address-watch/index.js

'use strict';

var util = require('util');
var EventEmitter = require('events').EventEmitter;
var bitcore = require('bitcore-lib');
var spawn = require('child_process').spawn;

function SatoshiCoins(options) {
  EventEmitter.call(this, options);
  this.node = options.node;

  this.alarmActivated = false;
  this.child = false;
  this.interestingAddresses = [
    '1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa', //this is the address that the genesis paid its coinbase to. Can't be spent due to a bug in the code.
    '12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX', //Block 1
    '1HLoD9E4SDFFPDiYfNYnkBLQ85Y51J3Zb1' //Block 2
  ];
  this.node.services.bitcoind.on('tx', this.transactionHandler.bind(this));
}

/*
 * We are going to need bitcoind because we will be setting event listeners (subscribers)
 * on Blocks and such
 */
SatoshiCoins.dependencies = ['bitcoind'];

/*
 * inherits the serivce base class so we get some stuff for free
 */
util.inherits(SatoshiCoins, EventEmitter);

/*
 * start: REQUIRED!! Ours just calls the callback
 */
SatoshiCoins.prototype.start = function(callback) {
  callback();
};

/*
 * stop: REQUIRED!! Ours just calls the callback
 */
SatoshiCoins.prototype.stop = function(callback) {
  callback();
};

SatoshiCoins.prototype.getAPIMethods = function() {
  return [];
};

SatoshiCoins.prototype.getPublishEvents = function() {
  return [];
};

/*
 * transactionHandler: this is the delegate when a transaction is received by your node
 */
SatoshiCoins.prototype.transactionHandler = function(txBuffer) {
  var self = this;

  var tx = bitcore.Transaction().fromBuffer(txBuffer);

  for (var i = 0; i < tx.inputs.length; i++) {
    self.transactionInputHandler(tx.inputs[i]);
  }

};

/*
 * transactionInputHandler: helper for transactionHandler
 */
SatoshiCoins.prototype.transactionInputHandler = function(input) {
  if (!input.script) {
    return;
  }
  var address = input.script.toAddress(this.node.network);
  if (address && this.interestingAddresses.indexOf(address.toString()) != -1) {
    this.soundAlarm();
  }
};

/*
 * soundAlarm: will launch a separate alarm program (not provided)
 */
SatoshiCoins.prototype.soundAlarm = function() {
  if (this.alarmActivated) {
    return;
  }

  this.alarmActivated = true;
  this.child = spawn('alarm', []);
};

SatoshiCoins.prototype.resetAlarm = function() {
  if (this.child) {
    this.child.kill();
  }
  this.alarmActivated = false;
};

module.exports = SatoshiCoins;