// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC777/IERC777.sol";

import "@openzeppelin/contracts/token/ERC777/IERC777Recipient.sol";

import "@openzeppelin/contracts/utils/introspection/ERC1820Implementer.sol";

import "@openzeppelin/contracts/utils/introspection/IERC1820Registry.sol";

contract AOVRecipient is IERC777Recipient, ERC1820Implementer {

IERC1820Registry private _erc1820 = IERC1820Registry(0x1820a4B7618BdE71Dce8cdc73aAB6C95905faD24);

bytes32 constant private TOKENS_RECIPIENT_INTERFACE_HASH = keccak256("ERC777TokensRecipient");

IERC777 private _token;

event DoneStuff(address operator, address from, address to, uint256 amount, bytes userData, bytes operatorData);

constructor (address token) {

_token = IERC777(token);

_erc1820.setInterfaceImplementer(address(this), TOKENS_RECIPIENT_INTERFACE_HASH, address(this));

}

function tokensReceived(

address operator,

address from,

address to,

uint256 amount,

bytes calldata userData,

bytes calldata operatorData

) external override {

require(msg.sender == address(_token), "AOVRecipient: Invalid token");

// do stuff

emit DoneStuff(operator, from, to, amount, userData, operatorData);

}

}