Contract Source Code:
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
/**
* @dev Interface of the smart contract that configures rules
* and executes burning of the passed {ERC20Burnable} token.
*/
interface IBurning {
/**
* @dev Emitted when `value` tokens are burned via `burningContract`.
*/
event LogPeriodicTokenBurn(address indexed burningContract, uint256 value);
/**
* @dev Attempts to burn tokens.
*/
function burn() external returns (bool);
/**
* @dev Returns a total amount of tokens that were already burned.
*/
function burned() external view returns (uint256);
/**
* @dev Returns a total maximum amount of tokens to be burnt.
*/
function burnLimit() external view returns (uint256);
/**
* @dev Returns a one-time amount to be burned upon each request.
*/
function singleBurnAmount() external view returns (uint256);
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
/**
* @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 `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);
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
/**
* @dev Interface of the ERC900 standard with custom modifications.
*
* See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-900.md
*/
interface IStaking {
/**
* @dev Emitted when the `user` stakes an `amount` of tokens and
* passes arbitrary `data`, therefore `total` is changed as well,
* `personalStakeIndex`, `unlockedTimestamp` and `stakePercentageBasisPoints` are captured
* according to the chosen stake option.
*/
event LogStaked(
address indexed user,
uint256 amount,
uint256 personalStakeIndex,
uint256 unlockedTimestamp,
uint16 stakePercentageBasisPoints,
uint256 total,
bytes data
);
/**
* @dev Emitted when the `user` unstakes an `amount` of tokens and
* passes arbitrary `data`, therefore `total` is changed as well,
* `personalStakeIndex` and `stakeReward` are captured.
*/
event LogUnstaked(
address indexed user,
uint256 amount,
uint256 personalStakeIndex,
uint256 stakeReward,
uint256 total,
bytes data
);
/**
* @notice Stakes a certain amount of tokens, this MUST transfer the given amount from the user
* @notice MUST trigger Staked event
* @param stakeOptionIndex uint8 the chosen stake option
* @param amount uint256 the amount of tokens to stake
* @param data bytes optional data to include in the Stake event
*/
function stake(
uint8 stakeOptionIndex,
uint256 amount,
bytes calldata data
) external;
/**
* @notice Stakes a certain amount of tokens, this MUST transfer the given amount from the caller
* @notice MUST trigger Staked event
* @param stakeOptionIndex uint8 the chosen stake option
* @param user address the address the tokens are staked for
* @param amount uint256 the amount of tokens to stake
* @param data bytes optional data to include in the Stake event
*/
function stakeFor(
uint8 stakeOptionIndex,
address user,
uint256 amount,
bytes calldata data
) external;
/**
* @notice Unstakes tokens, this SHOULD return the given amount of tokens to the user,
* if unstaking is currently not possible the function MUST revert
* @notice MUST trigger Unstaked event
* @dev Unstaking tokens is an atomic operation—either all of the tokens in a stake, or none of the tokens.
* @dev Stake reward is minted if function is called after the stake's `unlockTimestamp`.
* @param personalStakeIndex uint256 index of the stake to withdraw in the personalStakes mapping
* @param data bytes optional data to include in the Unstake event
*/
function unstake(uint256 personalStakeIndex, bytes calldata data) external;
/**
* @notice Returns the current total of tokens staked for an address
* @param addr address The address to query
* @return uint256 The number of tokens staked for the given address
*/
function totalStakedFor(address addr) external view returns (uint256);
/**
* @notice Returns the current total of tokens staked
* @return uint256 The number of tokens staked in the contract
*/
function totalStaked() external view returns (uint256);
/**
* @notice Address of the token being used by the staking interface
* @return address The address of the ERC20 token used for staking
*/
function token() external view returns (address);
/**
* @notice MUST return true if the optional history functions are implemented, otherwise false
* @dev Since we don't implement the optional interface, this always returns false
* @return bool Whether or not the optional history functions are implemented
*/
function supportsHistory() external pure returns (bool);
/**
* @notice Sets the pairs of currently available staking options,
* which will regulate the stake duration and reward percentage.
* Stakes that were created through the old stake options will remain unchanged.
* @param stakeDurations uint256[] array of stake option durations
* @param stakePercentageBasisPoints uint16[] array of stake rewarding percentages (basis points)
*/
function setStakingOptions(
uint256[] memory stakeDurations,
uint16[] memory stakePercentageBasisPoints
) external;
/**
* @notice Returns the pairs of currently available staking options,
* so that staker can choose a suitable combination of
* stake duration and reward percentage.
* @return stakeOptionIndexes uint256[] array of the stake option indexes used in other functions of this contract
* @return stakeDurations uint256[] array of stake option durations
* @return stakePercentageBasisPoints uint16[] array of stake rewarding percentages (basis points)
*/
function getStakingOptions()
external
view
returns (
uint256[] memory stakeOptionIndexes,
uint256[] memory stakeDurations,
uint16[] memory stakePercentageBasisPoints
);
/**
* @dev Returns the stake indexes for
* the last `amountToRetrieve` (with `offset` for pagination)
* personal stakes created by `user`.
* @param user address The address to query
* @param amountToRetrieve uint256 Configures the amount of stakes to gather data for
* @param offset uint256 Configures the offset for results pagination
* @return uint256[] stake indexes array
*/
function getPersonalStakeIndexes(
address user,
uint256 amountToRetrieve,
uint256 offset
) external view returns (uint256[] memory);
/**
* @dev Returns the stake unlock timestamps for
* the last `amountToRetrieve` (with `offset` for pagination)
* personal stakes created by `user`.
* @param user address The address to query
* @param amountToRetrieve uint256 Configures the amount of stakes to gather data for
* @param offset uint256 Configures the offset for results pagination
* @return uint256[] stake unlock timestamps array
*/
function getPersonalStakeUnlockedTimestamps(
address user,
uint256 amountToRetrieve,
uint256 offset
) external view returns (uint256[] memory);
/**
* @dev Returns the stake values of
* the last `amountToRetrieve` (with `offset` for pagination)
* the personal stakes created by `user`.
* @param user address The address to query
* @param amountToRetrieve uint256 Configures the amount of stakes to gather data for
* @param offset uint256 Configures the offset for results pagination
* @return uint256[] stake values array
*/
function getPersonalStakeActualAmounts(
address user,
uint256 amountToRetrieve,
uint256 offset
) external view returns (uint256[] memory);
/**
* @dev Returns the adresses of stake owners of
* the last `amountToRetrieve` (with `offset` for pagination)
* personal stakes created by `user`.
* @param user address The address to query
* @param amountToRetrieve uint256 Configures the amount of stakes to gather data for
* @param offset uint256 Configures the offset for results pagination
* @return address[] addresses of stake owners array
*/
function getPersonalStakeForAddresses(
address user,
uint256 amountToRetrieve,
uint256 offset
) external view returns (address[] memory);
/**
* @dev Returns the stake rewards percentage (basis points) of
* the last `amountToRetrieve` (with `offset` for pagination)
* personal stakes created by `user`.
* @param user address The address to query
* @param amountToRetrieve uint256 Configures the amount of stakes to gather data for
* @param offset uint256 Configures the offset for results pagination
* @return uint256[] stake rewards percentage (basis points) array
*/
function getPersonalStakePercentageBasisPoints(
address user,
uint256 amountToRetrieve,
uint256 offset
) external view returns (uint256[] memory);
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
/**
* @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.
* `SafeMathUint` 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 SafeMathUint {
/**
* @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) {
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;
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;
}
/**
* @dev Converts an unsigned integer to a signed integer,
* Reverts when convertation overflows.
*
* Requirements:
*
* - Operation cannot overflow.
*/
function toInt256Safe(uint256 a) internal pure returns (int256) {
int256 b = int256(a);
require(b >= 0, "SafeMath: convertation overflow");
return b;
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "../utils/Context.sol";
import "../interfaces/IERC20.sol";
import "../libraries/SafeMathUint.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
*
* Functions revert instead of returning `false` on failure.
* This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* The non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20 {
using SafeMathUint for uint256;
mapping(address => uint256) internal _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 internal _totalSupply;
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name, string memory symbol) {
_name = name;
_symbol = symbol;
_decimals = 18;
}
/**
* @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. This is the value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* 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;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public override view returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public override view returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender)
public
virtual
override
view
returns (uint256)
{
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(
sender,
_msgSender(),
_allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")
);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue)
public
virtual
returns (bool)
{
_approve(
_msgSender(),
spender,
_allowances[_msgSender()][spender].sub(
subtractedValue,
"ERC20: decreased allowance below zero"
)
);
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, 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 virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeMint();
_beforeTokenTransfer(address(0), account, amount);
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), 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 virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called before any token mint.
*/
function _beforeMint() internal virtual {}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "../utils/Context.sol";
import "./ERC20.sol";
import "../libraries/SafeMathUint.sol";
/**
* @dev Extension of {ERC20} that allows token holders to destroy both their own
* tokens and those that they have an allowance for, in a way that can be
* recognized off-chain (via event analysis).
*/
abstract contract ERC20Burnable is Context, ERC20 {
using SafeMathUint for uint256;
/**
* @dev Destroys `amount` tokens from the caller.
*
* See {ERC20-_burn}.
*/
function burn(uint256 amount) external virtual returns (bool success) {
_burn(_msgSender(), amount);
return true;
}
/**
* @dev Destroys `amount` tokens from `account`, deducting from the caller's
* allowance.
*
* See {ERC20-_burn} and {ERC20-allowance}.
*
* Requirements:
*
* - the caller must have allowance for `accounts`'s tokens of at least
* `amount`.
*/
function burnFrom(address account, uint256 amount) external virtual returns (bool success) {
uint256 decreasedAllowance = allowance(account, _msgSender()).sub(
amount,
"ERC20Burnable: burn amount exceeds allowance"
);
_approve(account, _msgSender(), decreasedAllowance);
_burn(account, amount);
return true;
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "../utils/Context.sol";
import "./ERC20Pausable.sol";
import "../libraries/SafeMathUint.sol";
/**
* @dev Extension of {ERC20} that allows to set up a 'lock-in' period for tokens,
* which means a percentage of tokens received through from {LockableDistribution} contract
* will not be transferrable until the end of 'lock-in' period.
*/
abstract contract ERC20Lockable is Context, ERC20Pausable {
using SafeMathUint for uint256;
address _lockableDistribution;
struct BalanceLock {
uint256 lockedAmount;
uint256 unlockTimestamp;
}
mapping(address => BalanceLock) internal _balanceLocks;
/**
* @dev Creates a 'lock-in' period for `lockAmount` tokens on `lockFor` address
* that lasts until `unlockTimestamp` timestamp.
*/
function lock(
address lockFor,
uint256 lockAmount,
uint256 unlockTimestamp
) external {
require(
_msgSender() == _lockableDistribution,
"ERC20Lockable: only distribution contract can lock tokens"
);
_balanceLocks[lockFor].lockedAmount = lockAmount;
_balanceLocks[lockFor].unlockTimestamp = unlockTimestamp;
}
/**
* @dev Returns a 'lock-in' period details for `account` address.
*/
function lockOf(address account)
public
view
returns (uint256 lockedAmount, uint256 unlockTimestamp)
{
return (_balanceLocks[account].lockedAmount, _balanceLocks[account].unlockTimestamp);
}
/**
* @dev Hook that restricts transfers according to the 'lock-in' period.
*
* See {ERC20-_beforeTokenTransfer}.
*
* Requirements:
*
* - transferred amount should not include tokens that are 'locked-in'.
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual override {
super._beforeTokenTransfer(from, to, amount);
uint256 lockedAmount;
uint256 unlockTimestamp;
(lockedAmount, unlockTimestamp) = lockOf(from);
if (unlockTimestamp != 0 && block.timestamp < unlockTimestamp) {
require(
amount <= balanceOf(from).sub(lockedAmount),
"ERC20Lockable: transfer amount exceeds the non-locked balance"
);
}
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "../utils/Context.sol";
import "./ERC20.sol";
/**
* @dev Extension of {ERC20} that allows new tokens to be created,
* in a way that can be recognized off-chain (via event analysis).
*/
abstract contract ERC20Mintable is Context, ERC20 {
/**
* @dev Creates `amount` tokens for `account`.
*
* See {ERC20-_mint}.
*/
function mint(address account, uint256 amount) external virtual returns (bool success) {
_mint(account, amount);
return true;
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "./ERC20.sol";
import "../utils/Pausable.sol";
/**
* @dev Extension of {ERC20} with pausable token transfers, minting and burning.
*
* Useful for scenarios such as preventing trades until the end of an evaluation
* period, or having an emergency switch for freezing all token transfers in the
* event of a large bug.
*/
abstract contract ERC20Pausable is ERC20, Pausable {
/**
* @dev See {ERC20-_beforeTokenTransfer}.
*
* Requirements:
*
* - the contract must not be paused.
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual override {
super._beforeTokenTransfer(from, to, amount);
require(!paused(), "ERC20Pausable: token transfer while paused");
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "./ERC20Pausable.sol";
import "./ERC20Burnable.sol";
import "./ERC20Mintable.sol";
import "./ERC20Lockable.sol";
import "../interfaces/IBurning.sol";
import "../interfaces/IStaking.sol";
import "../libraries/SafeMathUint.sol";
/**
* @dev EggToken is a {ERC20} implementation with various extensions
* and custom functionality.
*/
contract EggToken is ERC20Burnable, ERC20Mintable, ERC20Pausable, ERC20Lockable {
using SafeMathUint for uint256;
IBurning _burning;
IStaking _staking;
/**
* @dev Sets the values for {name} and {symbol}, allocates the `initialTotalSupply`.
*/
constructor(
string memory name,
string memory symbol,
uint256 initialTotalSupply
) ERC20(name, symbol) {
_totalSupply = initialTotalSupply;
_balances[_msgSender()] = _balances[_msgSender()].add(_totalSupply);
emit Transfer(address(0), _msgSender(), _totalSupply);
}
/**
* @dev Enables the burning, allocates the `burningBalance` to {IBurning} contract.
*/
function setBurningContract(IBurning burning, uint256 burningBalance) external onlyOwner {
_burning = burning;
_totalSupply = _totalSupply.add(burningBalance);
_balances[address(burning)] = _balances[address(burning)].add(burningBalance);
emit Transfer(address(0), address(burning), burningBalance);
}
/**
* @dev Enables the staking via {IStaking} contract.
*/
function setStakingContract(IStaking staking) external onlyOwner {
_staking = staking;
}
/**
* @dev Enables the token distribution with 'lock-in' period via {LockableDistribution} contract.
*
* See {ERC20Lockable}.
*/
function setLockableDistributionContract(address lockableDistribution) external onlyOwner {
_lockableDistribution = lockableDistribution;
}
/**
* @dev Moves each of `values` in tokens from the caller's account to the list of `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event per each transfer.
*/
function transferBatch(address[] calldata to, uint256[] calldata values) external returns (bool) {
require(
to.length == values.length && to.length > 0,
"EggToken: to and values arrays should be equal in size and non-empty"
);
uint256 i = 0;
while (i < to.length) {
require(to[i] != address(0), "EggToken: transfer to the zero address");
_beforeTokenTransfer(_msgSender(), to[i], values[i]);
_balances[_msgSender()] = _balances[_msgSender()].sub(
values[i],
"EggToken: transfer amount exceeds balance"
);
_balances[to[i]] = _balances[to[i]].add(values[i]);
emit Transfer(_msgSender(), to[i], values[i]);
i++;
}
return true;
}
/**
* @dev Triggers token burn through the {IBurning} `_burning` contract.
*
* Requirements:
*
* - only contract owner can trigger the burning.
*/
function periodicBurn() external onlyOwner returns (bool success) {
require(_burning.burn(), "Burning: not possible to perform the periodic token burn");
return true;
}
/**
* @dev Enables withdrawal of {ERC20} tokens accidentally sent to this smart contract.
*
* Requirements:
*
* - only contract owner can transfer out {ERC20} tokens.
*/
function transferAnyERC20Token(address tokenAddress, uint256 tokens)
external
onlyOwner
returns (bool success)
{
return IERC20(tokenAddress).transfer(_msgSender(), tokens);
}
/**
* @dev See {ERC20-_beforeTokenTransfer},
* {ERC20Pausable-_beforeTokenTransfer}, {ERC20Lockable-_beforeTokenTransfer}.
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual override(ERC20, ERC20Pausable, ERC20Lockable) {
super._beforeTokenTransfer(from, to, amount);
}
/**
* @dev Restricts token minting.
*
* Requirements:
*
* - only {IStaking} `_staking` contract can mint tokens (staking rewards).
*/
function _beforeMint() internal virtual override {
require(_msgSender() == address(_staking), "Staking: only staking contract can mint tokens");
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
/*
* @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 virtual view returns (address payable) {
return msg.sender;
}
function _msgData() internal virtual view returns (bytes memory) {
this;
return msg.data;
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "./Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* 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 {
event LogOwnershipTransferred(address indexed previousOwner, address indexed newOwner);
address private _owner;
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_owner = _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(_msgSender() == _owner, "Ownable: only contract owner can call this function.");
_;
}
/**
* @dev Checks if transaction sender account is an owner.
*/
function isOwner() external view returns (bool) {
return _msgSender() == _owner;
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) external onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit LogOwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
// SPDX-License-Identifier: Apache license 2.0
pragma solidity ^0.7.0;
import "./Context.sol";
import "./Ownable.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
abstract contract Pausable is Context, Ownable {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event LogPaused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event LogUnpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
constructor() {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
require(!_paused, "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
require(_paused, "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function pause() external virtual whenNotPaused onlyOwner {
_paused = true;
emit LogPaused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function unpause() external virtual whenPaused onlyOwner {
_paused = false;
emit LogUnpaused(_msgSender());
}
}