// File: contracts/JoystickPresale.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.6;

import "@openzeppelin/contracts/utils/math/Math.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "./libraries/Authorizable.sol";
import "./tokens/xJoyToken.sol";

contract JoystickPresale is Context, Ownable, Authorizable {
    using SafeMath for uint256;

    // Info of each coin like USDT, USDC
    struct CoinInfo {
        address addr;
        uint256 rate;
    }

    // Info of each Purchaser
    struct UserInfo {
        uint256 depositedAmount;      // How many Coins amount the user has deposited.
        uint256 purchasedAmount;      // How many JOY tokens the user has purchased.
        uint256 withdrawnAmount;      // Withdrawn amount
        uint256 lastWithdrawnTime;    // Last Withdrawn time  
    }

    // Sale flag and related times.
    bool public SALE_FLAG;
    uint256 public SALE_START;
    uint256 public SALE_DURATION;
    uint256 public LOCKING_DURATION;
    uint256 public VESTING_DURATION;

    // Coin Info list
    mapping(uint => CoinInfo) public coinInfo;
    uint8 public coinInfoCount;
    uint8 public COIN_DECIMALS = 18;

    // The JOY Token
    IERC20 public govToken;
    // The xJOY Token
    IERC20 public xGovToken;
    // User address => UserInfo
    mapping(address => UserInfo) public userInfo;
    address[] public userAddrs;

    // total tokens amounts (all 18 decimals)
    uint256 public totalSaleAmount;
    uint256 public totalCoinAmount;
    uint256 public totalSoldAmount;

    // Events.
    event TokensPurchased(address indexed purchaser, uint256 coinAmount, uint256 tokenAmount);
    event TokensWithdrawed(address indexed purchaser, uint256 tokenAmount);

    // Modifiers.
    modifier whenSale() {
        require(checkSalePeriod(), "This is not sale period.");
        _;
    }
    modifier whenVesting() {
        require(checkVestingPeriod(), "This is not vesting period.");
        _;
    }

    constructor(IERC20 _govToken, IERC20 _xGovToken, CoinInfo[] memory _coinInfo, uint256 _totalSaleAmount)
    {
        addAuthorized(_msgSender());

        govToken = _govToken;
        xGovToken = _xGovToken;
        totalSaleAmount = _totalSaleAmount.mul(10 ** ERC20(address(xGovToken)).decimals());

        for (uint i=0; i<_coinInfo.length; i++) {
            addCoinInfo(_coinInfo[i].addr, _coinInfo[i].rate);
        }

        SALE_FLAG = true;
        SALE_START = block.timestamp;
        SALE_DURATION = 60 days;
        LOCKING_DURATION = 730 days;
        VESTING_DURATION = 365 days;
    }

    // Update token
    function updateTokens(IERC20 _govToken, IERC20 _xGovToken) public onlyAuthorized {
        govToken = _govToken;
        xGovToken = _xGovToken;
    }

    // Start stop sale
    function startSale(bool bStart) public onlyAuthorized {
        SALE_FLAG = bStart;
        if (bStart) {
            SALE_START = block.timestamp;
        }
    }

    // Set durations
    function setDurations(uint256 saleDuration, uint256 lockingDuration, uint256 vestingDuration) public onlyAuthorized {
        SALE_DURATION = saleDuration;
        LOCKING_DURATION = lockingDuration;
        VESTING_DURATION = vestingDuration;
    }

    // check sale period
    function checkSalePeriod() public view returns (bool) {
        return SALE_FLAG && block.timestamp >= SALE_START && block.timestamp <= SALE_START.add(SALE_DURATION);
    }

    // check locking period
    function checkLockingPeriod() public view returns (bool) {
        return block.timestamp >= SALE_START && block.timestamp <= SALE_START.add(LOCKING_DURATION);
    }

    // check vesting period
    function checkVestingPeriod() public view returns (bool) {
        uint256 VESTING_START = SALE_START.add(LOCKING_DURATION);
        return block.timestamp >= VESTING_START;
    }

    // Add coin info
    function addCoinInfo(address addr, uint256 rate) public onlyAuthorized {
        coinInfo[coinInfoCount] = CoinInfo(addr, rate);
        coinInfoCount++;
    }

    // Set coin info
    function setCoinInfo(address addr, uint256 rate, uint8 index) public onlyAuthorized {
        coinInfo[index] = CoinInfo(addr, rate);
    }

    // Set total sale amount
    function setTotalSaleAmount(uint256 amount) public onlyAuthorized {
        totalSaleAmount = amount;
    }

    // Get user count
    function getUserCount() public view returns (uint256) {
        return userAddrs.length;
    }

    // Get user addrs
    function getUserAddrs() public view returns (address[] memory) {
        address[] memory returnData = new address[](userAddrs.length);
        for (uint i=0; i<userAddrs.length; i++) {
            returnData[i] = userAddrs[i];
        }
        return returnData;
    }
    
    // Get user infos
    function getUserInfos() public view returns (UserInfo[] memory returnData) {
        returnData = new UserInfo[](userAddrs.length);
        for (uint i=0; i<userAddrs.length; i++) {
            UserInfo storage _userInfo = userInfo[userAddrs[i]];
            returnData[i] = _userInfo;
        }
        return returnData;
    }    

    // deposit
    // coinAmount (decimals: COIN_DECIMALS) 
    function deposit(uint256 _coinAmount, uint8 coinIndex) external whenSale {
        require( totalSaleAmount >= totalSoldAmount, "totalSaleAmount >= totalSoldAmount");

        CoinInfo storage _coinInfo = coinInfo[coinIndex];
        IERC20 coin = IERC20(_coinInfo.addr);

        // calculate token amount to be transferred
        (uint256 tokenAmount, uint256 coinAmount) = calcTokenAmount(_coinAmount, coinIndex);
        uint256 availableTokenAmount = totalSaleAmount.sub(totalSoldAmount);

        // if the token amount is less than remaining
        if (availableTokenAmount < tokenAmount) {
            tokenAmount = availableTokenAmount;
            (_coinAmount, coinAmount) = calcCoinAmount(availableTokenAmount, coinIndex);
        }

        // validate purchasing
        _preValidatePurchase(_msgSender(), tokenAmount, coinAmount, coinIndex);

        // transfer coin and token
        coin.transferFrom(_msgSender(), address(this), coinAmount);
        xGovToken.transfer(_msgSender(), tokenAmount);

        // update global state
        totalCoinAmount = totalCoinAmount.add(_coinAmount);
        totalSoldAmount = totalSoldAmount.add(tokenAmount);
        
       // update purchased token list
       UserInfo storage _userInfo = userInfo[_msgSender()];
       if (_userInfo.depositedAmount == 0) {
           userAddrs.push(_msgSender());
       }
       _userInfo.depositedAmount = _userInfo.depositedAmount.add(_coinAmount);
       _userInfo.purchasedAmount = _userInfo.purchasedAmount.add(tokenAmount);
       
       emit TokensPurchased(_msgSender(), _coinAmount, tokenAmount);

       xJoyToken _xJoyToken = xJoyToken(address(xGovToken));
       _xJoyToken.addPurchaser(_msgSender(), tokenAmount);
    }

    // withdraw
    function withdraw() external whenVesting {
        uint256 withdrawalAmount = calcWithdrawalAmount(_msgSender());
        uint256 govTokenAmount = govToken.balanceOf(address(this));
        uint256 xGovTokenAmount = xGovToken.balanceOf(address(_msgSender()));
        uint256 withdrawAmount = Math.min(withdrawalAmount, Math.min(govTokenAmount, xGovTokenAmount));
       
        require(withdrawAmount > 0, "No withdraw amount!");
        require(xGovToken.allowance(msg.sender, address(this)) >= withdrawAmount, "withdraw's allowance is low!");

        xGovToken.transferFrom(_msgSender(), address(this), withdrawAmount);
        govToken.transfer(_msgSender(), withdrawAmount);

        UserInfo storage _userInfo = userInfo[_msgSender()];
        _userInfo.withdrawnAmount = _userInfo.withdrawnAmount.add(withdrawAmount);
        _userInfo.lastWithdrawnTime = block.timestamp;

        emit TokensWithdrawed(_msgSender(), withdrawAmount);
    }

    // Calc token amount by coin amount
    function calcWithdrawalAmount(address addr) public view returns (uint256) {
        require(checkVestingPeriod(), "This is not vesting period.");

        uint256 VESTING_START = SALE_START.add(LOCKING_DURATION);

        UserInfo storage _userInfo = userInfo[addr];
        uint256 totalAmount = 0;
        if (block.timestamp >= VESTING_START.add(VESTING_DURATION)) {
            totalAmount = _userInfo.purchasedAmount;
        } else {
            totalAmount = _userInfo.purchasedAmount.mul(block.timestamp.sub(VESTING_START)).div(VESTING_DURATION);
        }

        uint256 withdrawalAmount = totalAmount.sub(_userInfo.withdrawnAmount);
        return withdrawalAmount;
    }

    // Calc token amount by coin amount
    function calcTokenAmount(uint256 _coinAmount, uint8 coinIndex) public view returns (uint256, uint256) {
        require( coinInfoCount >= coinIndex, "coinInfoCount >= coinIndex");

        CoinInfo storage _coinInfo = coinInfo[coinIndex];
        ERC20 coin = ERC20(_coinInfo.addr);
        uint256 rate = _coinInfo.rate;

        uint tokenDecimal =  ERC20(address(xGovToken)).decimals() + coin.decimals() - COIN_DECIMALS;
        uint256 tokenAmount = _coinAmount
        .mul(10**tokenDecimal)
        .div(rate);
        
        uint coinDecimal =  COIN_DECIMALS - coin.decimals();
        uint256 coinAmount = _coinAmount
        .div(10**coinDecimal);

        return (tokenAmount, coinAmount);
    }

    // Calc coin amount by token amount
    function calcCoinAmount(uint256 _tokenAmount, uint8 coinIndex) public view returns (uint256, uint256) {
        require( coinInfoCount >= coinIndex, "coinInfoCount >= coinIndex");

        CoinInfo storage _coinInfo = coinInfo[coinIndex];
        ERC20 coin = ERC20(_coinInfo.addr);
        uint256 rate = _coinInfo.rate;

        uint _coinDecimal =  ERC20(address(xGovToken)).decimals() + coin.decimals() - COIN_DECIMALS;
        uint256 _coinAmount = _tokenAmount
        .div(10**_coinDecimal)
        .mul(rate);
        
        uint coinDecimal =  COIN_DECIMALS - coin.decimals();
        uint256 coinAmount = _coinAmount
        .div(10**coinDecimal);

        return (_coinAmount, coinAmount);
    }

    // Calc max coin amount to be deposit
    function calcMaxCoinAmountToBeDeposit(uint8 coinIndex) public view returns (uint256) {
        uint256 availableTokenAmount = totalSaleAmount.sub(totalSoldAmount);
        (uint256 _coinAmount,) = calcCoinAmount(availableTokenAmount, coinIndex);
        return _coinAmount;
    }

    // Validate purchase
    function _preValidatePurchase(address purchaser, uint256 tokenAmount, uint256 coinAmount, uint8 coinIndex) internal view {
        require( coinInfoCount >= coinIndex, "coinInfoCount >= coinIndex");
        CoinInfo storage _coinInfo = coinInfo[coinIndex];
        IERC20 coin = IERC20(_coinInfo.addr);

        require(purchaser != address(0), "Purchaser is the zero address");
        require(coinAmount != 0, "Coin amount is 0");
        require(tokenAmount != 0, "Token amount is 0");

        require(xGovToken.balanceOf(address(this)) >= tokenAmount, "$xJoyToken amount is lack!");
        require(coin.balanceOf(msg.sender) >= coinAmount, "Purchaser's coin amount is lack!");
        require(coin.allowance(msg.sender, address(this)) >= coinAmount, "Purchaser's allowance is low!");

        this;
    }

    /**
     * withdraw all coins by owner
     */
    function withdrawAllCoins(address treasury) public onlyOwner {
        for (uint i=0; i<coinInfoCount; i++) {
            CoinInfo storage _coinInfo = coinInfo[i];
            ERC20 _coin = ERC20(_coinInfo.addr);
            uint256 coinAmount = _coin.balanceOf(address(this));
            _coin.transfer(treasury, coinAmount);
        }
    }

    /**
     * withdraw all xJOY by owner
     */
    function withdrawAllxGovTokens(address treasury) public onlyOwner {
        uint256 tokenAmount = xGovToken.balanceOf(address(this));
        xGovToken.transfer(treasury, tokenAmount);
    }

    /**
     * withdraw all $JOY by owner
     */
    function withdrawAllGovTokens(address treasury) public onlyOwner {
        uint256 tokenAmount = govToken.balanceOf(address(this));
        govToken.transfer(treasury, tokenAmount);
    }    
}
// File: @openzeppelin/contracts/utils/math/Math.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a / b + (a % b == 0 ? 0 : 1);
    }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. The compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

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



// 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;
    }
}

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



// SPDX-License-Identifier: MIT

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() {
        _setOwner(_msgSender());
    }

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

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

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: contracts/libraries/Authorizable.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.6;

import "@openzeppelin/contracts/access/Ownable.sol";

contract Authorizable is Ownable {
    mapping(address => bool) public authorized;

    modifier onlyAuthorized() {
        require(authorized[msg.sender] || owner() == msg.sender, "caller is not authorized");
        _;
    }

    function addAuthorized(address _toAdd) public onlyOwner {
        authorized[_toAdd] = true;
    }

    function removeAuthorized(address _toRemove) public onlyOwner {
        require(_toRemove != msg.sender);
        authorized[_toRemove] = false;
    }
}

// File: contracts/tokens/xJoyToken.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.6;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "../libraries/Authorizable.sol";

contract xJoyToken is ERC20, Ownable, Authorizable {
    using SafeMath for uint256;
    bool public PURCHASER_TRANSFER_LOCK_FLAG;
    address[] public purchasers;
    mapping(address => uint256) public purchasedAmounts;
    uint256 public manualMinted = 0;

    // Modifiers.
    /**
     * @dev Ensures that the anti-whale rules are enforced.
     */
    modifier canTransfer(address sender) {
        require(checkTransferable(sender), "The purchaser can't transfer in locking period");
        _;
    }

    constructor(
      string memory _name,
      string memory _symbol
    ) ERC20(_name, _symbol) {
      addAuthorized(_msgSender());
      PURCHASER_TRANSFER_LOCK_FLAG = true;
    }

    /// @notice Creates `_amount` token to `_to`. Must only be called by the owner.
    function mint(address _to, uint256 _amount) public onlyOwner {
        _mint(_to, _amount);
    }

    function manualMint(address _to, uint256 _amount) public onlyAuthorized {
        _mint(_to, _amount);
        manualMinted = manualMinted.add(_amount);
    }

    // add purchaser
    function addPurchaser(address addr, uint256 amount) public onlyAuthorized {
      uint256 purchasedAmount = purchasedAmounts[addr];
      if (purchasedAmount == 0) {
          purchasers.push(addr);
      }
      purchasedAmounts[addr] = purchasedAmount + amount;       
    }

    // add transfer
    function lockTransferForPurchaser(bool bFlag) public onlyAuthorized {
      PURCHASER_TRANSFER_LOCK_FLAG = bFlag;
    }

    // check sale period
    function checkTransferable(address sender) public view returns (bool) {
      uint256  purchasedAmount = purchasedAmounts[sender];
      bool bFlag = PURCHASER_TRANSFER_LOCK_FLAG && purchasedAmount > 0;
      return !bFlag;
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual override
    canTransfer(sender) {
        super._transfer(sender, recipient, amount);
    }    
}
// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

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

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}