pragma solidity ^0.5.0;

library Address {
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        assembly { size := extcodesize(account) }
        return size > 0;
    }
    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }
    function owner() public view returns (address) {
        return _owner;
    }
    modifier onlyOwner() {
        require(isOwner(), "Ownable: caller is not the owner");
        _;
    }
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    function transferOwnership(address newOwner) public onlyOwner {
        //_transferOwnership(newOwner);
        _pendingowner = newOwner;
        emit OwnershipTransferPending(_owner, newOwner);
    }

    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
    address private _pendingowner;
    event OwnershipTransferPending(address indexed previousOwner, address indexed newOwner);
    function pendingowner() public view returns (address) {
        return _pendingowner;
    }

    modifier onlyPendingOwner() {
        require(msg.sender == _pendingowner, "Ownable: caller is not the pending owner");
        _;
    }
    function claimOwnership() public onlyPendingOwner {
        _transferOwnership(msg.sender);
    }

}

contract Pausable is Ownable {
    event Pause();
    event Unpause();

    bool public paused = false;
    modifier whenNotPaused() {
        require(!paused, "Pausable: paused");
        _;
    }
    modifier whenPaused() {
        require(paused, "Pausable: not paused");
        _;
    }
    function pause() public onlyOwner whenNotPaused {
        paused = true;
        emit Pause();
    }
    function unpause() public onlyOwner whenPaused {
        paused = false;
        emit Unpause();
    }
}


contract ERC20Token is IERC20, Pausable {
    using SafeMath for uint256;
    using Address for address;

    string internal _name;
    string internal _symbol;
    uint8 internal _decimals;
    uint256 internal _totalSupply;

    mapping (address => uint256) internal _balances;
    mapping (address => mapping (address => uint256)) internal _allowances;

    constructor(string memory name, string memory symbol, uint8 decimals, uint256 totalSupply) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
        _totalSupply = totalSupply;
        _balances[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);
    }

    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;
    }

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

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


    // Function that is called when a user or another contract wants to transfer funds .
    function transfer(address recipient, uint256 amount)
    public
    whenNotPaused
    returns (bool success)
    {
        _transfer(msg.sender, recipient, amount);
        return true;
    }

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

    function approve(address spender, uint256 value)
    public
    whenNotPaused
    returns (bool)
    {
        _approve(msg.sender, spender, value);
        return true;
    }


    function transferFrom(address sender, address recipient, uint256 amount)
    public
    whenNotPaused
    returns (bool)
    {
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount));
        return true;
    }



    function increaseAllowance(address spender, uint256 addedValue)
    public
    whenNotPaused
    returns (bool)
    {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue)
    public
    whenNotPaused
    returns (bool)
    {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue));
        return true;
    }

    function _transfer(address sender, address recipient, uint256 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);
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    function _approve(address owner, address spender, uint256 value) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = value;
        emit Approval(owner, spender, value);
    }
   
}

contract DroneCoin is ERC20Token {
    constructor() public
    ERC20Token("DroneCoin", "DRC", 18, 3300000000 * (10 ** 18)) {
    }
    mapping (address => uint256) internal _locked_balances;

    event TokenLocked(address indexed owner, uint256 value);
    event TokenUnlocked(address indexed beneficiary, uint256 value);

    function balanceOfLocked(address account) public view returns (uint256 balance)
    {
        return _locked_balances[account];
    }

    function lockToken(address account, uint256 amount)
    public
    onlyOwner
    returns (bool) {
        _lock_token(account, amount);
        return true;
    }

    function lockTokenWhole(address account)
    public
    onlyOwner
    returns (bool) {
        _lock_token(account, _balances[account]);
        return true;
    }

    function unlockToken(address account, uint256 amount)
    public
    onlyOwner
    returns (bool) {
        _unlock_token(account, amount);
        return true;
    }

    function _lock_token(address account, uint256 amount) internal {
        require(amount > 0, "LockToken: the amount is empty");

        _balances[account] = _balances[account].sub(amount);
        _locked_balances[account] = _locked_balances[account].add(amount);
        emit TokenLocked(account, amount);
    }

    function _unlock_token(address account, uint256 amount) internal {
        require(amount > 0, "LockToken: the amount is empty");

        _locked_balances[account] = _locked_balances[account].sub(amount);
        _balances[account] = _balances[account].add(amount);
        emit TokenUnlocked(account, amount);
    }


}

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) {
        require(b <= a, "SafeMath: subtraction overflow");
        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) {
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}

{
  "compilationTarget": {
    "DroneCoin.sol": "DroneCoin"
  },
  "evmVersion": "byzantium",
  "libraries": {},
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}