refactor(plugins): DO NOT MERGE server-side support for new plugins API added

lib/app.js

@@ -5,7 +5,7 @@ var https = require('https');
 var express = require('express');
 var LamassuConfig = require('lamassu-config');
 var routes = require('./routes');
-var Trader = require('./trader');
+var tmpName = require('./tmpName');
 var PostgresqlInterface = require('./postgresql_interface');
 var logger = require('./logger');
 
@@ -14,7 +14,6 @@ module.exports = function (options) {
   var connectionString;
   var server;
   var config;
-  var trader;
   var db;
 
   connectionString = options.postgres ||
@@ -22,7 +21,8 @@ module.exports = function (options) {
 
   config = new LamassuConfig(connectionString);
   db = new PostgresqlInterface(connectionString);
-  trader = new Trader(db);
+  tmpName.init(db);
+
 
   config.load(function (err, config) {
     if (err) {
@@ -30,8 +30,8 @@ module.exports = function (options) {
       throw err;
     }
 
-    trader.configure(config);
+    tmpName.configure(config);
-    trader.startPolling();
+    tmpName.startPolling();
   });
 
   config.on('configUpdate', function () {
@@ -40,7 +40,7 @@ module.exports = function (options) {
         return logger.error('Error while reloading config');
       }
 
-      trader.configure(config);
+      tmpName.configure(config);
       logger.info('Config reloaded');
     });
   });
@@ -89,7 +89,7 @@ module.exports = function (options) {
   routes.init({
     app: app,
     lamassuConfig: config,
-    trader: trader,
+    tmpName: tmpName,
     authMiddleware: authMiddleware,
     mock: options.mock
   });

lib/routes.js

@@ -1,12 +1,13 @@
 'use strict';
 
-var _trader;
-var _lamassuConfig;
-var _idVerifier = null;
-var _trader = null;
-var _mock = false;
 var logger = require('./logger');
 
+var idVerifier = null;
+var mock = false;
+
+var tmpName;
+var config;
+
 module.exports = {
   init: init,
   getFingerprint: getFingerprint
@@ -18,8 +19,8 @@ var STALE_TICKER  = 180000;
 var STALE_BALANCE = 180000;
 
 function poll(req, res) {
-  var rateRec = _trader.rate();
+  var rateRec = tmpName.getDeviceRate();
-  var balanceRec = _trader.balance;
+  var balanceRec = tmpName.getBalance();
   var fingerprint = getFingerprint(req);
 
   logger.debug('poll request from: %s', fingerprint);
@@ -39,9 +40,9 @@ function poll(req, res) {
     return res.json({err: 'Stale balance'});
   }
 
-  var rate = rateRec.rate;
+  var rate = rateRec.rates.ask;
   if (rate === null) return res.json({err: 'No rate available'});
-  var fiatBalance = _trader.fiatBalance(fingerprint);
+  var fiatBalance = tmpName.fiatBalance(fingerprint);
   if (fiatBalance === null) return res.json({err: 'No balance available'});
 
   var idVerificationLimit = _trader.config.exchanges.settings.
@@ -51,18 +52,17 @@ function poll(req, res) {
 
   res.json({
     err: null,
-    rate: rate * _trader.config.exchanges.settings.commission,
+    rate: rate * config.exchanges.settings.commission,
     fiat: fiatBalance,
-    locale: _trader.config.brain.locale,
+    locale: config.brain.locale,
-    txLimit: parseInt(_trader.config.exchanges.settings.compliance.maximum.limit, 10),
+    txLimit: parseInt(config.exchanges.settings.compliance.maximum.limit, 10),
     idVerificationLimit: idVerificationLimit
   });
 }
 
 function trade(req, res) {
   var fingerprint = getFingerprint(req);
-  _trader.trade(req.body, fingerprint);
+  tmpName.trade(req.body, fingerprint);
-
   res.json({err: null});
 }
 
@@ -73,9 +73,9 @@ function deviceEvent(req, res) {
 }
 
 function verifyUser(req, res) {
-  if (_mock) return res.json({success: true});
+  if (mock) return res.json({success: true});
 
-  _idVerifier.verifyUser(req.body, function (err, idResult) {
+  idVerifier.verifyUser(req.body, function (err, idResult) {
     if (err) {
       logger.error(err);
       return res.json({err: 'Verification failed'});
@@ -87,7 +87,7 @@ function verifyUser(req, res) {
 function verifyTransaction(req, res) {
   if (_mock) return res.json({success: true});
 
-  _idVerifier.verifyTransaction(req.body, function (err, idResult) {
+  idVerifier.verifyTransaction(req.body, function (err, idResult) {
     if (err) {
       logger.error(err);
       return res.json({err: 'Verification failed'});
@@ -98,7 +98,7 @@ function verifyTransaction(req, res) {
 
 function send(req, res) {
   var fingerprint = getFingerprint(req);
-  _trader.sendBitcoins(fingerprint, req.body, function(err, txHash) {
+  tmpName.sendBitcoins(fingerprint, req.body, function(err, txHash) {
     res.json({
       err: err && err.message,
       txHash: txHash,
@@ -111,7 +111,7 @@ function pair(req, res) {
   var token = req.body.token;
   var name = req.body.name;
 
-  _lamassuConfig.pair(
+  config.pair(
     token,
     getFingerprint(req),
     name,
@@ -125,17 +125,17 @@ function pair(req, res) {
   );
 }
 
-function init(config) {
+function init(localConfig) {
-  _lamassuConfig = config.lamassuConfig;
+  config = localConfig.lamassuConfig;
-  _trader = config.trader;
+  tmpName = localConfig.tmpName;
-  _mock = config.mock;
+  mock = localConfig.mock;
 
-  var authMiddleware = config.authMiddleware;
+  var authMiddleware = localConfig.authMiddleware;
-  var app = config.app;
+  var app = localConfig.app;
-  _lamassuConfig.readExchangesConfig(function (err, res) {
+  config.readExchangesConfig(function (err, res) {
     var idVerifyConfig = res.exchanges.plugins.settings.identitymind;
-    _idVerifier = require('lamassu-identitymind');
+    idVerifier = require('lamassu-identitymind');
-    _idVerifier.init(idVerifyConfig);
+    idVerifier.init(idVerifyConfig);
   });
 
   app.get('/poll', authMiddleware, poll);

lib/tmpName.js

@@ -0,0 +1,356 @@
+'use strict';
+
+var async   = require('async');
+
+var logger  = require('./logger');
+
+
+var SATOSHI_FACTOR = 1e8;
+var SESSION_TIMEOUT = 60 * 60 * 1000;
+var POLLING_RATE = 60 * 1000; // poll each minute
+
+var db = null;
+
+var tickerPlugin = null;
+var traderPlugin = null;
+var walletPlugin = null;
+
+var cachedConfig = null;
+var deviceCurrency = 'USD'; // Can 'USD' it be set as default?
+
+var lastBalances = null;
+var lastRates = {};
+
+var balanceInterval = null;
+var rateInterval = null;
+var tradeInterval = null;
+
+var tradesQueue = [];
+var sessions = {};
+
+
+// that's basically a constructor
+exports.init = function init(databaseHandle) {
+  if (!databaseHandle) {
+    throw new Error('`db` is required');
+  }
+
+  db = databaseHandle;
+}
+
+
+function loadPlugin(name, config) {
+  var moduleMethods = {
+    ticker: [ 'ticker' ],
+    trader: [ 'balance', 'purchase', 'sell' ],
+    wallet: [ 'balance', 'sendBitcoins' ]
+  };
+
+  var plugin = null;
+
+  try {
+    plugin = require('lamassu-' + name);
+
+  } catch(_) {
+    throw new Error(name + ' module is not installed. Try running \'npm install --save lamassu-' + name + '\' first');
+  }
+
+  plugin.SUPPORTED_MODULES.forEach(function(moduleName) {
+    moduleMethods[moduleName].forEach(function(methodName) {
+      if (typeof plugin[methodName] !== 'function') {
+        throw new Error('\'' + name + '\' declares \'' + moduleName + '\', but fails to implement \'' + methodName + '\' method');
+      }
+    });
+  });
+
+  if (config !== null) {
+    plugin.config(config);
+  }
+
+  return plugin;
+};
+
+
+exports.configure = function configure(config) {
+  if (config.exchanges.settings.lowBalanceMargin < 1) {
+    throw new Error('`settings.lowBalanceMargin` has to be >= 1');
+  }
+
+  deviceCurrency = config.exchanges.settings.currency;
+  var plugins = config.exchanges.plugins
+
+  // [required] configure (or load) ticker
+  var tickerName = plugins.current.ticker;
+  var tickerConfig = plugins.settings[tickerName] || {};
+  tickerConfig.currency = deviceCurrency;
+
+  if (tickerPlugin) tickerPlugin.config(tickerConfig);
+  else tickerPlugin = loadPlugin(tickerName, tickerConfig);
+
+
+  // [required] configure (or load) wallet
+  var walletName = plugins.current.transfer;
+  var walletConfig = plugins.settings[walletName];
+
+  if (walletPlugin) walletPlugin.config(walletConfig);
+  else walletPlugin = loadPlugin(walletName, walletConfig);
+
+
+  // [optional] configure (or load) trader
+  var traderName = plugins.current.trade;
+  if (traderName) { // traderPlugin may be disabled
+    var traderConfig = plugins.settings[traderName];
+
+    if (traderPlugin) traderPlugin.config(traderConfig);
+    else traderPlugin = loadPlugin(traderName, traderConfig);
+  }
+
+  cachedConfig = config;
+
+  pollBalance();
+  pollRate();
+};
+
+
+// This is where we record starting trade balance at the beginning
+// of the user session
+exports.trade = function trade(rawTrade, deviceFingerprint) {
+  var sessionInfo = sessions[deviceFingerprint];
+
+  if (!sessionInfo) {
+    sessions[deviceFingerprint] = {
+      timestamp: Date.now(),
+      reaper: setTimeout(function() {
+        delete sessions[deviceFingerprint];
+      }, SESSION_TIMEOUT)
+    };
+  }
+
+  tradesQueue.push({
+    currency: rawTrade.currency,
+    satoshis: rawTrade.satoshis
+  });
+};
+
+exports.fiatBalance = function fiatBalance(deviceFingerprint) {
+  var rawRate = getDeviceRate().rates.ask;
+  var commision = cachedConfig.exchanges.settings.commision;
+
+  if (!rawRate || !lastBalances) return null;
+
+  // The rate is actually our commission times real rate.
+  var rate = commission * rawRate;
+
+  // `lowBalanceMargin` is our safety net. It's a number > 1, and we divide
+  // all our balances by it to provide a safety margin.
+  var lowBalanceMargin = cachedConfig.exchanges.settings.lowBalanceMargin;
+
+  // `balance.transferBalance` is the balance of our transfer account (the one
+  // we use to send Bitcoins to clients) in satoshis.
+  var transferBalance = balance.transferBalance;
+
+  // Since `transferBalance` is in satoshis, we need to turn it into
+  // bitcoins and then fiat to learn how much fiat currency we can exchange.
+  //
+  // Unit validity proof: [ $ ] = [ (B * 10^8) / 10^8 * $/B ]
+  //                      [ $ ] = [ B * $/B ]
+  //                      [ $ ] = [ $ ]
+  var fiatTransferBalance = ((transferBalance / SATOSHI_FACTOR) * rate) / lowBalanceMargin;
+
+  return fiatTransferBalance;
+};
+
+exports.sendBitcoins = function sendBitcoins(deviceFingerprint, tx, callback) {
+  db.summonTransaction(deviceFingerprint, tx, function(err, txInfo) {
+    if (err) return callback(err);
+
+    if (!txInfo) {
+      clearSession(deviceFingerprint);
+
+      return walletPlugin.sendBitcoins(
+        tx.toAddress,
+        tx.satoshis,
+        cachedConfig.exchanges.settings.transactionFee,
+
+        function(err, txHash) {
+          if (err) {
+            var status = err.name === 'InsufficientFunds' ?
+              'insufficientFunds' :
+              'failed';
+
+            db.reportTransactionError(tx, err.message, status);
+            return callback(err);
+          }
+
+          db.completeTransaction(tx, txHash);
+          pollBalance();
+          callback(null, txHash);
+        }
+      );
+    }
+
+    // Out of bitcoins: special case
+    var txErr = null;
+    if (txInfo.err) {
+      txErr = new Error(txInfo.err);
+      if (txInfo.status === 'insufficientFunds') {
+        txErr.name = 'InsufficientFunds';
+      }
+    }
+
+    // transaction exists, but txHash might be null,
+    // in which case ATM should continue polling
+    pollBalance();
+    callback(txErr, txInfo.txHash);
+  });
+};
+
+
+/*
+ * Polling livecycle
+ */
+exports.startPolling = function startPolling() {
+  executeTrades();
+
+  if (!balanceInterval) {
+    balanceInterval = setInterval(pollBalance, POLLING_RATE);
+  }
+
+  if (!rateInterval) {
+    rateInterval = setInterval(pollRate, POLLING_RATE);
+  }
+
+  // Always start trading, even if we don't have a trade exchange configured,
+  // since configuration can always change in `Trader#configure`.
+  // `Trader#executeTrades` returns early if we don't have a trade exchange
+  // configured at the moment.
+  if (!tradeInterval) {
+    tradeInterval = setInterval(
+      executeTrades,
+      cachedConfig.exchanges.settings.tradeInterval
+    );
+  }
+};
+function stopPolling() {
+  clearInterval(balanceInterval);
+  clearInterval(rateInterval);
+  // clearInterval(tradeInterval); // TODO: should this get cleared too?
+};
+
+
+function pollBalance(callback) {
+  logger.debug('collecting balance');
+
+  var jobs = {
+    transferBalance: walletPlugin.balance
+  };
+
+  // only add if trader is enabled
+  // if (traderPlugin) {
+  //   // NOTE: we would need to handle when traderCurrency!=deviceCurrency
+  //   jobs.tradeBalance = traderPlugin.balance;
+  // }
+
+  async.parallel(jobs, function(err, balance) {
+    if (err) {
+      logger.error(err);
+      return callback && callback(err);
+    }
+
+    logger.debug('Balance update:', balance);
+    balance.timestamp = Date.now();
+    lastBalances = balance;
+
+    return callback && callback(null, lastBalances);
+  });
+};
+
+function pollRate(callback) {
+  logger.debug('polling for rates');
+
+  tickerPlugin.ticker(deviceCurrency, function(err, resRates) {
+    if (err) {
+      logger.error(err);
+      return callback && callback(err);
+    }
+
+    logger.debug('got rates: %j', resRates);
+    resRates.timestamp = new Date();
+    lastRates = resRates;
+
+    return callback && callback(null, lastRates);
+  });
+};
+
+
+/*
+ * Getters | Helpers
+ */
+function getLastRate(currency) {
+  if (!lastRates) return null;
+
+  var tmpCurrency = currency || deviceCurrency;
+  if (!lastRates[tmpCurrency]) return null;
+
+  return lastRates[tmpCurrency];
+};
+function getDeviceRate() {
+  return getLastRate(deviceCurrency);
+};
+
+function getBalance() {
+  if (!lastBalances) return null;
+
+  return lastBalances.transferBalance;
+};
+
+function clearSession(deviceFingerprint) {
+  var session = sessions[deviceFingerprint];
+  if (session) {
+    clearTimeout(session.reaper);
+    delete sessions[deviceFingerprint];
+  }
+};
+
+
+/*
+ * Trader functions
+ */
+function purchase(trade, callback) {
+  traderPlugin.purchase(trade.satoshis, null, function(err, _) {
+    if (err) return callback(err);
+    pollBalance();
+    callback && callback();
+  });
+};
+
+function consolidateTrades() {
+  // NOTE: value in satoshis stays the same no matter the currency
+  var consolidatedTrade = {
+    currency: deviceCurrency,
+    satoshis: tradesQueue.reduce(function(prev, current) {
+      return prev + current.satoshis;
+    }, 0)
+  };
+
+  logger.debug('consolidated: ', JSON.stringify(consolidatedTrade));
+  return consolidatedTrade;
+};
+
+function executeTrades() {
+  if (!traderPlugin) return;
+
+  logger.debug('checking for trades');
+
+  var trade = consolidateTrades();
+
+  if (trade.satoshis === 0) {
+    logger.debug('rejecting 0 trade');
+    return;
+  }
+
+  logger.trade.debug('making a trade: %d', trade.satoshis / SATOSHI_FACTOR);
+  purchase(trade, function(err) {
+    if (err) logger.error(err);
+  });
+};

lib/trader.js

@@ -1,367 +0,0 @@
-'use strict';
-
-var async = require('async');
-var logger = require('./logger');
-
-var SATOSHI_FACTOR = 1e8;
-
-// TODO: Define this somewhere more global
-var SESSION_TIMEOUT = 60 * 60 * 1000;   // an hour
-
-
-function findExchange(name) {
-  try {
-    return require('lamassu-' + name);
-
-  } catch(_) {
-    throw new Error(name + ' module is not installed. Try running `npm install --save lamassu-' + name + '` first');
-  }
-};
-
-function findTicker (name) {
-  var exchange = findExchange(name);
-  return exchange.ticker || exchange;
-};
-
-function findTrader (name) {
-  var exchange = findExchange(name);
-  return exchange.trader || exchange;
-};
-
-function findWallet (name) {
-  var exchange = findExchange(name);
-  return exchange.wallet || exchange;
-};
-
-
-var Trader = module.exports = function (db) {
-  if (!db) {
-    throw new Error('`db` is required');
-  }
-
-  this.db = db;
-  this.rates = {};
-  this._tradeQueue = [];
-  this._sessionInfo = {};
-  this.rateInfo = null;
-};
-
-Trader.prototype._consolidateTrades = function () {
-  var queue = this._tradeQueue;
-
-  // NOTE: value in satoshis stays the same no matter the currency
-  var consolidatedTrade = {
-    currency: this.config.exchanges.settings.currency,
-    satoshis: queue.reduce(function (prev, current) {
-      return prev + current.satoshis;
-    }, 0)
-  };
-
-  return consolidatedTrade;
-};
-
-Trader.prototype._purchase = function (trade, cb) {
-  var self = this;
-  var tradeCurrency = this.tradeExchange.currency();
-  var rate = this.rate(tradeCurrency).rate;
-  this.tradeExchange.purchase(trade.satoshis, rate, function (err) {
-    if (err) return cb(err);
-    self.pollBalance();
-    cb();
-  });
-};
-
-Trader.prototype.configure = function (config) {
-  if (config.exchanges.settings.lowBalanceMargin < 1) {
-    throw new Error('`settings.lowBalanceMargin` has to be >= 1');
-  }
-
-  var plugins = config.exchanges.plugins
-
-  // source of current BTC price (init and configure)
-  var tickerName = plugins.current.ticker;
-  var tickerConfig = plugins.settings[tickerName] || {};
-  tickerConfig.currency = config.exchanges.settings.currency;
-  this.tickerExchange = findTicker(tickerName).factory(tickerConfig);
-
-  // Exchange used for trading (init and configure)
-  var traderName = plugins.current.trade;
-  if (traderName) {
-    var tradeConfig = plugins.settings[traderName];
-    this.tradeExchange = findTrader(traderName).factory(tradeConfig);
-  }
-
-  // Wallet (init and configure)
-  var walletName = plugins.current.transfer;
-  var walletConfig = plugins.settings[walletName];
-  this.transferExchange = findWallet(walletName).factory(walletConfig);
-
-  this.config = config;
-
-  this.pollBalance();
-  this.pollRate();
-};
-
-// IMPORTANT: This function returns the estimated minimum available balance
-// in fiat as of the start of the current user session on the device. User
-// session starts when a user presses then Start button and ends when we
-// send the bitcoins.
-Trader.prototype.fiatBalance = function (deviceFingerprint) {
-  var rawRate = this.rate(this.config.exchanges.settings.currency).rate;
-  var balance = this.balance;
-  var commission = this.config.exchanges.settings.commission;
-
-  if (!rawRate || !balance) {
-    return null;
-  }
-
-  // The rate is actually our commission times real rate.
-  var rate = commission * rawRate;
-
-  // `lowBalanceMargin` is our safety net. It's a number > 1, and we divide
-  // all our balances by it to provide a safety margin.
-  var lowBalanceMargin = this.config.exchanges.settings.lowBalanceMargin;
-
-  // `balance.transferBalance` is the balance of our transfer account (the one
-  // we use to send Bitcoins to clients) in satoshis.
-  var transferBalance = balance.transferBalance;
-
-  // Since `transferBalance` is in satoshis, we need to turn it into
-  // bitcoins and then fiat to learn how much fiat currency we can exchange.
-  //
-  // Unit validity proof: [ $ ] = [ (B * 10^8) / 10^8 * $/B ]
-  //                      [ $ ] = [ B * $/B ]
-  //                      [ $ ] = [ $ ]
-  var fiatTransferBalance = ((transferBalance / SATOSHI_FACTOR) * rate) / lowBalanceMargin;
-
-  // If this server is also configured to trade received fiat for Bitcoins,
-  // we also need to calculate if we have enough funds on our trade exchange.
-  if (balance.tradeBalance === null) return fiatTransferBalance;
-  var tradeBalance = balance.tradeBalance;
-
-  // We're reporting balance as of the start of the user session.
-  var sessionInfo = this._sessionInfo[deviceFingerprint];
-  var sessionBalance = sessionInfo ? sessionInfo.tradeBalance : tradeBalance;
-  var fiatTradeBalance = sessionBalance / lowBalanceMargin;
-
-  // And we return the smallest number.
-  return Math.min(fiatTransferBalance, fiatTradeBalance);
-};
-
-Trader.prototype._clearSession = function (deviceFingerprint) {
-  var sessionInfo = this._sessionInfo[deviceFingerprint];
-  if (sessionInfo) {
-    clearTimeout(sessionInfo.reaper);
-    delete this._sessionInfo[deviceFingerprint];
-  }
-};
-
-Trader.prototype.sendBitcoins = function (deviceFingerprint, tx, cb) {
-  var self = this;
-
-  self.db.summonTransaction(deviceFingerprint, tx, function (err, txRec) {
-    if (err) return cb(err);
-
-    if (!txRec) {
-      self._clearSession(deviceFingerprint);
-      return self.transferExchange.sendBitcoins(
-        tx.toAddress,
-        tx.satoshis,
-        self.config.exchanges.settings.transactionFee,
-        function(err, txHash) {
-          if (err) {
-            var status = err.name === 'InsufficientFunds' ?
-              'insufficientFunds' :
-              'failed';
-            self.db.reportTransactionError(tx, err.message, status);
-            return cb(err);
-          }
-
-          self.db.completeTransaction(tx, txHash);
-          self.pollBalance();
-          cb(null, txHash);
-        }
-      );
-    }
-
-    // Out of bitcoins: special case
-    var txErr = null;
-    if (txRec.err) {
-      txErr = new Error(txRec.err);
-      if (txRec.status === 'insufficientFunds') txErr.name = 'InsufficientFunds';
-    }
-
-    // transaction exists, but txHash might be null,
-    // in which case ATM should continue polling
-    self.pollBalance();
-    cb(txErr, txRec.txHash);
-  });
-};
-
-Trader.prototype.deviceEvent = function deviceEvent(rec, deviceFingerprint) {
-  this.db.recordDeviceEvent(deviceFingerprint, rec, function (err) {
-    if (err) logger.error(err);
-  });
-};
-
-Trader.prototype.trade = function (rec, deviceFingerprint) {
-  this.db.recordBill(deviceFingerprint, rec, function (err) {
-    if (err) logger.error(err);
-  });
-
-  // This is where we record starting trade balance at the beginning
-  // of the user session
-  var sessionInfo = this._sessionInfo[deviceFingerprint];
-  var self = this;
-  if (!sessionInfo) {
-    this._sessionInfo[deviceFingerprint] = {
-      tradeBalance: this.balance.tradeBalance,
-      timestamp: Date.now(),
-      reaper: setTimeout(function () {
-        delete self._sessionInfo[deviceFingerprint];
-      }, SESSION_TIMEOUT)
-    };
-  }
-  this._tradeQueue.push({
-    satoshis: rec.satoshis,
-    currency: rec.currency
-  });
-};
-
-Trader.prototype.executeTrades = function () {
-  if (!this.tradeExchange) return;
-
-  logger.debug('checking for trades');
-
-  var trade = this._consolidateTrades();
-  logger.debug('consolidated: ', JSON.stringify(trade));
-
-  if (trade.satoshis === 0) {
-    logger.debug('rejecting 0 trade');
-    return;
-  }
-
-  logger.debug('making a trade: %d', trade.satoshis / SATOSHI_FACTOR);
-  this._purchase(trade, function (err) {
-    if (err) logger.error(err);
-  });
-};
-
-Trader.prototype.startPolling = function () {
-  this.executeTrades();
-
-  this.balanceInterval = setInterval(this.pollBalance.bind(this), 60 * 1000);
-  this.rateInterval = setInterval(this.pollRate.bind(this), 60 * 1000);
-
-  // Always start trading, even if we don't have a trade exchange configured,
-  // since configuration can always change in `Trader#configure`.
-  // `Trader#executeTrades` returns early if we don't have a trade exchange
-  // configured at the moment.
-  this.tradeInterval = setInterval(
-    this.executeTrades.bind(this),
-    this.config.exchanges.settings.tradeInterval
-  );
-};
-
-Trader.prototype.stopPolling = function () {
-  clearInterval(this.balanceInterval);
-  clearInterval(this.rateInterval);
-};
-
-// Trade exchange could be in a different currency than Bitcoin Machine.
-// For instance, trade exchange could be Bitstamp, denominated in USD,
-// while Bitcoin Machine is set to ILS.
-//
-// We need this function to convert the trade exchange balance into the
-// Bitcoin Machine denomination, in the example case: ILS.
-//
-// The best way to do that with available data is to take the ratio between
-// the exchange rates for the Bitcoin Machine and the trade exchange.
-Trader.prototype._tradeForexMultiplier = function _tradeForexMultiplier() {
-  var deviceCurrency = this.config.exchanges.settings.currency;
-  var tradeCurrency = this.tradeExchange.currency();
-  if (deviceCurrency === tradeCurrency)
-    return 1;
-
-  var deviceRate = this._deviceRate();
-  var tradeRate = this._tradeRate();
-  return deviceRate && tradeRate ?
-    deviceRate / tradeRate :
-    null;
-};
-
-Trader.prototype._tradeBalanceFunc = function _tradeBalanceFunc(callback) {
-  if (!this.tradeExchange) return callback(null, null);
-  var forexMultiplier = this._tradeForexMultiplier();
-  if (!forexMultiplier) return callback(new Error('Can\'t compute balance, no tickers yet.'));
-  this.tradeExchange.balance(function (err, localBalance) {
-    if (err) return callback(err);
-    callback(null, localBalance * forexMultiplier);
-  });
-};
-
-Trader.prototype.pollBalance = function (callback) {
-  var self = this;
-
-  logger.debug('collecting balance');
-
-  var transferBalanceFunc = this.transferExchange.balance.bind(this.transferExchange);
-  var tradeBalanceFunc = this._tradeBalanceFunc.bind(this);
-
-  async.parallel({
-    transferBalance: transferBalanceFunc,
-    tradeBalance: tradeBalanceFunc
-  }, function (err, balance) {
-    if (err) {
-      return callback && callback(err);
-    }
-
-    balance.timestamp = Date.now();
-    logger.debug('Balance update:', balance);
-    self.balance = balance;
-
-    return callback && callback();
-  });
-};
-
-Trader.prototype.pollRate = function (callback) {
-  var self = this;
-
-  logger.debug('polling for rates...');
-  var deviceCurrency = this.config.exchanges.settings.currency;
-  var currencies = [deviceCurrency];
-  if (this.tradeExchange) {
-    var tradeCurrency = this.tradeExchange.currency();
-    if (tradeCurrency !== deviceCurrency) currencies.push(tradeCurrency);
-  }
-
-  self.tickerExchange.ticker(currencies, function(err, resRates) {
-    if (err) {
-      logger.error(err);
-      return callback && callback(err);
-    }
-
-    logger.debug('got rates: %j', resRates);
-    self.rateInfo = {rates: resRates, timestamp: new Date()};
-    if (callback) callback();
-  });
-};
-
-Trader.prototype._deviceRate = function _deviceRate() {
-  if (!this.rateInfo) return null;
-  return this.rateInfo.rates[this.config.exchanges.settings.currency].rate;
-};
-
-Trader.prototype._tradeRate = function _tradeRate() {
-  if (!this.tradeExchange || !this.rateInfo) return null;
-  return this.rateInfo.rates[this.tradeExchange.currency()].rate;
-};
-
-// This is the rate in local currency to quote to the user
-Trader.prototype.rate = function () {
-  if (!this.rateInfo) return null;
-  return {
-    rate: this._deviceRate(),
-    timestamp: this.rateInfo.timestamp
-  };
-};