var bcoin = require('bcoin');
var net = require('net');
var fs = require('fs');

// Standard bitcoin seeds
var seeds = [
  'seed.bitcoin.sipa.be',
  'dnsseed.bluematt.me',
  'dnsseed.bitcoin.dashjr.org',
  'seed.bitcoinstats.com',
  'seed.bitnodes.io',
  'bitseed.xf2.org'
];

var index = 0;
var pool = new bcoin.pool({
  // Number of peers allowed
  size: 32,
  // This function must return a socket that supports the standard
  // node socket model: `write()`, `destroy()` `on('data')`, etc.
  createConnection: function() {
    if (index >= seeds.length) {
      index = 0;
    }

    var addr = seeds[index++];
    var parts = addr.split(':');
    var host = parts[0];
    var port = +parts[1] || 8333;
    var socket = net.connect(port, host);

    socket.on('connect', function() {
      console.log('Connected to %s:%d', host, port);
    });

    return socket;
  },
  // Storage DB for transactions and wallet, must support
  // the levelup `put`/`del`/`createReadStream` methods.
  storage: require('levelup')(process.env.HOME + '/.bcoin', {
    db: require('leveldown'),
    valueEncoding: 'json'
  })
});

// Receive the address of another peer.
pool.on('addr', function(data, peer) {
  var host = data.ipv4 + ':' + data.port;
  if (!~seeds.indexOf(host)) {
    console.log('Found new peer: %s', host);
    seeds.push(host);
  }
});

// Receive a block.
pool.on('block', function(block, peer) {
  var hash = bcoin.utils.revHex(block.hash('hex'));
  var ip = peer.socket.remoteAddress;
  console.log(block);
  console.log('Received block %s from %s.', hash, ip);
  // Add tx hashes to our bloom filter. They're not useful if they're not our
  // own, but what the hell: let's see what's going on in the world of bitcoin.
  block.tx.forEach(function(hash) {
    pool.watch(hash);
  });
});

// Receive a transaction.
pool.on('tx', function(tx, peer) {
  var hash = bcoin.utils.revHex(tx.hash('hex'));
  var ip = peer.socket.remoteAddress;
  console.log(tx);
  console.log('Received transaction %s from %s.', hash, ip);
});

// Open our ecdsa private key (our bitcoin address is derived from this)
// `priv` can be a hex string, a binary array, or a big number (bn.js)
var privkeyfile = process.env.HOME + '/.bcoin/priv';
if (!fs.existsSync(privkeyfile)) {
  try {
    var privkey = bcoin.wallet().getPrivateKey('base58');
    fs.writeFileSync(privkeyfile, privkey);
  }
  catch(err) {
    console.log('Error creating private key file: '+err);
    return;
  }
}

var wallet = new bcoin.wallet({
  priv: fs.readFileSync(privkeyfile),
  storage: pool.storage
});

console.log('Opened our wallet with address: %s', wallet.getAddress());

// Make sure we keep an eye on any transactions pertaining to us.
pool.watch(wallet.getPublicKey());
pool.watch(wallet.getHash());

// Watch our balance update as we receive transactions.
wallet.on('balance', function(balance) {
  // Convert satoshis to BTC.
  var btc = bcoin.utils.toBTC(balance);
  console.log('Your wallet balance has been updated: %s', btc);
});