// File: /contracts/RewardStaked.sol



// contracts/CawName.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./interfaces/IERC20.sol";
import "./libraries/TransferHelper.sol";
import "../node_modules/@openzeppelin/contracts/access/Ownable.sol";
import "../node_modules/@openzeppelin/contracts/security/ReentrancyGuard.sol";

/// @title RewardStaked
/// @notice A contract that allows users to stake a specific ERC20 token and earn rewards in other ERC20 tokens.
contract RewardStaked is 
  Context, Ownable,
  ReentrancyGuard
{

  IERC20 public immutable Stakeable;
  address[] public rewardTokens;

  uint256 public totalStaked;
  mapping(address => uint256) public deposits;
  mapping(address => uint256) public lockedUntil;
  mapping(address => mapping(address => uint256)) public nullifiedRewards;


  mapping(address => uint256) public rewardsPerDeposit;
  mapping(address => uint256) public totalRewarded;

  uint256 public precision = 10 ** 8;
  uint256 public lockTime;

  /// @notice Initializes the contract with the stakeable token, lock time, and initial reward tokens.
  /// @param _stakeable The token that users can stake.
  /// @param _lockTime The time that users must wait after unlocking their stake before they can withdraw it.
  /// @param _rewardTokens An array of tokens that users can earn as rewards.
  constructor(address _stakeable, uint256 _lockTime, address[] memory _rewardTokens) {
    Stakeable = IERC20(_stakeable);
    lockTime = _lockTime;

    for (uint16 i=0; i < _rewardTokens.length; i++)
      addRewardToken(_rewardTokens[i]);
  }

  /// @notice Returns the array of reward tokens.
  function getRewardTokens() public virtual view returns (address[] memory) {
    return rewardTokens;
  }

  /// @notice Allows a user to deposit the stakeable token.
  /// @param amount The amount of the stakeable token to deposit.
  function deposit(uint256 amount) external nonReentrant {
    require(!unlockInitiated(msg.sender), "you must wait until you withdraw your tokens");

    TransferHelper.safeTransferFrom(address(Stakeable), msg.sender, address(this), amount);

    // Claims all rewards before updating the user's stake.
    claimAll(getRewardTokens());

    deposits[msg.sender] += amount;
    totalStaked += amount;
  }

  /// @notice Allows a user to unlock their stake.
  function unlock() external nonReentrant {
    require(!unlockInitiated(msg.sender), "Unlock is already pending");

    // Claims all rewards before updating the user's stake.
    claimAll(getRewardTokens());

    totalStaked -= deposits[msg.sender];
    lockedUntil[msg.sender] = block.timestamp + lockTime;
  }

  /// @notice Allows a user to withdraw their stake after it has been unlocked.
  function withdraw() external nonReentrant {
    require(unlockInitiated(msg.sender), "you must unlock your staked tokens first");
    require(isUnlocked(msg.sender), "your staked tokens are still locked");

    uint256 withdrawable = deposits[msg.sender];
    deposits[msg.sender] = 0;

    TransferHelper.safeTransfer(address(Stakeable), msg.sender, withdrawable);
    lockedUntil[msg.sender] = 0;
  }

  /// @notice Nullifies the user's claimable rewards for the given token.
  /// @param token The token for which to nullify the user's rewards.
  function nullifyRewardsForToken(address token) internal {
    nullifiedRewards[token][msg.sender] = rewardsPerDeposit[token];
  }

  /// @notice Allows anyone to add rewards for all stakers.
  /// @param token The token in which the rewards are being added.
  /// @param amount The amount of rewards to add.
  function addRewards(address token, uint256 amount) external {
    require(totalStaked > 0, "can not add rewards if there are no stakers");

    TransferHelper.safeTransferFrom(token, msg.sender, address(this), amount);
    rewardsPerDeposit[token] += precision * amount / totalStaked;
    totalRewarded[token] += amount;
  }

  /// @notice Returns various information about the current state of the contract and the user's stake.
  /// @param user The user to retrieve information for.
  function getInfo(address user) external view returns (uint256, uint256, uint256, uint256, uint256, uint256) {
    return (
      totalStaked,
      deposits[user],
      lockedUntil[user],
      Stakeable.decimals(),
      Stakeable.balanceOf(user),
      Stakeable.allowance(user, address(this))
    );
  }

  /// @notice Returns various information about all of the reward tokens and the user's claimable rewards.
  /// @param user The user to retrieve information for.
  function allClaimable(address user) external view returns (address[] memory, string[] memory, uint256[] memory, uint256[] memory, uint256[] memory) {
    address[] memory tokens = getRewardTokens();
    uint256[] memory totalRewards = new uint256[](tokens.length);
    uint256[] memory canClaim = new uint256[](tokens.length);
    uint256[] memory decimals = new uint256[](tokens.length);
    string[] memory symbols = new string[](tokens.length);

    for (uint16 i=0; i < tokens.length; i++) {
      IERC20 token = IERC20(tokens[i]);

      symbols[i] = token.symbol();
      decimals[i] = token.decimals();
      canClaim[i] = claimable(tokens[i], user);
      totalRewards[i] = totalRewarded[tokens[i]];
    }

    return (tokens, symbols, decimals, canClaim, totalRewards);
  }

  /// @notice Returns the amount of the given token that the user can claim as rewards.
  /// @param token The token to check.
  /// @param user The user to check.
  function claimable(address token, address user) public view returns (uint256){
    if (unlockInitiated(user)) return 0;

    return deposits[user] * (rewardsPerDeposit[token] - nullifiedRewards[token][user]) / precision;
  }

  /// @notice Allows the user to claim their rewards in the given token.
  /// @param token The token to claim rewards in.
  function claim(address token) internal {
    uint256 willClaim = claimable(token, msg.sender);
    nullifyRewardsForToken(token);

    if (willClaim > 0)
      IERC20(token).transfer(msg.sender, willClaim);
  }

  /// @notice Allows the user to claim their rewards in all tokens.
  /// @param rewards An array of tokens to claim rewards in.
  function claimAll(address[] memory rewards) public {
    for (uint16 i=0; i < rewards.length; i++)
      claim(rewards[i]);
  }

  /// @notice Returns whether the user has initiated an unlock.
  /// @param user The user to check.
  function unlockInitiated(address user) public view returns (bool) {
    return lockedUntil[user] > 0;
  }

  /// @notice Returns whether the user's stake is currently locked.
  /// @param user The user to check.
  function isUnlocked(address user) public view returns (bool) {
    return unlockInitiated(user) && lockedUntil[user] < block.timestamp;
  }

  /// @notice Removes a reward token.
  /// @param index The index of the token to remove.
  function removeRewardToken(uint16 index) public onlyOwner {
    require(rewardTokens.length > index, "invalid index");

    address lastToken = rewardTokens[rewardTokens.length - 1];
    rewardTokens.pop();

    if (rewardTokens.length > index)
      rewardTokens[index] = lastToken;
  }

  /// @notice Adds a new reward token.
  /// @param token The token to add.
  function addRewardToken(address token) public onlyOwner {
    for (uint16 i=0; i < rewardTokens.length; i++)
      require(rewardTokens[i] != token, "this token is already a reward token");

    rewardTokens.push(token);
  }

}

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



// SPDX-License-Identifier: MIT
// 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: /node_modules/@openzeppelin/contracts/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: /node_modules/@openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/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;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @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 {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @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() 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 {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _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: /contracts/libraries/TransferHelper.sol



// SPDX-License-Identifier: GPL-3.0-or-later

pragma solidity >=0.6.0;

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
  function safeApprove(
    address token,
    address to,
    uint256 value
  ) internal {
    // bytes4(keccak256(bytes('approve(address,uint256)')));
    (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
    require(
      success && (data.length == 0 || abi.decode(data, (bool))),
      'TransferHelper::safeApprove: approve failed'
    );
  }

  function safeTransfer(
    address token,
    address to,
    uint256 value
  ) internal {
    // bytes4(keccak256(bytes('transfer(address,uint256)')));
    (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
    require(
      success && (data.length == 0 || abi.decode(data, (bool))),
      'TransferHelper::safeTransfer: transfer failed'
    );
  }

  function safeTransferFrom(
    address token,
    address from,
    address to,
    uint256 value
  ) internal {
    // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
    (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
    require(
      success && (data.length == 0 || abi.decode(data, (bool))),
      'TransferHelper::transferFrom: transferFrom failed'
    );
  }

  function safeTransferETH(address to, uint256 value) internal {
    (bool success, ) = to.call{value: value}(new bytes(0));
    require(success, 'TransferHelper::safeTransferETH: ETH transfer failed');
  }
}

// File: /contracts/interfaces/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

    /**
     * @dev Returns the amount of decimals of the token
     */
    function decimals() 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);
}