pragma solidity 0.4.24;

// import "./SafeMath.sol";
// import "./Ownable.sol";
// import "./ERC20Detailed.sol";

// import "./SafeMathInt.sol";


library SafeMath {

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {

        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}
contract Context {
    function _msgSender() internal constant returns (address ) {
        return msg.sender;
    }

    function _msgData() internal constant returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    
    constructor () public {
        address msgSender = _msgSender();
        _owner = msgSender;
        
        emit OwnershipTransferred(address(0), msgSender);
    }

    function owner() public constant returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

library SafeMathInt {
    int256 private constant MIN_INT256 = int256(1) << 255;
    int256 private constant MAX_INT256 = ~(int256(1) << 255);

    function mul(int256 a, int256 b)
        internal
        pure
        returns (int256)
    {
        int256 c = a * b;

        // Detect overflow when multiplying MIN_INT256 with -1
        require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
        require((b == 0) || (c / b == a));
        return c;
    }

    function div(int256 a, int256 b)
        internal
        pure
        returns (int256)
    {
        // Prevent overflow when dividing MIN_INT256 by -1
        require(b != -1 || a != MIN_INT256);

        // Solidity already throws when dividing by 0.
        return a / b;
    }

    function sub(int256 a, int256 b)
        internal
        pure
        returns (int256)
    {
        int256 c = a - b;
        require((b >= 0 && c <= a) || (b < 0 && c > a));
        return c;
    }

    function add(int256 a, int256 b)
        internal
        pure
        returns (int256)
    {
        int256 c = a + b;
        require((b >= 0 && c >= a) || (b < 0 && c < a));
        return c;
    }

    function abs(int256 a)
        internal
        pure
        returns (int256)
    {
        require(a != MIN_INT256);
        return a < 0 ? -a : a;
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function balanceOf(address who) external view returns (uint256);

    function allowance(address owner, address spender) external view returns (uint256);

    function transfer(address to, uint256 value) external returns (bool);

    function approve(address spender, uint256 value) external returns (bool);

    function transferFrom(address from, address to, uint256 value) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract ERC20 is IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowed;

    uint256 private _totalSupply;

    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address owner) public view returns (uint256) {
        return _balances[owner];
    }

    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowed[owner][spender];
    }

    function transfer(address to, uint256 value) public returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function approve(address spender, uint256 value) public returns (bool) {
        require(spender != address(0));

        _allowed[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function transferFrom(address from, address to, uint256 value) public returns (bool) {
        require(from != address(0));
        require(to != address(0));
        _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);
        _transfer(from, to, value);
        emit Approval(from, msg.sender, _allowed[from][msg.sender]);
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        require(spender != address(0));

        _allowed[msg.sender][spender] = _allowed[msg.sender][spender].add(addedValue);
        emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        require(spender != address(0));

        _allowed[msg.sender][spender] = _allowed[msg.sender][spender].sub(subtractedValue);
        emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
        return true;
    }

    function _transfer(address from, address to, uint256 value) internal {
        require(to != address(0), "invalid to address");
        require(from != address(0), "invalid from address");

        _balances[from] = _balances[from].sub(value);
        _balances[to] = _balances[to].add(value);
        emit Transfer(from, to, value);
    }

    function _mint(address account, uint256 value) internal {
        require(account != address(0));

        _totalSupply = _totalSupply.add(value);
        _balances[account] = _balances[account].add(value);
        emit Transfer(address(0), account, value);
    }

    function _burn(address account, uint256 value) internal {
        require(account != address(0));

        _totalSupply = _totalSupply.sub(value);
        _balances[account] = _balances[account].sub(value);
        emit Transfer(account, address(0), value);
    }

    function _burnFrom(address account, uint256 value) internal {
        require(account != address(0));
        _allowed[account][msg.sender] = _allowed[account][msg.sender].sub(value);
        _burn(account, value);
        emit Approval(account, msg.sender, _allowed[account][msg.sender]);
    }
}

contract ERC20Detailed is ERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    
    constructor(string name, string symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    function name() public view returns (string) {
        return _name;
    }

    function symbol() public view returns (string) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

contract GatorToken is ERC20Detailed {

    using SafeMath for uint256;
    using SafeMathInt for int256;
    address private _owner;

    event LogRebase(uint256 indexed epoch, uint256 totalSupply);
    event LogMonetaryPolicyUpdated(address monetaryPolicy);

    // Used for authentication
    address public monetaryPolicy;

    modifier onlyMonetaryPolicy() {
        require(msg.sender == monetaryPolicy);
        _;
    }

    modifier validRecipient(address to) {
        require(to != address(0));
        require(to != address(this));
        _;
    }

    uint256 public constant DECIMALS = 18;
    uint256 private constant MAX_UINT256 = ~uint256(0);
    
    uint256 private constant INITIAL_FRAGMENTS_SUPPLY = 350000*10**DECIMALS;

    // uint256 private constant MAX_SUPPLY = 300000*10**DECIMALS;  // (2^128) - 1
    uint256 private constant TOTAL_GONS = MAX_UINT256 - (MAX_UINT256 % INITIAL_FRAGMENTS_SUPPLY);
    uint256 private _totalSupply;
    uint256 private _gonsPerFragment;
    mapping(address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowedFragments;

    function owner() public constant returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == msg.sender, "Ownable: caller is not the owner");
        _;
    }
    function renounceOwnership() public onlyOwner {
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _owner = newOwner;
    }

    function setMonetaryPolicy(address monetaryPolicy_)
        external
        onlyOwner
    {
        require(monetaryPolicy_ != address(0), "empty monetaryPolicy address");
        
        monetaryPolicy = monetaryPolicy_;
        emit LogMonetaryPolicyUpdated(monetaryPolicy_);
    }

    function rebase(uint256 epoch, int256 supplyDelta)
        external
        onlyMonetaryPolicy
        returns (uint256)
    {   

        if (supplyDelta == 0) {
            emit LogRebase(epoch, _totalSupply);
            return _totalSupply;
        }
        uint256 _supplyDelta = uint256(supplyDelta);

        _totalSupply = _totalSupply.div(_gonsPerFragment);

        if (supplyDelta >= 0) {
            _totalSupply = _totalSupply.add(_supplyDelta);
        }
        _gonsPerFragment = TOTAL_GONS.div(_totalSupply);

        _totalSupply = _totalSupply.mul(_gonsPerFragment);

        emit LogRebase(epoch, _totalSupply);
        return _totalSupply;
    }

    constructor() ERC20Detailed("GATOR", "GATR", uint8(DECIMALS))
        public
    {
        _owner = msg.sender;
        
        _totalSupply = INITIAL_FRAGMENTS_SUPPLY;
        _gonsPerFragment = TOTAL_GONS.div(_totalSupply);
        _totalSupply = INITIAL_FRAGMENTS_SUPPLY.mul(_gonsPerFragment);
        _balances[_owner] = INITIAL_FRAGMENTS_SUPPLY.mul(_gonsPerFragment);

        emit Transfer(address(0), _owner, _totalSupply);
    }

    function totalSupply()
        public
        view
        returns (uint256)
    {
        return _totalSupply.div(_gonsPerFragment);
    }

    function balanceOf(address who)
        public
        view
        returns (uint256)
    {
        return _balances[who].div(_gonsPerFragment);
    }

    function transfer(address to, uint256 value)
        public
        validRecipient(to)
        returns (bool)
    {
        require(to != address(0));
        uint256 gonValue = value.mul(_gonsPerFragment);
        _balances[msg.sender] = _balances[msg.sender].sub(gonValue);
        _balances[to] = _balances[to].add(gonValue);
        emit Transfer(msg.sender, to, value);
        return true;
    }

    function allowance(address owner_, address spender)
        public
        view
        returns (uint256)
    {
        return _allowedFragments[owner_][spender];
    }

    function transferFrom(address from, address to, uint256 value)
        public
        validRecipient(to)
        returns (bool)
    {
        require(from != address(0));
        _allowedFragments[from][msg.sender] = _allowedFragments[from][msg.sender].sub(value);

        uint256 gonValue = value.mul(_gonsPerFragment);
        _balances[from] = _balances[from].sub(gonValue);
        _balances[to] = _balances[to].add(gonValue);
        emit Transfer(from, to, value);

        return true;
    }

    function approve(address spender, uint256 value)
        public
        returns (bool)
    {
        require(spender != address(0));
        _allowedFragments[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue)
        public
        returns (bool)
    {
        require(spender != address(0));
        _allowedFragments[msg.sender][spender] =
            _allowedFragments[msg.sender][spender].add(addedValue);
        emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue)
        public
        returns (bool)
    {
        require(spender != address(0));
        uint256 oldValue = _allowedFragments[msg.sender][spender];
        if (subtractedValue >= oldValue) {
            _allowedFragments[msg.sender][spender] = 0;
        } else {
            _allowedFragments[msg.sender][spender] = oldValue.sub(subtractedValue);
        }
        emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
        return true;
    }
    
    /*
    function mint(address account, uint256 amount)
    public
    onlyOwner
    {
        require(account != address(0), "ERC20: mint to the zero address");
        amount = amount.mul(10**DECIMALS);
        _totalSupply = _totalSupply.div(_gonsPerFragment);
        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].div(_gonsPerFragment);
        _gonsPerFragment = TOTAL_GONS.div(_totalSupply);

        _totalSupply = _totalSupply.mul(_gonsPerFragment);

        _balances[account] = _balances[account].add(amount);
        _balances[account] = _balances[account].mul(_gonsPerFragment);

        emit Transfer(address(0), account, amount);
    }
    */
}

{
  "compilationTarget": {
    "Gator.sol": "GatorToken"
  },
  "evmVersion": "byzantium",
  "libraries": {},
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}