fix(trader): improved consolidation; readability improvements and cleanup

lib/trader.js

@@ -8,6 +8,32 @@ 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');
@@ -20,49 +46,18 @@ var Trader = module.exports = function (db) {
   this.rateInfo = null;
 };
 
-Trader.prototype._findExchange = function (name) {
-  try {
-    return require('lamassu-' + name);
-
-  } catch(_) {
-    throw new Error(name + ' module is not installed. Try running `npm install --save lamassu-' + name + '` first');
-  }
-};
-
-Trader.prototype._findTicker = function (name) {
-  var exchange = Trader.prototype._findExchange(name);
-  return exchange.ticker || exchange;
-};
-
-Trader.prototype._findTrader = function (name) {
-  var exchange = Trader.prototype._findExchange(name);
-  return exchange.trader || exchange;
-};
-
-Trader.prototype._findWallet = function (name) {
-  var exchange = Trader.prototype._findExchange(name);
-  return exchange.wallet || exchange;
-};
-
 Trader.prototype._consolidateTrades = function () {
   var queue = this._tradeQueue;
 
-  var tradeRec = {
+  // NOTE: value in satoshis stays the same no matter the currency
-    fiat: 0,
+  var consolidatedTrade = {
-    satoshis: 0,
+    currency: this.config.exchanges.settings.currency,
-    currency: this.config.exchanges.settings.currency
+    satoshis: queue.reduce(function (prev, current) {
+      return prev + current.satoshis;
+    }, 0)
   };
 
-  while (true) {
+  return consolidatedTrade;
-    var lastRec = queue.shift();
-    if (!lastRec) {
-      break;
-    }
-    tradeRec.fiat += lastRec.fiat;
-    tradeRec.satoshis += lastRec.satoshis;
-    tradeRec.currency = lastRec.currency;
-  }
-  return tradeRec;
 };
 
 Trader.prototype._purchase = function (trade, cb) {
@@ -81,20 +76,25 @@ Trader.prototype.configure = function (config) {
     throw new Error('`settings.lowBalanceMargin` has to be >= 1');
   }
 
-  var tickerExchangeCode = config.exchanges.plugins.current.ticker;
+  var plugins = config.exchanges.plugins
-  var tickerExchangeConfig = config.exchanges.plugins.settings[tickerExchangeCode] || {};
-  tickerExchangeConfig.currency = config.exchanges.settings.currency;
-  this.tickerExchange = this._findTicker(tickerExchangeCode).factory(tickerExchangeConfig);
 
-  var tradeExchangeCode = config.exchanges.plugins.current.trade;
+  // source of current BTC price (init and configure)
-  if (tradeExchangeCode) {
+  var tickerName = plugins.current.ticker;
-    var tradeExchangeConfig = config.exchanges.plugins.settings[tradeExchangeCode];
+  var tickerConfig = plugins.settings[tickerName] || {};
-    this.tradeExchange = this._findTrader(tradeExchangeCode).factory(tradeExchangeConfig);
+  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);
   }
 
-  var transferExchangeCode = config.exchanges.plugins.current.transfer;
+  // Wallet (init and configure)
-  var transferExchangeConfig = config.exchanges.plugins.settings[transferExchangeCode];
+  var walletName = plugins.current.transfer;
-  this.transferExchange = this._findWallet(transferExchangeCode).factory(transferExchangeConfig);
+  var walletConfig = plugins.settings[walletName];
+  this.transferExchange = findWallet(walletName).factory(walletConfig);
 
   this.config = config;
 
@@ -160,9 +160,7 @@ Trader.prototype.sendBitcoins = function (deviceFingerprint, tx, cb) {
   var self = this;
 
   self.db.summonTransaction(deviceFingerprint, tx, function (err, txRec) {
-    if (err) {
+    if (err) return cb(err);
-      return cb(err);
-    }
 
     if (!txRec) {
       self._clearSession(deviceFingerprint);
@@ -214,7 +212,10 @@ Trader.prototype.trade = function (rec, deviceFingerprint) {
       }, SESSION_TIMEOUT)
     };
   }
-  this._tradeQueue.push({fiat: rec.fiat, satoshis: rec.satoshis, currency: rec.currency});
+  this._tradeQueue.push({
+    satoshis: rec.satoshis,
+    currency: rec.currency
+  });
 };
 
 Trader.prototype.executeTrades = function () {
@@ -225,19 +226,12 @@ Trader.prototype.executeTrades = function () {
   var trade = this._consolidateTrades();
   logger.debug('consolidated: ', JSON.stringify(trade));
 
-  if (trade.fiat === 0) {
+  if (trade.satoshis === 0) {
     logger.debug('rejecting 0 trade');
     return;
   }
 
-  if (trade.fiat < this.config.exchanges.settings.minimumTradeFiat) {
+  logger.debug('making a trade: %d', trade.satoshis / SATOSHI_FACTOR);
-    // throw it back in the water
-    logger.debug('reject fiat too small');
-    this._tradeQueue.unshift(trade);
-    return;
-  }
-
-  logger.debug('making a trade: %d', trade.satoshis / Math.pow(10, 8));
   this._purchase(trade, function (err) {
     if (err) logger.error(err);
   });
@@ -276,16 +270,14 @@ Trader.prototype.stopPolling = function () {
 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 ?
-  var forexMultiplier = deviceRate && tradeRate ?
     deviceRate / tradeRate :
     null;
-
-  return deviceCurrency === tradeCurrency ?
-    1 :
-    forexMultiplier;
 };
 
 Trader.prototype._tradeBalanceFunc = function _tradeBalanceFunc(callback) {