// File: Frogs_ERC1155PackedLean.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.7.4;

// ERC1155Supply: Extension of ERC1155 that adds tracking of total supply per id
import "ERC1155MintBurnPackedBalance.sol";
import "ERC1155Metadata.sol";
import "SafeMath.sol";
import "Ownable.sol";

contract Frogs_ERC1155PBL is ERC1155MintBurnPackedBalance, ERC1155Metadata, Ownable {

    using SafeMath for uint256;

    uint256 public constant MAX_TOKENS = 5000; // max allowable tokens
    uint256 public totalSupply = 0; //currently issued tokens (variable initialized at 0)
    string public name = "Fallout Frogs";
    string public symbol = "FRG";
    

    //constructor () public ERC1155PackedBalance (){}

    /***********************************|
    |           URI Functions           |
    |__________________________________*/

    /**
    * @dev Will update the base URL of token's URI
    * @param _newBaseMetadataURI New base URL of token's URI
    */
    function setBaseMetadataURI(string memory _newBaseMetadataURI) external onlyOwner {
    _setBaseMetadataURI(_newBaseMetadataURI);
    }
    
    /***********************************|
    |          ERC165 Functions         |
    |__________________________________*/

    /**
    * @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`
    */
    function supportsInterface(bytes4 _interfaceID) public override(ERC1155PackedBalance, ERC1155Metadata) virtual pure returns (bool) {
    return super.supportsInterface(_interfaceID);
    }


    /***********************************|
    |     Minting & Supply Functions    |
    |__________________________________*/

    function batchMint(uint256 _count) external onlyOwner {
      uint256[] memory _amounts = new uint256[](_count);
      uint256[] memory _ids = new uint256[](_count);
      for (uint256 i = 0; i < _count; i++) {
            _amounts[i] = 1;
            _ids[i] = totalSupply+i;
            require(totalSupply + _count < MAX_TOKENS + 1, "Exceeds maximum tokens available for purchase");
      }
      
      // If hasn't reverted yet, all IDs are allowed for factory
      _batchMint(msg.sender, _ids, _amounts, "");
      totalSupply += _count; // add count to totalSupply if mint succeeded
    }
}
// File: ERC1155MintBurnPackedBalance.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.4;

import "ERC1155PackedBalance.sol";


/**
 * @dev Multi-Fungible Tokens with minting and burning methods. These methods assume
 *      a parent contract to be executed as they are `internal` functions.
 */
contract ERC1155MintBurnPackedBalance is ERC1155PackedBalance {

  /****************************************|
  |            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
    _updateIDBalance(_to,   _id, _amount, Operations.Add); // Add amount to recipient

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

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

  /**
   * @notice Mint tokens for each (_ids[i], _amounts[i]) pair
   * @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, "ERC1155MintBurnPackedBalance#_batchMint: INVALID_ARRAYS_LENGTH");

    if (_ids.length > 0) {
      // Load first bin and index where the token ID balance exists
      (uint256 bin, uint256 index) = getIDBinIndex(_ids[0]);

      // Balance for current bin in memory (initialized with first transfer)
      uint256 balTo = _viewUpdateBinValue(balances[_to][bin], index, _amounts[0], Operations.Add);

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

      // Last bin updated
      uint256 lastBin = bin;

      for (uint256 i = 1; i < nTransfer; i++) {
        (bin, index) = getIDBinIndex(_ids[i]);

        // If new bin
        if (bin != lastBin) {
          // Update storage balance of previous bin
          balances[_to][lastBin] = balTo;
          balTo = balances[_to][bin];

          // Bin will be the most recent bin
          lastBin = bin;
        }

        // Update memory balance
        balTo = _viewUpdateBinValue(balTo, index, _amounts[i], Operations.Add);
      }

      // Update storage of the last bin visited
      balances[_to][bin] = balTo;
    }

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

    // Calling onReceive method if recipient is contract
    _callonERC1155BatchReceived(address(0x0), _to, _ids, _amounts, gasleft(), _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
    _updateIDBalance(_from, _id, _amount, Operations.Sub);

    // 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
   * @dev This batchBurn method does not implement the most efficient way of updating
   *      balances to reduce the potential bug surface as this function is expected to
   *      be less common than transfers. EIP-2200 makes this method significantly
   *      more efficient already for packed balances.
   * @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
  {
    // Number of burning to execute
    uint256 nBurn = _ids.length;
    require(nBurn == _amounts.length, "ERC1155MintBurnPackedBalance#batchBurn: INVALID_ARRAYS_LENGTH");

    // Executing all burning
    for (uint256 i = 0; i < nBurn; i++) {
      // Update storage balance
      _updateIDBalance(_from,   _ids[i], _amounts[i], Operations.Sub); // Add amount to recipient
    }

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

// File: ERC1155PackedBalance.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.4;

import "SafeMath.sol";
import "IERC1155TokenReceiver.sol";
import "IERC1155.sol";
import "Address.sol";
import "ERC165.sol";


/**
 * @dev Implementation of Multi-Token Standard contract. This implementation of the ERC-1155 standard
 *      utilizes the fact that balances of different token ids can be concatenated within individual
 *      uint256 storage slots. This allows the contract to batch transfer tokens more efficiently at
 *      the cost of limiting the maximum token balance each address can hold. This limit is
 *      2^IDS_BITS_SIZE, which can be adjusted below. In practice, using IDS_BITS_SIZE smaller than 16
 *      did not lead to major efficiency gains.
 */
contract ERC1155PackedBalance is IERC1155, ERC165 {
  using SafeMath for uint256;
  using Address for address;

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

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

  // Constants regarding bin sizes for balance packing
  // IDS_BITS_SIZE **MUST** be a power of 2 (e.g. 2, 4, 8, 16, 32, 64, 128)
  uint256 internal constant IDS_BITS_SIZE   = 32;                  // Max balance amount in bits per token ID
  uint256 internal constant IDS_PER_UINT256 = 256 / IDS_BITS_SIZE; // Number of ids per uint256

  // Operations for _updateIDBalance
  enum Operations { Add, Sub }

  // Token IDs balances ; balances[address][id] => balance (using array instead of mapping for efficiency)
  mapping (address => mapping(uint256 => uint256)) internal balances;

  // Operators
  mapping (address => mapping(address => bool)) internal operators;


  /***********************************|
  |     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 override
  {
    // Requirements
    require((msg.sender == _from) || isApprovedForAll(_from, msg.sender), "ERC1155PackedBalance#safeTransferFrom: INVALID_OPERATOR");
    require(_to != address(0),"ERC1155PackedBalance#safeTransferFrom: INVALID_RECIPIENT");
    // require(_amount <= balances);  Not necessary since checked with _viewUpdateBinValue() checks

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

  /**
   * @notice Send multiple types of Tokens from the _from address to the _to address (with safety call)
   * @dev Arrays should be sorted so that all ids in a same storage slot are adjacent (more efficient)
   * @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 override
  {
    // Requirements
    require((msg.sender == _from) || isApprovedForAll(_from, msg.sender), "ERC1155PackedBalance#safeBatchTransferFrom: INVALID_OPERATOR");
    require(_to != address(0),"ERC1155PackedBalance#safeBatchTransferFrom: INVALID_RECIPIENT");

    _safeBatchTransferFrom(_from, _to, _ids, _amounts);
    _callonERC1155BatchReceived(_from, _to, _ids, _amounts, gasleft(), _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
    _updateIDBalance(_from, _id, _amount, Operations.Sub); // Subtract amount from sender
    _updateIDBalance(_to,   _id, _amount, Operations.Add); // Add amount to recipient

    // 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, uint256 _gasLimit, bytes memory _data)
    internal
  {
    // Check if recipient is contract
    if (_to.isContract()) {
      bytes4 retval = IERC1155TokenReceiver(_to).onERC1155Received{gas:_gasLimit}(msg.sender, _from, _id, _amount, _data);
      require(retval == ERC1155_RECEIVED_VALUE, "ERC1155PackedBalance#_callonERC1155Received: INVALID_ON_RECEIVE_MESSAGE");
    }
  }

  /**
   * @notice Send multiple types of Tokens from the _from address to the _to address (with safety call)
   * @dev Arrays should be sorted so that all ids in a same storage slot are adjacent (more efficient)
   * @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
  {
    uint256 nTransfer = _ids.length; // Number of transfer to execute
    require(nTransfer == _amounts.length, "ERC1155PackedBalance#_safeBatchTransferFrom: INVALID_ARRAYS_LENGTH");

    if (_from != _to && nTransfer > 0) {
      // Load first bin and index where the token ID balance exists
      (uint256 bin, uint256 index) = getIDBinIndex(_ids[0]);

      // Balance for current bin in memory (initialized with first transfer)
      uint256 balFrom = _viewUpdateBinValue(balances[_from][bin], index, _amounts[0], Operations.Sub);
      uint256 balTo = _viewUpdateBinValue(balances[_to][bin], index, _amounts[0], Operations.Add);

      // Last bin updated
      uint256 lastBin = bin;

      for (uint256 i = 1; i < nTransfer; i++) {
        (bin, index) = getIDBinIndex(_ids[i]);

        // If new bin
        if (bin != lastBin) {
          // Update storage balance of previous bin
          balances[_from][lastBin] = balFrom;
          balances[_to][lastBin] = balTo;

          balFrom = balances[_from][bin];
          balTo = balances[_to][bin];

          // Bin will be the most recent bin
          lastBin = bin;
        }

        // Update memory balance
        balFrom = _viewUpdateBinValue(balFrom, index, _amounts[i], Operations.Sub);
        balTo = _viewUpdateBinValue(balTo, index, _amounts[i], Operations.Add);
      }

      // Update storage of the last bin visited
      balances[_from][bin] = balFrom;
      balances[_to][bin] = balTo;

    // If transfer to self, just make sure all amounts are valid
    } else {
      for (uint256 i = 0; i < nTransfer; i++) {
        require(balanceOf(_from, _ids[i]) >= _amounts[i], "ERC1155PackedBalance#_safeBatchTransferFrom: UNDERFLOW");
      }
    }

    // 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, uint256 _gasLimit, bytes memory _data)
    internal
  {
    // Pass data if recipient is contract
    if (_to.isContract()) {
      bytes4 retval = IERC1155TokenReceiver(_to).onERC1155BatchReceived{gas: _gasLimit}(msg.sender, _from, _ids, _amounts, _data);
      require(retval == ERC1155_BATCH_RECEIVED_VALUE, "ERC1155PackedBalance#_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 override
  {
    // 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 override view returns (bool isOperator)
  {
    return operators[_owner][_operator];
  }


  /***********************************|
  |     Public 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 override view returns (uint256)
  {
    uint256 bin;
    uint256 index;

    //Get bin and index of _id
    (bin, index) = getIDBinIndex(_id);
    return getValueInBin(balances[_owner][bin], index);
  }

  /**
   * @notice Get the balance of multiple account/token pairs
   * @param _owners The addresses of the token holders (sorted owners will lead to less gas usage)
   * @param _ids    ID of the Tokens (sorted ids will lead to less gas usage
   * @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 override view returns (uint256[] memory)
  {
    uint256 n_owners = _owners.length;
    require(n_owners == _ids.length, "ERC1155PackedBalance#balanceOfBatch: INVALID_ARRAY_LENGTH");

    // First values
    (uint256 bin, uint256 index) = getIDBinIndex(_ids[0]);
    uint256 balance_bin = balances[_owners[0]][bin];
    uint256 last_bin = bin;

    // Initialization
    uint256[] memory batchBalances = new uint256[](n_owners);
    batchBalances[0] = getValueInBin(balance_bin, index);

    // Iterate over each owner and token ID
    for (uint256 i = 1; i < n_owners; i++) {
      (bin, index) = getIDBinIndex(_ids[i]);

      // SLOAD if bin changed for the same owner or if owner changed
      if (bin != last_bin || _owners[i-1] != _owners[i]) {
        balance_bin = balances[_owners[i]][bin];
        last_bin = bin;
      }

      batchBalances[i] = getValueInBin(balance_bin, index);
    }

    return batchBalances;
  }


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

  /**
   * @notice Update the balance of a id for a given address
   * @param _address    Address to update id balance
   * @param _id         Id to update balance of
   * @param _amount     Amount to update the id balance
   * @param _operation  Which operation to conduct :
   *   Operations.Add: Add _amount to id balance
   *   Operations.Sub: Substract _amount from id balance
   */
  function _updateIDBalance(address _address, uint256 _id, uint256 _amount, Operations _operation)
    internal
  {
    uint256 bin;
    uint256 index;

    // Get bin and index of _id
    (bin, index) = getIDBinIndex(_id);

    // Update balance
    balances[_address][bin] = _viewUpdateBinValue(balances[_address][bin], index, _amount, _operation);
  }

  /**
   * @notice Update a value in _binValues
   * @param _binValues  Uint256 containing values of size IDS_BITS_SIZE (the token balances)
   * @param _index      Index of the value in the provided bin
   * @param _amount     Amount to update the id balance
   * @param _operation  Which operation to conduct :
   *   Operations.Add: Add _amount to value in _binValues at _index
   *   Operations.Sub: Substract _amount from value in _binValues at _index
   */
  function _viewUpdateBinValue(uint256 _binValues, uint256 _index, uint256 _amount, Operations _operation)
    internal pure returns (uint256 newBinValues)
  {
    uint256 shift = IDS_BITS_SIZE * _index;
    uint256 mask = (uint256(1) << IDS_BITS_SIZE) - 1;

    if (_operation == Operations.Add) {
      newBinValues = _binValues + (_amount << shift);
      require(newBinValues >= _binValues, "ERC1155PackedBalance#_viewUpdateBinValue: OVERFLOW");
      require(
        ((_binValues >> shift) & mask) + _amount < 2**IDS_BITS_SIZE, // Checks that no other id changed
        "ERC1155PackedBalance#_viewUpdateBinValue: OVERFLOW"
      );

    } else if (_operation == Operations.Sub) {
      newBinValues = _binValues - (_amount << shift);
      require(newBinValues <= _binValues, "ERC1155PackedBalance#_viewUpdateBinValue: UNDERFLOW");
      require(
        ((_binValues >> shift) & mask) >= _amount, // Checks that no other id changed
        "ERC1155PackedBalance#_viewUpdateBinValue: UNDERFLOW"
      );

    } else {
      revert("ERC1155PackedBalance#_viewUpdateBinValue: INVALID_BIN_WRITE_OPERATION"); // Bad operation
    }

    return newBinValues;
  }

  /**
  * @notice Return the bin number and index within that bin where ID is
  * @param _id  Token id
  * @return bin index (Bin number, ID"s index within that bin)
  */
  function getIDBinIndex(uint256 _id)
    public pure returns (uint256 bin, uint256 index)
  {
    bin = _id / IDS_PER_UINT256;
    index = _id % IDS_PER_UINT256;
    return (bin, index);
  }

  /**
   * @notice Return amount in _binValues at position _index
   * @param _binValues  uint256 containing the balances of IDS_PER_UINT256 ids
   * @param _index      Index at which to retrieve amount
   * @return amount at given _index in _bin
   */
  function getValueInBin(uint256 _binValues, uint256 _index)
    public pure returns (uint256)
  {
    // require(_index < IDS_PER_UINT256) is not required since getIDBinIndex ensures `_index < IDS_PER_UINT256`

    // Mask to retrieve data for a given binData
    uint256 mask = (uint256(1) << IDS_BITS_SIZE) - 1;

    // Shift amount
    uint256 rightShift = IDS_BITS_SIZE * _index;
    return (_binValues >> rightShift) & mask;
  }


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

  /**
   * @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) public override(ERC165, IERC165) virtual pure returns (bool) {
    if (_interfaceID == type(IERC1155).interfaceId) {
      return true;
    }
    return super.supportsInterface(_interfaceID);
  }
}

// File: SafeMath.sol



pragma solidity 0.7.4;


/**
 * @title SafeMath
 * @dev Unsigned math operations with safety checks that revert on error
 */
library SafeMath {

  /**
   * @dev Multiplies two unsigned integers, reverts on 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-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    uint256 c = a * b;
    require(c / a == b, "SafeMath#mul: OVERFLOW");

    return c;
  }

  /**
   * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
   */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0, "SafeMath#div: DIVISION_BY_ZERO");
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
   * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
   */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b <= a, "SafeMath#sub: UNDERFLOW");
    uint256 c = a - b;

    return c;
  }

  /**
   * @dev Adds two unsigned integers, reverts on overflow.
   */
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    require(c >= a, "SafeMath#add: OVERFLOW");

    return c; 
  }

  /**
   * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
   * reverts when dividing by zero.
   */
  function mod(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b != 0, "SafeMath#mod: DIVISION_BY_ZERO");
    return a % b;
  }
}
// File: IERC1155TokenReceiver.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.4;

/**
 * @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);
}

// File: IERC1155.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.4;
import './IERC165.sol';


interface IERC1155 is IERC165 {

  /****************************************|
  |                 Events                 |
  |_______________________________________*/

  /**
   * @dev Either TransferSingle or TransferBatch MUST emit when tokens are transferred, including zero amount transfers as well as minting or burning
   *   Operator MUST be msg.sender
   *   When minting/creating tokens, the `_from` field MUST be set to `0x0`
   *   When burning/destroying tokens, the `_to` field MUST be set to `0x0`
   *   The total amount transferred from address 0x0 minus the total amount transferred to 0x0 may be used by clients and exchanges to be added to the "circulating supply" for a given token ID
   *   To broadcast the existence of a token ID with no initial balance, the contract SHOULD emit the TransferSingle event from `0x0` to `0x0`, with the token creator as `_operator`, and a `_amount` of 0
   */
  event TransferSingle(address indexed _operator, address indexed _from, address indexed _to, uint256 _id, uint256 _amount);

  /**
   * @dev Either TransferSingle or TransferBatch MUST emit when tokens are transferred, including zero amount transfers as well as minting or burning
   *   Operator MUST be msg.sender
   *   When minting/creating tokens, the `_from` field MUST be set to `0x0`
   *   When burning/destroying tokens, the `_to` field MUST be set to `0x0`
   *   The total amount transferred from address 0x0 minus the total amount transferred to 0x0 may be used by clients and exchanges to be added to the "circulating supply" for a given token ID
   *   To broadcast the existence of multiple token IDs with no initial balance, this SHOULD emit the TransferBatch event from `0x0` to `0x0`, with the token creator as `_operator`, and a `_amount` of 0
   */
  event TransferBatch(address indexed _operator, address indexed _from, address indexed _to, uint256[] _ids, uint256[] _amounts);

  /**
   * @dev MUST emit when an approval is updated
   */
  event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);


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

  /**
    * @notice Transfers amount of an _id from the _from address to the _to address specified
    * @dev MUST emit TransferSingle event on success
    * Caller must be approved to manage the _from account's tokens (see isApprovedForAll)
    * MUST throw if `_to` is the zero address
    * MUST throw if balance of sender for token `_id` is lower than the `_amount` sent
    * MUST throw on any other error
    * When transfer is complete, this function MUST check if `_to` is a smart contract (code size > 0). If so, it MUST call `onERC1155Received` on `_to` and revert if the return amount is not `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
    * @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 calldata _data) external;

  /**
    * @notice Send multiple types of Tokens from the _from address to the _to address (with safety call)
    * @dev MUST emit TransferBatch event on success
    * Caller must be approved to manage the _from account's tokens (see isApprovedForAll)
    * MUST throw if `_to` is the zero address
    * MUST throw if length of `_ids` is not the same as length of `_amounts`
    * MUST throw if any of the balance of sender for token `_ids` is lower than the respective `_amounts` sent
    * MUST throw on any other error
    * When transfer is complete, this function MUST check if `_to` is a smart contract (code size > 0). If so, it MUST call `onERC1155BatchReceived` on `_to` and revert if the return amount is not `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
    * Transfers and events MUST occur in the array order they were submitted (_ids[0] before _ids[1], etc)
    * @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[] calldata _ids, uint256[] calldata _amounts, bytes calldata _data) external;

  /**
   * @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) external view returns (uint256);

  /**
   * @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[] calldata _owners, uint256[] calldata _ids) external view returns (uint256[] memory);

  /**
   * @notice Enable or disable approval for a third party ("operator") to manage all of caller's tokens
   * @dev MUST emit the ApprovalForAll event on success
   * @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;

  /**
   * @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) external view returns (bool isOperator);
}

// File: Address.sol



pragma solidity 0.7.4;


/**
 * Utility library of inline functions on addresses
 */
library Address {

  // Default hash for EOA accounts returned by extcodehash
  bytes32 constant internal ACCOUNT_HASH = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;

  /**
   * Returns whether the target address is a contract
   * @dev This function will return false if invoked during the constructor of a contract.
   * @param _address address of the account to check
   * @return Whether the target address is a contract
   */
  function isContract(address _address) internal view returns (bool) {
    bytes32 codehash;

    // Currently there is no better way to check if there is a contract in an address
    // than to check the size of the code at that address or if it has a non-zero code hash or account hash
    assembly { codehash := extcodehash(_address) }
    return (codehash != 0x0 && codehash != ACCOUNT_HASH);
  }
}
// File: ERC165.sol



pragma solidity 0.7.4;
import "IERC165.sol";

abstract contract ERC165 is IERC165 {
  /**
   * @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`
   */
  function supportsInterface(bytes4 _interfaceID) virtual override public pure returns (bool) {
    return _interfaceID == this.supportsInterface.selector;
  }
}
// File: IERC165.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.4;


/**
 * @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);
}

// File: ERC1155Metadata.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.4;
import "IERC1155Metadata.sol";
import "ERC165.sol";


/**
 * @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 is IERC1155Metadata, ERC165 {
  // URI's default URI prefix
  string internal baseMetadataURI;

  /***********************************|
  |     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
   * @return URI string
   */
  function uri(uint256 _id) public override view 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 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;
  }

  /**
   * @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) public override virtual pure returns (bool) {
    if (_interfaceID == type(IERC1155Metadata).interfaceId) {
      return true;
    }
    return super.supportsInterface(_interfaceID);
  }


  /***********************************|
  |    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--] = byte(uint8(48 + ii % 10));
      ii /= 10;
    }

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

// File: IERC1155Metadata.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.7.4;


interface IERC1155Metadata {

  event URI(string _uri, uint256 indexed _id);

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

  /**
   * @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) external view returns (string memory);
}

// File: Ownable.sol



pragma solidity 0.7.4;


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

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

  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor () {
    _owner_ = msg.sender;
    emit OwnershipTransferred(address(0), _owner_);
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == _owner_, "Ownable#onlyOwner: SENDER_IS_NOT_OWNER");
    _;
  }

  /**
   * @notice Transfers the ownership of the contract to new address
   * @param _newOwner Address of the new owner
   */
  function transferOwnership(address _newOwner) public onlyOwner {
    require(_newOwner != address(0), "Ownable#transferOwnership: INVALID_ADDRESS");
    emit OwnershipTransferred(_owner_, _newOwner);
    _owner_ = _newOwner;
  }

  /**
   * @notice Returns the address of the owner.
   */
  function owner() public view returns (address) {
    return _owner_;
  }
}