// SPDX-License-Identifier: MIT

pragma solidity ^0.8.9;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

import "../IERC677.sol";
import "../IERC677Receiver.sol";

/**
 * Mintable TestToken for contract tests
 * Transfers of 666 are rejected with return value false
 */
contract TestToken is ERC20, IERC677 {
    constructor (string memory name, string memory symbol) ERC20(name, symbol) {
        // solhint-disable-previous-line no-empty-blocks
    }

    /**
     * Token contract owner can create tokens
     * @param recipient address where new tokens are transferred (from 0x0)
     * @param amount scaled so that 10^18 equals 1 token (multiply by 10^18)
     */
    function mint(address recipient, uint amount) external {
        _mint(recipient, amount);
    }

    function transferAndCall(
        address to,
        uint256 amount,
        bytes calldata data
    ) external override returns (bool) {
        transfer(to, amount);

        uint256 recipientCodeSize;
        assembly { // solhint-disable-line no-inline-assembly
            recipientCodeSize := extcodesize(to)
        }
        if (recipientCodeSize > 0) {
            IERC677Receiver receiver = IERC677Receiver(to);
            receiver.onTokenTransfer(msg.sender, amount, data);
        }
        return true;
    }
}