Contract Name:
StakingPlatform
Contract Source Code:
File 1 of 1 : StakingPlatform
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (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);
}
/// @author RetreebInc
/// @title Interface Staking Platform with fixed APY and lockup
interface IStakingPlatform {
/**
* @notice function that start the staking
* @dev set `startPeriod` to the current current `block.timestamp`
* set `lockupPeriod` which is `block.timestamp` + `lockupDuration`
* and `endPeriod` which is `startPeriod` + `stakingDuration`
*/
function startStaking() external;
/**
* @notice function that allows a user to deposit tokens
* @dev user must first approve the amount to deposit before calling this function,
* cannot exceed the `maxAmountStaked`
* @param amount, the amount to be deposited
* @dev `endPeriod` to equal 0 (Staking didn't started yet),
* or `endPeriod` more than current `block.timestamp` (staking not finished yet)
* @dev `totalStaked + amount` must be less than `stakingMax`
* @dev that the amount deposited should greater than 0
*/
function deposit(uint amount) external;
/**
* @notice function that allows a user to withdraw its initial deposit
* @dev must be called only when `block.timestamp` >= `endPeriod`
* @dev `block.timestamp` higher than `lockupPeriod` (lockupPeriod finished)
* withdraw reset all states variable for the `msg.sender` to 0, and claim rewards
* if rewards to claim
*/
function withdrawAll() external;
/**
* @notice function that allows a user to withdraw its initial deposit
* @param amount, amount to withdraw
* @dev `block.timestamp` must be higher than `lockupPeriod` (lockupPeriod finished)
* @dev `amount` must be higher than `0`
* @dev `amount` must be lower or equal to the amount staked
* withdraw reset all states variable for the `msg.sender` to 0, and claim rewards
* if rewards to claim
*/
function withdraw(uint amount) external;
/**
* @notice function that returns the amount of total Staked tokens
* for a specific user
* @param stakeHolder, address of the user to check
* @return uint amount of the total deposited Tokens by the caller
*/
function amountStaked(address stakeHolder) external view returns (uint);
/**
* @notice function that returns the amount of total Staked tokens
* on the smart contract
* @return uint amount of the total deposited Tokens
*/
function totalDeposited() external view returns (uint);
/**
* @notice function that returns the amount of pending rewards
* that can be claimed by the user
* @param stakeHolder, address of the user to be checked
* @return uint amount of claimable rewards
*/
function rewardOf(address stakeHolder) external view returns (uint);
/**
* @notice function that claims pending rewards
* @dev transfer the pending rewards to the `msg.sender`
*/
function claimRewards() external;
/**
* @dev Emitted when `amount` tokens are deposited into
* staking platform
*/
event Deposit(address indexed owner, uint amount);
/**
* @dev Emitted when user withdraw deposited `amount`
*/
event Withdraw(address indexed owner, uint amount);
/**
* @dev Emitted when `stakeHolder` claim rewards
*/
event Claim(address indexed stakeHolder, uint amount);
/**
* @dev Emitted when staking has started
*/
event StartStaking(uint startPeriod, uint lockupPeriod, uint endingPeriod);
}
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
// 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;
}
}
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
// OpenZeppelin Contracts (last updated v4.5.0) (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
* ====
*
* [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 functionCall(target, data, "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");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(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) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(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) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason 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 {
// 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
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
/**
* @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));
}
}
/**
* @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");
}
}
}
/// @author RetreebInc
/// @title Staking Platform with fixed APY and lockup
contract StakingPlatform is IStakingPlatform, Ownable {
using SafeERC20 for IERC20;
IERC20 public immutable token;
uint8 public immutable fixedAPY;
uint public immutable stakingDuration;
uint public immutable lockupDuration;
uint public immutable stakingMax;
uint public startPeriod;
uint public lockupPeriod;
uint public endPeriod;
uint private _totalStaked;
uint internal _precision = 1E6;
mapping(address => uint) public staked;
mapping(address => uint) private _rewardsToClaim;
mapping(address => uint) public _userStartTime;
/**
* @notice constructor contains all the parameters of the staking platform
* @dev all parameters are immutable
*/
constructor(address _token, uint8 _fixedAPY, uint _durationInDays, uint _lockDurationInDays, uint _maxAmountStaked) {
stakingDuration = _durationInDays * 1 days;
lockupDuration = _lockDurationInDays * 1 days;
token = IERC20(_token);
fixedAPY = _fixedAPY;
stakingMax = _maxAmountStaked;
}
/**
* @notice function that start the staking
* @dev set `startPeriod` to the current current `block.timestamp`
* set `lockupPeriod` which is `block.timestamp` + `lockupDuration`
* and `endPeriod` which is `startPeriod` + `stakingDuration`
*/
function startStaking() external override onlyOwner {
require(startPeriod == 0, "Staking has already started");
startPeriod = block.timestamp;
lockupPeriod = block.timestamp + lockupDuration;
endPeriod = block.timestamp + stakingDuration;
emit StartStaking(startPeriod, lockupDuration, endPeriod);
}
/**
* @notice function that allows a user to deposit tokens
* @dev user must first approve the amount to deposit before calling this function,
* cannot exceed the `maxAmountStaked`
* @param amount, the amount to be deposited
* @dev `endPeriod` to equal 0 (Staking didn't started yet),
* or `endPeriod` more than current `block.timestamp` (staking not finished yet)
* @dev `totalStaked + amount` must be less than `stakingMax`
* @dev that the amount deposited should greater than 0
*/
function deposit(uint amount) external override {
require(endPeriod == 0 || endPeriod > block.timestamp, "Staking period ended");
require(_totalStaked + amount <= stakingMax, "Amount staked exceeds MaxStake");
require(amount > 0, "Amount must be greater than 0");
if (_userStartTime[_msgSender()] == 0) {
_userStartTime[_msgSender()] = block.timestamp;
}
_updateRewards();
staked[_msgSender()] += amount;
_totalStaked += amount;
token.safeTransferFrom(_msgSender(), address(this), amount);
emit Deposit(_msgSender(), amount);
}
/**
* @notice function that allows a user to withdraw its initial deposit
* @param amount, amount to withdraw
* @dev `block.timestamp` must be higher than `lockupPeriod` (lockupPeriod finished)
* @dev `amount` must be higher than `0`
* @dev `amount` must be lower or equal to the amount staked
* withdraw reset all states variable for the `msg.sender` to 0, and claim rewards
* if rewards to claim
*/
function withdraw(uint amount) external override {
require(block.timestamp >= lockupPeriod, "No withdraw until lockup ends");
require(amount > 0, "Amount must be greater than 0");
require(amount <= staked[_msgSender()], "Amount higher than stakedAmount");
_updateRewards();
if (_rewardsToClaim[_msgSender()] > 0) {
_claimRewards();
}
_totalStaked -= amount;
staked[_msgSender()] -= amount;
token.safeTransfer(_msgSender(), amount);
emit Withdraw(_msgSender(), amount);
}
/**
* @notice function that allows a user to withdraw its initial deposit
* @dev must be called only when `block.timestamp` >= `lockupPeriod`
* @dev `block.timestamp` higher than `lockupPeriod` (lockupPeriod finished)
* withdraw reset all states variable for the `msg.sender` to 0, and claim rewards
* if rewards to claim
*/
function withdrawAll() external override {
require(block.timestamp >= lockupPeriod, "No withdraw until lockup ends");
_updateRewards();
if (_rewardsToClaim[_msgSender()] > 0) {
_claimRewards();
}
_userStartTime[_msgSender()] = 0;
_totalStaked -= staked[_msgSender()];
uint stakedBalance = staked[_msgSender()];
staked[_msgSender()] = 0;
token.safeTransfer(_msgSender(), stakedBalance);
emit Withdraw(_msgSender(), stakedBalance);
}
/**
* @notice claim all remaining balance on the contract
* Residual balance is all the remaining tokens that have not been distributed
* (e.g, in case the number of stakeholders is not sufficient)
* @dev Can only be called one year after the end of the staking period
* Cannot claim initial stakeholders deposit
*/
function withdrawResidualBalance() external onlyOwner {
require(block.timestamp >= endPeriod + (365 * 1 days), "Withdraw 1year after endPeriod");
uint balance = token.balanceOf(address(this));
uint residualBalance = balance - (_totalStaked);
require(residualBalance > 0, "No residual Balance to withdraw");
token.safeTransfer(owner(), residualBalance);
}
/**
* @notice function that returns the amount of total Staked tokens
* for a specific user
* @param stakeHolder, address of the user to check
* @return uint amount of the total deposited Tokens by the caller
*/
function amountStaked(address stakeHolder) external view override returns (uint){
return staked[stakeHolder];
}
/**
* @notice function that returns the amount of total Staked tokens
* on the smart contract
* @return uint amount of the total deposited Tokens
*/
function totalDeposited() external view override returns (uint) {
return _totalStaked;
}
/**
* @notice function that returns the amount of pending rewards
* that can be claimed by the user
* @param stakeHolder, address of the user to be checked
* @return uint amount of claimable rewards
*/
function rewardOf(address stakeHolder) external view override returns (uint){
return _calculateRewards(stakeHolder);
}
/**
* @notice function that claims pending rewards
* @dev transfer the pending rewards to the `msg.sender`
*/
function claimRewards() external override {
_claimRewards();
}
/**
* @notice calculate rewards based on the `fixedAPY`, `_percentageTimeRemaining()`
* @dev the higher is the precision and the more the time remaining will be precise
* @param stakeHolder, address of the user to be checked
* @return uint amount of claimable tokens of the specified address
*/
function _calculateRewards(address stakeHolder) internal view returns (uint){
if (startPeriod == 0 || staked[stakeHolder] == 0) {
return 0;
}
return
(((staked[stakeHolder] * fixedAPY) *
_percentageTimeRemaining(stakeHolder)) / (_precision * 100)) +
_rewardsToClaim[stakeHolder];
}
/**
* @notice function that returns the remaining time in seconds of the staking period
* @dev the higher is the precision and the more the time remaining will be precise
* @param stakeHolder, address of the user to be checked
* @return uint percentage of time remaining * precision
*/
function _percentageTimeRemaining(address stakeHolder) internal view returns (uint){
bool early = startPeriod > _userStartTime[stakeHolder];
uint startTime;
if (endPeriod > block.timestamp) {
startTime = early ? startPeriod : _userStartTime[stakeHolder];
uint timeRemaining = stakingDuration -
(block.timestamp - startTime);
return
(_precision * (stakingDuration - timeRemaining)) /
stakingDuration;
}
startTime = early
? 0
: stakingDuration - (endPeriod - _userStartTime[stakeHolder]);
return (_precision * (stakingDuration - startTime)) / stakingDuration;
}
/**
* @notice internal function that claims pending rewards
* @dev transfer the pending rewards to the user address
*/
function _claimRewards() private {
_updateRewards();
uint rewardsToClaim = _rewardsToClaim[_msgSender()];
require(rewardsToClaim > 0, "Nothing to claim");
_rewardsToClaim[_msgSender()] = 0;
token.safeTransfer(_msgSender(), rewardsToClaim);
emit Claim(_msgSender(), rewardsToClaim);
}
/**
* @notice function that update pending rewards
* and shift them to rewardsToClaim
* @dev update rewards claimable
* and check the time spent since deposit for the `msg.sender`
*/
function _updateRewards() private {
_rewardsToClaim[_msgSender()] = _calculateRewards(_msgSender());
_userStartTime[_msgSender()] = (block.timestamp >= endPeriod)
? endPeriod
: block.timestamp;
}
}