{"Bridgers.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity ^0.8.0;\r\n\r\nimport \"./IERC20.sol\";\r\nimport \"./Ownable.sol\";\r\nimport \"./ReentrancyGuard.sol\";\r\nimport \"./SafeMath.sol\";\r\nimport \"./TransferHelper.sol\";\r\n\r\n\r\ncontract Bridgers is ReentrancyGuard, Ownable {\r\n    using SafeMath for uint256;\r\n\r\n    string public name;\r\n\r\n    string public symbol;\r\n\r\n    event Swap(\r\n        address fromToken,\r\n        string toToken,\r\n        address sender,\r\n        string destination,\r\n        uint256 fromAmount,\r\n        uint256 minReturnAmount\r\n    );\r\n\r\n\r\n    event SwapEth(\r\n        string toToken,\r\n        address sender,\r\n        string destination,\r\n        uint256 fromAmount,\r\n        uint256 minReturnAmount\r\n    );\r\n\r\n    event WithdrawETH(uint256 amount);\r\n\r\n    event Withdtraw(address token, uint256 amount);\r\n\r\n    constructor() {\r\n        name = \"Bridgers1.1\";\r\n        symbol = \"Bridgers\";\r\n    }\r\n\r\n\r\n    function swap(\r\n        address fromToken,\r\n        string memory toToken,\r\n        string memory destination,\r\n        uint256 fromAmount,\r\n        uint256 minReturnAmount\r\n    ) external nonReentrant {\r\n        require(fromToken != address(0), \"FROMTOKEN_CANT_T_BE_0\");\r\n        require(fromAmount \u003e 0, \"FROM_TOKEN_AMOUNT_MUST_BE_MORE_THAN_0\");\r\n        uint256 _inputAmount;\r\n        uint256 _fromTokenBalanceOrigin = IERC20(fromToken).balanceOf(address(this));\r\n        TransferHelper.safeTransferFrom(fromToken, msg.sender, address(this), fromAmount);\r\n        uint256 _fromTokenBalanceNew = IERC20(fromToken).balanceOf(address(this));\r\n        _inputAmount = _fromTokenBalanceNew.sub(_fromTokenBalanceOrigin);\r\n        require(_inputAmount \u003e 0, \"NO_FROM_TOKEN_TRANSFER_TO_THIS_CONTRACT\");\r\n        emit Swap(fromToken, toToken, msg.sender, destination, fromAmount, minReturnAmount);\r\n    }\r\n\r\n\r\n    function swapEth(string memory toToken, string memory destination, uint256 minReturnAmount\r\n    ) external payable nonReentrant {\r\n        uint256 _ethAmount = msg.value;\r\n        require(_ethAmount \u003e 0, \"ETH_AMOUNT_MUST_BE_MORE_THAN_0\");\r\n        emit SwapEth(toToken, msg.sender, destination, _ethAmount, minReturnAmount);\r\n    }\r\n\r\n    function withdrawETH(address destination, uint256 amount) external onlyOwner {\r\n        require(destination != address(0), \"DESTINATION_CANNT_BE_0_ADDRESS\");\r\n        uint256 balance = address(this).balance;\r\n        require(balance \u003e= amount, \"AMOUNT_CANNT_MORE_THAN_BALANCE\");\r\n        TransferHelper.safeTransferETH(destination, amount);\r\n        emit WithdrawETH(amount);\r\n    }\r\n\r\n    function withdraw(address token, address destination, uint256 amount) external onlyOwner {\r\n        require(destination != address(0), \"DESTINATION_CANNT_BE_0_ADDRESS\");\r\n        require(token != address(0), \"TOKEN_MUST_NOT_BE_0\");\r\n        uint256 balance = IERC20(token).balanceOf(address(this));\r\n        require(balance \u003e= amount, \"AMOUNT_CANNT_MORE_THAN_BALANCE\");\r\n        TransferHelper.safeTransfer(token, destination, amount);\r\n        emit Withdtraw(token, amount);\r\n    }\r\n\r\n    receive() external payable {}\r\n}"},"Context.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n  function _msgSender() internal view virtual returns (address) {\n    return msg.sender;\n  }\n\n  function _msgData() internal view virtual returns (bytes calldata) {\n    return msg.data;\n  }\n}\n"},"IERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller\u0027s account to `recipient`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address recipient, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `sender` to `recipient` using the\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address sender,\n        address recipient,\n        uint256 amount\n    ) external returns (bool);\n\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n}\n"},"Ownable.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\nimport \"./Context.sol\";\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n  address private _owner;\n\n  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n  /**\n   * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n  constructor() {\n    _setOwner(_msgSender());\n  }\n\n  /**\n   * @dev Returns the address of the current owner.\n     */\n  function owner() public view virtual returns (address) {\n    return _owner;\n  }\n\n  /**\n   * @dev Throws if called by any account other than the owner.\n     */\n  modifier onlyOwner() {\n    require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n    _;\n  }\n\n  /**\n   * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n  function renounceOwnership() public virtual onlyOwner {\n    _setOwner(address(0));\n  }\n\n  /**\n   * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n  function transferOwnership(address newOwner) public virtual onlyOwner {\n    require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n    _setOwner(newOwner);\n  }\n\n  function _setOwner(address newOwner) private {\n    address oldOwner = _owner;\n    _owner = newOwner;\n    emit OwnershipTransferred(oldOwner, newOwner);\n  }\n}\n"},"ReentrancyGuard.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Contract module that helps prevent reentrant calls to a function.\n *\n * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier\n * available, which can be applied to functions to make sure there are no nested\n * (reentrant) calls to them.\n *\n * Note that because there is a single `nonReentrant` guard, functions marked as\n * `nonReentrant` may not call one another. This can be worked around by making\n * those functions `private`, and then adding `external` `nonReentrant` entry\n * points to them.\n *\n * TIP: If you would like to learn more about reentrancy and alternative ways\n * to protect against it, check out our blog post\n * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].\n */\nabstract contract ReentrancyGuard {\n  // Booleans are more expensive than uint256 or any type that takes up a full\n  // word because each write operation emits an extra SLOAD to first read the\n  // slot\u0027s contents, replace the bits taken up by the boolean, and then write\n  // back. This is the compiler\u0027s defense against contract upgrades and\n  // pointer aliasing, and it cannot be disabled.\n\n  // The values being non-zero value makes deployment a bit more expensive,\n  // but in exchange the refund on every call to nonReentrant will be lower in\n  // amount. Since refunds are capped to a percentage of the total\n  // transaction\u0027s gas, it is best to keep them low in cases like this one, to\n  // increase the likelihood of the full refund coming into effect.\n  uint256 private constant _NOT_ENTERED = 1;\n  uint256 private constant _ENTERED = 2;\n\n  uint256 private _status;\n\n  constructor() {\n    _status = _NOT_ENTERED;\n  }\n\n  /**\n   * @dev Prevents a contract from calling itself, directly or indirectly.\n     * Calling a `nonReentrant` function from another `nonReentrant`\n     * function is not supported. It is possible to prevent this from happening\n     * by making the `nonReentrant` function external, and make it call a\n     * `private` function that does the actual work.\n     */\n  modifier nonReentrant() {\n    // On the first call to nonReentrant, _notEntered will be true\n    require(_status != _ENTERED, \"ReentrancyGuard: reentrant call\");\n\n    // Any calls to nonReentrant after this point will fail\n    _status = _ENTERED;\n\n    _;\n\n    // By storing the original value once again, a refund is triggered (see\n    // https://eips.ethereum.org/EIPS/eip-2200)\n    _status = _NOT_ENTERED;\n  }\n}\n"},"SafeMath.sol":{"content":"// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.0;\n\n// CAUTION\n// This version of SafeMath should only be used with Solidity 0.8 or later,\n// because it relies on the compiler\u0027s built in overflow checks.\n\n/**\n * @dev Wrappers over Solidity\u0027s arithmetic operations.\n *\n * NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. The compiler\n * now has built in overflow checking.\n */\nlibrary SafeMath {\n  /**\n   * @dev Returns the addition of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n  function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n  unchecked {\n    uint256 c = a + b;\n    if (c \u003c a) return (false, 0);\n    return (true, c);\n  }\n  }\n\n  /**\n   * @dev Returns the substraction of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n  function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n  unchecked {\n    if (b \u003e a) return (false, 0);\n    return (true, a - b);\n  }\n  }\n\n  /**\n   * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\n     *\n     * _Available since v3.4._\n     */\n  function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n  unchecked {\n    // Gas optimization: this is cheaper than requiring \u0027a\u0027 not being zero, but the\n    // benefit is lost if \u0027b\u0027 is also tested.\n    // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n    if (a == 0) return (true, 0);\n    uint256 c = a * b;\n    if (c / a != b) return (false, 0);\n    return (true, c);\n  }\n  }\n\n  /**\n   * @dev Returns the division of two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n  function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n  unchecked {\n    if (b == 0) return (false, 0);\n    return (true, a / b);\n  }\n  }\n\n  /**\n   * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\n     *\n     * _Available since v3.4._\n     */\n  function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n  unchecked {\n    if (b == 0) return (false, 0);\n    return (true, a % b);\n  }\n  }\n\n  /**\n   * @dev Returns the addition of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `+` operator.\n     *\n     * Requirements:\n     *\n     * - Addition cannot overflow.\n     */\n  function add(uint256 a, uint256 b) internal pure returns (uint256) {\n    return a + b;\n  }\n\n  /**\n   * @dev Returns the subtraction of two unsigned integers, reverting on\n     * overflow (when the result is negative).\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n  function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n    return a - b;\n  }\n\n  /**\n   * @dev Returns the multiplication of two unsigned integers, reverting on\n     * overflow.\n     *\n     * Counterpart to Solidity\u0027s `*` operator.\n     *\n     * Requirements:\n     *\n     * - Multiplication cannot overflow.\n     */\n  function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n    return a * b;\n  }\n\n  /**\n   * @dev Returns the integer division of two unsigned integers, reverting on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator.\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n  function div(uint256 a, uint256 b) internal pure returns (uint256) {\n    return a / b;\n  }\n\n  /**\n   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting when dividing by zero.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n  function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n    return a % b;\n  }\n\n  /**\n   * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n     * overflow (when the result is negative).\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {trySub}.\n     *\n     * Counterpart to Solidity\u0027s `-` operator.\n     *\n     * Requirements:\n     *\n     * - Subtraction cannot overflow.\n     */\n  function sub(\n    uint256 a,\n    uint256 b,\n    string memory errorMessage\n  ) internal pure returns (uint256) {\n  unchecked {\n    require(b \u003c= a, errorMessage);\n    return a - b;\n  }\n  }\n\n  /**\n   * @dev Returns the integer division of two unsigned integers, reverting with custom message on\n     * division by zero. The result is rounded towards zero.\n     *\n     * Counterpart to Solidity\u0027s `/` operator. Note: this function uses a\n     * `revert` opcode (which leaves remaining gas untouched) while Solidity\n     * uses an invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n  function div(\n    uint256 a,\n    uint256 b,\n    string memory errorMessage\n  ) internal pure returns (uint256) {\n  unchecked {\n    require(b \u003e 0, errorMessage);\n    return a / b;\n  }\n  }\n\n  /**\n   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n     * reverting with custom message when dividing by zero.\n     *\n     * CAUTION: This function is deprecated because it requires allocating memory for the error\n     * message unnecessarily. For custom revert reasons use {tryMod}.\n     *\n     * Counterpart to Solidity\u0027s `%` operator. This function uses a `revert`\n     * opcode (which leaves remaining gas untouched) while Solidity uses an\n     * invalid opcode to revert (consuming all remaining gas).\n     *\n     * Requirements:\n     *\n     * - The divisor cannot be zero.\n     */\n  function mod(\n    uint256 a,\n    uint256 b,\n    string memory errorMessage\n  ) internal pure returns (uint256) {\n  unchecked {\n    require(b \u003e 0, errorMessage);\n    return a % b;\n  }\n  }\n}\n"},"TransferHelper.sol":{"content":"// SPDX-License-Identifier: MIT\r\n\r\npragma solidity \u003e=0.8.0;\r\n\r\nlibrary TransferHelper {\r\n    function safeApprove(address token, address to, uint value) internal {\r\n        // bytes4(keccak256(bytes(\u0027approve(address,uint256)\u0027)));\r\n        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));\r\n        require(success \u0026\u0026 (data.length == 0 || abi.decode(data, (bool))), \u0027TransferHelper: APPROVE_FAILED\u0027);\r\n    }\r\n\r\n    function safeTransfer(address token, address to, uint value) internal {\r\n        // bytes4(keccak256(bytes(\u0027transfer(address,uint256)\u0027)));\r\n        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));\r\n        require(success \u0026\u0026 (data.length == 0 || abi.decode(data, (bool))), \u0027TransferHelper: TRANSFER_FAILED\u0027);\r\n    }\r\n\r\n    function safeTransferFrom(address token, address from, address to, uint value) internal {\r\n        // bytes4(keccak256(bytes(\u0027transferFrom(address,address,uint256)\u0027)));\r\n        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));\r\n        require(success \u0026\u0026 (data.length == 0 || abi.decode(data, (bool))), \u0027TransferHelper: TRANSFER_FROM_FAILED\u0027);\r\n    }\r\n\r\n    function safeTransferETH(address to, uint value) internal {\r\n        (bool success,) = to.call{value:value}(new bytes(0));\r\n        require(success, \u0027TransferHelper: ETH_TRANSFER_FAILED\u0027);\r\n    }\r\n}\r\n"}}

pragma solidity ^0.4.17;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        assert(c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // assert(b > 0); // Solidity automatically throws when dividing by 0
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
    address public owner;

    /**
      * @dev The Ownable constructor sets the original `owner` of the contract to the sender
      * account.
      */
    function Ownable() public {
        owner = msg.sender;
    }

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

    /**
    * @dev Allows the current owner to transfer control of the contract to a newOwner.
    * @param newOwner The address to transfer ownership to.
    */
    function transferOwnership(address newOwner) public onlyOwner {
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }

}

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20Basic {
    uint public _totalSupply;
    function totalSupply() public constant returns (uint);
    function balanceOf(address who) public constant returns (uint);
    function transfer(address to, uint value) public;
    event Transfer(address indexed from, address indexed to, uint value);
}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public constant returns (uint);
    function transferFrom(address from, address to, uint value) public;
    function approve(address spender, uint value) public;
    event Approval(address indexed owner, address indexed spender, uint value);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is Ownable, ERC20Basic {
    using SafeMath for uint;

    mapping(address => uint) public balances;

    // additional variables for use if transaction fees ever became necessary
    uint public basisPointsRate = 0;
    uint public maximumFee = 0;

    /**
    * @dev Fix for the ERC20 short address attack.
    */
    modifier onlyPayloadSize(uint size) {
        require(!(msg.data.length < size + 4));
        _;
    }

    /**
    * @dev transfer token for a specified address
    * @param _to The address to transfer to.
    * @param _value The amount to be transferred.
    */
    function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        uint sendAmount = _value.sub(fee);
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(msg.sender, owner, fee);
        }
        Transfer(msg.sender, _to, sendAmount);
    }

    /**
    * @dev Gets the balance of the specified address.
    * @param _owner The address to query the the balance of.
    * @return An uint representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public constant returns (uint balance) {
        return balances[_owner];
    }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is BasicToken, ERC20 {

    mapping (address => mapping (address => uint)) public allowed;

    uint public constant MAX_UINT = 2**256 - 1;

    /**
    * @dev Transfer tokens from one address to another
    * @param _from address The address which you want to send tokens from
    * @param _to address The address which you want to transfer to
    * @param _value uint the amount of tokens to be transferred
    */
    function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
        var _allowance = allowed[_from][msg.sender];

        // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
        // if (_value > _allowance) throw;

        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        if (_allowance < MAX_UINT) {
            allowed[_from][msg.sender] = _allowance.sub(_value);
        }
        uint sendAmount = _value.sub(fee);
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(_from, owner, fee);
        }
        Transfer(_from, _to, sendAmount);
    }

    /**
    * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
    * @param _spender The address which will spend the funds.
    * @param _value The amount of tokens to be spent.
    */
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender, 0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));

        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
    }

    /**
    * @dev Function to check the amount of tokens than an owner allowed to a spender.
    * @param _owner address The address which owns the funds.
    * @param _spender address The address which will spend the funds.
    * @return A uint specifying the amount of tokens still available for the spender.
    */
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        return allowed[_owner][_spender];
    }

}


/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!paused);
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(paused);
    _;
  }

  /**
   * @dev called by the owner to pause, triggers stopped state
   */
  function pause() onlyOwner whenNotPaused public {
    paused = true;
    Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() onlyOwner whenPaused public {
    paused = false;
    Unpause();
  }
}

contract BlackList is Ownable, BasicToken {

    /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
    function getBlackListStatus(address _maker) external constant returns (bool) {
        return isBlackListed[_maker];
    }

    function getOwner() external constant returns (address) {
        return owner;
    }

    mapping (address => bool) public isBlackListed;
    
    function addBlackList (address _evilUser) public onlyOwner {
        isBlackListed[_evilUser] = true;
        AddedBlackList(_evilUser);
    }

    function removeBlackList (address _clearedUser) public onlyOwner {
        isBlackListed[_clearedUser] = false;
        RemovedBlackList(_clearedUser);
    }

    function destroyBlackFunds (address _blackListedUser) public onlyOwner {
        require(isBlackListed[_blackListedUser]);
        uint dirtyFunds = balanceOf(_blackListedUser);
        balances[_blackListedUser] = 0;
        _totalSupply -= dirtyFunds;
        DestroyedBlackFunds(_blackListedUser, dirtyFunds);
    }

    event DestroyedBlackFunds(address _blackListedUser, uint _balance);

    event AddedBlackList(address _user);

    event RemovedBlackList(address _user);

}

contract UpgradedStandardToken is StandardToken{
    // those methods are called by the legacy contract
    // and they must ensure msg.sender to be the contract address
    function transferByLegacy(address from, address to, uint value) public;
    function transferFromByLegacy(address sender, address from, address spender, uint value) public;
    function approveByLegacy(address from, address spender, uint value) public;
}

contract TetherToken is Pausable, StandardToken, BlackList {

    string public name;
    string public symbol;
    uint public decimals;
    address public upgradedAddress;
    bool public deprecated;

    //  The contract can be initialized with a number of tokens
    //  All the tokens are deposited to the owner address
    //
    // @param _balance Initial supply of the contract
    // @param _name Token Name
    // @param _symbol Token symbol
    // @param _decimals Token decimals
    function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
        _totalSupply = _initialSupply;
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        balances[owner] = _initialSupply;
        deprecated = false;
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transfer(address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[msg.sender]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
        } else {
            return super.transfer(_to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[_from]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
        } else {
            return super.transferFrom(_from, _to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function balanceOf(address who) public constant returns (uint) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).balanceOf(who);
        } else {
            return super.balanceOf(who);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
        } else {
            return super.approve(_spender, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        if (deprecated) {
            return StandardToken(upgradedAddress).allowance(_owner, _spender);
        } else {
            return super.allowance(_owner, _spender);
        }
    }

    // deprecate current contract in favour of a new one
    function deprecate(address _upgradedAddress) public onlyOwner {
        deprecated = true;
        upgradedAddress = _upgradedAddress;
        Deprecate(_upgradedAddress);
    }

    // deprecate current contract if favour of a new one
    function totalSupply() public constant returns (uint) {
        if (deprecated) {
            return StandardToken(upgradedAddress).totalSupply();
        } else {
            return _totalSupply;
        }
    }

    // Issue a new amount of tokens
    // these tokens are deposited into the owner address
    //
    // @param _amount Number of tokens to be issued
    function issue(uint amount) public onlyOwner {
        require(_totalSupply + amount > _totalSupply);
        require(balances[owner] + amount > balances[owner]);

        balances[owner] += amount;
        _totalSupply += amount;
        Issue(amount);
    }

    // Redeem tokens.
    // These tokens are withdrawn from the owner address
    // if the balance must be enough to cover the redeem
    // or the call will fail.
    // @param _amount Number of tokens to be issued
    function redeem(uint amount) public onlyOwner {
        require(_totalSupply >= amount);
        require(balances[owner] >= amount);

        _totalSupply -= amount;
        balances[owner] -= amount;
        Redeem(amount);
    }

    function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
        // Ensure transparency by hardcoding limit beyond which fees can never be added
        require(newBasisPoints < 20);
        require(newMaxFee < 50);

        basisPointsRate = newBasisPoints;
        maximumFee = newMaxFee.mul(10**decimals);

        Params(basisPointsRate, maximumFee);
    }

    // Called when new token are issued
    event Issue(uint amount);

    // Called when tokens are redeemed
    event Redeem(uint amount);

    // Called when contract is deprecated
    event Deprecate(address newAddress);

    // Called if contract ever adds fees
    event Params(uint feeBasisPoints, uint maxFee);
}