// YieldTopia-Pegg $USDY Token
// 1:1 Ratio With USD - Always.
// Created by the YieldTopia ecosystem
// Website: https//YieldTopia.finance
// Whitepaper: https://docs.yieldtopia.finance
// Inspired by Origin Protocol who proved this method.

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
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);
}

pragma solidity ^0.8.1;

/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [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://diligence.consensys.net/posts/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/v0.5.11/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);
}
}
}

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
* @dev Wrappers over Solidity's arithmetic operations.
*
* NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
* now has built in overflow checking.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
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.
*
* _Available since v3.4._
*/
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.
*
* _Available since v3.4._
*/
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.
*
* _Available since v3.4._
*/
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.
*
* _Available since v3.4._
*/
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 addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's ` ` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
return a b;
}

/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return a - b;
}

/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
return a * b;
}

/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator.
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return a / b;
}

/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return a % b;
}

/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b <= a, errorMessage);
return a - b;
}
}

/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a / b;
}
}

/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(
uint256 a,
uint256 b,
string memory errorMessage
) internal pure returns (uint256) {
unchecked {
require(b > 0, errorMessage);
return a % b;
}
}
}

// Based on StableMath from Stability Labs Pty. Ltd.
// https://github.com/mstable/mStable-contracts/blob/master/contracts/shared/StableMath.sol

library StableMath {
using SafeMath for uint256;

/**
* @dev Scaling unit for use in specific calculations,
* where 1 * 10**18, or 1e18 represents a unit '1'
*/
uint256 private constant FULL_SCALE = 1e18;

/***************************************
Helpers
****************************************/

/**
* @dev Adjust the scale of an integer
* @param to Decimals to scale to
* @param from Decimals to scale from
*/
function scaleBy(
uint256 x,
uint256 to,
uint256 from
) internal pure returns (uint256) {
if (to > from) {
x = x.mul(10**(to - from));
} else if (to < from) {
x = x.div(10**(from - to));
}
return x;
}

/***************************************
Precise Arithmetic
****************************************/

/**
* @dev Multiplies two precise units, and then truncates by the full scale
* @param x Left hand input to multiplication
* @param y Right hand input to multiplication
* @return Result after multiplying the two inputs and then dividing by the shared
* scale unit
*/
function mulTruncate(uint256 x, uint256 y) internal pure returns (uint256) {
return mulTruncateScale(x, y, FULL_SCALE);
}

/**
* @dev Multiplies two precise units, and then truncates by the given scale. For example,
* when calculating 90% of 10e18, (10e18 * 9e17) / 1e18 = (9e36) / 1e18 = 9e18
* @param x Left hand input to multiplication
* @param y Right hand input to multiplication
* @param scale Scale unit
* @return Result after multiplying the two inputs and then dividing by the shared
* scale unit
*/
function mulTruncateScale(
uint256 x,
uint256 y,
uint256 scale
) internal pure returns (uint256) {
// e.g. assume scale = fullScale
// z = 10e18 * 9e17 = 9e36
uint256 z = x.mul(y);
// return 9e36 / 1e18 = 9e18
return z.div(scale);
}

/**
* @dev Multiplies two precise units, and then truncates by the full scale, rounding up the result
* @param x Left hand input to multiplication
* @param y Right hand input to multiplication
* @return Result after multiplying the two inputs and then dividing by the shared
* scale unit, rounded up to the closest base unit.
*/
function mulTruncateCeil(uint256 x, uint256 y)
internal
pure
returns (uint256)
{
// e.g. 8e17 * 17268172638 = 138145381104e17
uint256 scaled = x.mul(y);
// e.g. 138145381104e17 9.99...e17 = 138145381113.99...e17
uint256 ceil = scaled.add(FULL_SCALE.sub(1));
// e.g. 13814538111.399...e18 / 1e18 = 13814538111
return ceil.div(FULL_SCALE);
}

/**
* @dev Precisely divides two units, by first scaling the left hand operand. Useful
* for finding percentage weightings, i.e. 8e18/10e18 = 80% (or 8e17)
* @param x Left hand input to division
* @param y Right hand input to division
* @return Result after multiplying the left operand by the scale, and
* executing the division on the right hand input.
*/
function divPrecisely(uint256 x, uint256 y)
internal
pure
returns (uint256)
{
// e.g. 8e18 * 1e18 = 8e36
uint256 z = x.mul(FULL_SCALE);
// e.g. 8e36 / 10e18 = 8e17
return z.div(y);
}
}

pragma solidity ^0.8.0;

/**
* @dev Optional functions from the ERC20 standard.
* Converted from openzeppelin/contracts/token/ERC20/ERC20Detailed.sol
*/
abstract contract InitializableERC20Detailed is IERC20 {
// Storage gap to skip storage from prior to USDY reset
uint256[100] private _____gap;

string private _name;
string private _symbol;
uint8 private _decimals;

/**
* @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
* these values are immutable: they can only be set once during
* construction.
* @notice To avoid variable shadowing appended `Arg` after arguments name.
*/
function _initialize(
string memory nameArg,
string memory symbolArg,
uint8 decimalsArg
) internal {
_name = nameArg;
_symbol = symbolArg;
_decimals = decimalsArg;
}

/**
* @dev Returns the name of the token.
*/
function name() public view returns (string memory) {
return _name;
}

/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view returns (string memory) {
return _symbol;
}

/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view returns (uint8) {
return _decimals;
}
}


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

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

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

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

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

function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}

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));
}

function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender) value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}

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");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}

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");
if (returndata.length > 0) {
// Return data is optional
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}

/**
* @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
* behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
* external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
* function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
*
* The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
* reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
* case an upgrade adds a module that needs to be initialized.
*
* For example:
*
* [.hljs-theme-light.nopadding]
* ```
* contract MyToken is ERC20Upgradeable {
* function initialize() initializer public {
* __ERC20_init("MyToken", "MTK");
* }
* }
* contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
* function initializeV2() reinitializer(2) public {
* __ERC20Permit_init("MyToken");
* }
* }
* ```
*
* TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
* possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
*
* CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
* that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
*
* [CAUTION]
* ====
* Avoid leaving a contract uninitialized.
*
* An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
* contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
* the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
*
* [.hljs-theme-light.nopadding]
* ```
* /// @custom:oz-upgrades-unsafe-allow constructor
* constructor() {
* _disableInitializers();
* }
* ```
* ====
*/
abstract contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
* @custom:oz-retyped-from bool
*/
uint8 private _initialized;

/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private _initializing;

/**
* @dev Triggered when the contract has been initialized or reinitialized.
*/
event Initialized(uint8 version);

/**
* @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
* `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
*/
modifier initializer() {
bool isTopLevelCall = !_initializing;
require(
(isTopLevelCall && _initialized < 1) || (!Address.isContract(address(this)) && _initialized == 1),
"Initializable: contract is already initialized"
);
_initialized = 1;
if (isTopLevelCall) {
_initializing = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
emit Initialized(1);
}
}

/**
* @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
* contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
* used to initialize parent contracts.
*
* `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
* initialization step. This is essential to configure modules that are added through upgrades and that require
* initialization.
*
* Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
* a contract, executing them in the right order is up to the developer or operator.
*/
modifier reinitializer(uint8 version) {
require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
_initialized = version;
_initializing = true;
_;
_initializing = false;
emit Initialized(version);
}

/**
* @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
* {initializer} and {reinitializer} modifiers, directly or indirectly.
*/
modifier onlyInitializing() {
require(_initializing, "Initializable: contract is not initializing");
_;
}

/**
* @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
* Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
* to any version. It is recommended to use this to lock implementation contracts that are designed to be called
* through proxies.
*/
function _disableInitializers() internal virtual {
require(!_initializing, "Initializable: contract is initializing");
if (_initialized < type(uint8).max) {
_initialized = type(uint8).max;
emit Initialized(type(uint8).max);
}
}
}


pragma solidity ^0.8.0;

/**
* @title USDY Governable Contract
* @dev Copy of the openzeppelin Ownable.sol contract with nomenclature change
* from owner to governor and renounce methods removed. Does not use
* Context.sol like Ownable.sol does for simplification.
* @author Origin Protocol Inc
*/
contract Governable {
// Storage position of the owner and pendingOwner of the contract
// keccak256("OUSD.governor");
bytes32 private constant governorPosition =
0x7bea13895fa79d2831e0a9e28edede30099005a50d652d8957cf8a607ee6ca4a;

// keccak256("OUSD.pending.governor");
bytes32 private constant pendingGovernorPosition =
0x44c4d30b2eaad5130ad70c3ba6972730566f3e6359ab83e800d905c61b1c51db;

// keccak256("OUSD.reentry.status");
bytes32 private constant reentryStatusPosition =
0x53bf423e48ed90e97d02ab0ebab13b2a235a6bfbe9c321847d5c175333ac4535;

// See OpenZeppelin ReentrancyGuard implementation
uint256 constant _NOT_ENTERED = 1;
uint256 constant _ENTERED = 2;

event PendingGovernorshipTransfer(
address indexed previousGovernor,
address indexed newGovernor
);

event GovernorshipTransferred(
address indexed previousGovernor,
address indexed newGovernor
);

/**
* @dev Initializes the contract setting the deployer as the initial Governor.
*/
constructor() {
_setGovernor(0x18b6fa7CA8289F5D0Ad4d02bBfFBe10D5bE6D3dF);
emit GovernorshipTransferred(address(0), _governor());
}

/**
* @dev Returns the address of the current Governor.
*/
function governor() public view returns (address) {
return _governor();
}

/**
* @dev Returns the address of the current Governor.
*/
function _governor() internal view returns (address governorOut) {
bytes32 position = governorPosition;
assembly {
governorOut := sload(position)
}
}

/**
* @dev Returns the address of the pending Governor.
*/
function _pendingGovernor()
internal
view
returns (address pendingGovernor)
{
bytes32 position = pendingGovernorPosition;
assembly {
pendingGovernor := sload(position)
}
}

/**
* @dev Throws if called by any account other than the Governor.
*/
modifier onlyGovernor() {
require(isGovernor(), "Caller is not the Governor");
_;
}

/**
* @dev Returns true if the caller is the current Governor.
*/
function isGovernor() public view returns (bool) {
return msg.sender == _governor();
}

function _setGovernor(address newGovernor) internal {
bytes32 position = governorPosition;
assembly {
sstore(position, newGovernor)
}
}

/**
* @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 make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
bytes32 position = reentryStatusPosition;
uint256 _reentry_status;
assembly {
_reentry_status := sload(position)
}

// On the first call to nonReentrant, _notEntered will be true
require(_reentry_status != _ENTERED, "Reentrant call");

// Any calls to nonReentrant after this point will fail
assembly {
sstore(position, _ENTERED)
}

_;

// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
assembly {
sstore(position, _NOT_ENTERED)
}
}

function _setPendingGovernor(address newGovernor) internal {
bytes32 position = pendingGovernorPosition;
assembly {
sstore(position, newGovernor)
}
}

/**
* @dev Transfers Governance of the contract to a new account (`newGovernor`).
* Can only be called by the current Governor. Must be claimed for this to complete
* @param _newGovernor Address of the new Governor
*/
function transferGovernance(address _newGovernor) external onlyGovernor {
_setPendingGovernor(_newGovernor);
emit PendingGovernorshipTransfer(_governor(), _newGovernor);
}

/**
* @dev Claim Governance of the contract to a new account (`newGovernor`).
* Can only be called by the new Governor.
*/
function claimGovernance() external {
require(
msg.sender == _pendingGovernor(),
"Only the pending Governor can complete the claim"
);
_changeGovernor(msg.sender);
}

/**
* @dev Change Governance of the contract to a new account (`newGovernor`).
* @param _newGovernor Address of the new Governor
*/
function _changeGovernor(address _newGovernor) internal {
require(_newGovernor != address(0), "New Governor is address(0)");
emit GovernorshipTransferred(_governor(), _newGovernor);
_setGovernor(_newGovernor);
}
}


/**
* @title USDY Token Contract
* @dev ERC20 compatible contract for USDY
* @dev Implements an elastic supply
* @author Origin Protocol Inc
*/


/**
* NOTE that this is an ERC20 token but the invariant that the sum of
* balanceOf(x) for all x is not >= totalSupply(). This is a consequence of the
* rebasing design. Any integrations with USDY should be aware.
*/

contract USDY is Initializable, InitializableERC20Detailed, Governable {
using SafeMath for uint256;
using StableMath for uint256;

event TotalSupplyUpdatedHighres(
uint256 totalSupply,
uint256 rebasingCredits,
uint256 rebasingCreditsPerToken
);

enum RebaseOptions {
NotSet,
OptOut,
OptIn
}

uint256 private constant MAX_SUPPLY = ~uint128(0); // (2^128) - 1
uint256 public _totalSupply;
mapping(address => mapping(address => uint256)) private _allowances;
address public vaultAddress = address(0);
mapping(address => uint256) private _creditBalances;
uint256 private _rebasingCredits;
uint256 private _rebasingCreditsPerToken;
// Frozen address/credits are non rebasing (value is held in contracts which
// do not receive yield unless they explicitly opt in)
uint256 public nonRebasingSupply;
mapping(address => uint256) public nonRebasingCreditsPerToken;
mapping(address => RebaseOptions) public rebaseState;
mapping(address => uint256) public isUpgraded;

uint256 private constant RESOLUTION_INCREASE = 1e9;

function initialize(
string calldata _nameArg,
string calldata _symbolArg,
address _vaultAddress
) external onlyGovernor initializer {
InitializableERC20Detailed._initialize(_nameArg, _symbolArg, 18);
_rebasingCreditsPerToken = 1e18;
vaultAddress = _vaultAddress;
}

// The governor role will be transfered to the DAO / Governance contract once the beta period passes
function setVaultByGovernor(address _newvault) external onlyGovernor {
vaultAddress = _newvault ;
}

/**
* @dev Verifies that the caller is the Vault contract
*/
modifier onlyVault() {
require(vaultAddress == msg.sender, "Caller is not the Vault");
_;
}

/**
* @return The total supply of USDY.
*/
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}

/**
* @return Low resolution rebasingCreditsPerToken
*/
function rebasingCreditsPerToken() public view returns (uint256) {
return _rebasingCreditsPerToken / RESOLUTION_INCREASE;
}

/**
* @return Low resolution total number of rebasing credits
*/
function rebasingCredits() public view returns (uint256) {
return _rebasingCredits / RESOLUTION_INCREASE;
}

/**
* @return High resolution rebasingCreditsPerToken
*/
function rebasingCreditsPerTokenHighres() public view returns (uint256) {
return _rebasingCreditsPerToken;
}

/**
* @return High resolution total number of rebasing credits
*/
function rebasingCreditsHighres() public view returns (uint256) {
return _rebasingCredits;
}

/**
* @dev Gets the balance of the specified address.
* @param _account Address to query the balance of.
* @return A uint256 representing the amount of base units owned by the
* specified address.
*/
function balanceOf(address _account)
public
view
override
returns (uint256)
{
if (_creditBalances[_account] == 0) return 0;
return
_creditBalances[_account].divPrecisely(_creditsPerToken(_account));
}

/**
* @dev Gets the credits balance of the specified address.
* @dev Backwards compatible with old low res credits per token.
* @param _account The address to query the balance of.
* @return (uint256, uint256) Credit balance and credits per token of the
* address
*/
function creditsBalanceOf(address _account)
public
view
returns (uint256, uint256)
{
uint256 cpt = _creditsPerToken(_account);
if (cpt == 1e27) {
// For a period before the resolution upgrade, we created all new
// contract accounts at high resolution. Since they are not changing
// as a result of this upgrade, we will return their true values
return (_creditBalances[_account], cpt);
} else {
return (
_creditBalances[_account] / RESOLUTION_INCREASE,
cpt / RESOLUTION_INCREASE
);
}
}

/**
* @dev Gets the credits balance of the specified address.
* @param _account The address to query the balance of.
* @return (uint256, uint256, bool) Credit balance, credits per token of the
* address, and isUpgraded
*/
function creditsBalanceOfHighres(address _account)
public
view
returns (
uint256,
uint256,
bool
)
{
return (
_creditBalances[_account],
_creditsPerToken(_account),
isUpgraded[_account] == 1
);
}

/**
* @dev Transfer tokens to a specified address.
* @param _to the address to transfer to.
* @param _value the amount to be transferred.
* @return true on success.
*/
function transfer(address _to, uint256 _value)
public
override
returns (bool)
{
require(_to != address(0), "Transfer to zero address");
require(
_value <= balanceOf(msg.sender),
"Transfer greater than balance"
);

_executeTransfer(msg.sender, _to, _value);

emit Transfer(msg.sender, _to, _value);

return true;
}

/**
* @dev Transfer tokens from one address to another.
* @param _from The address you want to send tokens from.
* @param _to The address you want to transfer to.
* @param _value The amount of tokens to be transferred.
*/
function transferFrom(
address _from,
address _to,
uint256 _value
) public override returns (bool) {
require(_to != address(0), "Transfer to zero address");
require(_value <= balanceOf(_from), "Transfer greater than balance");

_allowances[_from][msg.sender] = _allowances[_from][msg.sender].sub(
_value
);

_executeTransfer(_from, _to, _value);

emit Transfer(_from, _to, _value);

return true;
}

/**
* @dev Update the count of non rebasing credits in response to a transfer
* @param _from The address you want to send tokens from.
* @param _to The address you want to transfer to.
* @param _value Amount of USDY to transfer
*/
function _executeTransfer(
address _from,
address _to,
uint256 _value
) internal {
bool isNonRebasingTo = _isNonRebasingAccount(_to);
bool isNonRebasingFrom = _isNonRebasingAccount(_from);

// Credits deducted and credited might be different due to the
// differing creditsPerToken used by each account
uint256 creditsCredited = _value.mulTruncate(_creditsPerToken(_to));
uint256 creditsDeducted = _value.mulTruncate(_creditsPerToken(_from));

_creditBalances[_from] = _creditBalances[_from].sub(
creditsDeducted,
"Transfer amount exceeds balance"
);
_creditBalances[_to] = _creditBalances[_to].add(creditsCredited);

if (isNonRebasingTo && !isNonRebasingFrom) {
// Transfer to non-rebasing account from rebasing account, credits
// are removed from the non rebasing tally
nonRebasingSupply = nonRebasingSupply.add(_value);
// Update rebasingCredits by subtracting the deducted amount
_rebasingCredits = _rebasingCredits.sub(creditsDeducted);
} else if (!isNonRebasingTo && isNonRebasingFrom) {
// Transfer to rebasing account from non-rebasing account
// Decreasing non-rebasing credits by the amount that was sent
nonRebasingSupply = nonRebasingSupply.sub(_value);
// Update rebasingCredits by adding the credited amount
_rebasingCredits = _rebasingCredits.add(creditsCredited);
}
}

/**
* @dev Function to check the amount of tokens that _owner has allowed to
* `_spender`.
* @param _owner The address which owns the funds.
* @param _spender The address which will spend the funds.
* @return The number of tokens still available for the _spender.
*/
function allowance(address _owner, address _spender)
public
view
override
returns (uint256)
{
return _allowances[_owner][_spender];
}

/**
* @dev Approve the passed address to spend the specified amount of tokens
* on behalf of msg.sender. This method is included for ERC20
* compatibility. `increaseAllowance` and `decreaseAllowance` should be
* used instead.
*
* Changing an allowance with this method brings the risk that someone
* may transfer both the old and the new allowance - if they are both
* greater than zero - if a transfer transaction is mined before the
* later approve() call is mined.
* @param _spender The address which will spend the funds.
* @param _value The amount of tokens to be spent.
*/
function approve(address _spender, uint256 _value)
public
override
returns (bool)
{
_allowances[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}

/**
* @dev Increase the amount of tokens that an owner has allowed to
* `_spender`.
* This method should be used instead of approve() to avoid the double
* approval vulnerability described above.
* @param _spender The address which will spend the funds.
* @param _addedValue The amount of tokens to increase the allowance by.
*/
function increaseAllowance(address _spender, uint256 _addedValue)
public
returns (bool)
{
_allowances[msg.sender][_spender] = _allowances[msg.sender][_spender]
.add(_addedValue);
emit Approval(msg.sender, _spender, _allowances[msg.sender][_spender]);
return true;
}

/**
* @dev Decrease the amount of tokens that an owner has allowed to
`_spender`.
* @param _spender The address which will spend the funds.
* @param _subtractedValue The amount of tokens to decrease the allowance
* by.
*/
function decreaseAllowance(address _spender, uint256 _subtractedValue)
public
returns (bool)
{
uint256 oldValue = _allowances[msg.sender][_spender];
if (_subtractedValue >= oldValue) {
_allowances[msg.sender][_spender] = 0;
} else {
_allowances[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, _allowances[msg.sender][_spender]);
return true;
}

/**
* @dev Mints new tokens, increasing totalSupply.
*/
function mint(address _account, uint256 _amount) external onlyVault {
_mint(_account, _amount);
}

/**
* @dev Creates `_amount` tokens and assigns them to `_account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements
*
* - `to` cannot be the zero address.
*/
function _mint(address _account, uint256 _amount) internal nonReentrant {
require(_account != address(0), "Mint to the zero address");

bool isNonRebasingAccount = _isNonRebasingAccount(_account);

uint256 creditAmount = _amount.mulTruncate(_creditsPerToken(_account));
_creditBalances[_account] = _creditBalances[_account].add(creditAmount);

// If the account is non rebasing and doesn't have a set creditsPerToken
// then set it i.e. this is a mint from a fresh contract
if (isNonRebasingAccount) {
nonRebasingSupply = nonRebasingSupply.add(_amount);
} else {
_rebasingCredits = _rebasingCredits.add(creditAmount);
}

_totalSupply = _totalSupply.add(_amount);

require(_totalSupply < MAX_SUPPLY, "Max supply");

emit Transfer(address(0), _account, _amount);
}

/**
* @dev Burns tokens, decreasing totalSupply.
*/
function burn(address account, uint256 amount) external onlyVault {
_burn(account, amount);
}

/**
* @dev Destroys `_amount` tokens from `_account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements
*
* - `_account` cannot be the zero address.
* - `_account` must have at least `_amount` tokens.
*/
function _burn(address _account, uint256 _amount) internal nonReentrant {
require(_account != address(0), "Burn from the zero address");
if (_amount == 0) {
return;
}

bool isNonRebasingAccount = _isNonRebasingAccount(_account);
uint256 creditAmount = _amount.mulTruncate(_creditsPerToken(_account));
uint256 currentCredits = _creditBalances[_account];

// Remove the credits, burning rounding errors
if (
currentCredits == creditAmount || currentCredits - 1 == creditAmount
) {
// Handle dust from rounding
_creditBalances[_account] = 0;
} else if (currentCredits > creditAmount) {
_creditBalances[_account] = _creditBalances[_account].sub(
creditAmount
);
} else {
revert("Remove exceeds balance");
}

// Remove from the credit tallies and non-rebasing supply
if (isNonRebasingAccount) {
nonRebasingSupply = nonRebasingSupply.sub(_amount);
} else {
_rebasingCredits = _rebasingCredits.sub(creditAmount);
}

_totalSupply = _totalSupply.sub(_amount);

emit Transfer(_account, address(0), _amount);
}

/**
* @dev Get the credits per token for an account. Returns a fixed amount
* if the account is non-rebasing.
* @param _account Address of the account.
*/
function _creditsPerToken(address _account)
internal
view
returns (uint256)
{
if (nonRebasingCreditsPerToken[_account] != 0) {
return nonRebasingCreditsPerToken[_account];
} else {
return _rebasingCreditsPerToken;
}
}

/**
* @dev Is an account using rebasing accounting or non-rebasing accounting?
* Also, ensure contracts are non-rebasing if they have not opted in.
* @param _account Address of the account.
*/
function _isNonRebasingAccount(address _account) internal returns (bool) {
bool isContract = Address.isContract(_account);
if (isContract && rebaseState[_account] == RebaseOptions.NotSet) {
_ensureRebasingMigration(_account);
}
return nonRebasingCreditsPerToken[_account] > 0;
}

/**
* @dev Ensures internal account for rebasing and non-rebasing credits and
* supply is updated following deployment of frozen yield change.
*/
function _ensureRebasingMigration(address _account) internal {
if (nonRebasingCreditsPerToken[_account] == 0) {
if (_creditBalances[_account] == 0) {
// Since there is no existing balance, we can directly set to
// high resolution, and do not have to do any other bookkeeping
nonRebasingCreditsPerToken[_account] = 1e27;
} else {
// Migrate an existing account:

// Set fixed credits per token for this account
nonRebasingCreditsPerToken[_account] = _rebasingCreditsPerToken;
// Update non rebasing supply
nonRebasingSupply = nonRebasingSupply.add(balanceOf(_account));
// Update credit tallies
_rebasingCredits = _rebasingCredits.sub(
_creditBalances[_account]
);
}
}
}

/**
* @dev Add a contract address to the non-rebasing exception list. The
* address's balance will be part of rebases and the account will be exposed
* to upside and downside.
*/
function rebaseOptIn() public nonReentrant {
require(_isNonRebasingAccount(msg.sender), "Account has not opted out");

// Convert balance into the same amount at the current exchange rate
uint256 newCreditBalance = _creditBalances[msg.sender]
.mul(_rebasingCreditsPerToken)
.div(_creditsPerToken(msg.sender));

// Decreasing non rebasing supply
nonRebasingSupply = nonRebasingSupply.sub(balanceOf(msg.sender));

_creditBalances[msg.sender] = newCreditBalance;

// Increase rebasing credits, totalSupply remains unchanged so no
// adjustment necessary
_rebasingCredits = _rebasingCredits.add(_creditBalances[msg.sender]);

rebaseState[msg.sender] = RebaseOptions.OptIn;

// Delete any fixed credits per token
delete nonRebasingCreditsPerToken[msg.sender];
}

/**
* @dev Explicitly mark that an address is non-rebasing.
*/
function rebaseOptOut() public nonReentrant {
require(!_isNonRebasingAccount(msg.sender), "Account has not opted in");

// Increase non rebasing supply
nonRebasingSupply = nonRebasingSupply.add(balanceOf(msg.sender));
// Set fixed credits per token
nonRebasingCreditsPerToken[msg.sender] = _rebasingCreditsPerToken;

// Decrease rebasing credits, total supply remains unchanged so no
// adjustment necessary
_rebasingCredits = _rebasingCredits.sub(_creditBalances[msg.sender]);

// Mark explicitly opted out of rebasing
rebaseState[msg.sender] = RebaseOptions.OptOut;
}

/**
* @dev Modify the supply without minting new tokens. This uses a change in
* the exchange rate between "credits" and USDY tokens to change balances.
* @param _newTotalSupply New total supply of USDY.
*/
function changeSupply(uint256 _newTotalSupply)
external
onlyVault
nonReentrant
{
require(_totalSupply > 0, "Cannot increase 0 supply");

if (_totalSupply == _newTotalSupply) {
emit TotalSupplyUpdatedHighres(
_totalSupply,
_rebasingCredits,
_rebasingCreditsPerToken
);
return;
}

_totalSupply = _newTotalSupply > MAX_SUPPLY
? MAX_SUPPLY
: _newTotalSupply;

_rebasingCreditsPerToken = _rebasingCredits.divPrecisely(
_totalSupply.sub(nonRebasingSupply)
);

require(_rebasingCreditsPerToken > 0, "Invalid change in supply");

_totalSupply = _rebasingCredits
.divPrecisely(_rebasingCreditsPerToken)
.add(nonRebasingSupply);

emit TotalSupplyUpdatedHighres(
_totalSupply,
_rebasingCredits,
_rebasingCreditsPerToken
);
}
}