/** *Submitted for verification at Etherscan.io on 2019-09-03 */

pragma solidity ^0.4.23;

/**

• @title SafeMath
• @dev Math operations with safety checks that throw on error
• Name : KnoxsterChain (KNCT)
• Decimals : 18
• TotalSupply : 8000000

*/ library SafeMath {

/**
* @dev Multiplies two numbers, throws on overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
    if (a == 0) {
        return 0;
    }
    c = a * b;
    assert(c / a == b);
    return c;
}

/**
* @dev Integer division of two numbers, truncating the quotient.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    // uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return a / b;
}

/**
* @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
}

/**
* @dev Adds two numbers, throws on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
    c = a + b;
    assert(c >= a);
    return c;
}

}

contract ForeignToken { function balanceOf(address _owner) constant public returns (uint256); function transfer(address _to, uint256 _value) public returns (bool); }

contract ERC20Basic { uint256 public totalSupply; function balanceOf(address who) public constant returns (uint256); function transfer(address to, uint256 value) public returns (bool); event Transfer(address indexed from, address indexed to, uint256 value); }

contract ERC20 is ERC20Basic { function allowance(address owner, address spender) public constant returns (uint256); function transferFrom(address from, address to, uint256 value) public returns (bool); function approve(address spender, uint256 value) public returns (bool); event Approval(address indexed owner, address indexed spender, uint256 value); }

contract KnoxsterChain is ERC20 {

using SafeMath for uint256;
address owner = msg.sender;

mapping (address => uint256) balances;
mapping (address => mapping (address => uint256)) allowed;    

string public constant name = "KnoxsterChain";
string public constant symbol = "KNCT";
uint public constant decimals = 18;

uint256 public totalSupply = 8000000e18;
uint256 public totalDistributed =  3000000e18;    
uint256 public constant MIN_CONTRIBUTION = 1 ether / 100; // 0.01 Ether
uint256 public tokensPerEth = 16000e18;

event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);

event Distr(address indexed to, uint256 amount);
event DistrFinished();

event Airdrop(address indexed _owner, uint _amount, uint _balance);

event TokensPerEthUpdated(uint _tokensPerEth);

event Burn(address indexed burner, uint256 value);

bool public distributionFinished = false;

modifier canDistr() {
    require(!distributionFinished);
    _;
}

modifier onlyOwner() {
    require(msg.sender == owner);
    _;
}


function KnoxsterChain () public {
    owner = msg.sender;    
    distr(owner, totalDistributed);
}

function transferOwnership(address newOwner) onlyOwner public {
    if (newOwner != address(0)) {
        owner = newOwner;
    }
}


function finishDistribution() onlyOwner canDistr public returns (bool) {
    distributionFinished = true;
    emit DistrFinished();
    return true;
}

function distr(address _to, uint256 _amount) canDistr private returns (bool) {
    totalDistributed = totalDistributed.add(_amount);        
    balances[_to] = balances[_to].add(_amount);
    emit Distr(_to, _amount);
    emit Transfer(address(0), _to, _amount);

    return true;
}

function doAirdrop(address _participant, uint _amount) internal {

    require( _amount > 0 );      

    require( totalDistributed < totalSupply );
    
    balances[_participant] = balances[_participant].add(_amount);
    totalDistributed = totalDistributed.add(_amount);

    if (totalDistributed >= totalSupply) {
        distributionFinished = true;
    }

    // log
    emit Airdrop(_participant, _amount, balances[_participant]);
    emit Transfer(address(0), _participant, _amount);
}

function adminClaimAirdrop(address _participant, uint _amount) public onlyOwner {        
    doAirdrop(_participant, _amount);
}

function adminClaimAirdropMultiple(address[] _addresses, uint _amount) public onlyOwner {        
    for (uint i = 0; i < _addresses.length; i++) doAirdrop(_addresses[i], _amount);
}

function updateTokensPerEth(uint _tokensPerEth) public onlyOwner {        
    tokensPerEth = _tokensPerEth;
    emit TokensPerEthUpdated(_tokensPerEth);
}
       
function () external payable {
    getTokens();
 }

function getTokens() payable canDistr  public {
    uint256 tokens = 0;

    // minimum contribution
    require( msg.value >= MIN_CONTRIBUTION );

    require( msg.value > 0 );

    // get baseline number of tokens
    tokens = tokensPerEth.mul(msg.value) / 1 ether;        
    address investor = msg.sender;
    
    if (tokens > 0) {
        distr(investor, tokens);
    }

    if (totalDistributed >= totalSupply) {
        distributionFinished = true;
    }
}

function balanceOf(address _owner) constant public returns (uint256) {
    return balances[_owner];
}

// mitigates the ERC20 short address attack
modifier onlyPayloadSize(uint size) {
    assert(msg.data.length >= size + 4);
    _;
}

function transfer(address _to, uint256 _amount) onlyPayloadSize(2 * 32) public returns (bool success) {

    require(_to != address(0));
    require(_amount <= balances[msg.sender]);
    
    balances[msg.sender] = balances[msg.sender].sub(_amount);
    balances[_to] = balances[_to].add(_amount);
    emit Transfer(msg.sender, _to, _amount);
    return true;
}

function transferFrom(address _from, address _to, uint256 _amount) onlyPayloadSize(3 * 32) public returns (bool success) {

    require(_to != address(0));
    require(_amount <= balances[_from]);
    require(_amount <= allowed[_from][msg.sender]);
    
    balances[_from] = balances[_from].sub(_amount);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_amount);
    balances[_to] = balances[_to].add(_amount);
    emit Transfer(_from, _to, _amount);
    return true;
}

function approve(address _spender, uint256 _value) public returns (bool success) {
    // mitigates the ERC20 spend/approval race condition
    if (_value != 0 && allowed[msg.sender][_spender] != 0) { return false; }
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
}

function allowance(address _owner, address _spender) constant public returns (uint256) {
    return allowed[_owner][_spender];
}

function getTokenBalance(address tokenAddress, address who) constant public returns (uint){
    ForeignToken t = ForeignToken(tokenAddress);
    uint bal = t.balanceOf(who);
    return bal;
}

function withdraw() onlyOwner public {
    address myAddress = this;
    uint256 etherBalance = myAddress.balance;
    owner.transfer(etherBalance);
}

function burn(uint256 _value) onlyOwner public {
    require(_value <= balances[msg.sender]);
    // no need to require value <= totalSupply, since that would imply the
    // sender's balance is greater than the totalSupply, which should be an assertion failure

    address burner = msg.sender;
    balances[burner] = balances[burner].sub(_value);
    totalSupply = totalSupply.sub(_value);
    totalDistributed = totalDistributed.sub(_value);
    emit Burn(burner, _value);
}

function withdrawForeignTokens(address _tokenContract) onlyOwner public returns (bool) {
    ForeignToken token = ForeignToken(_tokenContract);
    uint256 amount = token.balanceOf(address(this));
    return token.transfer(owner, amount);
}

}