Migrate plugins to lib directory

lib/plugins/exchange/kraken/kraken.js

@@ -0,0 +1,54 @@
+const Kraken = require('kraken-api')
+const coinmath = require('../common/kraken')
+
+var PAIRS = {
+  BTC: {
+    USD: 'XXBTZUSD',
+    EUR: 'XXBTZEUR'
+  },
+  ETH: {
+    USD: 'XETHZUSD',
+    EUR: 'XETHZEUR'
+  }
+}
+
+module.exports = {buy, sell}
+
+function buy (account, cryptoAtoms, fiatCode, cryptoCode) {
+  return trade(account, 'buy', cryptoAtoms, fiatCode, cryptoCode)
+}
+
+function sell (account, cryptoAtoms, fiatCode, cryptoCode) {
+  return trade(account, 'sell', cryptoAtoms, fiatCode, cryptoCode)
+}
+
+function trade (account, type, cryptoAtoms, fiatCode, cryptoCode) {
+  const kraken = new Kraken(account.key, account.secret)
+  const amount = coinmath.toUnit(cryptoAtoms, cryptoCode)
+
+  if (amount.lte('0.01')) {
+    const err = new Error('Order size too small')
+    err.name = 'orderTooSmall'
+    return Promise.reject(err)
+  }
+
+  const amountStr = amount.toFixed(6)
+  const pair = PAIRS[cryptoCode][fiatCode]
+
+  var orderInfo = {
+    pair: pair,
+    type: type,
+    ordertype: 'market',
+    volume: amountStr,
+    expiretm: '+60'
+  }
+
+  kraken.api('AddOrder', orderInfo, function (error, response) {
+    if (error) {
+      // TODO: handle: EOrder:Order minimum not met (volume too low)
+      return Promise.reject(error)
+    } else {
+      return Promise.resolve()
+    }
+  })
+}