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*/

// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;

/**
 * @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: lib/SafeERC20.sol

// SPDX-License-Identifier: GPL-3.0-or-later

pragma solidity ^0.5.16;


// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library SafeERC20 {
    function safeApprove(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        /* solium-disable-next-line */
        (bool success, bytes memory data) = address(token).call(
            abi.encodeWithSelector(0x095ea7b3, to, value)
        );

        require(
            success && (data.length == 0 || abi.decode(data, (bool))),
            "SafeERC20: APPROVE_FAILED"
        );
    }

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        /* solium-disable-next-line */
        (bool success, bytes memory data) = address(token).call(
            abi.encodeWithSelector(0xa9059cbb, to, value)
        );

        require(
            success && (data.length == 0 || abi.decode(data, (bool))),
            "SafeERC20: TRANSFER_FAILED"
        );
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        /* solium-disable-next-line */
        (bool success, bytes memory data) = address(token).call(
            abi.encodeWithSelector(
                0x23b872dd,
                from,
                to,
                value
            )
        );

        require(
            success && (data.length == 0 || abi.decode(data, (bool))),
            "SafeERC20: TRANSFER_FROM_FAILED"
        );
    }
}
// File: lib/SafeMath.sol

pragma solidity ^0.5.16;

library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {

        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }
}
// File: lib/Ownable.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;

/**
 * @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.
 */
contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), msg.sender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == msg.sender, "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 onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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 onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
// File: browser/WhitelistSale.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;
pragma experimental ABIEncoderV2;





contract WhitelistSale is Ownable {

    /* ========== Libraries ========== */

    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    /* ========== Struct ========== */

    struct Participant {
        uint256 allocation;
        uint256 spent;
    }

    /* ========== Variables ========== */

    IERC20 public currency;

    mapping (address => Participant) public participants;

    uint256 public totalHardCap;

    uint256 public totalRaised;

    bool public saleOpen;

    /* ========== Events ========== */

    event AllocationClaimed(address user, uint256 amount);

    event AllocationSet(address user, uint256 amount);

    event SaleStatusUpdated(bool status);

    event HardCapUpdated(uint256 amount);

    /* ========== Constructor ========== */

    constructor(address currencyAddress) public {
        currency = IERC20(currencyAddress);
        saleOpen = false;
    }

    /* ========== Public Functions ========== */

    function claimAllocation(
        uint256 amount
    )
        external
    {
        // Get their total spend till date
        uint256 participantSpent = participants[msg.sender].spent.add(amount);

        uint256 newTotalRaised = totalRaised.add(amount);

        require(
            participantSpent <= participants[msg.sender].allocation,
            "You cannot spend more than your allocation"
        );

        require(
            saleOpen,
            "The sale is not currently open"
        );

        require(
            newTotalRaised <= totalHardCap,
            "You cannot purchase more than the hard cap"
        );

        // Increase the user's spend amount otherwise they can keep purchasing
        participants[msg.sender].spent = participantSpent;

        totalRaised = newTotalRaised;

        // Transfer the funds to the owner, no funds will be stored in this contract directly.
        currency.safeTransferFrom(
            msg.sender,
            owner(),
            amount
        );

        emit AllocationClaimed(msg.sender, amount);
    }

    /* ========== Admin Functions ========== */

    function setHardCap(uint256 amount)
        external
        onlyOwner
    {
        totalHardCap = amount;

        emit HardCapUpdated(amount);
    }

    function setAllocation(
        address[] calldata users,
        uint256[] calldata allocations
    )
        external
        onlyOwner
    {
        // If there is a mismatch something hasn't been done correctly
        require(
            users.length == allocations.length,
            "The users and amounts do not match"
        );

        for (uint256 i = 0; i < users.length; i++) {
            participants[users[i]].allocation = allocations[i];

            emit AllocationSet(users[i], allocations[i]);
        }
    }

    function updateSaleStatus(
        bool status
    )
        external
        onlyOwner
    {
        require(
            saleOpen != status,
            "Cannot re-set the same status"
        );

        saleOpen = status;

        emit SaleStatusUpdated(status);
    }
}