Contract Source Code:
File 1 of 1 : SwiftZap
pragma solidity ^0.8.4;
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.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 Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
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. 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 {
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);
}
}
interface IERC20 {
/**
* @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 amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` 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 amount) 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 `amount` 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 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` 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 amount) external returns (bool);
}
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.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 {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);
}
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
/**
* @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);
}
}
}
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. 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(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));
}
}
abstract contract ReentrancyGuard {
// 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;
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
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// 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;
}
}
interface IUniswapV2Pair {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function price0CumulativeLast() external view returns (uint);
function price1CumulativeLast() external view returns (uint);
function kLast() external view returns (uint);
function mint(address to) external returns (uint liquidity);
function burn(address to) external returns (uint amount0, uint amount1);
function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
interface IUniswapV2Router01 {
function factory() external pure returns (address);
function WETH() external pure returns (address);
function addLiquidity(
address tokenA,
address tokenB,
uint amountADesired,
uint amountBDesired,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) external returns (uint amountA, uint amountB, uint liquidity);
function addLiquidityETH(
address token,
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external payable returns (uint amountToken, uint amountETH, uint liquidity);
function removeLiquidity(
address tokenA,
address tokenB,
uint liquidity,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) external returns (uint amountA, uint amountB);
function removeLiquidityETH(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external returns (uint amountToken, uint amountETH);
function removeLiquidityWithPermit(
address tokenA,
address tokenB,
uint liquidity,
uint amountAMin,
uint amountBMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountA, uint amountB);
function removeLiquidityETHWithPermit(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountToken, uint amountETH);
function swapExactTokensForTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external returns (uint[] memory amounts);
function swapTokensForExactTokens(
uint amountOut,
uint amountInMax,
address[] calldata path,
address to,
uint deadline
) external returns (uint[] memory amounts);
function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
external
payable
returns (uint[] memory amounts);
function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
external
returns (uint[] memory amounts);
function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
external
returns (uint[] memory amounts);
function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
external
payable
returns (uint[] memory amounts);
function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}
interface IUniswapV2Router02 is IUniswapV2Router01 {
function removeLiquidityETHSupportingFeeOnTransferTokens(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external returns (uint amountETH);
function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountETH);
function swapExactTokensForTokensSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external;
function swapExactETHForTokensSupportingFeeOnTransferTokens(
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external payable;
function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external;
}
interface IWETH {
function deposit() external payable;
function transfer(address to, uint value) external returns (bool);
function withdraw(uint) external;
}
library Math {
function min(uint x, uint y) internal pure returns (uint z) {
z = x < y ? x : y;
}
// babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
function sqrt(uint y) internal pure returns (uint z) {
if (y > 3) {
z = y;
uint x = y / 2 + 1;
while (x < z) {
z = x;
x = (y / x + x) / 2;
}
} else if (y != 0) {
z = 1;
}
}
}
/*
* @author Adjusted PancakeSwap Zap contract for Swift Base.
*
*/
contract SwiftZap is Ownable, ReentrancyGuard {
using SafeERC20 for IERC20;
// Interface for Wrapped ETH (WETH)
IWETH public WETH;
// Router interface
IUniswapV2Router02 public swiftRouter;
// Maximum integer (used for managing allowance)
uint256 public constant MAX_INT = 2**256 - 1;
// Minimum amount for a swap
uint256 public constant MINIMUM_AMOUNT = 1000;
// Maximum reverse zap ratio (100 --> 1%, 1000 --> 0.1%)
uint256 public maxZapReverseRatio;
// Address Router
address private swiftRouterAddress;
// Address Wrapped ETH (WETH)
address private WETHAddress;
// Owner recovers token
event AdminTokenRecovery(address indexed tokenAddress, uint256 amountTokens);
// Owner changes the maxZapReverseRatio
event NewMaxZapReverseRatio(uint256 maxZapReverseRatio);
// tokenToZap = 0x00 address if ETH
event ZapIn(
address indexed tokenToZap,
address indexed lpToken,
uint256 tokenAmountIn,
uint256 lpTokenAmountReceived,
address indexed user
);
// token0ToZap = 0x00 address if ETH
event ZapInRebalancing(
address indexed token0ToZap,
address indexed token1ToZap,
address lpToken,
uint256 token0AmountIn,
uint256 token1AmountIn,
uint256 lpTokenAmountReceived,
address indexed user
);
// tokenToReceive = 0x00 address if ETH
event ZapOut(
address indexed lpToken,
address indexed tokenToReceive,
uint256 lpTokenAmount,
uint256 tokenAmountReceived,
address indexed user
);
/*
* @notice Fallback for WETH
*/
receive() external payable {
assert(msg.sender == WETHAddress);
}
/*
* @notice Constructor
* @param _WETHAddress: address of the WETH contract
* @param _swiftRouter: address of the Router
* @param _maxZapReverseRatio: inverse of maximum zappable swap, i.e max 2% of reserve = 50
*/
constructor(
address _WETHAddress,
address _swiftRouter,
uint256 _maxZapReverseRatio
) {
WETHAddress = _WETHAddress;
WETH = IWETH(_WETHAddress);
swiftRouterAddress = _swiftRouter;
swiftRouter = IUniswapV2Router02(_swiftRouter);
maxZapReverseRatio = _maxZapReverseRatio;
}
/*
* @notice Zap ETH in a WETH pool (e.g. WETH/token)
* @param _lpToken: LP token address (e.g. ALB/ETH)
* @param _tokenAmountOutMin: minimum token amount (e.g. ALB) to receive in the intermediary swap (e.g. ETH --> ALB)
*/
function zapInETH(address _lpToken, uint256 _tokenAmountOutMin) external payable nonReentrant {
WETH.deposit{value: msg.value}();
// Call zap function
uint256 lpTokenAmountTransferred = _zapIn(WETHAddress, msg.value, _lpToken, _tokenAmountOutMin);
// Emit event
emit ZapIn(
address(0x0000000000000000000000000000000000000000),
_lpToken,
msg.value,
lpTokenAmountTransferred,
msg.sender
);
}
/*
* @notice Zap a token in (e.g. token/other token)
* @param _tokenToZap: token to zap
* @param _tokenAmountIn: amount of token to swap
* @param _lpToken: LP token address (e.g. ALB/USDC)
* @param _tokenAmountOutMin: minimum token to receive (e.g. ALB) in the intermediary swap (e.g. USDC --> ALB)
*/
function zapInToken(
address _tokenToZap,
uint256 _tokenAmountIn,
address _lpToken,
uint256 _tokenAmountOutMin
) external nonReentrant {
// Transfer tokens to this contract
IERC20(_tokenToZap).safeTransferFrom(msg.sender, address(this), _tokenAmountIn);
// Call zap function
uint256 lpTokenAmountTransferred = _zapIn(_tokenToZap, _tokenAmountIn, _lpToken, _tokenAmountOutMin);
// Emit event
emit ZapIn(_tokenToZap, _lpToken, _tokenAmountIn, lpTokenAmountTransferred, msg.sender);
}
/*
* @notice Zap two tokens in, rebalance them to 50-50, before adding them to LP
* @param _token0ToZap: address of token0 to zap
* @param _token1ToZap: address of token1 to zap
* @param _token0AmountIn: amount of token0 to zap
* @param _token1AmountIn: amount of token1 to zap
* @param _lpToken: LP token address (token0/token1)
* @param _tokenAmountInMax: maximum token amount to sell (in token to sell in the intermediary swap)
* @param _tokenAmountOutMin: minimum token to receive in the intermediary swap
* @param _isToken0Sold: whether token0 is expected to be sold (if false, sell token1)
*/
function zapInTokenRebalancing(
address _token0ToZap,
address _token1ToZap,
uint256 _token0AmountIn,
uint256 _token1AmountIn,
address _lpToken,
uint256 _tokenAmountInMax,
uint256 _tokenAmountOutMin,
bool _isToken0Sold
) external nonReentrant {
// Transfer tokens to this contract
IERC20(_token0ToZap).safeTransferFrom(msg.sender, address(this), _token0AmountIn);
IERC20(_token1ToZap).safeTransferFrom(msg.sender, address(this), _token1AmountIn);
// Call zapIn function
uint256 lpTokenAmountTransferred = _zapInRebalancing(
_token0ToZap,
_token1ToZap,
_token0AmountIn,
_token1AmountIn,
_lpToken,
_tokenAmountInMax,
_tokenAmountOutMin,
_isToken0Sold
);
// Emit event
emit ZapInRebalancing(
_token0ToZap,
_token1ToZap,
_lpToken,
_token0AmountIn,
_token1AmountIn,
lpTokenAmountTransferred,
msg.sender
);
}
/*
* @notice Zap 1 token and ETH, rebalance them to 50-50, before adding them to LP
* @param _token1ToZap: address of token1 to zap
* @param _token1AmountIn: amount of token1 to zap
* @param _lpToken: LP token address
* @param _tokenAmountInMax: maximum token amount to sell (in token to sell in the intermediary swap)
* @param _tokenAmountOutMin: minimum token to receive in the intermediary swap
* @param _isToken0Sold: whether token0 is expected to be sold (if false, sell token1)
*/
function zapInETHRebalancing(
address _token1ToZap,
uint256 _token1AmountIn,
address _lpToken,
uint256 _tokenAmountInMax,
uint256 _tokenAmountOutMin,
bool _isToken0Sold
) external payable nonReentrant {
WETH.deposit{value: msg.value}();
IERC20(_token1ToZap).safeTransferFrom(msg.sender, address(this), _token1AmountIn);
// Call zapIn function
uint256 lpTokenAmountTransferred = _zapInRebalancing(
WETHAddress,
_token1ToZap,
msg.value,
_token1AmountIn,
_lpToken,
_tokenAmountInMax,
_tokenAmountOutMin,
_isToken0Sold
);
// Emit event
emit ZapInRebalancing(
address(0x0000000000000000000000000000000000000000),
_token1ToZap,
_lpToken,
msg.value,
_token1AmountIn,
lpTokenAmountTransferred,
msg.sender
);
}
/*
* @notice Zap a LP token out to receive ETH
* @param _lpToken: LP token address (e.g. ALB/WETH)
* @param _lpTokenAmount: amount of LP tokens to zap out
* @param _tokenAmountOutMin: minimum amount to receive (in ETH/WETH) in the intermediary swap (e.g. ALB --> ETH)
*/
function zapOutETH(
address _lpToken,
uint256 _lpTokenAmount,
uint256 _tokenAmountOutMin,
uint256 _totalTokenAmountOutMin
) external nonReentrant {
// Transfer LP token to this address
IERC20(_lpToken).safeTransferFrom(msg.sender, address(_lpToken), _lpTokenAmount);
// Call zapOut
uint256 tokenAmountToTransfer = _zapOut(_lpToken, WETHAddress, _tokenAmountOutMin, _totalTokenAmountOutMin);
// Unwrap ETH
WETH.withdraw(tokenAmountToTransfer);
// Transfer ETH to the msg.sender
(bool success, ) = msg.sender.call{value: tokenAmountToTransfer}(new bytes(0));
require(success, "ETH: transfer fail");
// Emit event
emit ZapOut(
_lpToken,
address(0x0000000000000000000000000000000000000000),
_lpTokenAmount,
tokenAmountToTransfer,
msg.sender
);
}
/*
* @notice Zap a LP token out (to receive a token)
* @param _lpToken: LP token address (e.g. ALB/USDC)
* @param _tokenToReceive: one of the 2 tokens from the LP (e.g. ALB or USDC)
* @param _lpTokenAmount: amount of LP tokens to zap out
* @param _tokenAmountOutMin: minimum token to receive (e.g. ALB) in the intermediary swap (e.g. USDC --> ALB)
*/
function zapOutToken(
address _lpToken,
address _tokenToReceive,
uint256 _lpTokenAmount,
uint256 _tokenAmountOutMin,
uint256 _totalTokenAmountOutMin
) external nonReentrant {
// Transfer LP token to this address
IERC20(_lpToken).safeTransferFrom(msg.sender, address(_lpToken), _lpTokenAmount);
uint256 tokenAmountToTransfer = _zapOut(_lpToken, _tokenToReceive, _tokenAmountOutMin, _totalTokenAmountOutMin);
IERC20(_tokenToReceive).safeTransfer(msg.sender, tokenAmountToTransfer);
emit ZapOut(_lpToken, _tokenToReceive, _lpTokenAmount, tokenAmountToTransfer, msg.sender);
}
/**
* @notice It allows the owner to change the risk parameter for quantities
* @param _maxZapInverseRatio: new inverse ratio
* @dev This function is only callable by owner.
*/
function updateMaxZapInverseRatio(uint256 _maxZapInverseRatio) external onlyOwner {
maxZapReverseRatio = _maxZapInverseRatio;
emit NewMaxZapReverseRatio(_maxZapInverseRatio);
}
/**
* @notice It allows the owner to recover wrong tokens sent to the contract
* @param _tokenAddress: the address of the token to withdraw (18 decimals)
* @param _tokenAmount: the number of token amount to withdraw
* @dev This function is only callable by owner.
*/
function recoverWrongTokens(address _tokenAddress, uint256 _tokenAmount) external onlyOwner {
IERC20(_tokenAddress).safeTransfer(msg.sender, _tokenAmount);
emit AdminTokenRecovery(_tokenAddress, _tokenAmount);
}
/*
* @notice View the details for single zap
* @dev Use WETH for _tokenToZap (if ETH is the input)
* @param _tokenToZap: address of the token to zap
* @param _tokenAmountIn: amount of token to zap inputed
* @param _lpToken: address of the LP token
* @return swapAmountIn: amount that is expected to get swapped in intermediary swap
* @return swapAmountOut: amount that is expected to get received in intermediary swap
* @return swapTokenOut: token address of the token that is used in the intermediary swap
*/
function estimateZapInSwap(
address _tokenToZap,
uint256 _tokenAmountIn,
address _lpToken
)
external
view
returns (
uint256 swapAmountIn,
uint256 swapAmountOut,
address swapTokenOut
)
{
address token0 = IUniswapV2Pair(_lpToken).token0();
address token1 = IUniswapV2Pair(_lpToken).token1();
require(_tokenToZap == token0 || _tokenToZap == token1, "Zap: Wrong tokens");
// Convert to uint256 (from uint112)
(uint256 reserveA, uint256 reserveB, ) = IUniswapV2Pair(_lpToken).getReserves();
if (token0 == _tokenToZap) {
swapTokenOut = token1;
swapAmountIn = _calculateAmountToSwap(_tokenAmountIn, reserveA, reserveB);
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveA, reserveB);
} else {
swapTokenOut = token0;
swapAmountIn = _calculateAmountToSwap(_tokenAmountIn, reserveB, reserveA);
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveB, reserveA);
}
return (swapAmountIn, swapAmountOut, swapTokenOut);
}
/*
* @notice View the details for a rebalancing zap
* @dev Use WETH for _token0ToZap (if ETH is the input)
* @param _token0ToZap: address of the token0 to zap
* @param _token1ToZap: address of the token0 to zap
* @param _token0AmountIn: amount for token0 to zap
* @param _token1AmountIn: amount for token1 to zap
* @param _lpToken: address of the LP token
* @return swapAmountIn: amount that is expected to get swapped in intermediary swap
* @return swapAmountOut: amount that is expected to get received in intermediary swap
* @return isToken0Sold: whether the token0 is sold (false --> token1 is sold in the intermediary swap)
*/
function estimateZapInRebalancingSwap(
address _token0ToZap,
address _token1ToZap,
uint256 _token0AmountIn,
uint256 _token1AmountIn,
address _lpToken
)
external
view
returns (
uint256 swapAmountIn,
uint256 swapAmountOut,
bool sellToken0
)
{
require(
_token0ToZap == IUniswapV2Pair(_lpToken).token0() || _token0ToZap == IUniswapV2Pair(_lpToken).token1(),
"Zap: Wrong token0"
);
require(
_token1ToZap == IUniswapV2Pair(_lpToken).token0() || _token1ToZap == IUniswapV2Pair(_lpToken).token1(),
"Zap: Wrong token1"
);
require(_token0ToZap != _token1ToZap, "Zap: Same tokens");
// Convert to uint256 (from uint112)
(uint256 reserveA, uint256 reserveB, ) = IUniswapV2Pair(_lpToken).getReserves();
if (_token0ToZap == IUniswapV2Pair(_lpToken).token0()) {
sellToken0 = (_token0AmountIn * reserveB > _token1AmountIn * reserveA) ? true : false;
// Calculate the amount that is expected to be swapped
swapAmountIn = _calculateAmountToSwapForRebalancing(
_token0AmountIn,
_token1AmountIn,
reserveA,
reserveB,
sellToken0
);
// Calculate the amount expected to be received in the intermediary swap
if (sellToken0) {
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveA, reserveB);
} else {
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveB, reserveA);
}
} else {
sellToken0 = (_token0AmountIn * reserveA > _token1AmountIn * reserveB) ? true : false;
// Calculate the amount that is expected to be swapped
swapAmountIn = _calculateAmountToSwapForRebalancing(
_token0AmountIn,
_token1AmountIn,
reserveB,
reserveA,
sellToken0
);
// Calculate the amount expected to be received in the intermediary swap
if (sellToken0) {
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveB, reserveA);
} else {
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveA, reserveB);
}
}
return (swapAmountIn, swapAmountOut, sellToken0);
}
/*
* @notice View the details for single zap
* @dev Use WETH for _tokenToReceive (if ETH is the asset to be received)
* @param _lpToken: address of the LP token to zap out
* @param _lpTokenAmount: amount of LP token to zap out
* @param _tokenToReceive: token address to receive
* @return swapAmountIn: amount that is expected to get swapped for intermediary swap
* @return swapAmountOut: amount that is expected to get received for intermediary swap
* @return swapTokenOut: address of the token that is sold in the intermediary swap
*/
function estimateZapOutSwap(
address _lpToken,
uint256 _lpTokenAmount,
address _tokenToReceive
)
external
view
returns (
uint256 swapAmountIn,
uint256 swapAmountOut,
address swapTokenOut
)
{
address token0 = IUniswapV2Pair(_lpToken).token0();
address token1 = IUniswapV2Pair(_lpToken).token1();
require(_tokenToReceive == token0 || _tokenToReceive == token1, "Zap: Token not in LP");
// Convert to uint256 (from uint112)
(uint256 reserveA, uint256 reserveB, ) = IUniswapV2Pair(_lpToken).getReserves();
if (token1 == _tokenToReceive) {
// sell token0
uint256 tokenAmountIn = (_lpTokenAmount * reserveA) / IUniswapV2Pair(_lpToken).totalSupply();
swapAmountIn = tokenAmountIn;
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveA, reserveB);
swapTokenOut = token0;
} else {
// sell token1
uint256 tokenAmountIn = (_lpTokenAmount * reserveB) / IUniswapV2Pair(_lpToken).totalSupply();
swapAmountIn = tokenAmountIn;
swapAmountOut = swiftRouter.getAmountOut(swapAmountIn, reserveB, reserveA);
swapTokenOut = token1;
}
return (swapAmountIn, swapAmountOut, swapTokenOut);
}
/*
* @notice Zap a token in (e.g. token/other token)
* @param _tokenToZap: token to zap
* @param _tokenAmountIn: amount of token to swap
* @param _lpToken: LP token address
* @param _tokenAmountOutMin: minimum token to receive in the intermediary swap
*/
function _zapIn(
address _tokenToZap,
uint256 _tokenAmountIn,
address _lpToken,
uint256 _tokenAmountOutMin
) internal returns (uint256 lpTokenReceived) {
require(_tokenAmountIn >= MINIMUM_AMOUNT, "Zap: Amount too low");
address token0 = IUniswapV2Pair(_lpToken).token0();
address token1 = IUniswapV2Pair(_lpToken).token1();
require(_tokenToZap == token0 || _tokenToZap == token1, "Zap: Wrong tokens");
// Retrieve the path
address[] memory path = new address[](2);
path[0] = _tokenToZap;
// Initiates an estimation to swap
uint256 swapAmountIn;
{
// Convert to uint256 (from uint112)
(uint256 reserveA, uint256 reserveB, ) = IUniswapV2Pair(_lpToken).getReserves();
require((reserveA >= MINIMUM_AMOUNT) && (reserveB >= MINIMUM_AMOUNT), "Zap: Reserves too low");
if (token0 == _tokenToZap) {
swapAmountIn = _calculateAmountToSwap(_tokenAmountIn, reserveA, reserveB);
path[1] = token1;
require(reserveA / swapAmountIn >= maxZapReverseRatio, "Zap: Quantity higher than limit");
} else {
swapAmountIn = _calculateAmountToSwap(_tokenAmountIn, reserveB, reserveA);
path[1] = token0;
require(reserveB / swapAmountIn >= maxZapReverseRatio, "Zap: Quantity higher than limit");
}
}
// Approve token to zap if necessary
_approveTokenIfNeeded(_tokenToZap, swapAmountIn);
uint256[] memory swappedAmounts = swiftRouter.swapExactTokensForTokens(
swapAmountIn,
_tokenAmountOutMin,
path,
address(this),
block.timestamp
);
// Approve other token if necessary
if (token0 == _tokenToZap) {
_approveTokenIfNeeded(token1, swapAmountIn);
} else {
_approveTokenIfNeeded(token0, swapAmountIn);
}
// Add liquidity and retrieve the amount of LP received by the sender
(, , lpTokenReceived) = swiftRouter.addLiquidity(
path[0],
path[1],
_tokenAmountIn - swappedAmounts[0],
swappedAmounts[1],
1,
1,
msg.sender,
block.timestamp
);
return lpTokenReceived;
}
/*
* @notice Zap two tokens in, rebalance them to 50-50, before adding them to LP
* @param _token0ToZap: address of token0 to zap
* @param _token1ToZap: address of token1 to zap
* @param _token0AmountIn: amount of token0 to zap
* @param _token1AmountIn: amount of token1 to zap
* @param _lpToken: LP token address
* @param _tokenAmountInMax: maximum token amount to sell (in token to sell in the intermediary swap)
* @param _tokenAmountOutMin: minimum token to receive in the intermediary swap
* @param _isToken0Sold: whether token0 is expected to be sold (if false, sell token1)
*/
function _zapInRebalancing(
address _token0ToZap,
address _token1ToZap,
uint256 _token0AmountIn,
uint256 _token1AmountIn,
address _lpToken,
uint256 _tokenAmountInMax,
uint256 _tokenAmountOutMin,
bool _isToken0Sold
) internal returns (uint256 lpTokenReceived) {
require(
_token0ToZap == IUniswapV2Pair(_lpToken).token0() || _token0ToZap == IUniswapV2Pair(_lpToken).token1(),
"Zap: Wrong token0"
);
require(
_token1ToZap == IUniswapV2Pair(_lpToken).token0() || _token1ToZap == IUniswapV2Pair(_lpToken).token1(),
"Zap: Wrong token1"
);
require(_token0ToZap != _token1ToZap, "Zap: Same tokens");
// Initiates an estimation to swap
uint256 swapAmountIn;
{
// Convert to uint256 (from uint112)
(uint256 reserveA, uint256 reserveB, ) = IUniswapV2Pair(_lpToken).getReserves();
require((reserveA >= MINIMUM_AMOUNT) && (reserveB >= MINIMUM_AMOUNT), "Zap: Reserves too low");
if (_token0ToZap == IUniswapV2Pair(_lpToken).token0()) {
swapAmountIn = _calculateAmountToSwapForRebalancing(
_token0AmountIn,
_token1AmountIn,
reserveA,
reserveB,
_isToken0Sold
);
require(reserveA / swapAmountIn >= maxZapReverseRatio, "Zap: Quantity higher than limit");
} else {
swapAmountIn = _calculateAmountToSwapForRebalancing(
_token0AmountIn,
_token1AmountIn,
reserveB,
reserveA,
_isToken0Sold
);
require(reserveB / swapAmountIn >= maxZapReverseRatio, "Zap: Quantity higher than limit");
}
}
require(swapAmountIn <= _tokenAmountInMax, "Zap: Amount to swap too high");
address[] memory path = new address[](2);
// Define path for swapping and check whether to approve token to sell in intermediary swap
if (_isToken0Sold) {
path[0] = _token0ToZap;
path[1] = _token1ToZap;
_approveTokenIfNeeded(_token0ToZap, swapAmountIn);
} else {
path[0] = _token1ToZap;
path[1] = _token0ToZap;
_approveTokenIfNeeded(_token1ToZap, swapAmountIn);
}
// Execute the swap and retrieve quantity received
uint256[] memory swappedAmounts = swiftRouter.swapExactTokensForTokens(
swapAmountIn,
_tokenAmountOutMin,
path,
address(this),
block.timestamp
);
// Check whether to approve other token and add liquidity to LP
if (_isToken0Sold) {
_approveTokenIfNeeded(_token1ToZap, swapAmountIn);
(, , lpTokenReceived) = swiftRouter.addLiquidity(
path[0],
path[1],
(_token0AmountIn - swappedAmounts[0]),
(_token1AmountIn + swappedAmounts[1]),
1,
1,
msg.sender,
block.timestamp
);
} else {
_approveTokenIfNeeded(_token0ToZap, swapAmountIn);
(, , lpTokenReceived) = swiftRouter.addLiquidity(
path[0],
path[1],
(_token1AmountIn - swappedAmounts[0]),
(_token0AmountIn + swappedAmounts[1]),
1,
1,
msg.sender,
block.timestamp
);
}
return lpTokenReceived;
}
/*
* @notice Zap a LP token out to a token (e.g. token/other token)
* @param _lpToken: LP token address
* @param _tokenToReceive: token address
* @param _tokenAmountOutMin: minimum token to receive in the intermediary swap
*/
function _zapOut(
address _lpToken,
address _tokenToReceive,
uint256 _tokenAmountOutMin,
uint256 _totalTokenAmountOutMin
) internal returns (uint256) {
address token0 = IUniswapV2Pair(_lpToken).token0();
address token1 = IUniswapV2Pair(_lpToken).token1();
require(_tokenToReceive == token0 || _tokenToReceive == token1, "Zap: Token not in LP");
// Burn all LP tokens to receive the two tokens to this address
(uint256 amount0, uint256 amount1) = IUniswapV2Pair(_lpToken).burn(address(this));
require(amount0 >= MINIMUM_AMOUNT, "SwiftRouter: INSUFFICIENT_A_AMOUNT");
require(amount1 >= MINIMUM_AMOUNT, "SwiftRouter: INSUFFICIENT_B_AMOUNT");
address[] memory path = new address[](2);
path[1] = _tokenToReceive;
uint256 swapAmountIn;
if (token0 == _tokenToReceive) {
path[0] = token1;
swapAmountIn = IERC20(token1).balanceOf(address(this));
// Approve token to sell if necessary
_approveTokenIfNeeded(token1, swapAmountIn);
} else {
path[0] = token0;
swapAmountIn = IERC20(token0).balanceOf(address(this));
// Approve token to sell if necessary
_approveTokenIfNeeded(token0, swapAmountIn);
}
// Swap tokens
swiftRouter.swapExactTokensForTokens(swapAmountIn, _tokenAmountOutMin, path, address(this), block.timestamp);
// Return full balance for the token to receive by the sender
require(_totalTokenAmountOutMin < IERC20(_tokenToReceive).balanceOf(address(this)), "amount is not enough");
return IERC20(_tokenToReceive).balanceOf(address(this));
}
/*
* @notice Allows to zap a token in (e.g. token/other token)
* @param _token: token address
*/
function _approveTokenIfNeeded(address _token, uint256 _swapAmountIn) private {
if (IERC20(_token).allowance(address(this), swiftRouterAddress) < _swapAmountIn) {
// Reset to 0
IERC20(_token).safeApprove(swiftRouterAddress, 0);
// Re-approve
IERC20(_token).safeApprove(swiftRouterAddress, MAX_INT);
}
}
/*
* @notice Calculate the swap amount to get the price at 50/50 split
* @param _token0AmountIn: amount of token 0
* @param _reserve0: amount in reserve for token0
* @param _reserve1: amount in reserve for token1
* @return amountToSwap: swapped amount (in token0)
*/
function _calculateAmountToSwap(
uint256 _token0AmountIn,
uint256 _reserve0,
uint256 _reserve1
) private view returns (uint256 amountToSwap) {
uint256 halfToken0Amount = _token0AmountIn / 2;
uint256 nominator = swiftRouter.getAmountOut(halfToken0Amount, _reserve0, _reserve1);
uint256 denominator = swiftRouter.quote(
halfToken0Amount,
_reserve0 + halfToken0Amount,
_reserve1 - nominator
);
// Adjustment for price impact
amountToSwap =
_token0AmountIn -
Math.sqrt((halfToken0Amount * halfToken0Amount * nominator) / denominator);
return amountToSwap;
}
/*
* @notice Calculate the amount to swap to get the tokens at a 50/50 split
* @param _token0AmountIn: amount of token 0
* @param _token1AmountIn: amount of token 1
* @param _reserve0: amount in reserve for token0
* @param _reserve1: amount in reserve for token1
* @param _isToken0Sold: whether token0 is expected to be sold (if false, sell token1)
* @return amountToSwap: swapped amount in token0 (if _isToken0Sold is true) or token1 (if _isToken0Sold is false)
*/
function _calculateAmountToSwapForRebalancing(
uint256 _token0AmountIn,
uint256 _token1AmountIn,
uint256 _reserve0,
uint256 _reserve1,
bool _isToken0Sold
) private view returns (uint256 amountToSwap) {
bool sellToken0 = (_token0AmountIn * _reserve1 > _token1AmountIn * _reserve0) ? true : false;
require(sellToken0 == _isToken0Sold, "Zap: Wrong trade direction");
if (sellToken0) {
uint256 token0AmountToSell = (_token0AmountIn - (_token1AmountIn * _reserve0) / _reserve1) / 2;
uint256 nominator = swiftRouter.getAmountOut(token0AmountToSell, _reserve0, _reserve1);
uint256 denominator = swiftRouter.quote(
token0AmountToSell,
_reserve0 + token0AmountToSell,
_reserve1 - nominator
);
// Calculate the amount to sell (in token0)
token0AmountToSell =
(_token0AmountIn - (_token1AmountIn * (_reserve0 + token0AmountToSell)) / (_reserve1 - nominator)) /
2;
// Adjustment for price impact
amountToSwap =
2 *
token0AmountToSell -
Math.sqrt((token0AmountToSell * token0AmountToSell * nominator) / denominator);
} else {
uint256 token1AmountToSell = (_token1AmountIn - (_token0AmountIn * _reserve1) / _reserve0) / 2;
uint256 nominator = swiftRouter.getAmountOut(token1AmountToSell, _reserve1, _reserve0);
uint256 denominator = swiftRouter.quote(
token1AmountToSell,
_reserve1 + token1AmountToSell,
_reserve0 - nominator
);
// Calculate the amount to sell (in token1)
token1AmountToSell =
(_token1AmountIn - ((_token0AmountIn * (_reserve1 + token1AmountToSell)) / (_reserve0 - nominator))) /
2;
// Adjustment for price impact
amountToSwap =
2 *
token1AmountToSell -
Math.sqrt((token1AmountToSell * token1AmountToSell * nominator) / denominator);
}
return amountToSwap;
}
}