contract iotpowerToken is ERC20Interface, Owned, SafeMath {
    string public symbol;
    string public  name;
    uint8 public decimals;
    uint public remaining;
    uint public _totalSupply;
    uint public startDate;
    uint public stageOneBegin;
    uint public stageOneEnd;
    uint public stageTwoBegin;
    uint public stageTwoEnd;
    uint public stageThreeBegin;
    uint public stageThreeEnd;
    uint public stageFourBegin;
    uint public stageFourEnd;
    uint public stageFiveBegin;
    uint public stageFiveEnd;
    uint public endDate;

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


    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------
    function iotpowerToken() public {
        symbol = "IP";
        name = "IOTPOWER Token";
        decimals = 0;
        _totalSupply = 900000000;
        stageOneBegin = 1537747200; 
        stageOneEnd = 1539561599;
        stageTwoBegin = 1539561600;
        stageTwoEnd = 1541375999;
        stageThreeBegin = 1541376000;
        stageThreeEnd = 1543190399;
        stageFourBegin = 1543190400;
        stageFourEnd = 1545004799;
        stageFiveBegin = 1545004800;
        stageFiveEnd = 1546819199;
        endDate = 1548633599;
        balances[0x7cf186Cad802cB992c4F14a634C7E81c9e8957b8] = _totalSupply;
        Transfer(address(0), 0x7cf186Cad802cB992c4F14a634C7E81c9e8957b8, _totalSupply);
    }


    // ------------------------------------------------------------------------
    // 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);
        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;
        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);
        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;
        Approval(msg.sender, spender, tokens);
        ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data);
        return true;
    }

    // ------------------------------------------------------------------------
    // 4,955 IP Tokens per 1 ETH
    // ------------------------------------------------------------------------
    function () public payable {
        
        require(now >= startDate && now <= endDate);
        require(msg.value > 0);                     // Require the sender to send an ETH tx higher than 0
        require(msg.value <= msg.sender.balance);   // Require the sender to have sufficient ETH balance for the tx

        uint tokens;
        uint weiAmount = msg.value;

        assert(remaining <= _totalSupply);

        if (now >= stageOneBegin && now <= stageOneEnd) {
            tokens = 7185 * weiAmount / 1 ether;
        } else if (now >= stageTwoBegin && now <= stageTwoEnd) {
            tokens = 6789 * weiAmount / 1 ether;
        } else if (now >= stageThreeBegin && now <= stageThreeEnd) {
            tokens = 6392 * weiAmount / 1 ether;
        } else if (now >= stageFourBegin && now <= stageFourEnd) {
            tokens = 5996 * weiAmount / 1 ether;
        }  else if (now >= stageFiveBegin && now <= stageFiveEnd) {
            tokens = 5600 * weiAmount / 1 ether;
        } else {
            tokens = 4955 * weiAmount / 1 ether;
        }

        balances[msg.sender] = safeAdd(balances[msg.sender], tokens);
        Transfer(address(0), msg.sender, tokens);
        owner.transfer(weiAmount);
        remaining = safeAdd(remaining,tokens);
  
    }



    // ------------------------------------------------------------------------
    // 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);
    }
}
// ----------------------------------------------------------------------------
// ERC20 Token, with the addition of symbol, name and decimals and assisted
// token transfers
// ----------------------------------------------------------------------------
function iotpowerToken() public {
    symbol = "IP";
    name = "IOTPOWER Token";
    decimals = 0;
    _totalSupply = 900000000;
    stageOneBegin = 1537747200; 
    stageOneEnd = 1539561599;
    stageTwoBegin = 1539561600;
    stageTwoEnd = 1541375999;
    stageThreeBegin = 1541376000;
    stageThreeEnd = 1543190399;
    stageFourBegin = 1543190400;
    stageFourEnd = 1545004799;
    stageFiveBegin = 1545004800;
    stageFiveEnd = 1546819199;
    endDate = 1548633599;
    balances[0x7cf186Cad802cB992c4F14a634C7E81c9e8957b8] = _totalSupply;
    Transfer(address(0), 0x7cf186Cad802cB992c4F14a634C7E81c9e8957b8, _totalSupply);
}

// ------------------------------------------------------------------------
// Constructor
// ------------------------------------------------------------------------