/**
 *Submitted for verification at Etherscan.io on 2022-08-06
*/

// SPDX-License-Identifier: MIT
pragma solidity 0.7.5;


interface IERC20 {
    function decimals() external view returns (uint8);
  /**
   * @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);
}

interface IStaking {
    function stake(uint256 _amount, address _recipient) external returns (bool);
    function claim(address _recipient) external;
}

contract StakingHelper {

    event LogStake(address indexed recipient, uint256 amount);

    IStaking public immutable staking;
    IERC20 public immutable BigToken;

    constructor (address _staking, address _Big) {
        require(_staking != address(0));
        require(_Big != address(0));
        staking = IStaking(_staking);
        BigToken = IERC20(_Big);
    }

    function stake(uint256 _amount, address recipient) external {
        BigToken.transferFrom(msg.sender, address(this), _amount);
        BigToken.approve(address(staking), _amount);
        staking.stake(_amount, recipient);
        staking.claim(recipient);
        emit LogStake(recipient, _amount);
    }
}