Contract Name:
StakingRewardsv2
Contract Source Code:
File 1 of 1 : StakingRewardsv2
// File: @openzeppelin/contracts/math/Math.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a >= b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow, so we distribute
return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
}
}
// File: @openzeppelin/contracts/math/SafeMath.sol
// -License-Identifier: MIT
pragma solidity ^0.6.0;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @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) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @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 sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @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) {
// 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 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts 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 mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
// -License-Identifier: MIT
pragma solidity ^0.6.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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 `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);
/**
* @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);
}
// File: @openzeppelin/contracts/utils/Address.sol
// -License-Identifier: MIT
pragma solidity ^0.6.2;
/**
* @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
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies in extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 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");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(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");
return _functionCallWithValue(target, data, value, errorMessage);
}
function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
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
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol
// -License-Identifier: MIT
pragma solidity ^0.6.0;
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using SafeMath for uint256;
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'
// solhint-disable-next-line max-line-length
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).add(value);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
_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
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// File: contracts/utils/ContractGuard.sol
pragma solidity ^0.6.12;
contract ContractGuard {
mapping(uint256 => mapping(address => bool)) private _status;
function checkSameOriginReentranted() internal view returns (bool) {
return _status[block.number][tx.origin];
}
function checkSameSenderReentranted() internal view returns (bool) {
return _status[block.number][msg.sender];
}
modifier onlyOneBlock() {
require(
!checkSameOriginReentranted(),
'ContractGuard: one block, one function'
);
require(
!checkSameSenderReentranted(),
'ContractGuard: one block, one function'
);
_;
_status[block.number][tx.origin] = true;
_status[block.number][msg.sender] = true;
}
}
// File: @openzeppelin/contracts/GSN/Context.sol
// -License-Identifier: MIT
pragma solidity ^0.6.0;
/*
* @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 GSN 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 payable) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// File: @openzeppelin/contracts/access/Ownable.sol
// -License-Identifier: MIT
pragma solidity ^0.6.0;
/**
* @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.
*/
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 () internal {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view 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 {
emit OwnershipTransferred(_owner, address(0));
_owner = 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");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
// File: contracts/interfaces/ILpMigratorRecipient.sol
pragma solidity ^0.6.0;
abstract contract ILpMigratorRecipient is Ownable {
address public lpMigrator;
modifier onlyLpMigrator() {
require(
_msgSender() == lpMigrator,
'Caller is not LpMigrator'
);
_;
}
function setLpMigrator(address _lpMigrator)
external
virtual
onlyOwner
{
lpMigrator = _lpMigrator;
}
}
// File: contracts/interfaces/IStakingRewardsv2.sol
pragma solidity ^0.6.0;
interface IStakingRewardsv2 {
function balanceOf(address account) external view returns (uint256);
function exit() external;
function getReward() external;
function stakeLockedFor(address user, uint256 amount, uint256 convertedAmount) external;
function totalSupply() external view returns (uint256);
function totalRewardAmount() external view returns (uint256);
function totalRewardBurned() external view returns (uint256);
function calculateRewardAmount(uint256 convertedAmount) external view returns (uint256);
function getRedeemableReward(address user) external view returns (uint256);
}
// File: contracts/interfaces/IOracle.sol
pragma solidity ^0.6.0;
interface IOracle {
function update() external;
function consult(address token, uint256 amountIn)
external
view
returns (uint256 amountOut);
// function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestamp);
}
// File: contracts/owner/Operator.sol
pragma solidity ^0.6.0;
contract Operator is Context, Ownable {
address private _operator;
event OperatorTransferred(
address indexed previousOperator,
address indexed newOperator
);
constructor() internal {
_operator = _msgSender();
emit OperatorTransferred(address(0), _operator);
}
function operator() public view returns (address) {
return _operator;
}
modifier onlyOperator() {
require(
_operator == msg.sender,
'operator: caller is not the operator'
);
_;
}
function isOperator() public view returns (bool) {
return _msgSender() == _operator;
}
function transferOperator(address newOperator_) public onlyOwner {
_transferOperator(newOperator_);
}
function _transferOperator(address newOperator_) internal {
require(
newOperator_ != address(0),
'operator: zero address given for new operator'
);
emit OperatorTransferred(address(0), newOperator_);
_operator = newOperator_;
}
}
// File: contracts/utils/Epoch.sol
pragma solidity ^0.6.0;
contract Epoch is Operator {
using SafeMath for uint256;
uint256 private period;
uint256 private startTime;
uint256 private lastExecutedAt;
/* ========== CONSTRUCTOR ========== */
constructor(
uint256 _period,
uint256 _startTime,
uint256 _startEpoch
) public {
require(_startTime > block.timestamp, 'Epoch: invalid start time');
period = _period;
startTime = _startTime;
lastExecutedAt = startTime.add(_startEpoch.mul(period));
}
/* ========== Modifier ========== */
modifier checkStartTime {
require(now >= startTime, 'Epoch: not started yet');
_;
}
modifier checkEpoch {
require(now > startTime, 'Epoch: not started yet');
require(getCurrentEpoch() >= getNextEpoch(), 'Epoch: not allowed');
_;
lastExecutedAt = block.timestamp;
}
/* ========== VIEW FUNCTIONS ========== */
// epoch
function getLastEpoch() public view returns (uint256) {
return lastExecutedAt.sub(startTime).div(period);
}
function getCurrentEpoch() public view returns (uint256) {
return Math.max(startTime, block.timestamp).sub(startTime).div(period);
}
function getNextEpoch() public view returns (uint256) {
if (startTime == lastExecutedAt) {
return getLastEpoch();
}
return getLastEpoch().add(1);
}
function nextEpochPoint() public view returns (uint256) {
return startTime.add(getNextEpoch().mul(period));
}
// params
function getPeriod() public view returns (uint256) {
return period;
}
function getStartTime() public view returns (uint256) {
return startTime;
}
/* ========== GOVERNANCE ========== */
function setPeriod(uint256 _period) external onlyOperator {
period = _period;
}
}
// File: contracts/distribution/StakingRewardsv2.sol
pragma solidity ^0.6.0;
// Inheritance
contract StakingRewardsv2 is IStakingRewardsv2, ILpMigratorRecipient, ContractGuard, Operator, Epoch {
using SafeMath for uint256;
using SafeERC20 for IERC20;
uint256 constant private ONE_DOLLAR_PRICE = 1000000;
uint256 constant TOTAL_EPOCH = 10;
/* ========== STATE VARIABLES ========== */
IERC20 public rewardsToken;
IERC20 public stakingToken;
uint256 public unlockEpoch;
bool public isStartRewards;
mapping(address => uint256) public rewardsPaid;
mapping(address => uint256) public rewards;
uint256 private _totalRewardAmount;
uint256 private _totalRewardBurned;
uint256 private _totalSupply;
mapping(address => uint256) private _balances;
//Tokens
address public cash_old;
//Contracts
address public cashOracle;
/* ========== CONSTRUCTOR ========== */
constructor(
address _lpMigrator,
address _rewardsToken,
address _stakingToken,
address _cash_old,
address _cashOracle,
uint256 _startTime,
uint256 _unlockEpoch
) Epoch(7 days, _startTime, 0) public
{
rewardsToken = IERC20(_rewardsToken);
stakingToken = IERC20(_stakingToken);
lpMigrator = _lpMigrator;
cash_old = _cash_old;
cashOracle = _cashOracle;
unlockEpoch = _unlockEpoch;
}
/* ========== VIEWS ========== */
function getOraclePrice() public view returns (uint256) {
try IOracle(cashOracle).consult(cash_old, 1e18) returns (uint256 price) {
return price;
} catch {
revert('StakingRewards: failed to consult cash price from the oracle');
}
}
function totalRewardAmount() external view override returns (uint256) {
return _totalRewardAmount;
}
function totalRewardBurned() external view override returns (uint256) {
return _totalRewardBurned;
}
function totalSupply() external view override returns (uint256) {
return _totalSupply;
}
function balanceOf(address account) external view override returns (uint256) {
return _balances[account];
}
function calculateRewardAmount(uint256 convertedAmount) public view override returns (uint256) {
uint256 price = getOraclePrice();
// no reward if MICv1 price > 1
if (price > ONE_DOLLAR_PRICE) {
return 0;
}
// rewards = MIC V1 converted * 1 / x - 1
return convertedAmount.mul(ONE_DOLLAR_PRICE).div(getOraclePrice()).sub(convertedAmount);
}
/* ========== MUTATIVE FUNCTIONS ========== */
function _burnReward(address user, uint256 amount) private {
uint256 currentReward = rewards[user];
require(currentReward.sub(amount) >= rewardsPaid[user], 'StakingRewards: reward burned should not exceed total reward');
rewards[user] = rewards[user].sub(amount);
_totalRewardBurned = _totalRewardBurned.add(amount);
_totalRewardAmount = _totalRewardAmount.sub(amount);
emit RewardBurn(user, amount);
}
function getRedeemableReward(address user) public view override returns (uint256){
uint256 reward = rewards[user];
if (getCurrentEpoch() >= TOTAL_EPOCH) {
return reward;
}
uint256 multiplier = ONE_DOLLAR_PRICE.mul(getCurrentEpoch()).div(TOTAL_EPOCH);
return reward.mul(multiplier).div(ONE_DOLLAR_PRICE);
}
function getReward() public override onlyOneBlock checkUnlock {
uint256 rewardPaid = rewardsPaid[msg.sender];
uint256 redeemableReward = getRedeemableReward(msg.sender);
if (rewardPaid < redeemableReward) {
uint256 currentRewardAmount = redeemableReward.sub(rewardPaid);
rewardsPaid[msg.sender] = rewardsPaid[msg.sender].add(currentRewardAmount);
rewardsToken.safeTransfer(msg.sender, currentRewardAmount);
emit RewardPaid(msg.sender, currentRewardAmount);
}
}
function _withdrawFor(address user, uint256 amount) private {
require(amount > 0, "StakingRewards: Cannot withdraw 0");
_totalSupply = _totalSupply.sub(amount);
_balances[user] = _balances[user].sub(amount);
stakingToken.safeTransfer(user, amount);
emit Withdrawn(user, amount);
}
function exit() public override checkUnlock {
// reward will be burned when users exit. get redeemable reward before exit.
getReward();
uint256 unredeemedReward = rewards[msg.sender].sub(rewardsPaid[msg.sender]);
_burnReward(msg.sender, unredeemedReward);
_withdrawFor(msg.sender, _balances[msg.sender]);
}
/* ========== RESTRICTED FUNCTIONS ========== */
// calculate the amount of MICv2 users can get for converted amount
function startRewards() public onlyOperator checkStartTime {
require(!isStartRewards, 'StakingRewards: Rewards already started');
isStartRewards = true;
rewardsToken.safeTransferFrom(msg.sender, address(this), _totalRewardAmount);
}
// stakeLockedFor locked MICV2 LP Token and distribute reward according to converted MICv1 amount
function stakeLockedFor(address user, uint256 stakeAmount, uint256 convertedAmount) external override onlyLpMigrator {
require(getOraclePrice() < ONE_DOLLAR_PRICE, 'StakingRewards: Cannot stake while price > 1');
require(stakeAmount > 0, 'StakingRewards: Cannot stake 0');
require(!isStartRewards, 'StakingRewards: Cannot stake after start time');
_totalSupply = _totalSupply.add(stakeAmount);
_balances[user] = _balances[user].add(stakeAmount);
uint256 rewardAmount = calculateRewardAmount(convertedAmount);
rewards[user] = rewards[user].add(rewardAmount);
_totalRewardAmount = _totalRewardAmount.add(rewardAmount);
stakingToken.safeTransferFrom(msg.sender, address(this), stakeAmount);
emit Staked(user, stakeAmount);
emit RewardAdded(rewardAmount);
}
// Added to support recovering LP Rewards from other systems such as BAL to be distributed to holders
function recoverERC20(address tokenAddress, uint256 tokenAmount) external onlyOwner {
require(tokenAddress != address(stakingToken), "StakingRewards: Cannot withdraw the staking token");
IERC20(tokenAddress).safeTransfer(msg.sender, tokenAmount);
emit Recovered(tokenAddress, tokenAmount);
}
/* ========== MODIFIERS ========== */
modifier checkUnlock {
require(getCurrentEpoch() >= unlockEpoch, 'StakingRewards: not unlocked yer');
_;
}
/* ========== EVENTS ========== */
event RewardAdded(uint256 reward);
event Staked(address indexed user, uint256 amount);
event Withdrawn(address indexed user, uint256 amount);
event RewardPaid(address indexed user, uint256 reward);
event RewardBurn(address indexed user, uint256 reward);
event Recovered(address token, uint256 amount);
}