;
feeBps = initialFeeBps;
emit FeeBpsUpdated(0, initialFeeBps);
}
/// @notice Escrow an NFT at a fixed SQK price. Approve this market before calling.
function list(uint256 tokenId, uint256 price) external nonReentrant {
if (price == 0) revert InvalidPrice();
_checkCanList(tokenId);
listings[tokenId] = Listing(msg.sender, price, price, block.timestamp, feeBps, false);
emit Listed(tokenId, msg.sender, price, feeBps);
squeek.safeTransferFrom(msg.sender, address(this), tokenId);
}
/// @notice Escrow an NFT for a Dutch auction, including NFTs obtained in liquidation.
/// @dev The seller chooses a premium startPrice strictly above a nonzero floorPrice.
/// The duration is fixed for this market. An unsold NFT remains purchasable at the
/// floor after that window, and only its seller may cancel it.
function startAuction(uint256 tokenId, uint256 startPrice, uint256 floorPrice) external nonReentrant {
if (floorPrice == 0 || startPrice <= floorPrice) revert InvalidAuctionPrices(startPrice, floorPrice);
_checkCanList(tokenId);
listings[tokenId] = Listing(msg.sender, startPrice, floorPrice, block.timestamp, feeBps, true);
emit AuctionStarted(tokenId, msg.sender, startPrice, floorPrice, block.timestamp, auctionDuration, feeBps);
squeek.safeTransferFrom(msg.sender, address(this), tokenId);
}
/// @notice Cancel either type of sale and return the escrowed NFT to its seller.
function cancel(uint256 tokenId) external nonReentrant {
address seller = listings[tokenId].seller;
if (seller == address(0)) revert NotListed(tokenId);
if (seller != msg.sender) revert NotSeller(tokenId);
delete listings[tokenId];
emit Cancelled(tokenId, seller);
squeek.safeTransferFrom(address(this), seller, tokenId);
}
/// @notice Buy a fixed-price listing or auction for no more than maxPrice SQK.
/// @dev There is deliberately no unbounded overload: a seller could otherwise cancel
/// and relist at any price up to the buyer's allowance ahead of the purchase.
function buy(uint256 tokenId, uint256 maxPrice) external nonReentrant {
_buy(tokenId, maxPrice);
}
/// @notice Quote the current gross price, including the fee, for either sale type.
function currentPrice(uint256 tokenId) external view returns (uint256) {
Listing memory listing = listings[tokenId];
if (listing.seller == address(0)) revert NotListed(tokenId);
return _price(listing);
}
/// @notice Set the fee for future listings; existing sellers keep their agreed fee.
function setFeeBps(uint256 newFeeBps) external onlyOwner nonReentrant {
if (newFeeBps > MAX_FEE_BPS) revert FeeTooHigh(newFeeBps);
uint256 oldFeeBps = feeBps;
feeBps = newFeeBps;
emit FeeBpsUpdated(oldFeeBps, newFeeBps);
}
/// @dev Accept only the safe transfer initiated by list/startAuction. This callback
/// performs no value transfer and runs inside their nonReentrant guard. Unsolicited
/// safe transfers are rejected; do not send NFTs here with unsafe transferFrom.
function onERC721Received(address operator, address from, uint256 tokenId, bytes memory)
public
view
override
returns (bytes4)
{
if (
msg.sender != address(squeek) || operator != address(this) || !_reentrancyGuardEntered()
|| from == address(0) || listings[tokenId].seller != from
) revert UnexpectedNFT();
return BurrowMarketIERC721Receiver.onERC721Received.selector;
}
function _checkCanList(uint256 tokenId) private view {
if (listings[tokenId].seller != address(0)) revert AlreadyListed(tokenId);
if (squeek.ownerOf(tokenId) != msg.sender) revert NotTokenOwner(tokenId);
}
function _price(Listing memory listing) private view returns (uint256) {
if (!listing.isAuction) return listing.price;
uint256 elapsed = block.timestamp - listing.startedAt;
if (elapsed >= auctionDuration) return listing.floorPrice;
// Full-precision multiplication avoids overflow even for extreme prices.
// Round the discount down so the gross price rounds up and never undershoots.
return listing.price - BurrowMarketMath.mulDiv(listing.price - listing.floorPrice, elapsed, auctionDuration);
}
function _buy(uint256 tokenId, uint256 maxPrice) private {
Listing memory listing = listings[tokenId];
if (listing.seller == address(0)) revert NotListed(tokenId);
uint256 price = _price(listing);
if (price > maxPrice) revert PriceExceedsLimit(price, maxPrice);
uint256 fee = BurrowMarketMath.mulDiv(price, listing.saleFeeBps, BPS);
// Consume the listing before any token, vault or recipient callback.
delete listings[tokenId];
emit Sold(tokenId, listing.seller, msg.sender, price, fee);
uint256 balanceBefore = sqk.balanceOf(address(this));
sqk.safeTransferFrom(msg.sender, address(this), price);
uint256 balanceAfter = sqk.balanceOf(address(this));
if (balanceAfter < balanceBefore || balanceAfter - balanceBefore != price) revert UnexpectedSQKTransfer();
if (fee != 0) {
// donate pulls SQK. Approve only this fee and revoke any residual allowance.
sqk.forceApprove(address(vault), fee);
vault.donate(fee);
sqk.forceApprove(address(vault), 0);
uint256 balanceAfterDonation = sqk.balanceOf(address(this));
if (balanceAfterDonation > balanceAfter || balanceAfter - balanceAfterDonation != fee) {
revert FeeNotCollected();
}
}
sqk.safeTransfer(listing.seller, price - fee);
squeek.safeTransferFrom(address(this), msg.sender, tokenId);
}
}