// File: node_modules\@openzeppelin\contracts\introspection\IERC165.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: @openzeppelin\contracts\token\ERC1155\IERC1155.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.2;


/**
 * @dev Required interface of an ERC1155 compliant contract, as defined in the
 * https://eips.ethereum.org/EIPS/eip-1155[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155 is IERC165 {
    /**
     * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
     */
    event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);

    /**
     * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
     * transfers.
     */
    event TransferBatch(address indexed operator, address indexed from, address indexed to, uint256[] ids, uint256[] values);

    /**
     * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
     * `approved`.
     */
    event ApprovalForAll(address indexed account, address indexed operator, bool approved);

    /**
     * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
     *
     * If an {URI} event was emitted for `id`, the standard
     * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
     * returned by {IERC1155MetadataURI-uri}.
     */
    event URI(string value, uint256 indexed id);

    /**
     * @dev Returns the amount of tokens of token type `id` owned by `account`.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function balanceOf(address account, uint256 id) external view returns (uint256);

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids) external view returns (uint256[] memory);

    /**
     * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
     *
     * Emits an {ApprovalForAll} event.
     *
     * Requirements:
     *
     * - `operator` cannot be the caller.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address account, address operator) external view returns (bool);

    /**
     * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
     * - `from` must have a balance of tokens of type `id` of at least `amount`.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes calldata data) external;

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function safeBatchTransferFrom(address from, address to, uint256[] calldata ids, uint256[] calldata amounts, bytes calldata data) external;
}

// File: @openzeppelin\contracts\token\ERC1155\IERC1155Receiver.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;


/**
 * _Available since v3.1._
 */
interface IERC1155Receiver is IERC165 {

    /**
        @dev Handles the receipt of a single ERC1155 token type. This function is
        called at the end of a `safeTransferFrom` after the balance has been updated.
        To accept the transfer, this must return
        `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
        (i.e. 0xf23a6e61, or its own function selector).
        @param operator The address which initiated the transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param id The ID of the token being transferred
        @param value The amount of tokens being transferred
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
    */
    function onERC1155Received(
        address operator,
        address from,
        uint256 id,
        uint256 value,
        bytes calldata data
    )
        external
        returns(bytes4);

    /**
        @dev Handles the receipt of a multiple ERC1155 token types. This function
        is called at the end of a `safeBatchTransferFrom` after the balances have
        been updated. To accept the transfer(s), this must return
        `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
        (i.e. 0xbc197c81, or its own function selector).
        @param operator The address which initiated the batch transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param ids An array containing ids of each token being transferred (order and length must match values array)
        @param values An array containing amounts of each token being transferred (order and length must match ids array)
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
    */
    function onERC1155BatchReceived(
        address operator,
        address from,
        uint256[] calldata ids,
        uint256[] calldata values,
        bytes calldata data
    )
        external
        returns(bytes4);
}

// File: node_modules\eth-item-token-standard\IERC1155Views.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @title IERC1155Views - An optional utility interface to improve the ERC-1155 Standard.
 * @dev This interface introduces some additional capabilities for ERC-1155 Tokens.
 */
interface IERC1155Views {

    /**
     * @dev Returns the total supply of the given token id
     * @param objectId the id of the token whose availability you want to know 
     */
    function totalSupply(uint256 objectId) external view returns (uint256);

    /**
     * @dev Returns the name of the given token id
     * @param objectId the id of the token whose name you want to know 
     */
    function name(uint256 objectId) external view returns (string memory);

    /**
     * @dev Returns the symbol of the given token id
     * @param objectId the id of the token whose symbol you want to know 
     */
    function symbol(uint256 objectId) external view returns (string memory);

    /**
     * @dev Returns the decimals of the given token id
     * @param objectId the id of the token whose decimals you want to know 
     */
    function decimals(uint256 objectId) external view returns (uint256);

    /**
     * @dev Returns the uri of the given token id
     * @param objectId the id of the token whose uri you want to know 
     */
    function uri(uint256 objectId) external view returns (string memory);
}

// File: @openzeppelin\contracts\token\ERC20\IERC20.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: node_modules\eth-item-token-standard\IBaseTokenData.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;

interface IBaseTokenData {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);
}

// File: node_modules\eth-item-token-standard\IERC20Data.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;



interface IERC20Data is IBaseTokenData, IERC20 {
    function decimals() external view returns (uint256);
}

// File: node_modules\eth-item-token-standard\IEthItemInteroperableInterface.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;



interface IEthItemInteroperableInterface is IERC20, IERC20Data {

    function init(uint256 objectId, string memory name, string memory symbol, uint256 decimals) external;

    function mainInterface() external view returns (address);

    function objectId() external view returns (uint256);

    function mint(address owner, uint256 amount) external;

    function burn(address owner, uint256 amount) external;

    function permitNonce(address sender) external view returns(uint256);

    function permit(address owner, address spender, uint value, uint8 v, bytes32 r, bytes32 s) external;

    function interoperableInterfaceVersion() external pure returns(uint256 ethItemInteroperableInterfaceVersion);
}

// File: eth-item-token-standard\IEthItemMainInterface.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;






interface IEthItemMainInterface is IERC1155, IERC1155Views, IBaseTokenData {

    function init(
        address interoperableInterfaceModel,
        string calldata name,
        string calldata symbol
    ) external;

    function mainInterfaceVersion() external pure returns(uint256 ethItemInteroperableVersion);

    function toInteroperableInterfaceAmount(uint256 objectId, uint256 ethItemAmount) external view returns (uint256 interoperableInterfaceAmount);

    function toMainInterfaceAmount(uint256 objectId, uint256 erc20WrapperAmount) external view returns (uint256 mainInterfaceAmount);

    function interoperableInterfaceModel() external view returns (address, uint256);

    function asInteroperable(uint256 objectId) external view returns (IEthItemInteroperableInterface);

    function emitTransferSingleEvent(address sender, address from, address to, uint256 objectId, uint256 amount) external;

    function mint(uint256 amount, string calldata partialUri)
        external
        returns (uint256, address);

    function burn(
        uint256 objectId,
        uint256 amount
    ) external;

    function burnBatch(
        uint256[] calldata objectIds,
        uint256[] calldata amounts
    ) external;

    event NewItem(uint256 indexed objectId, address indexed tokenAddress);
    event Mint(uint256 objectId, address tokenAddress, uint256 amount);
}

// File: models\common\IEthItemModelBase.sol

//SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;


/**
 * @dev This interface contains the commonn data provided by all the EthItem models
 */
interface IEthItemModelBase is IEthItemMainInterface {

    /**
     * @dev Contract Initialization, the caller of this method should be a Contract containing the logic to provide the EthItemERC20WrapperModel to be used to create ERC20-based objectIds
     * @param name the chosen name for this NFT
     * @param symbol the chosen symbol (Ticker) for this NFT
     */
    function init(string calldata name, string calldata symbol) external;

    /**
     * @return modelVersionNumber The version number of the Model, it should be progressive
     */
    function modelVersion() external pure returns(uint256 modelVersionNumber);

    /**
     * @return factoryAddress the address of the Contract which initialized this EthItem
     */
    function factory() external view returns(address factoryAddress);
}

// File: models\ERC1155Wrapper\1\IERC1155WrapperV1.sol

//SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;



/**
 * @title ERC1155 NFT-Based EthItem, version 1.
 * @dev All the wrapped ERC1155 NFTs will be created following this Model.
 * The minting operation can be done only by transfering the original ERC1155 Item through the classic 'safeTransferFrom/safeBatchTransferFrom' calls.
 * The burning operation will send back the original wrapped NFT.
 */
interface IERC1155WrapperV1 is IEthItemModelBase, IERC1155Receiver {

    /**
     * @dev Contract initialization
     * @param name the chosen name for this NFT
     * @param symbol the chosen symbol (Ticker) for this NFT
     * @param source - The address of the Original ERC1155 NFT Wrapped in this collection
     * @param supportsSpecificName - Set to true if the given source NFT supports the 'name(uint256)' function.
     * @param supportsSpecificSymbol - Set to true if the given source NFT supports the 'symbol(uint256)' function.
     * @param supportsSpecificDecimals - Set to true if the given source NFT supports the 'decimals(uint256)' function.
     */
    function init(
        address source,
        string calldata name,
        string calldata symbol,
        bool supportsSpecificName,
        bool supportsSpecificSymbol,
        bool supportsSpecificDecimals
    ) external;

    /**
     * @return sourceAddress The address of the original wrapped ERC1155 NFT
     */
    function source() external view returns(address sourceAddress);
}

// File: @openzeppelin\contracts\GSN\Context.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with 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.
 */
abstract contract Context {
    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;
    }
}

// File: @openzeppelin\contracts\math\SafeMath.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @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;
    }

    /**
     * @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) {
        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;
    }
}

// File: @openzeppelin\contracts\utils\Address.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.2;

/**
 * @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) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @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 Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin\contracts\introspection\ERC165.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;


/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts may inherit from this and call {_registerInterface} to declare
 * their support of an interface.
 */
contract ERC165 is IERC165 {
    /*
     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
     */
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;

    /**
     * @dev Mapping of interface ids to whether or not it's supported.
     */
    mapping(bytes4 => bool) private _supportedInterfaces;

    constructor () internal {
        // Derived contracts need only register support for their own interfaces,
        // we register support for ERC165 itself here
        _registerInterface(_INTERFACE_ID_ERC165);
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     *
     * Time complexity O(1), guaranteed to always use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) public view override returns (bool) {
        return _supportedInterfaces[interfaceId];
    }

    /**
     * @dev Registers the contract as an implementer of the interface defined by
     * `interfaceId`. Support of the actual ERC165 interface is automatic and
     * registering its interface id is not required.
     *
     * See {IERC165-supportsInterface}.
     *
     * Requirements:
     *
     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
     */
    function _registerInterface(bytes4 interfaceId) internal virtual {
        require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
        _supportedInterfaces[interfaceId] = true;
    }
}

// File: eth-item-token-standard\EthItemMainInterface.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;








/**
 * @title EthItem - An improved ERC1155 token with ERC20 trading capabilities.
 * @dev In the EthItem standard, there is no a centralized storage where to save every objectId info.
 * In fact every NFT data is saved in a specific ERC20 token that can also work as a standalone one, and let transfer parts of an atomic object.
 * The ERC20 represents a unique Token Id, and its supply represents the entire supply of that Token Id.
 * You can instantiate a EthItem as a brand-new one, or as a wrapper for pre-existent classic ERC1155 NFT.
 * In the first case, you can introduce some particular permissions to mint new tokens.
 * In the second case, you need to send your NFTs to the Wrapped EthItem (using the classic safeTransferFrom or safeBatchTransferFrom methods)
 * and it will create a brand new ERC20 Token or mint new supply (in the case some tokens with the same id were transfered before yours).
 */
contract EthItemMainInterface is IEthItemMainInterface, Context, ERC165 {
    using SafeMath for uint256;
    using Address for address;

    bytes4 internal constant _INTERFACEobjectId_ERC1155 = 0xd9b67a26;

    string internal _name;
    string internal _symbol;

    mapping(uint256 => string) internal _objectUris;

    mapping(uint256 => address) internal _dest;
    mapping(address => bool) internal _isMine;

    mapping(address => mapping(address => bool)) internal _operatorApprovals;

    address internal _interoperableInterfaceModel;
    uint256 internal _interoperableInterfaceModelVersion;

    uint256 internal _decimals;

    /**
     * @dev Constructor
     * When you create a EthItem, you can specify if you want to create a brand new one, passing the classic data like name, symbol, amd URI,
     * or wrap a pre-existent ERC1155 NFT, passing its contract address.
     * You can use just one of the two modes at the same time.
     * In both cases, a ERC20 token address is mandatory. It will be used as a model to be cloned for every minted NFT.
     * @param erc20NFTWrapperModel the address of the ERC20 pre-deployed model. I will not be used in the procedure, but just cloned as a brand-new one every time a new NFT is minted.
     * @param name the name of the brand new EthItem to be created. If you are wrapping a pre-existing ERC1155 NFT, this must be blank.
     * @param symbol the symbol of the brand new EthItem to be created. If you are wrapping a pre-existing ERC1155 NFT, this must be blank.
     */
    constructor(
        address erc20NFTWrapperModel,
        string memory name,
        string memory symbol
    ) public {
        if(erc20NFTWrapperModel != address(0)) {
            init(erc20NFTWrapperModel, name, symbol);
        }
    }

    /**
     * @dev Utility method which contains the logic of the constructor.
     * This is a useful trick to instantiate a contract when it is cloned.
     */
    function init(
        address interoperableInterfaceModel,
        string memory name,
        string memory symbol
    ) public virtual override {
        require(
            _interoperableInterfaceModel == address(0),
            "Init already called!"
        );

        require(
            interoperableInterfaceModel != address(0),
            "Model should be a valid ethereum address"
        );
        _interoperableInterfaceModelVersion = IEthItemInteroperableInterface(_interoperableInterfaceModel = interoperableInterfaceModel).interoperableInterfaceVersion();
        require(
            keccak256(bytes(name)) != keccak256(""),
            "Name is mandatory"
        );
        require(
            keccak256(bytes(symbol)) != keccak256(""),
            "Symbol is mandatory"
        );

        _name = name;
        _symbol = symbol;
        _decimals = 18;

        _registerInterface(this.safeBatchTransferFrom.selector);
        _registerInterface(_INTERFACEobjectId_ERC1155);
        _registerInterface(this.balanceOf.selector);
        _registerInterface(this.balanceOfBatch.selector);
        _registerInterface(this.setApprovalForAll.selector);
        _registerInterface(this.isApprovedForAll.selector);
        _registerInterface(this.safeTransferFrom.selector);
        _registerInterface(this.uri.selector);
        _registerInterface(this.totalSupply.selector);
        _registerInterface(0x00ad800c); //name(uint256)
        _registerInterface(0x4e41a1fb); //symbol(uint256)
        _registerInterface(this.decimals.selector);
        _registerInterface(0x06fdde03); //name()
        _registerInterface(0x95d89b41); //symbol()
    }

    function mainInterfaceVersion() public pure virtual override returns(uint256) {
        return 1;
    }

    /**
     * @dev Mint
     * If the EthItem does not wrap a pre-existent NFT, this call is used to mint new NFTs, according to the permission rules provided by the Token creator.
     * @param amount The amount of tokens to be created. It must be greater than 1 unity.
     * @param objectUri The Uri to locate this new token's metadata.
     */
    function mint(uint256 amount, string memory objectUri)
        public
        virtual
        override
        returns (uint256 objectId, address tokenAddress)
    {
        require(
            amount > 1,
            "You need to pass more than a token"
        );
        require(
            keccak256(bytes(objectUri)) != keccak256(""),
            "Uri cannot be empty"
        );
        (objectId, tokenAddress) = _mint(msg.sender, amount);
        _objectUris[objectId] = objectUri;
    }

    /**
     * @dev Burn
     * You can choose to burn your NFTs.
     * In case this Token wraps a pre-existent ERC1155 NFT, you will receive the wrapped NFTs.
     */
    function burn(
        uint256 objectId,
        uint256 amount
    ) public virtual override {
        uint256[] memory objectIds = new uint256[](1);
        objectIds[0] = objectId;
        uint256[] memory amounts = new uint256[](1);
        amounts[0] = amount;
        _burn(msg.sender, objectIds, amounts);
        emit TransferSingle(msg.sender, msg.sender, address(0), objectId, amount);
    }

    /**
     * @dev Burn Batch
     * Same as burn, but for multiple NFTs at the same time
     */
    function burnBatch(
        uint256[] memory objectIds,
        uint256[] memory amounts
    ) public virtual override {
        _burn(msg.sender, objectIds, amounts);
        emit TransferBatch(msg.sender, msg.sender, address(0), objectIds, amounts);
    }

    function _burn(address owner, 
        uint256[] memory objectIds,
        uint256[] memory amounts) internal virtual {
        for (uint256 i = 0; i < objectIds.length; i++) {
            asInteroperable(objectIds[i]).burn(
                owner,
                toInteroperableInterfaceAmount(objectIds[i], amounts[i])
            );
        }
    }

    /**
     * @dev get the address of the ERC20 Contract used as a model
     */
    function interoperableInterfaceModel() public virtual override view returns (address, uint256) {
        return (_interoperableInterfaceModel, _interoperableInterfaceModelVersion);
    }

    /**
     * @dev Gives back the address of the ERC20 Token representing this Token Id
     */
    function asInteroperable(uint256 objectId)
        public
        virtual
        override
        view
        returns (IEthItemInteroperableInterface)
    {
        return IEthItemInteroperableInterface(_dest[objectId]);
    }

    /**
     * @dev Returns the total supply of the given token id
     * @param objectId the id of the token whose availability you want to know
     */
    function totalSupply(uint256 objectId)
        public
        virtual
        override
        view
        returns (uint256)
    {
        return toMainInterfaceAmount(objectId, asInteroperable(objectId).totalSupply());
    }

    /**
     * @dev Returns the name of the given token id
     * @param objectId the id of the token whose name you want to know
     */
    function name(uint256 objectId)
        public
        virtual
        override
        view
        returns (string memory)
    {
        return asInteroperable(objectId).name();
    }

    function name() public virtual override view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the given token id
     * @param objectId the id of the token whose symbol you want to know
     */
    function symbol(uint256 objectId)
        public
        virtual
        override
        view
        returns (string memory)
    {
        return asInteroperable(objectId).symbol();
    }

    function symbol() public virtual override view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the decimals of the given token id
     */
    function decimals(uint256)
        public
        virtual
        override
        view
        returns (uint256)
    {
        return 1;
    }

    /**
     * @dev Returns the uri of the given token id
     * @param objectId the id of the token whose uri you want to know
     */
    function uri(uint256 objectId)
        public
        virtual
        override
        view
        returns (string memory)
    {
        return _objectUris[objectId];
    }

    /**
     * @dev Classic ERC1155 Standard Method
     */
    function balanceOf(address account, uint256 objectId)
        public
        virtual
        override
        view
        returns (uint256)
    {
        return toMainInterfaceAmount(objectId, asInteroperable(objectId).balanceOf(account));
    }

    /**
     * @dev Classic ERC1155 Standard Method
     */
    function balanceOfBatch(
        address[] memory accounts,
        uint256[] memory objectIds
    ) public virtual override view returns (uint256[] memory balances) {
        balances = new uint256[](accounts.length);
        for (uint256 i = 0; i < accounts.length; i++) {
            balances[i] = balanceOf(accounts[i], objectIds[i]);
        }
    }

    /**
     * @dev Classic ERC1155 Standard Method
     */
    function setApprovalForAll(address operator, bool approved)
        public
        virtual
        override
    {
        address sender = _msgSender();
        require(
            sender != operator,
            "ERC1155: setting approval status for self"
        );

        _operatorApprovals[sender][operator] = approved;
        emit ApprovalForAll(sender, operator, approved);
    }

    /**
     * @dev Classic ERC1155 Standard Method
     */
    function isApprovedForAll(address account, address operator)
        public
        virtual
        override
        view
        returns (bool)
    {
        return _operatorApprovals[account][operator];
    }

    /**
     * @dev Classic ERC1155 Standard Method
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 objectId,
        uint256 amount,
        bytes memory data
    ) public virtual override {
        require(to != address(0), "ERC1155: transfer to the zero address");
        address operator = _msgSender();
        require(
            from == operator || isApprovedForAll(from, operator),
            "ERC1155: caller is not owner nor approved"
        );

        asInteroperable(objectId).transferFrom(from, to, toInteroperableInterfaceAmount(objectId, amount));

        emit TransferSingle(operator, from, to, objectId, amount);

        _doSafeTransferAcceptanceCheck(
            operator,
            from,
            to,
            objectId,
            amount,
            data
        );
    }

    /**
     * @dev Classic ERC1155 Standard Method
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory objectIds,
        uint256[] memory amounts,
        bytes memory data
    ) public virtual override {
        require(to != address(0), "ERC1155: transfer to the zero address");
        require(
            from == _msgSender() || isApprovedForAll(from, _msgSender()),
            "ERC1155: caller is not owner nor approved"
        );

        for (uint256 i = 0; i < objectIds.length; i++) {
            asInteroperable(objectIds[i]).transferFrom(
                from,
                to,
                toInteroperableInterfaceAmount(objectIds[i], amounts[i])
            );
        }

        address operator = _msgSender();

        emit TransferBatch(operator, from, to, objectIds, amounts);

        _doSafeBatchTransferAcceptanceCheck(
            operator,
            from,
            to,
            objectIds,
            amounts,
            data
        );
    }

    function emitTransferSingleEvent(address sender, address from, address to, uint256 objectId, uint256 amount) public override {
        require(_dest[objectId] == msg.sender, "Unauthorized Action!");
        uint256 entireAmount = toMainInterfaceAmount(objectId, amount);
        if(entireAmount == 0) {
            return;
        }
        emit TransferSingle(sender, from, to, objectId, entireAmount);
    }

    function toInteroperableInterfaceAmount(uint256 objectId, uint256 mainInterfaceAmount) public override virtual view returns (uint256 interoperableInterfaceAmount) {
        interoperableInterfaceAmount = mainInterfaceAmount * (10**asInteroperable(objectId).decimals());
    }

    function toMainInterfaceAmount(uint256 objectId, uint256 interoperableInterfaceAmount) public override virtual view returns (uint256 mainInterfaceAmount) {
        mainInterfaceAmount = interoperableInterfaceAmount / (10**asInteroperable(objectId).decimals());
    }

    function _doSafeTransferAcceptanceCheck(
        address operator,
        address from,
        address to,
        uint256 id,
        uint256 amount,
        bytes memory data
    ) internal virtual {
        if (to.isContract()) {
            try
                IERC1155Receiver(to).onERC1155Received(
                    operator,
                    from,
                    id,
                    amount,
                    data
                )
            returns (bytes4 response) {
                if (
                    response != IERC1155Receiver(to).onERC1155Received.selector
                ) {
                    revert("ERC1155: ERC1155Receiver rejected tokens");
                }
            } catch Error(string memory reason) {
                revert(reason);
            } catch {
                revert("ERC1155: transfer to non ERC1155Receiver implementer");
            }
        }
    }

    function _doSafeBatchTransferAcceptanceCheck(
        address operator,
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) internal virtual {
        if (to.isContract()) {
            try
                IERC1155Receiver(to).onERC1155BatchReceived(
                    operator,
                    from,
                    ids,
                    amounts,
                    data
                )
            returns (bytes4 response) {
                if (
                    response !=
                    IERC1155Receiver(to).onERC1155BatchReceived.selector
                ) {
                    revert("ERC1155: ERC1155Receiver rejected tokens");
                }
            } catch Error(string memory reason) {
                revert(reason);
            } catch {
                revert("ERC1155: transfer to non ERC1155Receiver implementer");
            }
        }
    }

    function _clone(address original) internal returns (address copy) {
        assembly {
            mstore(
                0,
                or(
                    0x5880730000000000000000000000000000000000000000803b80938091923cF3,
                    mul(original, 0x1000000000000000000)
                )
            )
            copy := create(0, 0, 32)
            switch extcodesize(copy)
                case 0 {
                    invalid()
                }
        }
    }

    function _mint(
        address from,
        uint256 amount
    ) internal virtual returns (uint256 objectId, address wrapperAddress) {
        IEthItemInteroperableInterface wrapper = IEthItemInteroperableInterface(wrapperAddress = _clone(_interoperableInterfaceModel));
        _isMine[_dest[objectId = uint256(wrapperAddress)] = wrapperAddress] = true;
        wrapper.init(objectId, _name, _symbol, _decimals);
        wrapper.mint(from, amount * (10**_decimals));
        emit NewItem(objectId, wrapperAddress);
        emit Mint(objectId, wrapperAddress, amount);
        emit TransferSingle(address(this), address(0), from, objectId, amount);
    }
}

// File: orchestrator\IEthItemOrchestratorDependantElement.sol

//SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;


interface IEthItemOrchestratorDependantElement is IERC165 {

    /**
     * @dev GET - The DoubleProxy of the DFO linked to this Contract
     */
    function doubleProxy() external view returns (address);

    /**
     * @dev SET - The DoubleProxy of the DFO linked to this Contract
     * It can be done only by the Factory controller
     * @param newDoubleProxy the new DoubleProxy address
     */
    function setDoubleProxy(address newDoubleProxy) external;

    function isAuthorizedOrchestrator(address operator) external view returns(bool);
}

// File: factory\IEthItemFactory.sol

//SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;


/**
 * @title IEthItemFactory
 * @dev This contract represents the Factory Used to deploy all the EthItems, keeping track of them.
 */
interface IEthItemFactory is IEthItemOrchestratorDependantElement {

    /**
     * @dev GET - The address of the Smart Contract whose code will serve as a model for all the EthItemERC20Wrappers (please see the eth-item-token-standard for further information).
     */
    function ethItemInteroperableInterfaceModel() external view returns (address ethItemInteroperableInterfaceModelAddress, uint256 ethItemInteroperableInterfaceModelVersion);

    /**
     * @dev SET - The address of the Smart Contract whose code will serve as a model for all the EthItemERC20Wrappers (please see the eth-item-token-standard for further information).
     * It can be done only by the Factory controller
     */
    function setEthItemInteroperableInterfaceModel(address ethItemInteroperableInterfaceModelAddress) external;

    /**
     * @dev GET - The address of the Smart Contract whose code will serve as a model for all the Native EthItems.
     * Every EthItem will have its own address, but the code will be cloned from this one.
     */
    function nativeModel() external view returns (address nativeModelAddress, uint256 nativeModelVersion);

    /**
     * @dev SET - The address of the Native EthItem model.
     * It can be done only by the Factory controller
     */
    function setNativeModel(address nativeModelAddress) external;

    /**
     * @dev GET - The address of the Smart Contract whose code will serve as a model for all the Wrapped ERC1155 EthItems.
     * Every EthItem will have its own address, but the code will be cloned from this one.
     */
    function erc1155WrapperModel() external view returns (address erc1155WrapperModelAddress, uint256 erc1155WrapperModelVersion);

    /**
     * @dev SET - The address of the ERC1155 NFT-Based EthItem model.
     * It can be done only by the Factory controller
     */
    function setERC1155WrapperModel(address erc1155WrapperModelAddress) external;

    /**
     * @dev GET - The address of the Smart Contract whose code will serve as a model for all the Wrapped ERC20 EthItems.
     */
    function erc20WrapperModel() external view returns (address erc20WrapperModelAddress, uint256 erc20WrapperModelVersion);

    /**
     * @dev SET - The address of the Smart Contract whose code will serve as a model for all the Wrapped ERC20 EthItems.
     * It can be done only by the Factory controller
     */
    function setERC20WrapperModel(address erc20WrapperModelAddress) external;

    /**
     * @dev GET - The address of the Smart Contract whose code will serve as a model for all the Wrapped ERC721 EthItems.
     */
    function erc721WrapperModel() external view returns (address erc721WrapperModelAddress, uint256 erc721WrapperModelVersion);

    /**
     * @dev SET - The address of the Smart Contract whose code will serve as a model for all the Wrapped ERC721 EthItems.
     * It can be done only by the Factory controller
     */
    function setERC721WrapperModel(address erc721WrapperModelAddress) external;

    /**
     * @dev GET - The elements (numerator and denominator) useful to calculate the percentage fee to be transfered to the DFO for every new Minted EthItem
     */
    function mintFeePercentage() external view returns (uint256 mintFeePercentageNumerator, uint256 mintFeePercentageDenominator);

    /**
     * @dev SET - The element useful to calculate the Percentage fee
     * It can be done only by the Factory controller
     */
    function setMintFeePercentage(uint256 mintFeePercentageNumerator, uint256 mintFeePercentageDenominator) external;

    /**
     * @dev Useful utility method to calculate the percentage fee to transfer to the DFO for the minted EthItem amount.
     * @param erc20WrapperAmount The amount of minted EthItem
     */
    function calculateMintFee(uint256 erc20WrapperAmount) external view returns (uint256 mintFee, address dfoWalletAddress);

    /**
     * @dev GET - The elements (numerator and denominator) useful to calculate the percentage fee to be transfered to the DFO for every Burned EthItem
     */
    function burnFeePercentage() external view returns (uint256 burnFeePercentageNumerator, uint256 burnFeePercentageDenominator);

    /**
     * @dev SET - The element useful to calculate the Percentage fee
     * It can be done only by the Factory controller
     */
    function setBurnFeePercentage(uint256 burnFeePercentageNumerator, uint256 burnFeePercentageDenominator) external;

    /**
     * @dev Useful utility method to calculate the percentage fee to transfer to the DFO for the burned EthItem amount.
     * @param erc20WrapperAmount The amount of burned EthItem
     */
    function calculateBurnFee(uint256 erc20WrapperAmount) external view returns (uint256 burnFee, address dfoWalletAddress);

    /**
     * @dev Business Logic to create a brand-new EthItem.
     * It raises the 'NewNativeCreated' events.
     * @param modelInitCallPayload The ABI-encoded input parameters to be passed to the model to phisically create the NFT.
     * It changes according to the Model Version.
     * @param ethItemAddress The address of the new EthItem
     * @param ethItemInitResponse The ABI-encoded output response eventually received by the Model initialization procedure.
     */
    function createNative(bytes calldata modelInitCallPayload) external returns (address ethItemAddress, bytes memory ethItemInitResponse);

    event NewNativeCreated(uint256 indexed standardVersion, uint256 indexed wrappedItemModelVersion, uint256 indexed modelVersion, address tokenCreated);
    event NewNativeCreated(address indexed model, uint256 indexed modelVersion, address indexed tokenCreated, address creator);

    /**
     * @dev Business Logic to wrap already existing ERC1155 Tokens to obtain a new NFT-Based EthItem.
     * It raises the 'NewWrappedERC1155Created' events.
     * @param modelInitCallPayload The ABI-encoded input parameters to be passed to the model to phisically create the NFT.
     * It changes according to the Model Version.
     * @param ethItemAddress The address of the new EthItem
     * @param ethItemInitResponse The ABI-encoded output response eventually received by the Model initialization procedure.
     */
    function createWrappedERC1155(bytes calldata modelInitCallPayload) external returns (address ethItemAddress, bytes memory ethItemInitResponse);

    event NewWrappedERC1155Created(uint256 indexed standardVersion, uint256 indexed wrappedItemModelVersion, uint256 indexed modelVersion, address tokenCreated);
    event NewWrappedERC1155Created(address indexed model, uint256 indexed modelVersion, address indexed tokenCreated, address creator);

    /**
     * @dev Business Logic to wrap already existing ERC20 Tokens to obtain a new NFT-Based EthItem.
     * It raises the 'NewWrappedERC20Created' events.
     * @param modelInitCallPayload The ABI-encoded input parameters to be passed to the model to phisically create the NFT.
     * It changes according to the Model Version.
     * @param ethItemAddress The address of the new EthItem
     * @param ethItemInitResponse The ABI-encoded output response eventually received by the Model initialization procedure.
     */
    function createWrappedERC20(bytes calldata modelInitCallPayload) external returns (address ethItemAddress, bytes memory ethItemInitResponse);

    event NewWrappedERC20Created(uint256 indexed standardVersion, uint256 indexed wrappedItemModelVersion, uint256 indexed modelVersion, address tokenCreated);
    event NewWrappedERC20Created(address indexed model, uint256 indexed modelVersion, address indexed tokenCreated, address creator);

    /**
     * @dev Business Logic to wrap already existing ERC721 Tokens to obtain a new NFT-Based EthItem.
     * It raises the 'NewWrappedERC721Created' events.
     * @param modelInitCallPayload The ABI-encoded input parameters to be passed to the model to phisically create the NFT.
     * It changes according to the Model Version.
     * @param ethItemAddress The address of the new EthItem
     * @param ethItemInitResponse The ABI-encoded output response eventually received by the Model initialization procedure.
     */
    function createWrappedERC721(bytes calldata modelInitCallPayload) external returns (address ethItemAddress, bytes memory ethItemInitResponse);

    event NewWrappedERC721Created(uint256 indexed standardVersion, uint256 indexed wrappedItemModelVersion, uint256 indexed modelVersion, address tokenCreated);
    event NewWrappedERC721Created(address indexed model, uint256 indexed modelVersion, address indexed tokenCreated, address creator);
}

// File: models\common\EthItemModelBase.sol

//SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;




abstract contract EthItemModelBase is IEthItemModelBase, EthItemMainInterface(address(0), "", "") {

    address internal _factoryAddress;

    function init(
        address,
        string memory,
        string memory
    ) public virtual override(IEthItemMainInterface, EthItemMainInterface) {
        revert("Cannot directly call this method.");
    }

    function init(
        string memory name,
        string memory symbol
    ) public override virtual {
        require(_factoryAddress == address(0), "Init already called!");
        (address ethItemInteroperableInterfaceModelAddress,) = IEthItemFactory(_factoryAddress = msg.sender).ethItemInteroperableInterfaceModel();
        super.init(ethItemInteroperableInterfaceModelAddress, name, symbol);
    }

    function modelVersion() public override virtual pure returns(uint256) {
        return 1;
    }

    function factory() public override view returns (address) {
        return _factoryAddress;
    }

    function _sendMintFeeToDFO(address from, uint256 objectId, uint256 erc20WrapperAmount) internal virtual returns(uint256 mintFeeToDFO) {
        address dfoWallet;
        (mintFeeToDFO, dfoWallet) = IEthItemFactory(_factoryAddress).calculateMintFee(erc20WrapperAmount);
        if(mintFeeToDFO > 0 && dfoWallet != address(0)) {
            asInteroperable(objectId).transferFrom(from, dfoWallet, mintFeeToDFO);
        }
    }

    function _sendBurnFeeToDFO(address from, uint256 objectId, uint256 erc20WrapperAmount) internal virtual returns(uint256 burnFeeToDFO) {
        address dfoWallet;
        (burnFeeToDFO, dfoWallet) = IEthItemFactory(_factoryAddress).calculateBurnFee(erc20WrapperAmount);
        if(burnFeeToDFO > 0 && dfoWallet != address(0)) {
            asInteroperable(objectId).transferFrom(from, dfoWallet, burnFeeToDFO);
        }
    }

    function mint(uint256, string memory)
        public
        virtual
        override(IEthItemMainInterface, EthItemMainInterface)
        returns (uint256, address)
    {
        revert("Cannot directly call this method.");
    }

    function safeTransferFrom(
        address from,
        address to,
        uint256 objectId,
        uint256 amount,
        bytes memory data
    ) public virtual override(IERC1155, EthItemMainInterface) {
        require(to != address(0), "ERC1155: transfer to the zero address");
        address operator = _msgSender();
        require(
            from == operator || isApprovedForAll(from, operator),
            "ERC1155: caller is not owner nor approved"
        );

        _doERC20Transfer(from, to, objectId, amount);

        emit TransferSingle(operator, from, to, objectId, amount);

        _doSafeTransferAcceptanceCheck(
            operator,
            from,
            to,
            objectId,
            amount,
            data
        );
    }

    /**
     * @dev Classic ERC1155 Standard Method
     */
    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory objectIds,
        uint256[] memory amounts,
        bytes memory data
    ) public virtual override(IERC1155, EthItemMainInterface) {
        require(to != address(0), "ERC1155: transfer to the zero address");
        require(
            from == _msgSender() || isApprovedForAll(from, _msgSender()),
            "ERC1155: caller is not owner nor approved"
        );

        for (uint256 i = 0; i < objectIds.length; i++) {
            _doERC20Transfer(from, to, objectIds[i], amounts[i]);
        }

        address operator = _msgSender();

        emit TransferBatch(operator, from, to, objectIds, amounts);

        _doSafeBatchTransferAcceptanceCheck(
            operator,
            from,
            to,
            objectIds,
            amounts,
            data
        );
    }

    function _doERC20Transfer(address from, address to, uint256 objectId, uint256 amount) internal virtual {
        (,uint256 result) = _getCorrectERC20ValueForTransferOrBurn(from, objectId, amount);
        asInteroperable(objectId).transferFrom(from, to, result);
    }

    function _getCorrectERC20ValueForTransferOrBurn(address from, uint256 objectId, uint256 amount) internal virtual view returns(uint256 balanceOfNormal, uint256 result) {
        uint256 toTransfer = toInteroperableInterfaceAmount(objectId, amount);
        uint256 balanceOfDecimals = asInteroperable(objectId).balanceOf(from);
        balanceOfNormal = balanceOf(from, objectId);
        result = amount == balanceOfNormal ? balanceOfDecimals : toTransfer;
    }

    function _burn(
        uint256 objectId,
        uint256 amount
    ) internal virtual returns(uint256 burnt, uint256 burnFeeToDFO) {
        (uint256 balanceOfNormal, uint256 result) = _getCorrectERC20ValueForTransferOrBurn(msg.sender, objectId, amount);
        require(balanceOfNormal >= amount, "Insufficient Amount");
        burnFeeToDFO = _sendBurnFeeToDFO(msg.sender, objectId, result);
        asInteroperable(objectId).burn(msg.sender, burnt = result - burnFeeToDFO);
    }

    function _isUnique(uint256 objectId) internal virtual view returns (bool unique, uint256 unity, uint256 totalSupply, uint256 erc20Decimals) {
        erc20Decimals = asInteroperable(objectId).decimals();
        unity = erc20Decimals <= 1 ? 1 : (10**erc20Decimals);
        totalSupply = asInteroperable(objectId).totalSupply();
        unique = totalSupply <= unity;
    }

    function toMainInterfaceAmount(uint256 objectId, uint256 interoperableInterfaceAmount) public virtual view override(IEthItemMainInterface, EthItemMainInterface) returns (uint256 mainInterfaceAmount) {
        (bool unique, uint256 unity,, uint256 erc20Decimals) = _isUnique(objectId);
        if(unique && interoperableInterfaceAmount < unity) {
            uint256 half = (unity * 51) / 100;
            return mainInterfaceAmount = interoperableInterfaceAmount <= half ? 0 : 1;
        }
        return mainInterfaceAmount = interoperableInterfaceAmount / (10**erc20Decimals);
    }
}

// File: @openzeppelin\contracts\token\ERC1155\IERC1155MetadataURI.sol

// SPDX_License_Identifier: MIT

pragma solidity ^0.6.2;


/**
 * @dev Interface of the optional ERC1155MetadataExtension interface, as defined
 * in the https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155MetadataURI is IERC1155 {
    /**
     * @dev Returns the URI for token type `id`.
     *
     * If the `\{id\}` substring is present in the URI, it must be replaced by
     * clients with the actual token type ID.
     */
    function uri(uint256 id) external view returns (string memory);
}

// File: models\ERC1155Wrapper\1\ERC1155WrapperV1.sol

//SPDX_License_Identifier: MIT

pragma solidity ^0.6.0;




contract ERC1155WrapperV1 is IERC1155WrapperV1, EthItemModelBase {

    address internal _source;

    bool internal _supportsSpecificName;
    bool internal _supportsSpecificSymbol;
    bool internal _supportsSpecificDecimals;
    bool internal _idAsName;
    mapping(uint256 => uint256) internal _decimalsMap;

    function init(
        address source,
        string memory name,
        string memory symbol,
        bool supportsSpecificName,
        bool supportsSpecificSymbol,
        bool supportsSpecificDecimals
    ) public override {
        require(source != address(0), "Source cannot be void");
        _source = source;
        _supportsSpecificName = supportsSpecificName;
        _supportsSpecificSymbol = supportsSpecificSymbol;
        _supportsSpecificDecimals = supportsSpecificDecimals;
        _idAsName = keccak256(bytes(name)) == keccak256(bytes(_toString(_source)));
        return super.init(name, symbol);
    }

    function source() public view virtual override returns (address) {
        return _source;
    }

    function decimals(uint256 objectId)
        public
        view
        virtual
        override
        returns (uint256)
    {
        return
            !_supportsSpecificDecimals
                ? 1
                : asInteroperable(objectId).decimals();
    }

    function uri(uint256 objectId)
        public
        virtual
        override
        view
        returns (string memory)
    {
        return IERC1155MetadataURI(_source).uri(objectId);
    }

    /**
     * @dev classic ERC-1155 onERC1155Received hook.
     * This method can be called only by the wrapped classic ERC1155 NFT, if it exists.
     * Call this method means that someone transfer original NFTs to receive wrapped ones.
     * So this method will provide brand new NFTs
     */
    function onERC1155Received(
        address,
        address owner,
        uint256 objectId,
        uint256 amount,
        bytes memory
    ) public virtual override returns (bytes4) {
        require(msg.sender == _source, "Unauthorized action!");
        _mint(owner, objectId, amount);
        return this.onERC1155Received.selector;
    }

    /**
     * @dev classic ERC-1155 onERC1155BatchReceived hook.
     * Same as onERC1155Received, but for multiple tokens at the same time
     */
    function onERC1155BatchReceived(
        address,
        address owner,
        uint256[] memory objectIds,
        uint256[] memory amounts,
        bytes memory
    ) public virtual override returns (bytes4) {
        require(msg.sender == _source, "Unauthorized action!");
        for (uint256 i = 0; i < objectIds.length; i++) {
            _mint(owner, objectIds[i], amounts[i]);
        }
        return this.onERC1155BatchReceived.selector;
    }

    function burn(
        uint256 objectId,
        uint256 amount
    ) public virtual override {
        _burn(objectId, amount);
        IERC1155(_source).safeTransferFrom(address(this), msg.sender, objectId, amount / (_supportsSpecificDecimals ? _itemDecimals(objectId) : 1), "");
        emit TransferSingle(msg.sender, msg.sender, address(0), objectId, amount);
    }

    function burnBatch(
        uint256[] memory objectIds,
        uint256[] memory amounts
    ) public virtual override {
        uint256[] memory normalAmounts = new uint256[](amounts.length);
        for (uint256 i = 0; i < objectIds.length; i++) {
            _burn(objectIds[i], amounts[i]);
            normalAmounts[i] = amounts[i] /  (_supportsSpecificDecimals ? _itemDecimals(objectIds[i]) : 1);
        }
        IERC1155(_source).safeBatchTransferFrom(address(this), msg.sender, objectIds, normalAmounts, "");
        emit TransferBatch(msg.sender, msg.sender, address(0), objectIds, amounts);
    }

    function toInteroperableInterfaceAmount(uint256 objectId, uint256 mainInterfaceAmount) public override virtual view returns (uint256 interoperableInterfaceAmount) {
        interoperableInterfaceAmount = _supportsSpecificDecimals ? mainInterfaceAmount : super.toInteroperableInterfaceAmount(objectId, mainInterfaceAmount);
    }

    function toMainInterfaceAmount(uint256 objectId, uint256 interoperableInterfaceAmount) public override(IEthItemMainInterface, EthItemModelBase) virtual view returns (uint256 mainInterfaceAmount) {
        mainInterfaceAmount = _supportsSpecificDecimals ? interoperableInterfaceAmount : super.toMainInterfaceAmount(objectId, interoperableInterfaceAmount);
    }

    function _mint(
        address from,
        uint256 objectIdInput,
        uint256 amount
    ) internal virtual returns (uint256 objectId, address wrapperAddress) {
        wrapperAddress = _dest[objectId = objectIdInput];
        if (wrapperAddress == address(0)) {
            (address interoperableInterfaceModelAddress,) = interoperableInterfaceModel();
            _isMine[_dest[objectId] = wrapperAddress = _clone(interoperableInterfaceModelAddress)] = true;
            (string memory name, string memory symbol, uint256 dec) = _getMintData(objectId);
            name = _idAsName ? _toString(objectId) : name;
            _decimalsMap[objectId] = dec;
            IEthItemInteroperableInterface(wrapperAddress).init(objectId, name, symbol, _decimals);
            emit NewItem(objectId, wrapperAddress);
        }
        uint256 itemDecimalsUnity = 10**_decimals;

        uint256 itemAmountDecimals = amount * (_supportsSpecificDecimals ? _itemDecimals(objectId) : itemDecimalsUnity);

        uint256 totalSupply = asInteroperable(objectId).totalSupply();
        uint256 toMint = itemDecimalsUnity > totalSupply ? itemDecimalsUnity - totalSupply : itemDecimalsUnity;
        if(itemAmountDecimals > itemDecimalsUnity) {
            uint256 first = itemDecimalsUnity > totalSupply ? itemDecimalsUnity - totalSupply : 0;
            uint256 entireAmount = first > 0 ? itemAmountDecimals - itemDecimalsUnity : itemAmountDecimals;
            toMint = first + entireAmount;
        }
        asInteroperable(objectId).mint(from, toMint);
        uint256 mintFeeToDFO = _sendMintFeeToDFO(from, objectId, toMint);
        uint256 nftAmount = toMainInterfaceAmount(objectId, toMint - mintFeeToDFO);
        if(nftAmount > 0) {
            emit Mint(objectId, wrapperAddress, nftAmount);
            emit TransferSingle(address(this), address(0), from, objectId, nftAmount);
        }
    }

    function _itemDecimals(uint256 objectId) internal view returns(uint256) {
        return (10**(_decimals - _decimalsMap[objectId]));
    }

    function _getMintData(uint256 objectId)
        internal
        virtual
        view
        returns (
            string memory name,
            string memory symbol,
            uint256 dec
        )
    {
        name = _supportsSpecificName ? IERC1155Views(_source).name(objectId) : _name;
        symbol = _supportsSpecificSymbol ? IERC1155Views(_source).symbol(objectId) : _symbol;
        dec = _supportsSpecificDecimals ? IERC1155Views(_source).decimals(objectId) : _decimals;
    }

    function _toString(address _addr) internal pure returns(string memory) {
        bytes32 value = bytes32(uint256(_addr));
        bytes memory alphabet = "0123456789abcdef";

        bytes memory str = new bytes(42);
        str[0] = '0';
        str[1] = 'x';
        for (uint i = 0; i < 20; i++) {
            str[2+i*2] = alphabet[uint(uint8(value[i + 12] >> 4))];
            str[3+i*2] = alphabet[uint(uint8(value[i + 12] & 0x0f))];
        }
        return string(str);
    }

    function _toString(uint _i) internal pure returns(string memory) {
        if (_i == 0) {
            return "0";
        }
        uint j = _i;
        uint len;
        while (j != 0) {
            len++;
            j /= 10;
        }
        bytes memory bstr = new bytes(len);
        uint k = len - 1;
        while (_i != 0) {
            bstr[k--] = byte(uint8(48 + _i % 10));
            _i /= 10;
        }
        return string(bstr);
    }
}