// SPDX-License-Identifier: MIT

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;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.9;

interface IERC20 {
    function totalSupply() external view returns (uint);

    function balanceOf(address account) external view returns (uint);

    function transfer(address recipient, uint amount) external returns (bool);

    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint amount) external returns (bool);

    function transferFrom(
        address sender,
        address recipient,
        uint amount
    ) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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 {
    address private _owner;
    address private _serviceAdmin;
    bool private initialized;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    event NewServiceAdmin(address indexed previousServiceAdmin, address indexed newServiceAdmin);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */

    function init(address serviceAdmin_) internal {
        require(!initialized, "Ownable: init done");
        _setOwner(_msgSender());
        _setServiceAdmin(serviceAdmin_);
        initialized = true;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Returns the address of the current service admin.
     */
    function serviceAdmin() public view virtual returns (address) {
        return _serviceAdmin;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Throws if called by any account other than the service Admin.
     */
    modifier onlyServiceAdmin() {
        require(serviceAdmin() == _msgSender(), "Ownable: caller is not the serviceAdmin");
        _;
    }

    modifier anyAdmin(){
        require(serviceAdmin() == _msgSender() || owner() == _msgSender(), "Ownable: Caller is not authorized");
        _;
    }

    /**
     * @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() external virtual onlyOwner {
        _setOwner(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) external virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }

    function _setServiceAdmin(address newServiceAdmin) private {
        address oldServiceAdmin = _serviceAdmin;
        _serviceAdmin = newServiceAdmin;
        emit NewServiceAdmin(oldServiceAdmin, newServiceAdmin);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)

pragma solidity ^0.8.0;

import "./Context.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 {

    bool private pauseInit;

    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */

    function _pausable_init() internal{
         require(!pauseInit, "init done");
        _paused = false;
        pauseInit = true;
    }


    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual 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() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.9;

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*/

// BETTER Staking Contract
// based on Synthetix StakingRewards

import "./IERC20.sol";
import "./Ownable.sol";
import "./Pauseable.sol";

contract StakingRewards is Ownable, Pausable{
    IERC20 public rewardsToken;
    IERC20 public stakingToken;

    uint256 public periodFinish;
    uint public rewardRate ;
    uint public lastUpdateTime;
    uint public rewardPerTokenStored;

    mapping(address => uint) public userRewardPerTokenPaid;
    mapping(address => uint) public rewards;

    uint private _totalSupply;
    mapping(address => uint) private _balances;

    event Staked(address indexed user, uint256 amount);
    event Withdrawn(address indexed user, uint256 amount);
    event RewardPaid(address indexed user, uint256 reward);
    event RewardsDurationUpdated(uint256 newDuration);

    constructor(address _stakingToken, address _rewardsToken, uint256 _endTime, uint256 _rewardRate, address serviceAdmin) {
        stakingToken = IERC20(_stakingToken);
        rewardsToken = IERC20(_rewardsToken);
        periodFinish = _endTime;
        rewardRate = _rewardRate;
        Ownable.init(serviceAdmin);
        _pausable_init();
    }

    function rewardPerToken() public view returns (uint) {
        if (_totalSupply == 0) {
            return 0;
        }
        return
            rewardPerTokenStored +
            (((lastTimeRewardApplicable() - lastUpdateTime) * rewardRate * 1e18) / _totalSupply);
    }

    function earned(address account) public view returns (uint) {
        return
            ((_balances[account] *
                (rewardPerToken() - userRewardPerTokenPaid[account])) / 1e18) +
            rewards[account];
    }

    modifier updateReward(address account) {
        rewardPerTokenStored = rewardPerToken();
        lastUpdateTime = lastTimeRewardApplicable();

        if (account != address(0)) {
            rewards[account] = earned(account);
            userRewardPerTokenPaid[account] = rewardPerTokenStored;
        }
        _;
    }

    function stake(uint _amount) external whenNotPaused updateReward(msg.sender) {
        require(_amount > 0, "Cannot withdraw 0");

        _totalSupply += _amount;
        _balances[msg.sender] += _amount;
        stakingToken.transferFrom(msg.sender, address(this), _amount);

        emit Staked(msg.sender, _amount);
    }

    function withdraw(uint _amount) public whenNotPaused updateReward(msg.sender) {
        require(_amount > 0, "Cannot withdraw 0");
        require(_balances[msg.sender] >= _amount,"Can not withdraw more than the current balance");

        _totalSupply -= _amount;
        _balances[msg.sender] -= _amount;
        stakingToken.transfer(msg.sender, _amount);

        emit Withdrawn(msg.sender, _amount);
    }

    function getReward() public whenNotPaused updateReward(msg.sender) {
        uint reward = rewards[msg.sender];
        if (reward > 0){
            rewards[msg.sender] = 0;
            rewardsToken.transfer(msg.sender, reward);

            emit RewardPaid(msg.sender, reward);
        }
    }
    
    function exit() whenNotPaused external {
        withdraw(_balances[msg.sender]);
        getReward();
    }
    
    function updatePeriod(uint256 _newperiod)public anyAdmin {
        require(_newperiod > periodFinish, "New time should be greater than old one");
        
        periodFinish = _newperiod;
        emit RewardsDurationUpdated(_newperiod);
    }

    function totalSupply() external view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) external view returns (uint256) {
        return _balances[account];
    }

    function lastTimeRewardApplicable() public view returns (uint256) {
        return block.timestamp < periodFinish ? block.timestamp : periodFinish;
    }
    
    // ================== Functions to pause and unpause contract ==================
    
    function PauseContract()public anyAdmin{
        _pause();
    }
    function UnPauseContract()public anyAdmin{
        _unpause();
    }
}

{
  "compilationTarget": {
    "StakingV1.sol": "StakingRewards"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}