文件 1 的 1：AItech.sol
pragma solidity ^0.5.16;
interface IERC20 {
function totalSupply() external view returns (uint);
function balanceOf(address account) external view returns (uint);
function transfer(address recipient, uint amount) external returns (bool);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint amount) external returns (bool);
function transferFrom(address sender, address recipient, uint amount) external returns (bool);
event Transfer(address indexed from, address indexed to, uint value);
event Approval(address indexed owner, address indexed spender, uint value);
}
contract Context {
constructor () internal { }
function _msgSender() internal view returns (address payable) {
return msg.sender;
}
}
contract ERC20 is Context, IERC20 {
using SafeMath for uint;
mapping (address => uint) private _balances;
mapping (address => mapping (address => uint)) private _allowances;
uint private _totalSupply;
function totalSupply() public view returns (uint) {
return _totalSupply;
}
function balanceOf(address account) public view returns (uint) {
return _balances[account];
}
function transfer(address recipient, uint amount) public returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
function allowance(address owner, address spender) public view returns (uint) {
return _allowances[owner][spender];
}
function approve(address spender, uint amount) public returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
function transferFrom(address sender, address recipient, uint amount) public returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
function increaseAllowance(address spender, uint addedValue) public returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
function decreaseAllowance(address spender, uint subtractedValue) public returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
function _transfer(address sender, address recipient, uint amount) internal {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
function _mint(address account, uint amount) internal {
require(account != address(0), "ERC20: mint to the zero address");
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
function _burn(address account, uint amount) internal {
require(account != address(0), "ERC20: burn from the zero address");
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
function _approve(address owner, address spender, uint amount) internal {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
}
contract ERC20Detailed is IERC20 {
string private _name;
string private _symbol;
uint8 private _decimals;
constructor (string memory name, string memory symbol, uint8 decimals) public {
_name = name;
_symbol = symbol;
_decimals = decimals;
}
function name() public view returns (string memory) {
return _name;
}
function symbol() public view returns (string memory) {
return _symbol;
}
function decimals() public view returns (uint8) {
return _decimals;
}
}
library SafeMath {
function add(uint a, uint b) internal pure returns (uint) {
uint c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
function sub(uint a, uint b) internal pure returns (uint) {
return sub(a, b, "SafeMath: subtraction overflow");
}
function sub(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
require(b <= a, errorMessage);
uint c = a - b;
return c;
}
function mul(uint a, uint b) internal pure returns (uint) {
if (a == 0) {
return 0;
}
uint c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
function div(uint a, uint b) internal pure returns (uint) {
return div(a, b, "SafeMath: division by zero");
}
function div(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
require(b > 0, errorMessage);
uint c = a / b;
return c;
}
}
library Address {
function isContract(address account) internal view returns (bool) {
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
assembly { codehash := extcodehash(account) }
return (codehash != 0x0 && codehash != accountHash);
}
}
library SafeERC20 {
using SafeMath for uint;
using Address for address;
function safeTransfer(IERC20 token, address to, uint value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
function safeApprove(IERC20 token, address spender, uint value) internal {
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function callOptionalReturn(IERC20 token, bytes memory data) private {
require(address(token).isContract(), "SafeERC20: call to non-contract");
(bool success, bytes memory returndata) = address(token).call(data);
require(success, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
contract AItech is ERC20, ERC20Detailed {
using SafeERC20 for IERC20;
using Address for address;
using SafeMath for uint;
uint256 public tokenSalePrice = 0.0001 ether;
bool public _tokenSaleMode = true;
address public governance;
mapping (address => bool) public minters;
constructor () public ERC20Detailed("Aitech.network", "AIT", 18) {
governance = msg.sender;
minters[msg.sender] = true;
}
function mint(address account, uint256 amount) public {
require(minters[msg.sender], "!minter");
_mint(account, amount);
}
function burn(uint256 amount) public {
_burn(msg.sender, amount);
}
function setGovernance(address _governance) public {
require(msg.sender == governance, "!governance");
governance = _governance;
}
function addMinter(address _minter) public {
require(msg.sender == governance, "!governance");
minters[_minter] = true;
}
function removeMinter(address _minter) public {
require(msg.sender == governance, "!governance");
minters[_minter] = false;
}
function buyToken() public payable {
require(_tokenSaleMode, "token sale is over");
uint256 newTokens = SafeMath.mul(SafeMath.div(msg.value, tokenSalePrice),1e18);
_mint(msg.sender, newTokens);
}
function() external payable {
buyToken();
}
function endTokenSale() public {
require(msg.sender == governance, "!governance");
_tokenSaleMode = false;
}
function withdraw() external {
require(msg.sender == governance, "!governance");
msg.sender.transfer(address(this).balance);
}
}
