/*28 September 2018 v2.0

                         -+/-           +oo/                             .ooo`
                        -NNNN.          hNNy                             :NNN.
                         +ss/           hNNy                             :NNN.
  `:+o+/.`//-  .//.`:+o. ://:    `:+o+/.hNNy     -/+o+/-  `///.    ://:  :NNN-:+o+/.       -/+++:`
`omNNNNNNmNNs  +NNdmNNN: hNNy   omNNNNNNNNNy   +dNNNNNNN+ .NNN:    hNNs  :NNNNNNNNNNy.   omNNmdmNms`
yNNm/. .+NNNs  +NNNy:..` hNNy  sNNm+. .+mNNy  sNNm+.``-:  .NNN:    hNNs  :NNNy-``:dNNd` yNNd-``.yNNy
NNNo     yNNs  +NNN      hNNy  mNNs     yNNy  mNNs        .NNN:    dNNs  :NNm     :NNN- mNNNNNNNNNNN
yNNm/` .+NNNs  +NNN      hNNy  sNNm/` `/mNNy  sNNm+. `.-  `mNNh:.-oNNNs  :NNNs. `:hNNd` yNNd:`  `/.
`sNNNNNNNNNNs  +NNN      hNNy   omNNNNNNmNNy   +mNNNNNNN+  -dNNNNNNmNNs  :NNmNNNNNNNy.   omNNNmmNNd`
  `:+o+/-mNN+  -++/      :++:    `:+oo/-`++:     -/+o+/-     -/oo+-`++:  .++-`/+o+/.       -/++++:`
  smyoooymNNh`
  .oydmNNmds:


https://gridcube.com has a unique approach to deploying Blockchain technology. Instead of focusing on the blockchain itself,
our breakthrough was discovering that the underlying infrastructure is just as important. Therefore,
we developed a “Smart Cloud Manager”, a middleware software capable of deploying a blockchain network efficiently,
fast, and optimized for cost. Gridcube Platform Token (GPT) Enables "Coding is Mining" Loyalty and Reward Program.
Also works as a way of Payment for Gridcube Services. https://ito.gridcube.com

28 September 2018 v2.0*/

pragma solidity ^0.4.25;

// ----------------------------------------------------------------------------
// 'Gridcube' CROWDSALE token contract
//
// Deployed to : 0X69A50B4989E00C1278A3135F60B4CCB49A97C465
// Symbol      : GPT
// Name        : Gridcube Platform Token
// Total supply: 30 000 000
// Decimals    : 18
//
//
//
// ----------------------------------------------------------------------------


// ----------------------------------------------------------------------------
// Safe maths
// ----------------------------------------------------------------------------
contract SafeMath {
    function safeAdd(uint a, uint b) internal pure returns (uint c) {
        c = a + b;
        require(c >= a);
    }
    function safeSub(uint a, uint b) internal pure returns (uint c) {
        require(b <= a);
        c = a - b;
    }
    function safeMul(uint a, uint b) internal pure returns (uint c) {
        c = a * b;
        require(a == 0 || c / a == b);
    }
    function safeDiv(uint a, uint b) internal pure returns (uint c) {
        require(b > 0);
        c = a / b;
    }
}


// ----------------------------------------------------------------------------
// ERC Token Standard #20 Interface
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
// ----------------------------------------------------------------------------
contract ERC20Interface {
    function totalSupply() public constant returns (uint);
    function balanceOf(address tokenOwner) public constant returns (uint balance);
    function allowance(address tokenOwner, address spender) public constant returns (uint remaining);
    function transfer(address to, uint tokens) public returns (bool success);
    function approve(address spender, uint tokens) public returns (bool success);
    function transferFrom(address from, address to, uint tokens) public returns (bool success);

    event Transfer(address indexed from, address indexed to, uint tokens);
    event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
}


// ----------------------------------------------------------------------------
// Contract function to receive approval and execute function in one call
//
// Borrowed from MiniMeToken
// ----------------------------------------------------------------------------
contract ApproveAndCallFallBack {
    function receiveApproval(address from, uint256 tokens, address token, bytes data) public;
}


// ----------------------------------------------------------------------------
// Owned contract
// ----------------------------------------------------------------------------
contract Owned {
    address public owner;
    address public newOwner;

    event OwnershipTransferred(address indexed _from, address indexed _to);

    constructor() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }

    function transferOwnership(address _newOwner) public onlyOwner {
        newOwner = _newOwner;
    }
    function acceptOwnership() public {
        require(msg.sender == newOwner);
        emit OwnershipTransferred(owner, newOwner);
        owner = newOwner;
        newOwner = address(0);
    }
}


// ----------------------------------------------------------------------------
// ERC20 Token, with the addition of symbol, name and decimals and assisted
// token transfers
// ----------------------------------------------------------------------------
contract GridcubePlatformToken is ERC20Interface, Owned, SafeMath {
    string public symbol;
    string public  name;
    uint8 public decimals;
    uint public _totalSupply;
    uint public startDate;
    uint public bonusEnds;
    uint public endDate;

    mapping(address => uint) balances;
    mapping(address => mapping(address => uint)) allowed;


    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------
    constructor() public {
        symbol = "GPT";
        name = "Gridcube Platform Token";
        decimals = 18;
        bonusEnds = now + 2 weeks;
        endDate = now + 12 weeks;
        _totalSupply = 30000000000000000000000000;
      }


    // ------------------------------------------------------------------------
    // Total supply
    // ------------------------------------------------------------------------
    function totalSupply() public constant returns (uint) {
        return _totalSupply  - balances[address(0)];
    }


    // ------------------------------------------------------------------------
    // Get the token balance for account `tokenOwner`
    // ------------------------------------------------------------------------
    function balanceOf(address tokenOwner) public constant returns (uint balance) {
        return balances[tokenOwner];
    }


    // ------------------------------------------------------------------------
    // Transfer the balance from token owner's account to `to` account
    // - Owner's account must have sufficient balance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transfer(address to, uint tokens) public returns (bool success) {
        balances[msg.sender] = safeSub(balances[msg.sender], tokens);
        balances[to] = safeAdd(balances[to], tokens);
        emit Transfer(msg.sender, to, tokens);
        return true;
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for `spender` to transferFrom(...) `tokens`
    // from the token owner's account
    //
    // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
    // recommends that there are no checks for the approval double-spend attack
    // as this should be implemented in user interfaces
    // ------------------------------------------------------------------------
    function approve(address spender, uint tokens) public returns (bool success) {
        allowed[msg.sender][spender] = tokens;
        emit Approval(msg.sender, spender, tokens);
        return true;
    }


    // ------------------------------------------------------------------------
    // Transfer `tokens` from the `from` account to the `to` account
    //
    // The calling account must already have sufficient tokens approve(...)-d
    // for spending from the `from` account and
    // - From account must have sufficient balance to transfer
    // - Spender must have sufficient allowance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transferFrom(address from, address to, uint tokens) public returns (bool success) {
        balances[from] = safeSub(balances[from], tokens);
        allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens);
        balances[to] = safeAdd(balances[to], tokens);
        emit Transfer(from, to, tokens);
        return true;
    }


    // ------------------------------------------------------------------------
    // Returns the amount of tokens approved by the owner that can be
    // transferred to the spender's account
    // ------------------------------------------------------------------------
    function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
        return allowed[tokenOwner][spender];
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for `spender` to transferFrom(...) `tokens`
    // from the token owner's account. The `spender` contract function
    // `receiveApproval(...)` is then executed
    // ------------------------------------------------------------------------
    function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) {
        allowed[msg.sender][spender] = tokens;
        emit Approval(msg.sender, spender, tokens);
        ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data);
        return true;
    }

    // ------------------------------------------------------------------------
    // 200 GRIDCUBE Tokens per 1 ETH
    // ------------------------------------------------------------------------
    function () public payable {
        require(now >= startDate && now <= endDate);
        uint tokens;
        if (now <= bonusEnds) {
            tokens = msg.value * 220;
        } else {
            tokens = msg.value * 200;
        }
        balances[msg.sender] = safeAdd(balances[msg.sender], tokens);
        _totalSupply = safeSub(_totalSupply, tokens);
        emit Transfer(address(0), msg.sender, tokens);
        owner.transfer(msg.value);
    }



    // ------------------------------------------------------------------------
    // Owner can transfer out any accidentally sent ERC20 tokens
    // ------------------------------------------------------------------------
    function transferAnyERC20Token(address tokenAddress, uint tokens) public onlyOwner returns (bool success) {
        return ERC20Interface(tokenAddress).transfer(owner, tokens);
    }
}