transactions.js

var bitcoin = require('bitcoinjs-lib');
var util = require('./util.js');

// public members
var txHash;

exports.txHash = function(){
  return txHash;
};

function scriptCompile(addrHash){
    script = bitcoin.script.compile(
        [
            bitcoin.opcodes.OP_DUP,
            bitcoin.opcodes.OP_HASH160,
            addrHash,
            bitcoin.opcodes.OP_EQUALVERIFY,
            bitcoin.opcodes.OP_CHECKSIG
        ]);
    return script;
}

function scriptFoundersCompile(address){
    script = bitcoin.script.compile(
        [
            bitcoin.opcodes.OP_HASH160,
            address,
            bitcoin.opcodes.OP_EQUAL
        ]);
    return script;
}


exports.createGeneration = function(rpcData, blockReward, feeReward, recipients, poolAddress){
    var _this = this;
    var blockPollingIntervalId;

    var emitLog = function (text) {
        _this.emit('log', 'debug', text);
    };
    var emitWarningLog = function (text) {
        _this.emit('log', 'warning', text);
    };
    var emitErrorLog = function (text) {
        _this.emit('log', 'error', text);
    };
    var emitSpecialLog = function (text) {
        _this.emit('log', 'special', text);
    };

    var poolAddrHash = bitcoin.address.fromBase58Check(poolAddress).hash;

    var tx = new bitcoin.Transaction();
    var blockHeight = rpcData.height;
    // input for coinbase tx
    if (blockHeight.toString(16).length % 2 === 0) {
        var blockHeightSerial = blockHeight.toString(16);
    } else {
        var blockHeightSerial = '0' + blockHeight.toString(16);
    }
    var height = Math.ceil((blockHeight << 1).toString(2).length / 8);
    var lengthDiff = blockHeightSerial.length/2 - height;
    for (var i = 0; i < lengthDiff; i++) {
        blockHeightSerial = blockHeightSerial + '00';
    }
    length = '0' + height;
    var serializedBlockHeight = new Buffer.concat([
        new Buffer(length, 'hex'),
        util.reverseBuffer(new Buffer(blockHeightSerial, 'hex')),
        new Buffer('00', 'hex') // OP_0
    ]);

    tx.addInput(new Buffer('0000000000000000000000000000000000000000000000000000000000000000', 'hex'),
        0xFFFFFFFF,
        0xFFFFFFFF,
        new Buffer.concat([serializedBlockHeight,
            Buffer('6b6177706f77', 'hex')])
    );

    // calculate total fees
    var feePercent = 0;
    for (var i = 0; i < recipients.length; i++) {
        feePercent = feePercent + recipients[i].percent;
    }

    tx.addOutput(
        scriptCompile(poolAddrHash),
        Math.floor(blockReward * (1 - (feePercent / 100)))
    );


    for (var i = 0; i < recipients.length; i++) {
       tx.addOutput(
           scriptCompile(bitcoin.address.fromBase58Check(recipients[i].address).hash),
           Math.round((blockReward) * (recipients[i].percent / 100))
       );
    }


    if (rpcData.default_witness_commitment !== undefined) {
        tx.addOutput(new Buffer(rpcData.default_witness_commitment, 'hex'), 0);
    }

    txHex = tx.toHex();

    // this txHash is used elsewhere. Don't remove it.
    txHash = tx.getHash().toString('hex');

    return txHex;
};

module.exports.getFees = function(feeArray){
    var fee = Number();
    feeArray.forEach(function(value) {
        fee = fee + Number(value.fee);
    });
    return fee;
};