EDDASwap

pragma solidity ^0.6.6;


// SPDX-License-Identifier: MIT
/*
 * @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;
    }
}

// SPDX-License-Identifier: MIT
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// SPDX-License-Identifier: MIT
/**
 * @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;
    }
}

// SPDX-License-Identifier: MIT
/**
 * @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 on 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");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        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);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
/**
 * @dev ERC-1155 interface for accepting safe transfers.
 */
interface IERC1155TokenReceiver {
  /**
   * @notice Handle the receipt of a single ERC1155 token type
   * @dev An ERC1155-compliant smart contract MUST call this function on the token recipient contract, at the end of a `safeTransferFrom` after the balance has been updated
   * This function MAY throw to revert and reject the transfer
   * Return of other amount than the magic value MUST result in the transaction being reverted
   * Note: The token contract address is always the message sender
   * @param _operator  The address which called the `safeTransferFrom` function
   * @param _from      The address which previously owned the token
   * @param _id        The id of the token being transferred
   * @param _amount    The amount of tokens being transferred
   * @param _data      Additional data with no specified format
   * @return           `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
   */
  function onERC1155Received(
    address _operator,
    address _from,
    uint256 _id,
    uint256 _amount,
    bytes calldata _data
  ) external returns (bytes4);

  /**
   * @notice Handle the receipt of multiple ERC1155 token types
   * @dev An ERC1155-compliant smart contract MUST call this function on the token recipient contract, at the end of a `safeBatchTransferFrom` after the balances have been updated
   * This function MAY throw to revert and reject the transfer
   * Return of other amount than the magic value WILL result in the transaction being reverted
   * Note: The token contract address is always the message sender
   * @param _operator  The address which called the `safeBatchTransferFrom` function
   * @param _from      The address which previously owned the token
   * @param _ids       An array containing ids of each token being transferred
   * @param _amounts   An array containing amounts of each token being transferred
   * @param _data      Additional data with no specified format
   * @return           `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
   */
  function onERC1155BatchReceived(
    address _operator,
    address _from,
    uint256[] calldata _ids,
    uint256[] calldata _amounts,
    bytes calldata _data
  ) external returns (bytes4);

  /**
   * @notice Indicates whether a contract implements the `ERC1155TokenReceiver` functions and so can accept ERC1155 token types.
   * @param  interfaceID The ERC-165 interface ID that is queried for support.s
   * @dev This function MUST return true if it implements the ERC1155TokenReceiver interface and ERC-165 interface.
   *      This function MUST NOT consume more than 5,000 gas.
   * @return Wheter ERC-165 or ERC1155TokenReceiver interfaces are supported.
   */
  function supportsInterface(bytes4 interfaceID) external view returns (bool);
}

// SPDX-License-Identifier: MIT
/**
 * @title ERC165
 * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
 */
interface IERC165 {
  /**
   * @notice Query if a contract implements an interface
   * @dev Interface identification is specified in ERC-165. This function
   * uses less than 30,000 gas
   * @param _interfaceId The interface identifier, as specified in ERC-165
   */
  function supportsInterface(bytes4 _interfaceId) external view returns (bool);
}

// SPDX-License-Identifier: MIT
/**
 * @dev Implementation of Multi-Token Standard contract
 */
contract ERC1155 is IERC165 {
  using SafeMath for uint256;
  using Address for address;

  /***********************************|
  |        Variables and Events       |
  |__________________________________*/

  // onReceive function signatures
  bytes4 internal constant ERC1155_RECEIVED_VALUE = 0xf23a6e61;
  bytes4 internal constant ERC1155_BATCH_RECEIVED_VALUE = 0xbc197c81;

  // Objects balances
  mapping(address => mapping(uint256 => uint256)) internal balances;

  // Operator Functions
  mapping(address => mapping(address => bool)) internal operators;

  // Events
  event TransferSingle(
    address indexed _operator,
    address indexed _from,
    address indexed _to,
    uint256 _id,
    uint256 _amount
  );
  event TransferBatch(
    address indexed _operator,
    address indexed _from,
    address indexed _to,
    uint256[] _ids,
    uint256[] _amounts
  );
  event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);
  event URI(string _uri, uint256 indexed _id);

  /***********************************|
  |     Public Transfer Functions     |
  |__________________________________*/

  /**
   * @notice Transfers amount amount of an _id from the _from address to the _to address specified
   * @param _from    Source address
   * @param _to      Target address
   * @param _id      ID of the token type
   * @param _amount  Transfered amount
   * @param _data    Additional data with no specified format, sent in call to `_to`
   */
  function safeTransferFrom(
    address _from,
    address _to,
    uint256 _id,
    uint256 _amount,
    bytes memory _data
  ) public {
    require((msg.sender == _from) || isApprovedForAll(_from, msg.sender), "ERC1155#safeTransferFrom: INVALID_OPERATOR");
    require(_to != address(0), "ERC1155#safeTransferFrom: INVALID_RECIPIENT");
    // require(_amount >= balances[_from][_id]) is not necessary since checked with safemath operations

    _safeTransferFrom(_from, _to, _id, _amount);
    _callonERC1155Received(_from, _to, _id, _amount, _data);
  }

  /**
   * @notice Send multiple types of Tokens from the _from address to the _to address (with safety call)
   * @param _from     Source addresses
   * @param _to       Target addresses
   * @param _ids      IDs of each token type
   * @param _amounts  Transfer amounts per token type
   * @param _data     Additional data with no specified format, sent in call to `_to`
   */
  function safeBatchTransferFrom(
    address _from,
    address _to,
    uint256[] memory _ids,
    uint256[] memory _amounts,
    bytes memory _data
  ) public {
    // Requirements
    require(
      (msg.sender == _from) || isApprovedForAll(_from, msg.sender),
      "ERC1155#safeBatchTransferFrom: INVALID_OPERATOR"
    );
    require(_to != address(0), "ERC1155#safeBatchTransferFrom: INVALID_RECIPIENT");

    _safeBatchTransferFrom(_from, _to, _ids, _amounts);
    _callonERC1155BatchReceived(_from, _to, _ids, _amounts, _data);
  }

  /***********************************|
  |    Internal Transfer Functions    |
  |__________________________________*/

  /**
   * @notice Transfers amount amount of an _id from the _from address to the _to address specified
   * @param _from    Source address
   * @param _to      Target address
   * @param _id      ID of the token type
   * @param _amount  Transfered amount
   */
  function _safeTransferFrom(
    address _from,
    address _to,
    uint256 _id,
    uint256 _amount
  ) internal {
    // Update balances
    balances[_from][_id] = balances[_from][_id].sub(_amount); // Subtract amount
    balances[_to][_id] = balances[_to][_id].add(_amount); // Add amount

    // Emit event
    emit TransferSingle(msg.sender, _from, _to, _id, _amount);
  }

  /**
   * @notice Verifies if receiver is contract and if so, calls (_to).onERC1155Received(...)
   */
  function _callonERC1155Received(
    address _from,
    address _to,
    uint256 _id,
    uint256 _amount,
    bytes memory _data
  ) internal {
    // Check if recipient is contract
    if (_to.isContract()) {
      bytes4 retval = IERC1155TokenReceiver(_to).onERC1155Received(msg.sender, _from, _id, _amount, _data);
      require(retval == ERC1155_RECEIVED_VALUE, "ERC1155#_callonERC1155Received: INVALID_ON_RECEIVE_MESSAGE");
    }
  }

  /**
   * @notice Send multiple types of Tokens from the _from address to the _to address (with safety call)
   * @param _from     Source addresses
   * @param _to       Target addresses
   * @param _ids      IDs of each token type
   * @param _amounts  Transfer amounts per token type
   */
  function _safeBatchTransferFrom(
    address _from,
    address _to,
    uint256[] memory _ids,
    uint256[] memory _amounts
  ) internal {
    require(_ids.length == _amounts.length, "ERC1155#_safeBatchTransferFrom: INVALID_ARRAYS_LENGTH");

    // Number of transfer to execute
    uint256 nTransfer = _ids.length;

    // Executing all transfers
    for (uint256 i = 0; i < nTransfer; i++) {
      // Update storage balance of previous bin
      balances[_from][_ids[i]] = balances[_from][_ids[i]].sub(_amounts[i]);
      balances[_to][_ids[i]] = balances[_to][_ids[i]].add(_amounts[i]);
    }

    // Emit event
    emit TransferBatch(msg.sender, _from, _to, _ids, _amounts);
  }

  /**
   * @notice Verifies if receiver is contract and if so, calls (_to).onERC1155BatchReceived(...)
   */
  function _callonERC1155BatchReceived(
    address _from,
    address _to,
    uint256[] memory _ids,
    uint256[] memory _amounts,
    bytes memory _data
  ) internal {
    // Pass data if recipient is contract
    if (_to.isContract()) {
      bytes4 retval = IERC1155TokenReceiver(_to).onERC1155BatchReceived(msg.sender, _from, _ids, _amounts, _data);
      require(
        retval == ERC1155_BATCH_RECEIVED_VALUE,
        "ERC1155#_callonERC1155BatchReceived: INVALID_ON_RECEIVE_MESSAGE"
      );
    }
  }

  /***********************************|
  |         Operator Functions        |
  |__________________________________*/

  /**
   * @notice Enable or disable approval for a third party ("operator") to manage all of caller's tokens
   * @param _operator  Address to add to the set of authorized operators
   * @param _approved  True if the operator is approved, false to revoke approval
   */
  function setApprovalForAll(address _operator, bool _approved) external {
    // Update operator status
    operators[msg.sender][_operator] = _approved;
    emit ApprovalForAll(msg.sender, _operator, _approved);
  }

  /**
   * @notice Queries the approval status of an operator for a given owner
   * @param _owner     The owner of the Tokens
   * @param _operator  Address of authorized operator
   * @return isOperator True if the operator is approved, false if not
   */
  function isApprovedForAll(address _owner, address _operator) public view virtual returns (bool isOperator) {
    return operators[_owner][_operator];
  }

  /***********************************|
  |         Balance Functions         |
  |__________________________________*/

  /**
   * @notice Get the balance of an account's Tokens
   * @param _owner  The address of the token holder
   * @param _id     ID of the Token
   * @return The _owner's balance of the Token type requested
   */
  function balanceOf(address _owner, uint256 _id) public view returns (uint256) {
    return balances[_owner][_id];
  }

  /**
   * @notice Get the balance of multiple account/token pairs
   * @param _owners The addresses of the token holders
   * @param _ids    ID of the Tokens
   * @return        The _owner's balance of the Token types requested (i.e. balance for each (owner, id) pair)
   */
  function balanceOfBatch(address[] memory _owners, uint256[] memory _ids) public view returns (uint256[] memory) {
    require(_owners.length == _ids.length, "ERC1155#balanceOfBatch: INVALID_ARRAY_LENGTH");

    // Variables
    uint256[] memory batchBalances = new uint256[](_owners.length);

    // Iterate over each owner and token ID
    for (uint256 i = 0; i < _owners.length; i++) {
      batchBalances[i] = balances[_owners[i]][_ids[i]];
    }

    return batchBalances;
  }

  /***********************************|
  |          ERC165 Functions         |
  |__________________________________*/

  /**
   * INTERFACE_SIGNATURE_ERC165 = bytes4(keccak256("supportsInterface(bytes4)"));
   */
  bytes4 private constant INTERFACE_SIGNATURE_ERC165 = 0x01ffc9a7;

  /**
   * INTERFACE_SIGNATURE_ERC1155 =
   * bytes4(keccak256("safeTransferFrom(address,address,uint256,uint256,bytes)")) ^
   * bytes4(keccak256("safeBatchTransferFrom(address,address,uint256[],uint256[],bytes)")) ^
   * bytes4(keccak256("balanceOf(address,uint256)")) ^
   * bytes4(keccak256("balanceOfBatch(address[],uint256[])")) ^
   * bytes4(keccak256("setApprovalForAll(address,bool)")) ^
   * bytes4(keccak256("isApprovedForAll(address,address)"));
   */
  bytes4 private constant INTERFACE_SIGNATURE_ERC1155 = 0xd9b67a26;

  /**
   * @notice Query if a contract implements an interface
   * @param _interfaceID  The interface identifier, as specified in ERC-165
   * @return `true` if the contract implements `_interfaceID` and
   */
  function supportsInterface(bytes4 _interfaceID) external view override(IERC165) returns (bool) {
    if (_interfaceID == INTERFACE_SIGNATURE_ERC165 || _interfaceID == INTERFACE_SIGNATURE_ERC1155) {
      return true;
    }
    return false;
  }
}

// SPDX-License-Identifier: MIT
/**
 * @notice Contract that handles metadata related methods.
 * @dev Methods assume a deterministic generation of URI based on token IDs.
 *      Methods also assume that URI uses hex representation of token IDs.
 */
contract ERC1155Metadata {
  // URI's default URI prefix
  string internal baseMetadataURI;
  event URI(string _uri, uint256 indexed _id);

  /***********************************|
  |     Metadata Public Function s    |
  |__________________________________*/

  /**
   * @notice A distinct Uniform Resource Identifier (URI) for a given token.
   * @dev URIs are defined in RFC 3986.
   *      URIs are assumed to be deterministically generated based on token ID
   *      Token IDs are assumed to be represented in their hex format in URIs
   * @return URI string
   */
  function uri(uint256 _id) public view virtual returns (string memory) {
    return string(abi.encodePacked(baseMetadataURI, _uint2str(_id), ".json"));
  }

  /***********************************|
  |    Metadata Internal Functions    |
  |__________________________________*/

  /**
   * @notice Will emit default URI log event for corresponding token _id
   * @param _tokenIDs Array of IDs of tokens to log default URI
   */
  function _logURIs(uint256[] memory _tokenIDs) internal {
    string memory baseURL = baseMetadataURI;
    string memory tokenURI;

    for (uint256 i = 0; i < _tokenIDs.length; i++) {
      tokenURI = string(abi.encodePacked(baseURL, _uint2str(_tokenIDs[i]), ".json"));
      emit URI(tokenURI, _tokenIDs[i]);
    }
  }

  /**
   * @notice Will emit a specific URI log event for corresponding token
   * @param _tokenIDs IDs of the token corresponding to the _uris logged
   * @param _URIs    The URIs of the specified _tokenIDs
   */
  function _logURIs(uint256[] memory _tokenIDs, string[] memory _URIs) internal {
    require(_tokenIDs.length == _URIs.length, "ERC1155Metadata#_logURIs: INVALID_ARRAYS_LENGTH");
    for (uint256 i = 0; i < _tokenIDs.length; i++) {
      emit URI(_URIs[i], _tokenIDs[i]);
    }
  }

  /**
   * @notice Will update the base URL of token's URI
   * @param _newBaseMetadataURI New base URL of token's URI
   */
  function _setBaseMetadataURI(string memory _newBaseMetadataURI) internal {
    baseMetadataURI = _newBaseMetadataURI;
  }

  /***********************************|
  |    Utility Internal Functions     |
  |__________________________________*/

  /**
   * @notice Convert uint256 to string
   * @param _i Unsigned integer to convert to string
   */
  function _uint2str(uint256 _i) internal pure returns (string memory _uintAsString) {
    if (_i == 0) {
      return "0";
    }

    uint256 j = _i;
    uint256 ii = _i;
    uint256 len;

    // Get number of bytes
    while (j != 0) {
      len++;
      j /= 10;
    }

    bytes memory bstr = new bytes(len);
    uint256 k = len - 1;

    // Get each individual ASCII
    while (ii != 0) {
      bstr[k--] = bytes1(uint8(48 + (ii % 10)));
      ii /= 10;
    }

    // Convert to string
    return string(bstr);
  }
}

// SPDX-License-Identifier: MIT
/**
 * @dev Multi-Fungible Tokens with minting and burning methods. These methods assume
 *      a parent contract to be executed as they are `internal` functions
 */
contract ERC1155MintBurn is ERC1155 {
  /****************************************|
  |            Minting Functions           |
  |_______________________________________*/

  /**
   * @notice Mint _amount of tokens of a given id
   * @param _to      The address to mint tokens to
   * @param _id      Token id to mint
   * @param _amount  The amount to be minted
   * @param _data    Data to pass if receiver is contract
   */
  function _mint(
    address _to,
    uint256 _id,
    uint256 _amount,
    bytes memory _data
  ) internal {
    // Add _amount
    balances[_to][_id] = balances[_to][_id].add(_amount);

    // Emit event
    emit TransferSingle(msg.sender, address(0x0), _to, _id, _amount);

    // Calling onReceive method if recipient is contract
    _callonERC1155Received(address(0x0), _to, _id, _amount, _data);
  }

  /**
   * @notice Mint tokens for each ids in _ids
   * @param _to       The address to mint tokens to
   * @param _ids      Array of ids to mint
   * @param _amounts  Array of amount of tokens to mint per id
   * @param _data    Data to pass if receiver is contract
   */
  function _batchMint(
    address _to,
    uint256[] memory _ids,
    uint256[] memory _amounts,
    bytes memory _data
  ) internal {
    require(_ids.length == _amounts.length, "ERC1155MintBurn#batchMint: INVALID_ARRAYS_LENGTH");

    // Number of mints to execute
    uint256 nMint = _ids.length;

    // Executing all minting
    for (uint256 i = 0; i < nMint; i++) {
      // Update storage balance
      balances[_to][_ids[i]] = balances[_to][_ids[i]].add(_amounts[i]);
    }

    // Emit batch mint event
    emit TransferBatch(msg.sender, address(0x0), _to, _ids, _amounts);

    // Calling onReceive method if recipient is contract
    _callonERC1155BatchReceived(address(0x0), _to, _ids, _amounts, _data);
  }

  /****************************************|
  |            Burning Functions           |
  |_______________________________________*/

  /**
   * @notice Burn _amount of tokens of a given token id
   * @param _from    The address to burn tokens from
   * @param _id      Token id to burn
   * @param _amount  The amount to be burned
   */
  function _burn(
    address _from,
    uint256 _id,
    uint256 _amount
  ) internal {
    //Substract _amount
    balances[_from][_id] = balances[_from][_id].sub(_amount);

    // Emit event
    emit TransferSingle(msg.sender, _from, address(0x0), _id, _amount);
  }

  /**
   * @notice Burn tokens of given token id for each (_ids[i], _amounts[i]) pair
   * @param _from     The address to burn tokens from
   * @param _ids      Array of token ids to burn
   * @param _amounts  Array of the amount to be burned
   */
  function _batchBurn(
    address _from,
    uint256[] memory _ids,
    uint256[] memory _amounts
  ) internal {
    require(_ids.length == _amounts.length, "ERC1155MintBurn#batchBurn: INVALID_ARRAYS_LENGTH");

    // Number of mints to execute
    uint256 nBurn = _ids.length;

    // Executing all minting
    for (uint256 i = 0; i < nBurn; i++) {
      // Update storage balance
      balances[_from][_ids[i]] = balances[_from][_ids[i]].sub(_amounts[i]);
    }

    // Emit batch mint event
    emit TransferBatch(msg.sender, _from, address(0x0), _ids, _amounts);
  }
}

// SPDX-License-Identifier: MIT
/**
 * @title Roles
 * @dev Library for managing addresses assigned to a Role.
 */
library Roles {
  struct Role {
    mapping(address => bool) bearer;
  }

  /**
   * @dev Give an account access to this role.
   */
  function add(Role storage role, address account) internal {
    require(!has(role, account), "Roles: account already has role");
    role.bearer[account] = true;
  }

  /**
   * @dev Remove an account's access to this role.
   */
  function remove(Role storage role, address account) internal {
    require(has(role, account), "Roles: account does not have role");
    role.bearer[account] = false;
  }

  /**
   * @dev Check if an account has this role.
   * @return bool
   */
  function has(Role storage role, address account) internal view returns (bool) {
    require(account != address(0), "Roles: account is the zero address");
    return role.bearer[account];
  }
}

// SPDX-License-Identifier: MIT
contract MinterRole is Context {
  using Roles for Roles.Role;

  event MinterAdded(address indexed account);
  event MinterRemoved(address indexed account);

  Roles.Role private _minters;

  constructor() internal {
    _addMinter(_msgSender());
  }

  modifier onlyMinter() {
    require(isMinter(_msgSender()), "MinterRole: caller does not have the Minter role");
    _;
  }

  function isMinter(address account) public view returns (bool) {
    return _minters.has(account);
  }

  function addMinter(address account) public onlyMinter {
    _addMinter(account);
  }

  function renounceMinter() public {
    _removeMinter(_msgSender());
  }

  function _addMinter(address account) internal {
    _minters.add(account);
    emit MinterAdded(account);
  }

  function _removeMinter(address account) internal {
    _minters.remove(account);
    emit MinterRemoved(account);
  }
}

// SPDX-License-Identifier: MIT
abstract contract Proxy {
  event ReceivedEther(address indexed sender, uint256 amount);

  /**
   * @dev Tells the address of the implementation where every call will be delegated.
   * @return address of the implementation to which it will be delegated
   */
  function implementation() public view virtual returns (address);

  /**
   * @dev Tells the type of proxy (EIP 897)
   * @return Type of proxy, 2 for upgradeable proxy
   */
  function proxyType() public pure virtual returns (uint256);

  /**
   * @dev Fallback function allowing to perform a delegatecall to the given implementation.
   * This function will return whatever the implementation call returns
   */
  fallback() external payable {
    address _impl = implementation();
    require(_impl != address(0));

    assembly {
      let ptr := mload(0x40)
      calldatacopy(ptr, 0, calldatasize())
      let result := delegatecall(gas(), _impl, ptr, calldatasize(), 0, 0)
      let size := returndatasize()
      returndatacopy(ptr, 0, size)

      switch result
        case 0 {
          revert(ptr, size)
        }
        default {
          return(ptr, size)
        }
    }
  }

  /**
   * @dev Receive Ether and generate a log event
   */
  receive() external payable {
    emit ReceivedEther(msg.sender, msg.value);
  }
}

// SPDX-License-Identifier: MIT
contract OwnedUpgradeabilityStorage is Proxy {
  // Current implementation
  address internal _implementation;

  // Owner of the contract
  address private _upgradeabilityOwner;

  /**
   * @dev Tells the address of the owner
   * @return the address of the owner
   */
  function upgradeabilityOwner() public view returns (address) {
    return _upgradeabilityOwner;
  }

  /**
   * @dev Sets the address of the owner
   */
  function setUpgradeabilityOwner(address newUpgradeabilityOwner) internal {
    _upgradeabilityOwner = newUpgradeabilityOwner;
  }

  /**
   * @dev Tells the address of the current implementation
   * @return address of the current implementation
   */
  function implementation() public view override returns (address) {
    return _implementation;
  }

  /**
   * @dev Tells the proxy type (EIP 897)
   * @return Proxy type, 2 for forwarding proxy
   */
  function proxyType() public pure override returns (uint256) {
    return 2;
  }
}

// SPDX-License-Identifier: MIT
contract OwnedUpgradeabilityProxy is OwnedUpgradeabilityStorage {
  /**
   * @dev Event to show ownership has been transferred
   * @param previousOwner representing the address of the previous owner
   * @param newOwner representing the address of the new owner
   */
  event ProxyOwnershipTransferred(address previousOwner, address newOwner);

  /**
   * @dev This event will be emitted every time the implementation gets upgraded
   * @param implementation representing the address of the upgraded implementation
   */
  event Upgraded(address indexed implementation);

  /**
   * @dev Upgrades the implementation address
   * @param implementation representing the address of the new implementation to be set
   */
  function _upgradeTo(address implementation) internal {
    require(_implementation != implementation);
    _implementation = implementation;
    emit Upgraded(implementation);
  }

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

  /**
   * @dev Tells the address of the proxy owner
   * @return the address of the proxy owner
   */
  function proxyOwner() public view returns (address) {
    return upgradeabilityOwner();
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.
   */
  function transferProxyOwnership(address newOwner) public onlyProxyOwner {
    require(newOwner != address(0));
    emit ProxyOwnershipTransferred(proxyOwner(), newOwner);
    setUpgradeabilityOwner(newOwner);
  }

  /**
   * @dev Allows the upgradeability owner to upgrade the current implementation of the proxy.
   * @param implementation representing the address of the new implementation to be set.
   */
  function upgradeTo(address implementation) public onlyProxyOwner {
    _upgradeTo(implementation);
  }

  /**
   * @dev Allows the upgradeability owner to upgrade the current implementation of the proxy
   * and delegatecall the new implementation for initialization.
   * @param implementation representing the address of the new implementation to be set.
   * @param data represents the msg.data to bet sent in the low level call. This parameter may include the function
   * signature of the implementation to be called with the needed payload
   */
  function upgradeToAndCall(address implementation, bytes memory data) public payable onlyProxyOwner {
    upgradeTo(implementation);
    (bool result, ) = address(this).delegatecall(data);
    require(result);
  }
}

// SPDX-License-Identifier: MIT
contract OwnableDelegateProxy is OwnedUpgradeabilityProxy {
  constructor(
    address owner,
    address initialImplementation,
    bytes memory callData
  ) public {
    setUpgradeabilityOwner(owner);
    _upgradeTo(initialImplementation);
    (bool result, ) = initialImplementation.delegatecall(callData);
    require(result);
  }
}

// SPDX-License-Identifier: MIT
contract ProxyRegistry is Ownable {
  /* DelegateProxy implementation contract. Must be initialized. */
  address public delegateProxyImplementation;

  /* Authenticated proxies by user. */
  mapping(address => OwnableDelegateProxy) public proxies;

  /* Contracts pending access. */
  mapping(address => uint256) public pending;

  /* Contracts allowed to call those proxies. */
  mapping(address => bool) public contracts;

  /* Delay period for adding an authenticated contract.
       This mitigates a particular class of potential attack on the Wyvern DAO (which owns this registry) - if at any point the value of assets held by proxy contracts exceeded the value of half the WYV supply (votes in the DAO),
       a malicious but rational attacker could buy half the Wyvern and grant themselves access to all the proxy contracts. A delay period renders this attack nonthreatening - given two weeks, if that happened, users would have
       plenty of time to notice and transfer their assets.
    */
  uint256 public DELAY_PERIOD = 2 weeks;

  /**
   * Start the process to enable access for specified contract. Subject to delay period.
   *
   * @dev ProxyRegistry owner only
   * @param addr Address to which to grant permissions
   */
  function startGrantAuthentication(address addr) public onlyOwner {
    require(!contracts[addr] && pending[addr] == 0);
    pending[addr] = now;
  }

  /**
   * End the process to nable access for specified contract after delay period has passed.
   *
   * @dev ProxyRegistry owner only
   * @param addr Address to which to grant permissions
   */
  function endGrantAuthentication(address addr) public onlyOwner {
    require(!contracts[addr] && pending[addr] != 0 && ((pending[addr] + DELAY_PERIOD) < now));
    pending[addr] = 0;
    contracts[addr] = true;
  }

  /**
   * Revoke access for specified contract. Can be done instantly.
   *
   * @dev ProxyRegistry owner only
   * @param addr Address of which to revoke permissions
   */
  function revokeAuthentication(address addr) public onlyOwner {
    contracts[addr] = false;
  }

  /**
   * Register a proxy contract with this registry
   *
   * @dev Must be called by the user which the proxy is for, creates a new AuthenticatedProxy
   * @return proxy New AuthenticatedProxy contract
   */
  function registerProxy() public returns (OwnableDelegateProxy proxy) {
    require(address(proxies[msg.sender]) == address(0));
    proxy = new OwnableDelegateProxy(
      msg.sender,
      delegateProxyImplementation,
      abi.encodeWithSignature("initialize(address,address)", msg.sender, address(this))
    );
    proxies[msg.sender] = proxy;
  }
}

// SPDX-License-Identifier: MIT
library Strings {
  // via https://github.com/oraclize/ethereum-api/blob/master/oraclizeAPI_0.5.sol
  function strConcat(
    string memory _a,
    string memory _b,
    string memory _c,
    string memory _d,
    string memory _e
  ) internal pure returns (string memory) {
    bytes memory _ba = bytes(_a);
    bytes memory _bb = bytes(_b);
    bytes memory _bc = bytes(_c);
    bytes memory _bd = bytes(_d);
    bytes memory _be = bytes(_e);
    string memory abcde = new string(_ba.length + _bb.length + _bc.length + _bd.length + _be.length);
    bytes memory babcde = bytes(abcde);
    uint256 k = 0;
    for (uint256 i = 0; i < _ba.length; i++) babcde[k++] = _ba[i];
    for (uint256 i = 0; i < _bb.length; i++) babcde[k++] = _bb[i];
    for (uint256 i = 0; i < _bc.length; i++) babcde[k++] = _bc[i];
    for (uint256 i = 0; i < _bd.length; i++) babcde[k++] = _bd[i];
    for (uint256 i = 0; i < _be.length; i++) babcde[k++] = _be[i];
    return string(babcde);
  }

  function strConcat(
    string memory _a,
    string memory _b,
    string memory _c,
    string memory _d
  ) internal pure returns (string memory) {
    return strConcat(_a, _b, _c, _d, "");
  }

  function strConcat(
    string memory _a,
    string memory _b,
    string memory _c
  ) internal pure returns (string memory) {
    return strConcat(_a, _b, _c, "", "");
  }

  function strConcat(string memory _a, string memory _b) internal pure returns (string memory) {
    return strConcat(_a, _b, "", "", "");
  }

  function uint2str(uint256 _i) internal pure returns (string memory _uintAsString) {
    if (_i == 0) {
      return "0";
    }
    uint256 j = _i;
    uint256 len;
    while (j != 0) {
      len++;
      j /= 10;
    }
    bytes memory bstr = new bytes(len);
    uint256 k = len - 1;
    while (_i != 0) {
      bstr[k--] = bytes1(uint8(48 + (_i % 10)));
      _i /= 10;
    }
    return string(bstr);
  }
}

// SPDX-License-Identifier: MIT
/**
 * @title WhitelistAdminRole
 * @dev WhitelistAdmins are responsible for assigning and removing Whitelisted accounts.
 */
contract WhitelistAdminRole is Context {
  using Roles for Roles.Role;

  event WhitelistAdminAdded(address indexed account);
  event WhitelistAdminRemoved(address indexed account);

  Roles.Role private _whitelistAdmins;

  constructor() internal {
    _addWhitelistAdmin(_msgSender());
  }

  modifier onlyWhitelistAdmin() {
    require(isWhitelistAdmin(_msgSender()), "WhitelistAdminRole: caller does not have the WhitelistAdmin role");
    _;
  }

  function isWhitelistAdmin(address account) public view returns (bool) {
    return _whitelistAdmins.has(account);
  }

  function addWhitelistAdmin(address account) public onlyWhitelistAdmin {
    _addWhitelistAdmin(account);
  }

  function renounceWhitelistAdmin() public {
    _removeWhitelistAdmin(_msgSender());
  }

  function _addWhitelistAdmin(address account) internal {
    _whitelistAdmins.add(account);
    emit WhitelistAdminAdded(account);
  }

  function _removeWhitelistAdmin(address account) internal {
    _whitelistAdmins.remove(account);
    emit WhitelistAdminRemoved(account);
  }
}

// SPDX-License-Identifier: MIT
/**
 * @title ERC1155Tradable
 * ERC1155Tradable - ERC1155 contract that whitelists an operator address, 
 * has create and mint functionality, and supports useful standards from OpenZeppelin,
  like _exists(), name(), symbol(), and totalSupply()
 */
contract ERC1155Tradable is ERC1155, ERC1155MintBurn, ERC1155Metadata, Ownable, MinterRole, WhitelistAdminRole {
  using Strings for string;

  address proxyRegistryAddress;
  uint256 private _currentTokenID = 0;
  mapping(uint256 => address) public creators;
  mapping(uint256 => uint256) public tokenSupply;
  mapping(uint256 => uint256) public tokenMaxSupply;
  // Contract name
  string public name;
  // Contract symbol
  string public symbol;

  constructor(
    string memory _name,
    string memory _symbol,
    address _proxyRegistryAddress
  ) public {
    name = _name;
    symbol = _symbol;
    proxyRegistryAddress = _proxyRegistryAddress;
  }

  function removeWhitelistAdmin(address account) public onlyOwner {
    _removeWhitelistAdmin(account);
  }

  function removeMinter(address account) public onlyOwner {
    _removeMinter(account);
  }

  function uri(uint256 _id) public view override returns (string memory) {
    require(_exists(_id), "ERC721Tradable#uri: NONEXISTENT_TOKEN");
    return Strings.strConcat(baseMetadataURI, Strings.uint2str(_id));
  }

  /**
   * @dev Returns the total quantity for a token ID
   * @param _id uint256 ID of the token to query
   * @return amount of token in existence
   */
  function totalSupply(uint256 _id) public view returns (uint256) {
    return tokenSupply[_id];
  }

  /**
   * @dev Returns the max quantity for a token ID
   * @param _id uint256 ID of the token to query
   * @return amount of token in existence
   */
  function maxSupply(uint256 _id) public view returns (uint256) {
    return tokenMaxSupply[_id];
  }

  /**
   * @dev Will update the base URL of token's URI
   * @param _newBaseMetadataURI New base URL of token's URI
   */
  function setBaseMetadataURI(string memory _newBaseMetadataURI) public onlyWhitelistAdmin {
    _setBaseMetadataURI(_newBaseMetadataURI);
  }

  /**
   * @dev Creates a new token type and assigns _initialSupply to an address
   * @param _maxSupply max supply allowed
   * @param _initialSupply Optional amount to supply the first owner
   * @param _uri Optional URI for this token type
   * @param _data Optional data to pass if receiver is contract
   * @return tokenId The newly created token ID
   */
  function create(
    uint256 _maxSupply,
    uint256 _initialSupply,
    string calldata _uri,
    bytes calldata _data
  ) external onlyWhitelistAdmin returns (uint256 tokenId) {
    require(_initialSupply <= _maxSupply, "Initial supply cannot be more than max supply");
    uint256 _id = _getNextTokenID();
    _incrementTokenTypeId();
    creators[_id] = msg.sender;

    if (bytes(_uri).length > 0) {
      emit URI(_uri, _id);
    }

    if (_initialSupply != 0) _mint(msg.sender, _id, _initialSupply, _data);
    tokenSupply[_id] = _initialSupply;
    tokenMaxSupply[_id] = _maxSupply;
    return _id;
  }

  /**
   * @dev Mints some amount of tokens to an address
   * @param _to          Address of the future owner of the token
   * @param _id          Token ID to mint
   * @param _quantity    Amount of tokens to mint
   * @param _data        Data to pass if receiver is contract
   */
  function mint(
    address _to,
    uint256 _id,
    uint256 _quantity,
    bytes memory _data
  ) public onlyMinter {
    uint256 tokenId = _id;
    require(tokenSupply[tokenId].add(_quantity) <= tokenMaxSupply[tokenId], "Max supply reached");
    _mint(_to, _id, _quantity, _data);
    tokenSupply[_id] = tokenSupply[_id].add(_quantity);
  }

  /**
   * Override isApprovedForAll to whitelist user's OpenSea proxy accounts to enable gas-free listings.
   */
  function isApprovedForAll(address _owner, address _operator) public view override returns (bool isOperator) {
    // Whitelist OpenSea proxy contract for easy trading.
    ProxyRegistry proxyRegistry = ProxyRegistry(proxyRegistryAddress);
    if (address(proxyRegistry.proxies(_owner)) == _operator) {
      return true;
    }

    return ERC1155.isApprovedForAll(_owner, _operator);
  }

  /**
   * @dev Returns whether the specified token exists by checking to see if it has a creator
   * @param _id uint256 ID of the token to query the existence of
   * @return bool whether the token exists
   */
  function _exists(uint256 _id) internal view returns (bool) {
    return creators[_id] != address(0);
  }

  /**
   * @dev calculates the next token ID based on value of _currentTokenID
   * @return uint256 for the next token ID
   */
  function _getNextTokenID() private view returns (uint256) {
    return _currentTokenID.add(1);
  }

  /**
   * @dev increments the value of _currentTokenID
   */
  function _incrementTokenTypeId() private {
    _currentTokenID++;
  }

  /**
   * @dev Updates token max supply
   * @param id_ uint256 ID of the token to update
   * @param maxSupply_ uint256 max supply allowed
   */
  function updateTokenMaxSupply(uint256 id_, uint256 maxSupply_) external onlyWhitelistAdmin {
    require(_exists(id_), "ERC1155Tradable#updateTokenMaxSupply: NONEXISTENT_TOKEN");
    require(tokenSupply[id_] <= maxSupply_, "already minted > new maxSupply");
    tokenMaxSupply[id_] = maxSupply_;
  }
}

// SPDX-License-Identifier: MIT
/**
 * @title EddaNft
 * EddaNft - Collect limited edition NFTs from Edda
 */
contract EddaNft is ERC1155Tradable {
  string public contractURI;

  constructor(
    string memory _name, //// "Meme Ltd."
    string memory _symbol, //// "MEMES"
    address _proxyRegistryAddress,
    string memory _baseMetadataURI, //// "https://api.dontbuymeme.com/memes/"
    string memory _contractURI //// "https://api.dontbuymeme.com/contract/memes-erc1155"
  ) public ERC1155Tradable(_name, _symbol, _proxyRegistryAddress) {
    contractURI = _contractURI;
    _setBaseMetadataURI(_baseMetadataURI);
  }

  //// function contractURI() public pure returns (string memory) {
  ////   return "https://api.dontbuymeme.com/contract/memes-erc1155";
  //// }
}

{
  "compilationTarget": {
    "EddaNft.sol": "EddaNft"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}