pragma solidity ^0.5.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see {ERC20Detailed}.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract KyberNetworkProxyInterface {
  function maxGasPrice() public view returns(uint);
  function getUserCapInWei(address user) public view returns(uint);
  function getUserCapInTokenWei(address user, IERC20 token) public view returns(uint);
  function enabled() public view returns(bool);
  function info(bytes32 id) public view returns(uint);

  function getExpectedRate(IERC20 src, IERC20 dest, uint srcQty) public view returns (uint expectedRate, uint slippageRate);

  function tradeWithHint(IERC20 src, uint srcAmount, IERC20 dest, address payable destAddress, uint maxDestAmount, uint minConversionRate, address walletId, bytes memory hint) public payable returns (uint);
}

/**
    Note: The ERC-165 identifier for this interface is 0x4e2312e0.
*/
interface ERC1155TokenReceiver {
    /**
        @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 MUST return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` (i.e. 0xf23a6e61) if it accepts the transfer.
        This function MUST revert if it rejects the transfer.
        Return of any other value than the prescribed keccak256 generated value MUST result in the transaction being reverted by the caller.
        @param _operator  The address which initiated the transfer (i.e. msg.sender)
        @param _from      The address which previously owned the token
        @param _id        The ID of the token being transferred
        @param _value     The amount of tokens being transferred
        @param _data      Additional data with no specified format
        @return           `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
    */
    function onERC1155Received(address _operator, address _from, uint256 _id, uint256 _value, 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 MUST return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` (i.e. 0xbc197c81) if it accepts the transfer(s).
        This function MUST revert if it rejects the transfer(s).
        Return of any other value than the prescribed keccak256 generated value MUST result in the transaction being reverted by the caller.
        @param _operator  The address which initiated the batch transfer (i.e. msg.sender)
        @param _from      The address which previously owned the token
        @param _ids       An array containing ids of each token being transferred (order and length must match _values array)
        @param _values    An array containing amounts of each token being transferred (order and length must match _ids array)
        @param _data      Additional data with no specified format
        @return           `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
    */
    function onERC1155BatchReceived(address _operator, address _from, uint256[] calldata _ids, uint256[] calldata _values, bytes calldata _data) external returns(bytes4);
}

/**
    Note: Simple contract to use as base for const vals
*/
contract CommonConstants {

    bytes4 constant internal ERC1155_ACCEPTED = 0xf23a6e61; // bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))
    bytes4 constant internal ERC1155_BATCH_ACCEPTED = 0xbc197c81; // bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))
}

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

/**
    @title ERC-1155 Multi Token Standard
    @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1155.md
    Note: The ERC-165 identifier for this interface is 0xd9b67a26.
 */
contract IERC1155 is IERC165 {
    /**
        @dev Either `TransferSingle` or `TransferBatch` MUST emit when tokens are transferred, including zero value transfers as well as minting or burning (see "Safe Transfer Rules" section of the standard).
        The `_operator` argument MUST be msg.sender.
        The `_from` argument MUST be the address of the holder whose balance is decreased.
        The `_to` argument MUST be the address of the recipient whose balance is increased.
        The `_id` argument MUST be the token type being transferred.
        The `_value` argument MUST be the number of tokens the holder balance is decreased by and match what the recipient balance is increased by.
        When minting/creating tokens, the `_from` argument MUST be set to `0x0` (i.e. zero address).
        When burning/destroying tokens, the `_to` argument MUST be set to `0x0` (i.e. zero address).
    */
    event TransferSingle(address indexed _operator, address indexed _from, address indexed _to, uint256 _id, uint256 _value);

    /**
        @dev Either `TransferSingle` or `TransferBatch` MUST emit when tokens are transferred, including zero value transfers as well as minting or burning (see "Safe Transfer Rules" section of the standard).
        The `_operator` argument MUST be msg.sender.
        The `_from` argument MUST be the address of the holder whose balance is decreased.
        The `_to` argument MUST be the address of the recipient whose balance is increased.
        The `_ids` argument MUST be the list of tokens being transferred.
        The `_values` argument MUST be the list of number of tokens (matching the list and order of tokens specified in _ids) the holder balance is decreased by and match what the recipient balance is increased by.
        When minting/creating tokens, the `_from` argument MUST be set to `0x0` (i.e. zero address).
        When burning/destroying tokens, the `_to` argument MUST be set to `0x0` (i.e. zero address).
    */
    event TransferBatch(address indexed _operator, address indexed _from, address indexed _to, uint256[] _ids, uint256[] _values);

    /**
        @dev MUST emit when approval for a second party/operator address to manage all tokens for an owner address is enabled or disabled (absense of an event assumes disabled).
    */
    event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);

    /**
        @dev MUST emit when the URI is updated for a token ID.
        URIs are defined in RFC 3986.
        The URI MUST point a JSON file that conforms to the "ERC-1155 Metadata URI JSON Schema".
    */
    event URI(string _value, uint256 indexed _id);

    /**
        @notice Transfers `_value` amount of an `_id` from the `_from` address to the `_to` address specified (with safety call).
        @dev Caller must be approved to manage the tokens being transferred out of the `_from` account (see "Approval" section of the standard).
        MUST revert if `_to` is the zero address.
        MUST revert if balance of holder for token `_id` is lower than the `_value` sent.
        MUST revert on any other error.
        MUST emit the `TransferSingle` event to reflect the balance change (see "Safe Transfer Rules" section of the standard).
        After the above conditions are met, this function MUST check if `_to` is a smart contract (e.g. code size > 0). If so, it MUST call `onERC1155Received` on `_to` and act appropriately (see "Safe Transfer Rules" section of the standard).
        @param _from    Source address
        @param _to      Target address
        @param _id      ID of the token type
        @param _value   Transfer amount
        @param _data    Additional data with no specified format, MUST be sent unaltered in call to `onERC1155Received` on `_to`
    */
    function safeTransferFrom(address _from, address _to, uint256 _id, uint256 _value, bytes calldata _data) external;

    /**
        @notice Transfers `_values` amount(s) of `_ids` from the `_from` address to the `_to` address specified (with safety call).
        @dev Caller must be approved to manage the tokens being transferred out of the `_from` account (see "Approval" section of the standard).
        MUST revert if `_to` is the zero address.
        MUST revert if length of `_ids` is not the same as length of `_values`.
        MUST revert if any of the balance(s) of the holder(s) for token(s) in `_ids` is lower than the respective amount(s) in `_values` sent to the recipient.
        MUST revert on any other error.
        MUST emit `TransferSingle` or `TransferBatch` event(s) such that all the balance changes are reflected (see "Safe Transfer Rules" section of the standard).
        Balance changes and events MUST follow the ordering of the arrays (_ids[0]/_values[0] before _ids[1]/_values[1], etc).
        After the above conditions for the transfer(s) in the batch are met, this function MUST check if `_to` is a smart contract (e.g. code size > 0). If so, it MUST call the relevant `ERC1155TokenReceiver` hook(s) on `_to` and act appropriately (see "Safe Transfer Rules" section of the standard).
        @param _from    Source address
        @param _to      Target address
        @param _ids     IDs of each token type (order and length must match _values array)
        @param _values  Transfer amounts per token type (order and length must match _ids array)
        @param _data    Additional data with no specified format, MUST be sent unaltered in call to the `ERC1155TokenReceiver` hook(s) on `_to`
    */
    function safeBatchTransferFrom(address _from, address _to, uint256[] calldata _ids, uint256[] calldata _values, 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 the 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           True if the operator is approved, false if not
    */
    function isApprovedForAll(address _owner, address _operator) external view returns (bool);
}

contract KyberNetwork1155Wrapper is ERC1155TokenReceiver, CommonConstants {

    event TokenChange(address token, uint change);
    event ETHReceived(address indexed sender, uint amount);

    IERC20 constant internal ETH_TOKEN_ADDRESS = IERC20(0x00eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee);

    function() payable external {
        emit ETHReceived(msg.sender, msg.value);
    }

    function onERC1155Received(address, address, uint256, uint256, bytes calldata) external returns(bytes4) {
        return ERC1155_ACCEPTED;
    }

    function onERC1155BatchReceived(address, address, uint256[] calldata, uint256[] calldata, bytes calldata) external returns(bytes4) {
        return ERC1155_BATCH_ACCEPTED;
    }

    function tradeAndBuy(
        IERC1155 nft,
        uint nftId,
        bytes memory buyData,
        uint256 buying,
        uint amount,
        KyberNetworkProxyInterface _kyberProxy,
        address sale,
        IERC20 token,
        uint tokenQty,
        uint minRate
    ) public {
        uint startTokenBalance = token.balanceOf(address(this));
        require(token.transferFrom(msg.sender, address(this), tokenQty));
        require(token.approve(address(_kyberProxy), tokenQty));
        uint userETH = _kyberProxy.tradeWithHint(token, tokenQty, ETH_TOKEN_ADDRESS, address(uint160(address(this))), amount, minRate, address(0x0), "");
        require(userETH >= amount, "not enough eth to buy nft");

        (bool success,) = sale.call.value(amount)(buyData);
        require(success, "buy error");
        nft.safeTransferFrom(address(this), msg.sender, nftId, buying, "");

        if (userETH > amount) {
            msg.sender.transfer(userETH - amount);
            emit TokenChange(address(ETH_TOKEN_ADDRESS), userETH - amount);
        }
        uint endTokenBalance = token.balanceOf(address(this));
        if (endTokenBalance > startTokenBalance) {
            token.transfer(msg.sender, endTokenBalance - startTokenBalance);
            emit TokenChange(address(token), endTokenBalance - startTokenBalance);
        }
    }
}