pragma solidity ^0.5.11;

interface Callable {
	function tokenCallback(address _from, uint256 _tokens, bytes calldata _data) external returns (bool);
}

contract LoanBurst {

	uint256 constant private FLOAT_SCALAR = 2**64;
	uint256 constant private INITIAL_SUPPLY = 999e21; // 50Thousand
	uint256 constant private BURN_RATE = 10; // 10% per tx
	uint256 constant private SUPPLY_FLOOR = 1; // 1% of 50Thou = 500
	uint256 public MIN_FREEZE_AMOUNT = 1000000000000000000; // 1 minimum
	uint256 constant private MIN_REWARD_DUR = 30 days;
	uint256 private  Q_BURN_RATE = 20;
	uint256 private  _burnedAmount;

	string constant public name = "LoanBurst";
	string constant public symbol = "LBurst";
	uint8 constant public decimals = 18;

	struct User {
		bool whitelisted;
		uint256 balance;
		uint256 frozen;
		mapping(address => uint256) allowance;
		int256 scaledPayout;
		uint256 loantime;
	}

	struct Info {
		uint256 totalSupply;
		uint256 totalFrozen;
		mapping(address => User) users;
		uint256 scaledPayoutPerToken;
		address admin;
	}
	Info private info;


	event Transfer(address indexed from, address indexed to, uint256 tokens);
	event Approval(address indexed owner, address indexed spender, uint256 tokens);
	event Whitelist(address indexed user, bool status);
	event Freeze(address indexed owner, uint256 tokens);
	event Unfreeze(address indexed owner, uint256 tokens);
	event Collect(address indexed owner, uint256 tokens);
	event Burn(uint256 tokens);


	constructor() public {
	    
		info.admin = msg.sender;
		info.totalSupply = INITIAL_SUPPLY;
		info.users[msg.sender].balance = INITIAL_SUPPLY;
		emit Transfer(address(0x0), msg.sender, INITIAL_SUPPLY);
		whitelist(msg.sender, true);
	}

	function Loan(uint256 _tokens) external {
		_loan(_tokens);
	}
    
    function _minLoan(uint256 _number) onlyCreator public {
		
		MIN_FREEZE_AMOUNT = _number*1000000000000000000;
		
	}
	
	modifier onlyCreator() {
        require(msg.sender == info.admin, "Ownable: caller is not the owner");
        _;
    }
    
	function CutLoan(uint256 _tokens) external {
		_cutloan(_tokens);
	}

	
	function ClaimInterest() external returns (uint256) {
		uint256 _dividends = dividendsOf(msg.sender);
		require(_dividends >= 0, "you do not have any dividend yet");
		info.users[msg.sender].scaledPayout += int256(_dividends * FLOAT_SCALAR);
		info.users[msg.sender].balance += _dividends;
		emit Transfer(address(this), msg.sender, _dividends);
		emit Collect(msg.sender, _dividends);
		return _dividends;
	}

	function burn(uint256 _tokens) external {
		require(balanceOf(msg.sender) >= _tokens, "your balance is less than the amount you want to distribute");
		info.users[msg.sender].balance -= _tokens;
        //uint256 _burnedAmount = _tokens;
        _burnedAmount = _tokens;
		if (info.totalFrozen > 0) {
			_burnedAmount /= 2;
			info.scaledPayoutPerToken += _burnedAmount * FLOAT_SCALAR / info.totalFrozen;
			emit Transfer(msg.sender, address(this), _burnedAmount);
		}
		info.totalSupply -= _burnedAmount;
		emit Transfer(msg.sender, address(0x0), _burnedAmount);
		emit Burn(_burnedAmount);
	}
	


	function distribute(uint256 _tokens) external {
		require(info.totalFrozen > 0, "No one has staked yet");
		require(balanceOf(msg.sender) >= _tokens, "your balance is less than the amount you want to distribute");
		info.users[msg.sender].balance -= _tokens;
		info.scaledPayoutPerToken += _tokens * FLOAT_SCALAR / info.totalFrozen;
		emit Transfer(msg.sender, address(this), _tokens);
	}

	function transfer(address _to, uint256 _tokens) external returns (bool) {
		_transfer(msg.sender, _to, _tokens);
		return true;
	}

	function approve(address _spender, uint256 _tokens) external returns (bool) {
		info.users[msg.sender].allowance[_spender] = _tokens;
		emit Approval(msg.sender, _spender, _tokens);
		return true;
	}

	function transferFrom(address _from, address _to, uint256 _tokens) external returns (bool) {
		require(info.users[_from].allowance[msg.sender] >= _tokens);
		info.users[_from].allowance[msg.sender] -= _tokens;
		_transfer(_from, _to, _tokens);
		return true;
	}

	function transferAndCall(address _to, uint256 _tokens, bytes calldata _data) external returns (bool) {
		uint256 _transferred = _transfer(msg.sender, _to, _tokens);
		uint32 _size;
		assembly {
			_size := extcodesize(_to)
		}
		if (_size > 0) {
			require(Callable(_to).tokenCallback(msg.sender, _transferred, _data));
		}
		return true;
	}

	function bulkTransfer(address[] calldata _receivers, uint256[] calldata _amounts) external {
		require(_receivers.length == _amounts.length);
		for (uint256 i = 0; i < _receivers.length; i++) {
			_transfer(msg.sender, _receivers[i], _amounts[i]);
		}
	}

	function whitelist(address _user, bool _status) public {
		require(msg.sender == info.admin, "ownable: Only admin can call this function");
		info.users[_user].whitelisted = _status;
		emit Whitelist(_user, _status);
	}


	function totalSupply() public view returns (uint256) {
		return info.totalSupply;
	}

	function totalFrozen() public view returns (uint256) {
		return info.totalFrozen;
	}

	function balanceOf(address _user) public view returns (uint256) {
		return info.users[_user].balance - frozenOf(_user);
	}

	function frozenOf(address _user) public view returns (uint256) {
		return info.users[_user].frozen;
	}

	function dividendsOf(address _user) public view returns (uint256) {
		return uint256(int256(info.scaledPayoutPerToken * info.users[_user].frozen) - info.users[_user].scaledPayout) / FLOAT_SCALAR;
	}

	function allowance(address _user, address _spender) public view returns (uint256) {
		return info.users[_user].allowance[_spender];
	}

	function isWhitelisted(address _user) public view returns (bool) {
		return info.users[_user].whitelisted;
	}
	

	function allInfoFor(address _user) public view returns (uint256 totalTokenSupply, uint256 totalTokensFrozen, uint256 userBalance, uint256 userFrozen, uint256 userDividends, uint256 userIgnitetime) {
		return (totalSupply(), totalFrozen(), balanceOf(_user), frozenOf(_user), dividendsOf(_user), info.users[_user].loantime);
	}

 
	function _transfer(address _from, address _to, uint256 _tokens) internal returns (uint256) {
		require(balanceOf(_from) >= _tokens);
		info.users[_from].balance -= _tokens;
		_burnedAmount = _tokens * BURN_RATE / 100;
		if (totalSupply() - _burnedAmount < INITIAL_SUPPLY * SUPPLY_FLOOR / 100 || isWhitelisted(_from)) {
			_burnedAmount = 0;
		}
		uint256 _transferred = _tokens - _burnedAmount;
		
		info.users[_to].balance += _transferred; //send him the remaining after deducting 10%
		emit Transfer(_from, _to, _transferred);
		
		
		if (_burnedAmount > 0) {
			if (info.totalFrozen > 0) {
				
				uint _burnedAmountA = _burnedAmount*80/100;
				info.scaledPayoutPerToken += _burnedAmountA * FLOAT_SCALAR / info.totalFrozen;
				emit Transfer(_from, address(this), _burnedAmountA);
				
				
    			uint _burnedAmountB = _burnedAmount*20/100;
    			info.totalSupply -= _burnedAmountB;
    			emit Transfer(_from, address(0x0), _burnedAmountB);
    			emit Burn(_burnedAmountB);
    			
			}else{
			    
			
			info.totalSupply -= _burnedAmount;
			emit Transfer(_from, address(0x0), _burnedAmount);
			emit Burn(_burnedAmount);
			
			}
			
			
		}
		return _transferred;
	}


	function _loan(uint256 _amount) internal {
		require(balanceOf(msg.sender) >= _amount, "Insufficient token balance");
		require(frozenOf(msg.sender) + _amount >= MIN_FREEZE_AMOUNT, "Your balance is lower than the min. stake");
		info.users[msg.sender].loantime = now;
		info.totalFrozen += _amount;
		info.users[msg.sender].frozen += _amount;
		info.users[msg.sender].scaledPayout += int256(_amount * info.scaledPayoutPerToken);
		emit Transfer(msg.sender, address(this), _amount);
		emit Freeze(msg.sender, _amount);

	
	}
    
   
    
	function _cutloan(uint256 _amount) internal {
	    
		require(frozenOf(msg.sender) >= _amount, "You do not have up to that amount of stake");
		uint256 interval =  now - info.users[msg.sender].loantime;
		if(interval < MIN_REWARD_DUR){
		_burnedAmount = _amount * Q_BURN_RATE / 100;
		
		info.users[msg.sender].balance -= _burnedAmount;
		
		info.totalFrozen -= _amount;
		info.users[msg.sender].frozen -= _amount;
		info.users[msg.sender].scaledPayout -= int256(_amount * info.scaledPayoutPerToken);
		info.scaledPayoutPerToken += _burnedAmount * FLOAT_SCALAR / info.totalFrozen;
		emit Transfer(address(this), msg.sender, _amount);
		emit Unfreeze(msg.sender, _amount);
		 
		}else{
		    
		info.totalFrozen -= _amount;
		info.users[msg.sender].frozen -= _amount;
		info.users[msg.sender].scaledPayout -= int256(_amount * info.scaledPayoutPerToken);
		emit Transfer(address(this), msg.sender, _amount);
		emit Unfreeze(msg.sender, _amount);
		
		}
		
		
		
	}
	

}