Theta Smart Contracts | ThetaScan.io

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Published Contract:

// File: @openzeppelin/contracts/utils/Context.sol


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @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 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;
 }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)


/**
 * @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);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)



/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
 /**
 * @dev Returns the name of the token.
 */
 function name() external view returns (string memory);

 /**
 * @dev Returns the symbol of the token.
 */
 function symbol() external view returns (string memory);

 /**
 * @dev Returns the decimals places of the token.
 */
 function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol


// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.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}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead 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.
 *
 * Finally, 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, IERC20Metadata {
 mapping(address => uint256) private _balances;

 mapping(address => mapping(address => uint256)) private _allowances;

 uint256 private _totalSupply;

 string private _name;
 string private _symbol;

 /**
 * @dev Sets the values for {name} and {symbol}.
 *
 * The default value of {decimals} is 18. To select a different value for
 * {decimals} you should overload it.
 *
 * All two of these values are immutable: they can only be set once during
 * construction.
 */
 constructor(string memory name_, string memory symbol_) {
 _name = name_;
 _symbol = symbol_;
 }

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

 /**
 * @dev Returns the symbol of the token, usually a shorter version of the
 * name.
 */
 function symbol() public view virtual override 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 this function is
 * overridden;
 *
 * 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 virtual override returns (uint8) {
 return 18;
 }

 /**
 * @dev See {IERC20-totalSupply}.
 */
 function totalSupply() public view virtual override returns (uint256) {
 return _totalSupply;
 }

 /**
 * @dev See {IERC20-balanceOf}.
 */
 function balanceOf(address account) public view virtual override returns (uint256) {
 return _balances[account];
 }

 /**
 * @dev See {IERC20-transfer}.
 *
 * Requirements:
 *
 * - `to` cannot be the zero address.
 * - the caller must have a balance of at least `amount`.
 */
 function transfer(address to, uint256 amount) public virtual override returns (bool) {
 address owner = _msgSender();
 _transfer(owner, to, amount);
 return true;
 }

 /**
 * @dev See {IERC20-allowance}.
 */
 function allowance(address owner, address spender) public view virtual override returns (uint256) {
 return _allowances[owner][spender];
 }

 /**
 * @dev See {IERC20-approve}.
 *
 * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
 * `transferFrom`. This is semantically equivalent to an infinite approval.
 *
 * Requirements:
 *
 * - `spender` cannot be the zero address.
 */
 function approve(address spender, uint256 amount) public virtual override returns (bool) {
 address owner = _msgSender();
 _approve(owner, 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}.
 *
 * NOTE: Does not update the allowance if the current allowance
 * is the maximum `uint256`.
 *
 * Requirements:
 *
 * - `from` and `to` cannot be the zero address.
 * - `from` must have a balance of at least `amount`.
 * - the caller must have allowance for ``from``'s tokens of at least
 * `amount`.
 */
 function transferFrom(
 address from,
 address to,
 uint256 amount
 ) public virtual override returns (bool) {
 address spender = _msgSender();
 _spendAllowance(from, spender, amount);
 _transfer(from, to, amount);
 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) {
 address owner = _msgSender();
 _approve(owner, spender, allowance(owner, spender) + 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) {
 address owner = _msgSender();
 uint256 currentAllowance = allowance(owner, spender);
 require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
 unchecked {
 _approve(owner, spender, currentAllowance - subtractedValue);
 }

 return true;
 }

 /**
 * @dev Moves `amount` of tokens from `from` to `to`.
 *
 * This 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:
 *
 * - `from` cannot be the zero address.
 * - `to` cannot be the zero address.
 * - `from` must have a balance of at least `amount`.
 */
 function _transfer(
 address from,
 address to,
 uint256 amount
 ) internal virtual {
 require(from != address(0), "ERC20: transfer from the zero address");
 require(to != address(0), "ERC20: transfer to the zero address");

 _beforeTokenTransfer(from, to, amount);

 uint256 fromBalance = _balances[from];
 require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
 unchecked {
 _balances[from] = fromBalance - amount;
 // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
 // decrementing then incrementing.
 _balances[to] += amount;
 }

 emit Transfer(from, to, amount);

 _afterTokenTransfer(from, to, 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:
 *
 * - `account` cannot be the zero address.
 */
 function _mint(address account, uint256 amount) internal virtual {
 require(account != address(0), "ERC20: mint to the zero address");

 _beforeTokenTransfer(address(0), account, amount);

 _totalSupply += amount;
 unchecked {
 // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
 _balances[account] += amount;
 }
 emit Transfer(address(0), account, amount);

 _afterTokenTransfer(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);

 uint256 accountBalance = _balances[account];
 require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
 unchecked {
 _balances[account] = accountBalance - amount;
 // Overflow not possible: amount <= accountBalance <= totalSupply.
 _totalSupply -= amount;
 }

 emit Transfer(account, address(0), amount);

 _afterTokenTransfer(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 Updates `owner` s allowance for `spender` based on spent `amount`.
 *
 * Does not update the allowance amount in case of infinite allowance.
 * Revert if not enough allowance is available.
 *
 * Might emit an {Approval} event.
 */
 function _spendAllowance(
 address owner,
 address spender,
 uint256 amount
 ) internal virtual {
 uint256 currentAllowance = allowance(owner, spender);
 if (currentAllowance != type(uint256).max) {
 require(currentAllowance >= amount, "ERC20: insufficient allowance");
 unchecked {
 _approve(owner, spender, currentAllowance - amount);
 }
 }
 }

 /**
 * @dev Hook that is called before any transfer of tokens. This includes
 * minting and burning.
 *
 * Calling conditions:
 *
 * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
 * will be transferred to `to`.
 * - when `from` is zero, `amount` tokens will be minted for `to`.
 * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
 * - `from` and `to` are never both zero.
 *
 * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
 */
 function _beforeTokenTransfer(
 address from,
 address to,
 uint256 amount
 ) internal virtual {}

 /**
 * @dev Hook that is called after any transfer of tokens. This includes
 * minting and burning.
 *
 * Calling conditions:
 *
 * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
 * has been transferred to `to`.
 * - when `from` is zero, `amount` tokens have been minted for `to`.
 * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
 * - `from` and `to` are never both zero.
 *
 * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
 */
 function _afterTokenTransfer(
 address from,
 address to,
 uint256 amount
 ) internal virtual {}
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol


// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)


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

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
 /**
 * @dev Returns the addition of two unsigned integers, with an overflow flag.
 *
 * _Available since v3.4._
 */
 function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
 unchecked {
 uint256 c = a + b;
 if (c < a) return (false, 0);
 return (true, c);
 }
 }

 /**
 * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
 *
 * _Available since v3.4._
 */
 function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
 unchecked {
 if (b > a) return (false, 0);
 return (true, a - b);
 }
 }

 /**
 * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
 *
 * _Available since v3.4._
 */
 function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
 unchecked {
 // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
 // benefit is lost if 'b' is also tested.
 // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
 if (a == 0) return (true, 0);
 uint256 c = a * b;
 if (c / a != b) return (false, 0);
 return (true, c);
 }
 }

 /**
 * @dev Returns the division of two unsigned integers, with a division by zero flag.
 *
 * _Available since v3.4._
 */
 function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
 unchecked {
 if (b == 0) return (false, 0);
 return (true, a / b);
 }
 }

 /**
 * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
 *
 * _Available since v3.4._
 */
 function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
 unchecked {
 if (b == 0) return (false, 0);
 return (true, a % b);
 }
 }

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

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

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

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

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

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

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

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

// File: ReplayToken.sol





/**
* @title ReplayToken
* @notice TNT20 token for Replay subchain on theta network blockchain
* @dev This token is the Governance token of Replay subchain on Theta Blockchain
*/
contract ReplayToken is ERC20 {
 using SafeMath for uint256;
 /**
 * @dev represents the decimal value of the token. Once set in constructor cannot be changes. Its set to 18
 */
 uint8 private immutable _decimals;

 /**
 * @dev Rewards earned by staker per block based on staked amount
 */
 uint256 private _stakerRewardPerBlock;

 /**
 * @dev Max supply of the token
 */
 uint256 public immutable maxSupply;

 /**
 * @dev Minter is the one who mints tokens per each block based on _stakerRewardPerBlock
 */
 address public minter;

 /**
 * @dev Admin of the contract - can mint tokens, change pendingAdmin and _stakerRewardPerBlock
 */
 address public admin;

 /**
 * @dev Pending admin can update the admin
 */
 address public pendingAdmin;

 /**
 * @dev Previous Minter emitted when replaced by new minter address
 */
 address public previousMinter;

 /**
 * @dev Previous Pending Admin emitted when replaced by new admin
 */
 address public previousPendingAdmin;

 /**
 * @dev Previous Admin emitted when replaced by new pending admin
 */
 address public previousAdmin;

 /**
 * @dev Event emitted when _stakerRewardPerBlock is updated by admin.
 * @param newStakerRewardPerBlock - this is the new _stakerRewardPerBlock value updated by admin.
 */
 event UpdateStakerRewardPerBlock(uint256 newStakerRewardPerBlock);

 /**
 * @dev Event emitted when setPendingAdmin is updated by admin.
 * @param previousPendingAdmin - the previous pendingAdmin value that was updated by admin
 * @param newPendingAdmin - the current pendingAdmin value that was added by admin
 */
 event SetPendingAdmin(address indexed previousPendingAdmin, address indexed newPendingAdmin);

 /**
 * @dev Event emitted when admin is updated - only pending admin can update.
 * @param previousAdmin - the previous admin value that was updated by pendingAdmin
 * @param newAdmin - the current admin value - this is usually the pendingAdmin value and only called by pendingAdmin to perform this function
 */
 event UpdateAdmin(address indexed previousAdmin, address indexed newAdmin);

 /**
 * @dev Event emitted when minted address is updated.
 * @param previousMinter - the address of previous minter
 * @param newMinter - the address of current minter
 */
 event UpdateMinter(address indexed previousMinter, address indexed newMinter);

 /**
 * @dev Restricts a function so it can only be executed by an admin role
 */
 modifier adminOnly() {
 require(msg.sender == admin, "Only admin can make this call");
 _;
 }

 /**
 * @dev Restricts a function so it can only be executed by a pending admin role
 */
 modifier pendingAdminOnly() {
 require(msg.sender == pendingAdmin, "Only pending admin can make this call");
 _;
 }

 /**
 * @dev Restricts a function so it can only be executed by a minter
 */
 modifier minterOnly() {
 require(msg.sender == minter, "Only minter can make this call");
 _;
 }

 /**
 * @dev Initializes the contract during deployment
 * @param name_ is the name of the token
 * @param symbol_ is the ticker symbol of the token
 * @param decimals_ set to 18 on deploy.
 * @param maxSupply_ is set to maxSupply of tokens allowed. The total supply of tokens should never exceed more than 1 billion
 * @param minter_ is the contract address of ValidatorStakeManager.
 * @param stakerRewardPerBlock_ will mint tokens based on stakerRewardPerBlock_ to reward the Subchain validator stakers.
 * @param initDistrWallet_ will hold the initial minted tokens
 * @param initMintAmount_ the initial mint tokens that will be held by initDistrWallet_
 * @param admin_ is the admin of the contract
 */
 constructor(
 string memory name_,
 string memory symbol_,
 uint8 decimals_,
 uint256 maxSupply_,
 address minter_,
 uint256 stakerRewardPerBlock_,
 address initDistrWallet_,
 uint256 initMintAmount_,
 address admin_
 ) ERC20(name_, symbol_)
 {
 require(admin_ != address(0x0), "invalid admin address");
 require(minter_ != address(0x0), "invalid minter_ address");
 require(initDistrWallet_ != address(0x0), "invalid initDistrWallet_ address");
 require(decimals_ != 0, "invalid decimals");
 require(maxSupply_ != 0, "invalid maxSupply");
 require(maxSupply_ <= 10 ** 27, "maxSupply too large");
 require(
 initMintAmount_ < maxSupply_,
 "Initial supply too large"
 );
 _decimals = decimals_;
 maxSupply = maxSupply_;
 minter = minter_;
 _stakerRewardPerBlock = stakerRewardPerBlock_;
 admin = admin_;
 _mint(initDistrWallet_, initMintAmount_);
 emit UpdateMinter(previousMinter, minter);
 emit UpdateAdmin(previousAdmin, admin);
 emit UpdateStakerRewardPerBlock(_stakerRewardPerBlock);
 }

 /**
 * @dev This method allows the minter (e.g. the ValidatorStakeManager contract) to mint new tokens to reward, Minter is the ValidatorStakeManager contract.
 * @param account - account to which the staker amount and rewards will be minted
 * @param amount - amount that needs to be minted by the VSM
 * @return bool - This returns true - if the rewards are minted and false if they are not.
 */
 function mintStakerReward(address account, uint256 amount)
 external
 minterOnly
 returns (bool)
 {
 if (account == address(0x0)) {
 return false;
 }
 uint256 currentSupply = this.totalSupply();
 if (currentSupply >= maxSupply) {
 return false;
 }
 if (currentSupply.add(amount) > maxSupply) {
 amount = maxSupply.sub(currentSupply);
 }
 _mint(account, amount);
 return true;
 }

 /**
 * @dev This function allows admin to mint additional tokens.
 * @param amount - amount of tokens that will be minted by admin. They are minted to admin wallet.
 */
 function mint(uint256 amount) external adminOnly {
 require(msg.sender == admin, "only admin can mint");
 uint256 currentSupply = this.totalSupply();
 require(currentSupply <= maxSupply, "already exceeded max supply");
 require(currentSupply.add(amount) < maxSupply, "exceeded max supply of tokens" );
 _mint(admin, amount);
 }

 /**
 * @dev This function allows admin to update Staker reward per block
 * @notice This value will be cut in half based on the rules in per white paper.
 * @param stakerRewardPerBlock_ - Minter will mint tokens based on stakerRewardPerBlock_ to reward the Subchain validator stakers.
 */
 function updateStakerRewardPerBlock(uint256 stakerRewardPerBlock_)
 external
 adminOnly
 {
 _stakerRewardPerBlock = stakerRewardPerBlock_;
 emit UpdateStakerRewardPerBlock(_stakerRewardPerBlock);
 }

 /**
 * @dev This function updates Minter and can be called by admin only.
 * @param minter_ - The address of the minted contract this will be VSM - Validator Stake manager.
 */
 function updateMinter(address minter_) external adminOnly {
 require(minter_ != address(0x0), "invalid minter address");
 previousMinter = minter;
 minter = minter_;
 emit UpdateMinter(previousMinter, minter);
 }

 /**
 * @dev Pending admin is an intermediate role which is only used to update an admin
 * @param admin_ the address of the pending admin that needs to be set
 */
 function setPendingAdmin(address admin_) external adminOnly {
 require(admin_ != address(0x0), "invalid pending admin address");
 previousPendingAdmin = pendingAdmin;
 pendingAdmin = admin_;
 emit SetPendingAdmin(previousPendingAdmin, pendingAdmin);
 }

 /**
 * @dev This function updates admin - only invoked by pending admin
 */
 function updateAdmin() external pendingAdminOnly {
 previousAdmin = admin;
 admin = pendingAdmin;
 emit UpdateAdmin(previousAdmin, admin);
 }

 /**
 * @dev This method tells the minter - ValidatorStakeManager contract how many new tokens are minted per block for the Subchain validator stakers
 * @return Returns reward per block that gets minted by minter for stakers based on their staked amount.
 */
 function stakerRewardPerBlock() external view returns (uint256) {
 return _stakerRewardPerBlock;
 }

 /**
 * @dev Read only function for returning the decimals of token.
 */
 function decimals() public view virtual override returns (uint8) {
 return _decimals;
 }
}

Contract ABI:

[]