// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Context.sol

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/Ownable.sol


// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;


/**
 * @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.
 *
 * The initial owner is set to the address provided by the deployer. 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;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(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) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
}

// File: contracts/staking-spec.sol



pragma solidity ^0.8.20;



error Staking__TransferFailed();
error Withdraw__TransferFailed();
error Staking__NeedsMoreThanZero();

contract SpectraStaking is Ownable {
    IERC20 public _stakingToken;
    IERC20 public _rewardToken;

    uint256 public TOKENS_PER_DAY = 86400;
    uint256 public REWARD_RATE;

    uint256 public _rewardPerTokenStored;

    uint256 public staked_totalSupply;
    uint256 public staked_lastUpdateTime;

    mapping(address => uint256) public staked_balances;
    mapping(address => uint256) public _userRewardPerToken;
    mapping(address => uint256) public _userRewards;
    mapping(address => uint256) public _userClaimedRewards;


    mapping(address => bool) public _usersStaked;
    uint256 public totalUsersStaked;

    bool public stakingEnabled = false;
    
    modifier updateReward(address account) {
        _rewardPerTokenStored = rewardPerToken();
        staked_lastUpdateTime = block.timestamp;
        _userRewards[account] = earned(account);
        _userRewardPerToken[account] = _rewardPerTokenStored;

        _;
    }

    modifier moreThanZero(uint256 amount) {
        if (amount == 0) {
            revert Staking__NeedsMoreThanZero();
        }
        _;
    }

    constructor(
        address stakingToken,
        address rewardToken,
        address initialOwner
    ) Ownable(initialOwner) {
        _stakingToken = IERC20(stakingToken);
        _rewardToken = IERC20(rewardToken);
        REWARD_RATE = (TOKENS_PER_DAY * 10**18) / 86400;
    }

    function earned(address account) public view returns (uint256) {
        uint256 currentBalance = staked_balances[account];
        uint256 amountPaid = _userRewardPerToken[account];
        uint256 currentRewardPerToken = rewardPerToken();

        uint256 pastRewards = _userRewards[account];

        uint256 _earned = ((currentBalance *
            (currentRewardPerToken - amountPaid)) / 1e18) + pastRewards;

        return _earned;
    }

    function rewardPerToken() public view returns (uint256) {
        if (staked_totalSupply == 0) {
            return _rewardPerTokenStored;
        } else {
            return
                _rewardPerTokenStored +
                (((block.timestamp - staked_lastUpdateTime) *
                    REWARD_RATE *
                    1e18) / staked_totalSupply);
        }
    }

    function stake(uint256 amount)
        external
        updateReward(msg.sender)
        moreThanZero(amount)
    {
        require(stakingEnabled,"Staking is not enabled yet!");
        if (!_usersStaked[msg.sender]) {
            _usersStaked[msg.sender] = true;
            totalUsersStaked++;
        }

        staked_balances[msg.sender] += amount;
        staked_totalSupply += amount;
        //emit event
        bool success = _stakingToken.transferFrom(
            msg.sender,
            address(this),
            amount
        );
        if (!success) {
            revert Staking__TransferFailed();
        }
    }

    function withdraw(uint256 amount)
        external
        updateReward(msg.sender)
        moreThanZero(amount)
    {
        require(amount <= staked_balances[msg.sender], "Insufficient balance");

        staked_balances[msg.sender] -= amount;
        staked_totalSupply -= amount;
        // emit event
        bool success = _stakingToken.transfer(msg.sender, amount);
        if (!success) {
            revert Withdraw__TransferFailed();
        }
    }

    function claimReward() external updateReward(msg.sender) {
        uint256 reward = earned(msg.sender) - _userClaimedRewards[msg.sender];
        bool success = _rewardToken.transfer(msg.sender, reward);
        _userClaimedRewards[msg.sender] += reward;
        if (!success) {
            revert Staking__TransferFailed();
        }
    }

    function getStaked(address account) public view returns (uint256) {
        return staked_balances[account];
    }

    function recoverTokens(address receiver, uint256 amount)
        external
        onlyOwner
    {
        uint256 rewardBalance = _rewardToken.balanceOf(address(this));
        require(amount <= rewardBalance, "Insufficient balance");

        bool success = _rewardToken.transfer(receiver, amount);
        require(success, "Transfer failed");
    }

    function updateRewardRates(uint256 tokensPerDay) external onlyOwner {
        TOKENS_PER_DAY = tokensPerDay;
        REWARD_RATE = (TOKENS_PER_DAY * 10**18) / 86400; 
    }

    function enableStaking(bool _enabled) external onlyOwner {
        stakingEnabled = _enabled;
    }
    
}

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