gdax.js

var Gdax = require('gdax');
var util = require('../core/util.js');
var _ = require('lodash');
var moment = require('moment');
var log = require('../core/log');

var batchSize = 100;

var Trader = function(config) {
    _.bindAll(this);

    this.post_only = true;
    this.use_sandbox = false;
    this.name = 'GDAX';
    this.import = false;
    this.scanback = false;
    this.scanbackTid = 0;
    this.scanbackResults = [];
    this.asset = config.asset;
    this.currency = config.currency;

    if(_.isObject(config)) {
        this.key = config.key;
        this.secret = config.secret;
        this.passphrase = config.passphrase;

        this.pair = [config.asset, config.currency].join('-').toUpperCase();
        this.post_only = (typeof config.post_only !== 'undefined') ? config.post_only : true;
    }

    this.gdax_public = new Gdax.PublicClient(this.pair, this.use_sandbox ? 'https://api-public.sandbox.gdax.com' : undefined);
    this.gdax = new Gdax.AuthenticatedClient(this.key, this.secret, this.passphrase, this.use_sandbox ? 'https://api-public.sandbox.gdax.com' : undefined);
}

// if the exchange errors we try the same call again after
// waiting 10 seconds
Trader.prototype.retry = function(method, args) {
    var wait = +moment.duration(10, 'seconds');
    log.debug(this.name, 'returned an error, retrying..');

    var self = this;

    // make sure the callback (and any other fn)
    // is bound to Trader
    _.each(args, function(arg, i) {
        if(_.isFunction(arg))
            args[i] = _.bind(arg, self);
    });

    // run the failed method again with the same
    // arguments after wait
    setTimeout(
        function() { method.apply(self, args) },
        wait
    );
}

Trader.prototype.getPortfolio = function(callback) {
    var result = function(err, response, data) {

        if(_.has(data, 'message')) {
            if(data.message === 'Invalid API Key' || data.message === 'Invalid Passphrase')
                util.die('GDAX said: ' + data.message);

            return callback(data.message, []);
        }

        var portfolio = data.map(function (account) {
                return {
                    name: account.currency.toUpperCase(),
                    amount: parseFloat(account.available)
                }
            }
        );
        callback(err, portfolio);
    };

    this.gdax.getAccounts(result);
}

Trader.prototype.getTicker = function(callback) {
    var result = function(err, response, data) {
        callback(err, {bid: +data.bid, ask: +data.ask})
    };

    this.gdax_public.getProductTicker(result);
}

Trader.prototype.getFee = function(callback) {
    //https://www.gdax.com/fees
    const fee = this.asset == 'BTC' ? 0.0025 : 0.003;

    //There is no maker fee, not sure if we need taker fee here
    //If post only is enabled, gdax only does maker trades which are free
    callback(false, this.post_only ? 0 : fee);
}

Trader.prototype.normalizeResult = callback => {
    return (err, resp, data) => {
        if(err)
            return callback(err);

        if(!data)
            return callback('No data');

        if(data.message)
            return callback(data);

        callback(undefined, data);
    }
}

Trader.prototype.buy = function(amount, price, callback) {
    var args = _.toArray(arguments);
    var buyParams = {
        'price': this.getMaxDecimalsNumber(price, this.currency == 'BTC' ? 5 : 2),
        'size': this.getMaxDecimalsNumber(amount),
        'product_id': this.pair,
        'post_only': this.post_only
    };

    var result = (err, data) => {
        if(err) {
            log.error('Error buying at GDAX:', err);
            return this.retry(this.buy, args);
        }
        callback(err, data.id);
    }

    this.gdax.buy(buyParams, this.normalizeResult(result));
}

Trader.prototype.sell = function(amount, price, callback) {
    var args = _.toArray(arguments);
    var sellParams = {
        'price': this.getMaxDecimalsNumber(price, this.currency == 'BTC' ? 5 : 2),
        'size': this.getMaxDecimalsNumber(amount),
        'product_id': this.pair,
        'post_only': this.post_only
    };
    var result = function(err, data) {
        if(err) {
            log.error('Error selling at GDAX:', err);
            return this.retry(this.sell, args);
        }
        callback(err, data.id);
    }.bind(this);

    this.gdax.sell(sellParams, this.normalizeResult(result));
}

Trader.prototype.checkOrder = function(order, callback) {
    var args = _.toArray(arguments);

    if (order == null) {
        return callback('EMPTY ORDER_ID', false);
    }

    var result = function(err, data) {
        if (err) {
            log.error('GDAX ERROR:', err);
            return this.retry(this.checkOrder, args);
        }

        var status = data.status;
        if (status == 'done') {
            return callback(err, true);
        } else if (status == 'rejected') {
            return callback(err, false);
        } else if (status == 'pending') {
            return callback(err, false);
        }
        callback(err, false);
    }.bind(this);

    this.gdax.getOrder(order, this.normalizeResult(result));
}

Trader.prototype.getOrder = function(order, callback) {
    var args = _.toArray(arguments);
    if (order == null) {
        return callback('EMPTY ORDER_ID', false);
    }

    var result = function(err, data) {
        if(err) {
            if(err.message === 'NotFound') {
                log.debug('GDAX NotFound error, spoofing order');
                return callback(undefined, {
                  price: 0,
                  amount: 0,
                  date: moment.unix(0)
                });
            }

            log.error('GDAX ERROR:', err);
            return this.retry(this.checkOrder, args);
        }

        var price = parseFloat( data.price );
        var amount = parseFloat( data.filled_size );
        var date = moment( data.done_at );

        callback(undefined, {price, amount, date});
    }.bind(this);

    this.gdax.getOrder(order, this.normalizeResult(result));
}

Trader.prototype.cancelOrder = function(order, callback) {
    var args = _.toArray(arguments);
    if (order == null) {
        return;
    }

    var result = function(err, data) {
        // todo, verify result..
        callback();
    };

    this.gdax.cancelOrder(order, this.normalizeResult(result));
}

Trader.prototype.getTrades = function(since, callback, descending) {
    var args = _.toArray(arguments);
    var lastScan = 0;

    var process = function(err, response, data) {
        if(err)
            return this.retry(this.getTrades, args);

        var result = _.map(data, function(trade) {
            return {
                tid: trade.trade_id,
                amount: parseFloat(trade.size),
                date: moment.utc(trade.time).format('X'),
                price: parseFloat(trade.price)
            };
        });

        if (this.scanback) {
            var last = _.last(data);
            var first = _.first(data);

            // Try to find trade id matching the since date
            if (!this.scanbackTid) {
                // either scan for new ones or we found it.
                if (moment.utc(last.time) < moment.utc(since)) {
                    this.scanbackTid = last.trade_id;
                } else {
                    log.debug('Scanning backwards...' + last.time);
                    this.gdax_public.getProductTrades({after: last.trade_id - (batchSize * lastScan) , limit: batchSize}, process);
                    lastScan++;
                    if (lastScan > 100) {
                        lastScan = 10;
                    }
                }
            }

            if (this.scanbackTid) {
            // if scanbackTid is set we need to move forward again
                log.debug('Backwards: ' + last.time + ' (' + last.trade_id + ') to ' + first.time + ' (' + first.trade_id + ')');

                if (this.import) {
                    this.scanbackTid = first.trade_id;
                    callback(null, result.reverse());
                } else {
                    this.scanbackResults = this.scanbackResults.concat(result.reverse());

                    if (this.scanbackTid != first.trade_id) {
                        this.scanbackTid = first.trade_id;
                        this.gdax_public.getProductTrades({after: this.scanbackTid + batchSize + 1, limit: batchSize}, process);
                    } else {
                        this.scanback = false;
                        this.scanbackTid = 0;
                        if (!this.import) {
                            log.debug('Scan finished: data found:' + this.scanbackResults.length);
                            callback(null, this.scanbackResults);
                        }
                        this.scanbackResults = [];
                    }
                }
            }
        } else {
            callback(null, result.reverse());
        }
    }.bind(this);

    if (since || this.scanback) {
        this.scanback = true;
        if (this.scanbackTid) {
            this.gdax_public.getProductTrades({after: this.scanbackTid + batchSize + 1, limit: batchSize}, process);
        } else {
            log.debug('Scanning back in the history needed...');
            log.debug(moment.utc(since).format());
            this.gdax_public.getProductTrades({limit: batchSize}, process);
        }
    } else {
        this.gdax_public.getProductTrades({limit: batchSize}, process);
    }

}

Trader.prototype.getMaxDecimalsNumber = function (number, decimalLimit = 8) {
  var decimalNumber = parseFloat(number);

  // The ^-?\d*\. strips off any sign, integer portion, and decimal point
  // leaving only the decimal fraction.
  // The 0+$ strips off any trailing zeroes.
  var decimalCount = ((+decimalNumber).toString()).replace(/^-?\d*\.?|0+$/g, '').length;

  var decimalMultiplier = 1;
  for (i = 0; i < decimalLimit; i++) {
      decimalMultiplier *= 10;
  }

  return decimalCount <= decimalLimit ? decimalNumber.toString() : (Math.floor(decimalNumber * decimalMultiplier) / decimalMultiplier).toFixed(decimalLimit);
};

Trader.getCapabilities = function () {
  return {
    name: 'GDAX',
    slug: 'gdax',
    currencies: ['USD', 'EUR', 'GBP', 'BTC'],
    assets: ['BTC', 'LTC', 'ETH'],
    markets: [
      { pair: ['USD', 'BTC'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['USD', 'LTC'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['USD', 'ETH'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['EUR', 'BTC'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['EUR', 'ETH'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['EUR', 'LTC'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['GBP', 'BTC'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['BTC', 'LTC'], minimalOrder: { amount: 0.01, unit: 'asset' } },
      { pair: ['BTC', 'ETH'], minimalOrder: { amount: 0.01, unit: 'asset' } }
    ],
    requires: ['key', 'secret', 'passphrase'],
    providesHistory: 'date',
    providesFullHistory: true,
    tid: 'tid',
    tradable: true,
    forceReorderDelay: true
  };
}

module.exports = Trader;