pragma solidity ^0.8.0;

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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);
}

pragma solidity ^0.8.0;


/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
    if (a == 0) {
      return 0;
    }
    c = a * b;
    assert(c / a == b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    // uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return a / b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
    c = a + b;
    assert(c >= a);
    return c;
  }
    }

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

contract Ownable is Context {
    address private _owner;
 
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
 
    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
 
    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
 
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
 
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
    }

contract Rewards is Ownable {
    using SafeMath for uint256;

    IERC20 private _token;
    mapping(address => uint256) private _claimedFees; 
    mapping(address => uint256) private _lastClaimedTimestamp; // new mapping to record the last claimed timestamp
    uint256 private _totalFees;
    uint256 private _feeCooldownTime = 30 minutes; // new variable to set the time between fee claims
    
    constructor(address tokenAddress) {
        require(tokenAddress != address(0), "FeeRecipient: token address is invalid");
        _token = IERC20(tokenAddress);
    }
    
    function claimFees() external {
        uint256 availableFees = getAvailableFees(msg.sender);
        require(availableFees > 0, "FeeRecipient: no available fees to claim");
        require(_token.balanceOf(msg.sender) > 0, "FeeRecipient: only token holders can claim fees");
        require(block.timestamp >= _lastClaimedTimestamp[msg.sender].add(_feeCooldownTime), "FeeRecipient: must wait before claiming fees again");
        require(_token.transfer(msg.sender, availableFees), "FeeRecipient: fee transfer failed");
        _claimedFees[msg.sender] = _claimedFees[msg.sender].add(availableFees);
        _lastClaimedTimestamp[msg.sender] = block.timestamp; // record the timestamp of the last claim
    }
    
    function getTotalFees() external view returns (uint256) {
        return _totalFees;
    }
    
    function getAvailableFees(address account) public view returns (uint256) {
        uint256 totalFees = _token.balanceOf(address(this));
        uint256 claimedFees = _claimedFees[account];
        uint256 accountBalance = _token.balanceOf(account);
        uint256 accountShare = totalFees.mul(accountBalance).div(_token.totalSupply());
        return accountShare.sub(claimedFees);
    }
}