// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;
pragma experimental ABIEncoderV2;

/**
 * @title Proxy
 * @dev Implements delegation of calls to other contracts, with proper
 * forwarding of return values and bubbling of failures.
 * It defines a fallback function that delegates all calls to the address
 * returned by the abstract _implementation() internal function.
 */
abstract contract Proxy {
  /**
   * @dev Fallback function.
   * Implemented entirely in `_fallback`.
   */
  fallback () payable external {
    _fallback();
  }
  
  receive () payable external {
    _fallback();
  }

  /**
   * @return The Address of the implementation.
   */
  function _implementation() virtual internal view returns (address);

  /**
   * @dev Delegates execution to an implementation contract.
   * This is a low level function that doesn't return to its internal call site.
   * It will return to the external caller whatever the implementation returns.
   * @param implementation Address to delegate.
   */
  function _delegate(address implementation) internal {
    assembly {
      // Copy msg.data. We take full control of memory in this inline assembly
      // block because it will not return to Solidity code. We overwrite the
      // Solidity scratch pad at memory position 0.
      calldatacopy(0, 0, calldatasize())

      // Call the implementation.
      // out and outsize are 0 because we don't know the size yet.
      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

      // Copy the returned data.
      returndatacopy(0, 0, returndatasize())

      switch result
      // delegatecall returns 0 on error.
      case 0 { revert(0, returndatasize()) }
      default { return(0, returndatasize()) }
    }
  }

  /**
   * @dev Function that is run as the first thing in the fallback function.
   * Can be redefined in derived contracts to add functionality.
   * Redefinitions must call super._willFallback().
   */
  function _willFallback() virtual internal {
      
  }

  /**
   * @dev fallback implementation.
   * Extracted to enable manual triggering.
   */
  function _fallback() internal {
    if(OpenZeppelinUpgradesAddress.isContract(msg.sender) && msg.data.length == 0 && gasleft() <= 2300)         // for receive ETH only from other contract
        return;
    _willFallback();
    _delegate(_implementation());
  }
}


/**
 * @title BaseUpgradeabilityProxy
 * @dev This contract implements a proxy that allows to change the
 * implementation address to which it will delegate.
 * Such a change is called an implementation upgrade.
 */
abstract contract BaseUpgradeabilityProxy is Proxy {
  /**
   * @dev Emitted when the implementation is upgraded.
   * @param implementation Address of the new implementation.
   */
  event Upgraded(address indexed implementation);

  /**
   * @dev Storage slot with the address of the current implementation.
   * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
   * validated in the constructor.
   */
  bytes32 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

  /**
   * @dev Returns the current implementation.
   * @return impl Address of the current implementation
   */
  function _implementation() override internal view returns (address impl) {
    bytes32 slot = IMPLEMENTATION_SLOT;
    assembly {
      impl := sload(slot)
    }
  }

  /**
   * @dev Upgrades the proxy to a new implementation.
   * @param newImplementation Address of the new implementation.
   */
  function _upgradeTo(address newImplementation) internal {
    _setImplementation(newImplementation);
    emit Upgraded(newImplementation);
  }

  /**
   * @dev Sets the implementation address of the proxy.
   * @param newImplementation Address of the new implementation.
   */
  function _setImplementation(address newImplementation) internal {
    require(OpenZeppelinUpgradesAddress.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");

    bytes32 slot = IMPLEMENTATION_SLOT;

    assembly {
      sstore(slot, newImplementation)
    }
  }
}


/**
 * @title BaseAdminUpgradeabilityProxy
 * @dev This contract combines an upgradeability proxy with an authorization
 * mechanism for administrative tasks.
 * All external functions in this contract must be guarded by the
 * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
 * feature proposal that would enable this to be done automatically.
 */
contract BaseAdminUpgradeabilityProxy is BaseUpgradeabilityProxy {
  /**
   * @dev Emitted when the administration has been transferred.
   * @param previousAdmin Address of the previous admin.
   * @param newAdmin Address of the new admin.
   */
  event AdminChanged(address previousAdmin, address newAdmin);

  /**
   * @dev Storage slot with the admin of the contract.
   * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
   * validated in the constructor.
   */

  bytes32 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

  /**
   * @dev Modifier to check whether the `msg.sender` is the admin.
   * If it is, it will run the function. Otherwise, it will delegate the call
   * to the implementation.
   */
  modifier ifAdmin() {
    if (msg.sender == _admin()) {
      _;
    } else {
      _fallback();
    }
  }

  /**
   * @return The address of the proxy admin.
   */
  function admin() external ifAdmin returns (address) {
    return _admin();
  }

  /**
   * @return The address of the implementation.
   */
  function implementation() external ifAdmin returns (address) {
    return _implementation();
  }

  /**
   * @dev Changes the admin of the proxy.
   * Only the current admin can call this function.
   * @param newAdmin Address to transfer proxy administration to.
   */
  function changeAdmin(address newAdmin) external ifAdmin {
    require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
    emit AdminChanged(_admin(), newAdmin);
    _setAdmin(newAdmin);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy.
   * Only the admin can call this function.
   * @param newImplementation Address of the new implementation.
   */
  function upgradeTo(address newImplementation) external ifAdmin {
    _upgradeTo(newImplementation);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy and call a function
   * on the new implementation.
   * This is useful to initialize the proxied contract.
   * @param newImplementation Address of the new implementation.
   * @param data Data to send as msg.data in the low level call.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   */
  function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin {
    _upgradeTo(newImplementation);
    (bool success,) = newImplementation.delegatecall(data);
    require(success);
  }

  /**
   * @return adm The admin slot.
   */
  function _admin() internal view returns (address adm) {
    bytes32 slot = ADMIN_SLOT;
    assembly {
      adm := sload(slot)
    }
  }

  /**
   * @dev Sets the address of the proxy admin.
   * @param newAdmin Address of the new proxy admin.
   */
  function _setAdmin(address newAdmin) internal {
    bytes32 slot = ADMIN_SLOT;

    assembly {
      sstore(slot, newAdmin)
    }
  }

  /**
   * @dev Only fall back when the sender is not the admin.
   */
  function _willFallback() virtual override internal {
    require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
    //super._willFallback();
  }
}

interface IAdminUpgradeabilityProxyView {
  function admin() external view returns (address);
  function implementation() external view returns (address);
}


/**
 * @title UpgradeabilityProxy
 * @dev Extends BaseUpgradeabilityProxy with a constructor for initializing
 * implementation and init data.
 */
abstract contract UpgradeabilityProxy is BaseUpgradeabilityProxy {
  /**
   * @dev Contract constructor.
   * @param _logic Address of the initial implementation.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  constructor(address _logic, bytes memory _data) public payable {
    assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1));
    _setImplementation(_logic);
    if(_data.length > 0) {
      (bool success,) = _logic.delegatecall(_data);
      require(success);
    }
  }  
  
  //function _willFallback() virtual override internal {
    //super._willFallback();
  //}
}


/**
 * @title AdminUpgradeabilityProxy
 * @dev Extends from BaseAdminUpgradeabilityProxy with a constructor for 
 * initializing the implementation, admin, and init data.
 */
contract AdminUpgradeabilityProxy is BaseAdminUpgradeabilityProxy, UpgradeabilityProxy {
  /**
   * Contract constructor.
   * @param _logic address of the initial implementation.
   * @param _admin Address of the proxy administrator.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  constructor(address _admin, address _logic, bytes memory _data) UpgradeabilityProxy(_logic, _data) public payable {
    assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1));
    _setAdmin(_admin);
  }
  
  function _willFallback() override(Proxy, BaseAdminUpgradeabilityProxy) internal {
    super._willFallback();
  }
}


/**
 * @title InitializableUpgradeabilityProxy
 * @dev Extends BaseUpgradeabilityProxy with an initializer for initializing
 * implementation and init data.
 */
abstract contract InitializableUpgradeabilityProxy is BaseUpgradeabilityProxy {
  /**
   * @dev Contract initializer.
   * @param _logic Address of the initial implementation.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  function initialize(address _logic, bytes memory _data) public payable {
    require(_implementation() == address(0));
    assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1));
    _setImplementation(_logic);
    if(_data.length > 0) {
      (bool success,) = _logic.delegatecall(_data);
      require(success);
    }
  }  
}


/**
 * @title InitializableAdminUpgradeabilityProxy
 * @dev Extends from BaseAdminUpgradeabilityProxy with an initializer for 
 * initializing the implementation, admin, and init data.
 */
contract InitializableAdminUpgradeabilityProxy is BaseAdminUpgradeabilityProxy, InitializableUpgradeabilityProxy {
  /**
   * Contract initializer.
   * @param _logic address of the initial implementation.
   * @param _admin Address of the proxy administrator.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  function initialize(address _admin, address _logic, bytes memory _data) public payable {
    require(_implementation() == address(0));
    InitializableUpgradeabilityProxy.initialize(_logic, _data);
    assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1));
    _setAdmin(_admin);
  }
  
  function _willFallback() override(Proxy, BaseAdminUpgradeabilityProxy) internal {
    super._willFallback();
  }

}


interface IProxyFactory {
    function productImplementation() external view returns (address);
    function productImplementations(bytes32 name) external view returns (address);
}


/**
 * @title ProductProxy
 * @dev This contract implements a proxy that 
 * it is deploied by ProxyFactory, 
 * and it's implementation is stored in factory.
 */
contract ProductProxy is Proxy {
    
  /**
   * @dev Storage slot with the address of the ProxyFactory.
   * This is the keccak-256 hash of "eip1967.proxy.factory" subtracted by 1, and is
   * validated in the constructor.
   */
  bytes32 internal constant FACTORY_SLOT = 0x7a45a402e4cb6e08ebc196f20f66d5d30e67285a2a8aa80503fa409e727a4af1;
  bytes32 internal constant NAME_SLOT    = 0x4cd9b827ca535ceb0880425d70eff88561ecdf04dc32fcf7ff3b15c587f8a870;      // bytes32(uint256(keccak256('eip1967.proxy.name')) - 1)

  function _name() virtual internal view returns (bytes32 name_) {
    bytes32 slot = NAME_SLOT;
    assembly {  name_ := sload(slot)  }
  }
  
  function _setName(bytes32 name_) internal {
    bytes32 slot = NAME_SLOT;
    assembly {  sstore(slot, name_)  }
  }

  /**
   * @dev Sets the factory address of the ProductProxy.
   * @param newFactory Address of the new factory.
   */
  function _setFactory(address newFactory) internal {
    require(OpenZeppelinUpgradesAddress.isContract(newFactory), "Cannot set a factory to a non-contract address");

    bytes32 slot = FACTORY_SLOT;

    assembly {
      sstore(slot, newFactory)
    }
  }

  /**
   * @dev Returns the factory.
   * @return factory_ Address of the factory.
   */
  function _factory() internal view returns (address factory_) {
    bytes32 slot = FACTORY_SLOT;
    assembly {
      factory_ := sload(slot)
    }
  }
  
  /**
   * @dev Returns the current implementation.
   * @return Address of the current implementation
   */
  function _implementation() virtual override internal view returns (address) {
    address factory_ = _factory();
    if(OpenZeppelinUpgradesAddress.isContract(factory_))
        return IProxyFactory(factory_).productImplementations(_name());
    else
        return address(0);
  }

}


/**
 * @title InitializableProductProxy
 * @dev Extends ProductProxy with an initializer for initializing
 * factory and init data.
 */
contract InitializableProductProxy is ProductProxy {
  /**
   * @dev Contract initializer.
   * @param factory_ Address of the initial factory.
   * @param data_ Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  function __InitializableProductProxy_init(address factory_, bytes32 name_, bytes memory data_) public payable {
    require(_factory() == address(0));
    assert(FACTORY_SLOT == bytes32(uint256(keccak256('eip1967.proxy.factory')) - 1));
    assert(NAME_SLOT    == bytes32(uint256(keccak256('eip1967.proxy.name')) - 1));
    _setFactory(factory_);
    _setName(name_);
    if(data_.length > 0) {
      (bool success,) = _implementation().delegatecall(data_);
      require(success);
    }
  }  
}


/**
 * @title Initializable
 *
 * @dev Helper contract to support initializer functions. To use it, replace
 * the constructor with a function that has the `initializer` modifier.
 * WARNING: Unlike constructors, initializer functions must be manually
 * invoked. This applies both to deploying an Initializable contract, as well
 * as extending an Initializable contract via inheritance.
 * WARNING: When used with inheritance, manual care must be taken to not invoke
 * a parent initializer twice, or ensure that all initializers are idempotent,
 * because this is not dealt with automatically as with constructors.
 */
contract Initializable {

  /**
   * @dev Indicates that the contract has been initialized.
   */
  bool private initialized;

  /**
   * @dev Indicates that the contract is in the process of being initialized.
   */
  bool private initializing;

  /**
   * @dev Modifier to use in the initializer function of a contract.
   */
  modifier initializer() {
    require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");

    bool isTopLevelCall = !initializing;
    if (isTopLevelCall) {
      initializing = true;
      initialized = true;
    }

    _;

    if (isTopLevelCall) {
      initializing = false;
    }
  }

  /// @dev Returns true if and only if the function is running in the constructor
  function isConstructor() private view returns (bool) {
    // extcodesize checks the size of the code stored in an address, and
    // address returns the current address. Since the code is still not
    // deployed when running a constructor, any checks on its code size will
    // yield zero, making it an effective way to detect if a contract is
    // under construction or not.
    address self = address(this);
    uint256 cs;
    assembly { cs := extcodesize(self) }
    return cs == 0;
  }

  // Reserved storage space to allow for layout changes in the future.
  uint256[50] private ______gap;
}


/*
 * @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 GSN 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.
 */
contract ContextUpgradeSafe is Initializable {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.

    function __Context_init() internal initializer {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal initializer {


    }


    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }

    uint256[50] private __gap;
}

/**
 * @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, so we distribute
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }
}

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @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 sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function sub0(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a - b : 0;
    }

    /**
     * @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) {
        // 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 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts 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 mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

/**
 * Utility library of inline functions on addresses
 *
 * Source https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-solidity/v2.1.3/contracts/utils/Address.sol
 * This contract is copied here and renamed from the original to avoid clashes in the compiled artifacts
 * when the user imports a zos-lib contract (that transitively causes this contract to be compiled and added to the
 * build/artifacts folder) as well as the vanilla Address implementation from an openzeppelin version.
 */
library OpenZeppelinUpgradesAddress {
    /**
     * Returns whether the target address is a contract
     * @dev This function will return false if invoked during the constructor of a contract,
     * as the code is not actually created until after the constructor finishes.
     * @param account address of the account to check
     * @return whether the target address is a contract
     */
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        // XXX Currently there is no better way to check if there is a contract in an address
        // than to check the size of the code at that address.
        // See https://ethereum.stackexchange.com/a/14016/36603
        // for more details about how this works.
        // TODO Check this again before the Serenity release, because all addresses will be
        // contracts then.
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
}

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

/**
 * @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);
}

/**
 * @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 {ERC20MinterPauser}.
 *
 * 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 guidelines: functions revert instead
 * of 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 ERC20UpgradeSafe is Initializable, ContextUpgradeSafe, IERC20 {
    using SafeMath for uint256;
    using Address for address;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */

    function __ERC20_init(string memory name, string memory symbol) internal initializer {
        __Context_init_unchained();
        __ERC20_init_unchained(name, symbol);
    }

    function __ERC20_init_unchained(string memory name, string memory symbol) internal initializer {


        _name = name;
        _symbol = symbol;
        _decimals = 18;

    }


    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view 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 {_setupDecimals} is
     * called.
     *
     * 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 returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view 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);
        if(sender != _msgSender() && _allowances[sender][_msgSender()] != uint(-1))
            _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        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].add(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) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is 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);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(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
     *
     * - `to` 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 = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(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);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
     *
     * This is 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 Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @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 to 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 { }

    uint256[44] private __gap;
}


/**
 * @dev Extension of {ERC20} that adds a cap to the supply of tokens.
 */
abstract contract ERC20CappedUpgradeSafe is Initializable, ERC20UpgradeSafe {
    uint256 private _cap;

    /**
     * @dev Sets the value of the `cap`. This value is immutable, it can only be
     * set once during construction.
     */

    function __ERC20Capped_init(uint256 cap) internal initializer {
        __Context_init_unchained();
        __ERC20Capped_init_unchained(cap);
    }

    function __ERC20Capped_init_unchained(uint256 cap) internal initializer {


        require(cap > 0, "ERC20Capped: cap is 0");
        _cap = cap;

    }


    /**
     * @dev Returns the cap on the token's total supply.
     */
    function cap() public view returns (uint256) {
        return _cap;
    }

    /**
     * @dev See {ERC20-_beforeTokenTransfer}.
     *
     * Requirements:
     *
     * - minted tokens must not cause the total supply to go over the cap.
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual override {
        super._beforeTokenTransfer(from, to, amount);

        if (from == address(0)) { // When minting tokens
            require(totalSupply().add(amount) <= _cap, "ERC20Capped: cap exceeded");
        }
    }

    uint256[49] private __gap;
}


/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}


contract Governable is Initializable {
    address public governor;

    event GovernorshipTransferred(address indexed previousGovernor, address indexed newGovernor);

    /**
     * @dev Contract initializer.
     * called once by the factory at time of deployment
     */
    function __Governable_init_unchained(address governor_) virtual public initializer {
        governor = governor_;
        emit GovernorshipTransferred(address(0), governor);
    }

    modifier governance() {
        require(msg.sender == governor);
        _;
    }

    /**
     * @dev Allows the current governor to relinquish control of the contract.
     * @notice Renouncing to governorship will leave the contract without an governor.
     * It will not be possible to call the functions with the `governance`
     * modifier anymore.
     */
    function renounceGovernorship() public governance {
        emit GovernorshipTransferred(governor, address(0));
        governor = address(0);
    }

    /**
     * @dev Allows the current governor to transfer control of the contract to a newGovernor.
     * @param newGovernor The address to transfer governorship to.
     */
    function transferGovernorship(address newGovernor) public governance {
        _transferGovernorship(newGovernor);
    }

    /**
     * @dev Transfers control of the contract to a newGovernor.
     * @param newGovernor The address to transfer governorship to.
     */
    function _transferGovernorship(address newGovernor) internal {
        require(newGovernor != address(0));
        emit GovernorshipTransferred(governor, newGovernor);
        governor = newGovernor;
    }
}


contract Configurable is Governable {

    mapping (bytes32 => uint) internal config;
    
    function getConfig(bytes32 key) public view returns (uint) {
        return config[key];
    }
    function getConfig(bytes32 key, uint index) public view returns (uint) {
        return config[bytes32(uint(key) ^ index)];
    }
    function getConfig(bytes32 key, address addr) public view returns (uint) {
        return config[bytes32(uint(key) ^ uint(addr))];
    }

    function _setConfig(bytes32 key, uint value) internal {
        if(config[key] != value)
            config[key] = value;
    }
    function _setConfig(bytes32 key, uint index, uint value) internal {
        _setConfig(bytes32(uint(key) ^ index), value);
    }
    function _setConfig(bytes32 key, address addr, uint value) internal {
        _setConfig(bytes32(uint(key) ^ uint(addr)), value);
    }
    
    function setConfig(bytes32 key, uint value) external governance {
        _setConfig(key, value);
    }
    function setConfig(bytes32 key, uint index, uint value) external governance {
        _setConfig(bytes32(uint(key) ^ index), value);
    }
    function setConfig(bytes32 key, address addr, uint value) public governance {
        _setConfig(bytes32(uint(key) ^ uint(addr)), value);
    }
}


contract Constants {
    bytes32 internal constant _TokenMapped_     = 'TokenMapped';
    bytes32 internal constant _MappableToken_   = 'MappableToken';
    bytes32 internal constant _MappingToken_    = 'MappingToken';
    bytes32 internal constant _fee_             = 'fee';
    bytes32 internal constant _feeCreate_       = 'feeCreate';
    bytes32 internal constant _feeTo_           = 'feeTo';
    bytes32 internal constant _minSignatures_   = 'minSignatures';
    bytes32 internal constant _uniswapRounter_  = 'uniswapRounter';
    
    function _chainId() internal pure returns (uint id) {
        assembly { id := chainid() }
    }
}

struct Signature {
    address signatory;
    uint8   v;
    bytes32 r;
    bytes32 s;
}

abstract contract MappingBase is ContextUpgradeSafe, Constants {
	using SafeMath for uint;

    bytes32 public constant RECEIVE_TYPEHASH = keccak256("Receive(uint256 fromChainId,address to,uint256 nonce,uint256 volume,address signatory)");
    bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
    bytes32 internal _DOMAIN_SEPARATOR;
    function DOMAIN_SEPARATOR() virtual public view returns (bytes32) {  return _DOMAIN_SEPARATOR;  }

    address public factory;
    uint256 public mainChainId;
    address public token;
    address public creator;
    
    mapping (address => uint) public authQuotaOf;                                       // signatory => quota
    mapping (uint => mapping (address => uint)) public sentCount;                       // toChainId => to => sentCount
    mapping (uint => mapping (address => mapping (uint => uint))) public sent;          // toChainId => to => nonce => volume
    mapping (uint => mapping (address => mapping (uint => uint))) public received;      // fromChainId => to => nonce => volume
    
    modifier onlyFactory {
        require(msg.sender == factory, 'Only called by Factory');
        _;
    }
    
    function increaseAuthQuotas(address[] memory signatorys, uint[] memory increments) virtual external returns (uint[] memory quotas) {
        require(signatorys.length == increments.length, 'two array lenth not equal');
        quotas = new uint[](signatorys.length);
        for(uint i=0; i<signatorys.length; i++)
            quotas[i] = increaseAuthQuota(signatorys[i], increments[i]);
    }
    
    function increaseAuthQuota(address signatory, uint increment) virtual public onlyFactory returns (uint quota) {
        quota = authQuotaOf[signatory].add(increment);
        authQuotaOf[signatory] = quota;
        emit IncreaseAuthQuota(signatory, increment, quota);
    }
    event IncreaseAuthQuota(address indexed signatory, uint increment, uint quota);
    
    function decreaseAuthQuotas(address[] memory signatorys, uint[] memory decrements) virtual external returns (uint[] memory quotas) {
        require(signatorys.length == decrements.length, 'two array lenth not equal');
        quotas = new uint[](signatorys.length);
        for(uint i=0; i<signatorys.length; i++)
            quotas[i] = decreaseAuthQuota(signatorys[i], decrements[i]);
    }
    
    function decreaseAuthQuota(address signatory, uint decrement) virtual public onlyFactory returns (uint quota) {
        quota = authQuotaOf[signatory];
        if(quota < decrement)
            decrement = quota;
        return _decreaseAuthQuota(signatory, decrement);
    }
    
    function _decreaseAuthQuota(address signatory, uint decrement) virtual internal returns (uint quota) {
        quota = authQuotaOf[signatory].sub(decrement);
        authQuotaOf[signatory] = quota;
        emit DecreaseAuthQuota(signatory, decrement, quota);
    }
    event DecreaseAuthQuota(address indexed signatory, uint decrement, uint quota);


    function needApprove() virtual public pure returns (bool);
    
    function send(uint toChainId, address to, uint volume) virtual external payable returns (uint nonce) {
        return sendFrom(_msgSender(), toChainId, to, volume);
    }
    
    function sendFrom(address from, uint toChainId, address to, uint volume) virtual public payable returns (uint nonce) {
        _chargeFee();
        _sendFrom(from, volume);
        nonce = sentCount[toChainId][to]++;
        sent[toChainId][to][nonce] = volume;
        emit Send(from, toChainId, to, nonce, volume);
    }
    event Send(address indexed from, uint indexed toChainId, address indexed to, uint nonce, uint volume);
    
    function _sendFrom(address from, uint volume) virtual internal;

    function receive(uint256 fromChainId, address to, uint256 nonce, uint256 volume, Signature[] memory signatures) virtual external payable {
        _chargeFee();
        require(received[fromChainId][to][nonce] == 0, 'withdrawn already');
        uint N = signatures.length;
        require(N >= MappingTokenFactory(factory).getConfig(_minSignatures_), 'too few signatures');
        for(uint i=0; i<N; i++) {
            for(uint j=0; j<i; j++)
                require(signatures[i].signatory != signatures[j].signatory, 'repetitive signatory');
            bytes32 structHash = keccak256(abi.encode(RECEIVE_TYPEHASH, fromChainId, to, nonce, volume, signatures[i].signatory));
            bytes32 digest = keccak256(abi.encodePacked("\x19\x01", _DOMAIN_SEPARATOR, structHash));
            address signatory = ecrecover(digest, signatures[i].v, signatures[i].r, signatures[i].s);
            require(signatory != address(0), "invalid signature");
            require(signatory == signatures[i].signatory, "unauthorized");
            _decreaseAuthQuota(signatures[i].signatory, volume);
            emit Authorize(fromChainId, to, nonce, volume, signatory);
        }
        received[fromChainId][to][nonce] = volume;
        _receive(to, volume);
        emit Receive(fromChainId, to, nonce, volume);
    }
    event Receive(uint256 indexed fromChainId, address indexed to, uint256 indexed nonce, uint256 volume);
    event Authorize(uint256 fromChainId, address indexed to, uint256 indexed nonce, uint256 volume, address indexed signatory);
    
    function _receive(address to, uint256 volume) virtual internal;
    
    function _chargeFee() virtual internal {
        require(msg.value >= MappingTokenFactory(factory).getConfig(_fee_), 'fee is too low');
        address payable feeTo = address(MappingTokenFactory(factory).getConfig(_feeTo_));
        if(feeTo == address(0))
            feeTo = address(uint160(factory));
        feeTo.transfer(msg.value);
        emit ChargeFee(_msgSender(), feeTo, msg.value);
    }
    event ChargeFee(address indexed from, address indexed to, uint value);

    uint256[50] private __gap;
}    
    
    
contract TokenMapped is MappingBase {
    using SafeERC20 for IERC20;
    
	function __TokenMapped_init(address factory_, address token_) external initializer {
        __Context_init_unchained();
		__TokenMapped_init_unchained(factory_, token_);
	}
	
	function __TokenMapped_init_unchained(address factory_, address token_) public initializer {
        factory = factory_;
        mainChainId = _chainId();
        token = token_;
        creator = address(0);
        _DOMAIN_SEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(ERC20UpgradeSafe(token).name())), _chainId(), address(this)));
	}
	
    function totalMapped() virtual public view returns (uint) {
        return IERC20(token).balanceOf(address(this));
    }
    
    function needApprove() virtual override public pure returns (bool) {
        return true;
    }
    
    function _sendFrom(address from, uint volume) virtual override internal {
        IERC20(token).safeTransferFrom(from, address(this), volume);
    }

    function _receive(address to, uint256 volume) virtual override internal {
        IERC20(token).safeTransfer(to, volume);
    }

    uint256[50] private __gap;
}


abstract contract Permit {
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    function DOMAIN_SEPARATOR() virtual public view returns (bytes32);

    mapping (address => uint) public nonces;

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'permit EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR(),
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'permit INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }

    function _approve(address owner, address spender, uint256 amount) internal virtual;    

    uint256[50] private __gap;
}

contract MappableToken is Permit, ERC20UpgradeSafe, MappingBase {
	function __MappableToken_init(address factory_, address creator_, string memory name_, string memory symbol_, uint8 decimals_, uint256 totalSupply_) external initializer {
        __Context_init_unchained();
		__ERC20_init_unchained(name_, symbol_);
		_setupDecimals(decimals_);
		_mint(creator_, totalSupply_);
		__MappableToken_init_unchained(factory_, creator_);
	}
	
	function __MappableToken_init_unchained(address factory_, address creator_) public initializer {
        factory = factory_;
        mainChainId = _chainId();
        token = address(0);
        creator = creator_;
        _DOMAIN_SEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), _chainId(), address(this)));
	}
	
    function DOMAIN_SEPARATOR() virtual override(Permit, MappingBase) public view returns (bytes32) {
        return MappingBase.DOMAIN_SEPARATOR();
    }
    
    function _approve(address owner, address spender, uint256 amount) virtual override(Permit, ERC20UpgradeSafe) internal {
        return ERC20UpgradeSafe._approve(owner, spender, amount);
    }
    
    function totalMapped() virtual public view returns (uint) {
        return balanceOf(address(this));
    }
    
    function needApprove() virtual override public pure returns (bool) {
        return false;
    }
    
    function _sendFrom(address from, uint volume) virtual override internal {
        transferFrom(from, address(this), volume);
    }

    function _receive(address to, uint256 volume) virtual override internal {
        _transfer(address(this), to, volume);
    }

    uint256[50] private __gap;
}


contract MappingToken is Permit, ERC20CappedUpgradeSafe, MappingBase {
	function __MappingToken_init(address factory_, uint mainChainId_, address token_, address creator_, string memory name_, string memory symbol_, uint8 decimals_, uint cap_) external initializer {
        __Context_init_unchained();
		__ERC20_init_unchained(name_, symbol_);
		_setupDecimals(decimals_);
		__ERC20Capped_init_unchained(cap_);
		__MappingToken_init_unchained(factory_, mainChainId_, token_, creator_);
	}
	
	function __MappingToken_init_unchained(address factory_, uint mainChainId_, address token_, address creator_) public initializer {
        factory = factory_;
        mainChainId = mainChainId_;
        token = token_;
        creator = (token_ == address(0)) ? creator_ : address(0);
        _DOMAIN_SEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), _chainId(), address(this)));
	}
	
    function DOMAIN_SEPARATOR() virtual override(Permit, MappingBase) public view returns (bytes32) {
        return MappingBase.DOMAIN_SEPARATOR();
    }
    
    function _approve(address owner, address spender, uint256 amount) virtual override(Permit, ERC20UpgradeSafe) internal {
        return ERC20UpgradeSafe._approve(owner, spender, amount);
    }
    
    function needApprove() virtual override public pure returns (bool) {
        return false;
    }
    
    function _sendFrom(address from, uint volume) virtual override internal {
        _burn(from, volume);
        if(from != _msgSender() && allowance(from, _msgSender()) != uint(-1))
            _approve(from, _msgSender(), allowance(from, _msgSender()).sub(volume, "ERC20: transfer volume exceeds allowance"));
    }

    function _receive(address to, uint256 volume) virtual override internal {
        _mint(to, volume);
    }

    uint256[50] private __gap;
}


contract MappingTokenFactory is ContextUpgradeSafe, Configurable, Constants {
    using SafeERC20 for IERC20;
    using SafeMath for uint;

    bytes32 public constant REGISTER_TYPEHASH   = keccak256("RegisterMapping(uint mainChainId,address token,uint[] chainIds,address[] mappingTokenMappeds_)");
    bytes32 public constant CREATE_TYPEHASH     = keccak256("CreateMappingToken(address creator,uint mainChainId,address token,string name,string symbol,uint8 decimals,uint cap)");
    bytes32 public constant DOMAIN_TYPEHASH     = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
    bytes32 public DOMAIN_SEPARATOR;

    mapping (bytes32 => address) public productImplementations;
    mapping (address => address) public tokenMappeds;                // token => tokenMapped
    mapping (address => address) public mappableTokens;              // creator => mappableTokens
    mapping (uint256 => mapping (address => address)) public mappingTokens;     // mainChainId => token or creator => mappableTokens
    mapping (address => bool) public authorties;
    
    // only on ethereum mainnet
    mapping (address => uint) public authCountOf;                   // signatory => count
    mapping (address => uint256) internal _mainChainIdTokens;       // mappingToken => mainChainId+token
    mapping (address => mapping (uint => address)) public mappingTokenMappeds;  // token => chainId => mappingToken or tokenMapped
    uint[] public supportChainIds;
    mapping (string  => uint256) internal _certifiedTokens;         // symbol => mainChainId+token
    string[] public certifiedSymbols;

    function __MappingTokenFactory_init(address _governor, address _implTokenMapped, address _implMappableToken, address _implMappingToken, address _feeTo) external initializer {
        __Governable_init_unchained(_governor);
        __MappingTokenFactory_init_unchained(_implTokenMapped, _implMappableToken, _implMappingToken, _feeTo);
    }
    
    function __MappingTokenFactory_init_unchained(address _implTokenMapped, address _implMappableToken, address _implMappingToken, address _feeTo) public governance {
        config[_fee_]                           = 0.005 ether;
        //config[_feeCreate_]                     = 0.200 ether;
        config[_feeTo_]                         = uint(_feeTo);
        config[_minSignatures_]                 = 3;
        config[_uniswapRounter_]                = uint(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);

        DOMAIN_SEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes('MappingTokenFactory')), _chainId(), address(this)));
        upgradeProductImplementationsTo(_implTokenMapped, _implMappableToken, _implMappingToken);
    }

    function upgradeProductImplementationsTo(address _implTokenMapped, address _implMappableToken, address _implMappingToken) public governance {
        productImplementations[_TokenMapped_]   = _implTokenMapped;
        productImplementations[_MappableToken_] = _implMappableToken;
        productImplementations[_MappingToken_]  = _implMappingToken;
    }
    
    function setAuthorty(address authorty, bool enable) virtual external governance {
        authorties[authorty] = enable;
        emit SetAuthorty(authorty, enable);
    }
    event SetAuthorty(address indexed authorty, bool indexed enable);
    
    modifier onlyAuthorty {
        require(authorties[_msgSender()], 'only authorty');
        _;
    }
    
    function increaseAuthQuotas(address mappingTokenMapped, address[] memory signatorys, uint[] memory increments) virtual external onlyAuthorty returns (uint[] memory quotas) {
        quotas = MappingBase(mappingTokenMapped).increaseAuthQuotas(signatorys, increments);
        for(uint i=0; i<signatorys.length; i++)
            emit IncreaseAuthQuota(_msgSender(), mappingTokenMapped, signatorys[i], increments[i], quotas[i]);
    }
    
    function increaseAuthQuota(address mappingTokenMapped, address signatory, uint increment) virtual external onlyAuthorty returns (uint quota) {
        quota = MappingBase(mappingTokenMapped).increaseAuthQuota(signatory, increment);
        emit IncreaseAuthQuota(_msgSender(), mappingTokenMapped, signatory, increment, quota);
    }
    event IncreaseAuthQuota(address indexed authorty, address indexed mappingTokenMapped, address indexed signatory, uint increment, uint quota);
    
    function decreaseAuthQuotas(address mappingTokenMapped, address[] memory signatorys, uint[] memory decrements) virtual external onlyAuthorty returns (uint[] memory quotas) {
        quotas = MappingBase(mappingTokenMapped).decreaseAuthQuotas(signatorys, decrements);
        for(uint i=0; i<signatorys.length; i++)
            emit DecreaseAuthQuota(_msgSender(), mappingTokenMapped, signatorys[i], decrements[i], quotas[i]);
    }
    
    function decreaseAuthQuota(address mappingTokenMapped, address signatory, uint decrement) virtual external onlyAuthorty returns (uint quota) {
        quota = MappingBase(mappingTokenMapped).decreaseAuthQuota(signatory, decrement);
        emit DecreaseAuthQuota(_msgSender(), mappingTokenMapped, signatory, decrement, quota);
    }
    event DecreaseAuthQuota(address indexed authorty, address indexed mappingTokenMapped, address indexed signatory, uint decrement, uint quota);

    function increaseAuthCount(address[] memory signatorys, uint[] memory increments) virtual external returns (uint[] memory counts) {
        require(signatorys.length == increments.length, 'two array lenth not equal');
        counts = new uint[](signatorys.length);
        for(uint i=0; i<signatorys.length; i++)
            counts[i] = increaseAuthCount(signatorys[i], increments[i]);
    }
    
    function increaseAuthCount(address signatory, uint increment) virtual public onlyAuthorty returns (uint count) {
        count = authCountOf[signatory].add(increment);
        authCountOf[signatory] = count;
        emit IncreaseAuthQuota(_msgSender(), signatory, increment, count);
    }
    event IncreaseAuthQuota(address indexed authorty, address indexed signatory, uint increment, uint quota);
    
    function decreaseAuthCounts(address[] memory signatorys, uint[] memory decrements) virtual external returns (uint[] memory counts) {
        require(signatorys.length == decrements.length, 'two array lenth not equal');
        counts = new uint[](signatorys.length);
        for(uint i=0; i<signatorys.length; i++)
            counts[i] = decreaseAuthCount(signatorys[i], decrements[i]);
    }
    
    function decreaseAuthCount(address signatory, uint decrement) virtual public onlyAuthorty returns (uint count) {
        count = authCountOf[signatory];
        if(count < decrement)
            decrement = count;
        return _decreaseAuthCount(signatory, decrement);
    }
    
    function _decreaseAuthCount(address signatory, uint decrement) virtual internal returns (uint count) {
        count = authCountOf[signatory].sub(decrement);
        authCountOf[signatory] = count;
        emit DecreaseAuthCount(_msgSender(), signatory, decrement, count);
    }
    event DecreaseAuthCount(address indexed authorty, address indexed signatory, uint decrement, uint count);

    function supportChainCount() public view returns (uint) {
        return supportChainIds.length;
    }
    
    function mainChainIdTokens(address mappingToken) virtual public view returns(uint mainChainId, address token) {
        uint256 chainIdToken = _mainChainIdTokens[mappingToken];
        mainChainId = chainIdToken >> 160;
        token = address(chainIdToken);
    }
    
    function chainIdMappingTokenMappeds(address tokenOrMappingToken) virtual external view returns (uint[] memory chainIds, address[] memory mappingTokenMappeds_) {
        (, address token) = mainChainIdTokens(tokenOrMappingToken);
        if(token == address(0))
            token = tokenOrMappingToken;
        uint N = 0;
        for(uint i=0; i<supportChainCount(); i++)
            if(mappingTokenMappeds[token][supportChainIds[i]] != address(0))
                N++;
        chainIds = new uint[](N);
        mappingTokenMappeds_ = new address[](N);
        uint j = 0;
        for(uint i=0; i<supportChainCount(); i++) {
            uint chainId = supportChainIds[i];
            address mappingTokenMapped = mappingTokenMappeds[token][chainId];
            if(mappingTokenMapped != address(0)) {
                chainIds[j] = chainId;
                mappingTokenMappeds_[j] = mappingTokenMapped;
                j++;
            }
        }
    }
    
    function isSupportChainId(uint chainId) virtual public view returns (bool) {
        for(uint i=0; i<supportChainCount(); i++)
            if(supportChainIds[i] == chainId)
                return true;
        return false;
    }
    
    function registerSupportChainId(uint chainId_) virtual external governance {
        require(_chainId() == 1 || _chainId() == 3, 'called only on ethereum mainnet');
        require(!isSupportChainId(chainId_), 'support chainId already');
        supportChainIds.push(chainId_);
    }
    
    function _registerMapping(uint mainChainId, address token, uint[] memory chainIds, address[] memory mappingTokenMappeds_) virtual internal {
        require(_chainId() == 1 || _chainId() == 3, 'called only on ethereum mainnet');
        require(chainIds.length == mappingTokenMappeds_.length, 'two array lenth not equal');
        require(isSupportChainId(mainChainId), 'Not support mainChainId');
        for(uint i=0; i<chainIds.length; i++) {
            require(isSupportChainId(chainIds[i]), 'Not support chainId');
            require(_mainChainIdTokens[mappingTokenMappeds_[i]] == 0 || _mainChainIdTokens[mappingTokenMappeds_[i]] == (mainChainId << 160) | uint(token), 'mainChainIdTokens exist already');
            require(mappingTokenMappeds[token][chainIds[i]] == address(0), 'mappingTokenMappeds exist already');
            if(_mainChainIdTokens[mappingTokenMappeds_[i]] == 0)
                _mainChainIdTokens[mappingTokenMappeds_[i]] = (mainChainId << 160) | uint(token);
            mappingTokenMappeds[token][chainIds[i]] = mappingTokenMappeds_[i];
            emit RegisterMapping(mainChainId, token, chainIds[i], mappingTokenMappeds_[i]);
        }
    }
    event RegisterMapping(uint mainChainId, address token, uint chainId, address mappingTokenMapped);
    
    function registerMapping(uint mainChainId, address token, uint[] memory chainIds, address[] memory mappingTokenMappeds_) virtual external governance {
        _registerMapping(mainChainId, token, chainIds, mappingTokenMappeds_);
    }
    
    function registerMapping(uint mainChainId, address token, uint[] memory chainIds, address[] memory mappingTokenMappeds_, Signature[] memory signatures) virtual external payable {
        _chargeFee();
        uint N = signatures.length;
        require(N >= getConfig(_minSignatures_), 'too few signatures');
        for(uint i=0; i<N; i++) {
            for(uint j=0; j<i; j++)
                require(signatures[i].signatory != signatures[j].signatory, 'repetitive signatory');
            bytes32 structHash = keccak256(abi.encode(REGISTER_TYPEHASH, mainChainId, token, chainIds, mappingTokenMappeds_, signatures[i].signatory));
            bytes32 digest = keccak256(abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR, structHash));
            address signatory = ecrecover(digest, signatures[i].v, signatures[i].r, signatures[i].s);
            require(signatory != address(0), "invalid signature");
            require(signatory == signatures[i].signatory, "unauthorized");
            _decreaseAuthCount(signatures[i].signatory, 1);
            emit AuthorizeRegister(mainChainId, token, signatory);
        }
        _registerMapping(mainChainId, token, chainIds, mappingTokenMappeds_);
    }
    event AuthorizeRegister(uint indexed mainChainId, address indexed token, address indexed signatory);

    function certifiedCount() external view returns (uint) {
        return certifiedSymbols.length;
    }
    
    function certifiedTokens(string memory symbol) public view returns (uint mainChainId, address token) {
        uint256 chainIdToken = _certifiedTokens[symbol];
        mainChainId = chainIdToken >> 160;
        token = address(chainIdToken);
    }
    
    function allCertifiedTokens() external view returns (string[] memory symbols, uint[] memory chainIds, address[] memory tokens) {
        symbols = certifiedSymbols;
        uint N = certifiedSymbols.length;
        chainIds = new uint[](N);
        tokens = new address[](N);
        for(uint i=0; i<N; i++)
            (chainIds[i], tokens[i]) = certifiedTokens(certifiedSymbols[i]);
    }

    function registerCertified(string memory symbol, uint mainChainId, address token) external governance {
        require(_chainId() == 1 || _chainId() == 3, 'called only on ethereum mainnet');
        require(isSupportChainId(mainChainId), 'Not support mainChainId');
        require(_certifiedTokens[symbol] == 0, 'Certified added already');
        if(mainChainId == _chainId())
            require(keccak256(bytes(symbol)) == keccak256(bytes(ERC20UpgradeSafe(token).symbol())), 'symbol different');
        _certifiedTokens[symbol] = (mainChainId << 160) | uint(token);
        certifiedSymbols.push(symbol);
        emit RegisterCertified(symbol, mainChainId, token);
    }
    event RegisterCertified(string indexed symbol, uint indexed mainChainId, address indexed token);
    
    function createTokenMapped(address token) external payable returns (address tokenMapped) {
        _chargeFee();
        IERC20(token).totalSupply();                                                            // just for check
        require(tokenMappeds[token] == address(0), 'TokenMapped created already');

        bytes32 salt = keccak256(abi.encodePacked(_chainId(), token));

        bytes memory bytecode = type(InitializableProductProxy).creationCode;
        assembly {
            tokenMapped := create2(0, add(bytecode, 32), mload(bytecode), salt)
        }
        InitializableProductProxy(payable(tokenMapped)).__InitializableProductProxy_init(address(this), _TokenMapped_, abi.encodeWithSignature('__TokenMapped_init(address,address)', address(this), token));
        
        tokenMappeds[token] = tokenMapped;
        emit CreateTokenMapped(_msgSender(), token, tokenMapped);
    }
    event CreateTokenMapped(address indexed creator, address indexed token, address indexed tokenMapped);
    
    function createMappableToken(string memory name, string memory symbol, uint8 decimals, uint totalSupply) external payable returns (address mappableToken) {
        _chargeFee();
        require(mappableTokens[_msgSender()] == address(0), 'MappableToken created already');

        bytes32 salt = keccak256(abi.encodePacked(_chainId(), _msgSender()));

        bytes memory bytecode = type(InitializableProductProxy).creationCode;
        assembly {
            mappableToken := create2(0, add(bytecode, 32), mload(bytecode), salt)
        }
        InitializableProductProxy(payable(mappableToken)).__InitializableProductProxy_init(address(this), _MappableToken_, abi.encodeWithSignature('__MappableToken_init(address,address,string,string,uint8,uint256)', address(this), _msgSender(), name, symbol, decimals, totalSupply));
        
        mappableTokens[_msgSender()] = mappableToken;
        emit CreateMappableToken(_msgSender(), name, symbol, decimals, totalSupply, mappableToken);
    }
    event CreateMappableToken(address indexed creator, string name, string symbol, uint8 decimals, uint totalSupply, address indexed mappableToken);
    
    function _createMappingToken(uint mainChainId, address token, address creator, string memory name, string memory symbol, uint8 decimals, uint cap) internal returns (address mappingToken) {
        _chargeFee();
        address tokenOrCreator = (token == address(0)) ? creator : token;
        require(mappingTokens[mainChainId][tokenOrCreator] == address(0), 'MappingToken created already');

        bytes32 salt = keccak256(abi.encodePacked(mainChainId, tokenOrCreator));

        bytes memory bytecode = type(InitializableProductProxy).creationCode;
        assembly {
            mappingToken := create2(0, add(bytecode, 32), mload(bytecode), salt)
        }
        InitializableProductProxy(payable(mappingToken)).__InitializableProductProxy_init(address(this), _MappingToken_, abi.encodeWithSignature('__MappingToken_init(address,uint256,address,address,string,string,uint8,uint256)', address(this), mainChainId, token, creator, name, symbol, decimals, cap));
        
        mappingTokens[mainChainId][tokenOrCreator] = mappingToken;
        emit CreateMappingToken(mainChainId, token, creator, name, symbol, decimals, cap, mappingToken);
    }
    event CreateMappingToken(uint mainChainId, address indexed token, address indexed creator, string name, string symbol, uint8 decimals, uint cap, address indexed mappingToken);
    
    function createMappingToken(uint mainChainId, address token, address creator, string memory name, string memory symbol, uint8 decimals, uint cap) public payable governance returns (address mappingToken) {
        return _createMappingToken(mainChainId, token, creator, name, symbol, decimals, cap);
    }
    
    function createMappingToken(uint mainChainId, address token, string memory name, string memory symbol, uint8 decimals, uint cap, Signature[] memory signatures) public payable returns (address mappingToken) {
        uint N = signatures.length;
        require(N >= getConfig(_minSignatures_), 'too few signatures');
        for(uint i=0; i<N; i++) {
            for(uint j=0; j<i; j++)
                require(signatures[i].signatory != signatures[j].signatory, 'repetitive signatory');
            bytes32 hash = keccak256(abi.encode(CREATE_TYPEHASH, _msgSender(), mainChainId, token, name, symbol, decimals, cap, signatures[i].signatory));
            hash = keccak256(abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR, hash));
            address signatory = ecrecover(hash, signatures[i].v, signatures[i].r, signatures[i].s);
            require(signatory != address(0), "invalid signature");
            require(signatory == signatures[i].signatory, "unauthorized");
            _decreaseAuthCount(signatures[i].signatory, 1);
            emit AuthorizeCreate(mainChainId, token, _msgSender(), name, symbol, decimals, cap, signatory);
        }
        return _createMappingToken(mainChainId, token, _msgSender(), name, symbol, decimals, cap);
    }
    event AuthorizeCreate(uint mainChainId, address indexed token, address indexed creator, string name, string symbol, uint8 decimals, uint cap, address indexed signatory);
    
    function _chargeFee() virtual internal {
        require(msg.value >= config[_feeCreate_], 'fee for Create is too low');
        address payable feeTo = address(config[_feeTo_]);
        if(feeTo == address(0))
            feeTo = address(uint160(address(this)));
        feeTo.transfer(msg.value);
        emit ChargeFee(_msgSender(), feeTo, msg.value);
    }
    event ChargeFee(address indexed from, address indexed to, uint value);

    uint256[50] private __gap;
}