var fromaddress = req.body._fromaddress;
var amount = req.body._amount;
var privatekey = req.body._privatekey;
var toAddress = req.body._toAddress;

// Step 1
var payloadData = web3.toHex(web3.toWei(amount, 'ether'));
var transactionObject = {
    'from': fromaddress,
    'to': toAddress,
    'value': payloadData
}
gasLimit = web3.eth.estimateGas(transactionObject);

// Step 2
gasPrice = web3.eth.gasPrice;
totalGas = gasPrice * gasLimit;

var amountToSend = web3.toWei(amount, 'ether') - totalGas;

payloadData = web3.toHex(amountToSend);
gasPriceHex = web3.toHex(gasPrice);
gasLimitHex = web3.toHex(gasLimit);


nonce = web3.eth.getTransactionCount(fromaddress, "pending");
nonceHex = web3.toHex(nonce);

var rawTx = {
    nonce: nonceHex,
    gasPrice: gasPriceHex,
    gasLimit: gasLimitHex,
    to: toAddress,
    from: fromaddress,
    value: payloadData,
    data: '0x00'
};

// Step 3
var key = Buffer.from(privatekey, 'hex');
var tx = new Tx(rawTx);
tx.sign(key);

var serializedTx = tx.serialize();

web3.eth.sendRawTransaction('0x' + serializedTx.toString('hex'), function (err, hash) {
    if (err) {
        res.status(401).json("" + err);
    }
    else {
        res.json({"status": true, "hash": hash});
    }
});