var tradeCurrency = {"name":"NVC", "nameTwo":"USD"};
var timeCount = 40;          // сколько минут ждать перед закрытием неисполнившихся ордеров
var spredMin = 0.004;      // минимальная величина спреда
var N = 0.001;   // это ваше +-N к цене

var priceSell = 0;
var priceBuy = 0;


trader.logClear();
trader.log('Script start...');

tradeCurrency.pair = tradeCurrency.name + tradeCurrency.nameTwo;
var startBalance = balanceCurrency = trader.get("Balance", tradeCurrency.name);
var startBalanceTwo = trader.get("Balance", tradeCurrency.nameTwo);

var timeSell = timeBuy = timeBal = trader.get("Time");
var lastPrice = trader.get("LastPrice");
var askPrice = trader.get("AskPrice");
var bidPrice = trader.get("BidPrice");
var lastBuyPrice;

trader.on("Balance", tradeCurrency.name).changed() {
  balanceCurrency = value;
  timeSell = timeBuy = trader.get("Time");
}

trader.on("AskPrice").changed() {
  askPrice = value;
}

trader.on("BidPrice").changed() {
  bidPrice = value;
}

trader.on("LastPrice").changed() {
  lastPrice = value;
}

trader.on("Time").changed() {
  if ( (askPrice - bidPrice) > spredMin ) {
    buyFunc();  
    sellFunc();
  }
  
  if (timeCount != 0 && value - timeSell > timeCount * 60) {
    if (trader.get("OpenAsksCount")>0) trader.cancelAsks(tradeCurrency.pair);
    timeSell = value;
  }
  
  if (timeCount != 0 && value - timeBuy > timeCount * 60) {
    if (trader.get("OpenBidsCount")>0) trader.cancelBids(tradeCurrency.pair);
    timeBuy = value;
  }
}

function sumCount () {
  return trader.get("Balance", tradeCurrency.nameTwo) / trader.get("AskPrice");
}


function sellFunc() {
  var sellPrice;
  var sellCount = balanceCurrency;
  if (sellCount < 0.1) return;
  if (priceSell > 0) {
    sellPrice = priceSell + N;
  } else {
    var askPrice = trader.get("AskPrice");
    sellPrice = lastPrice > askPrice ? lastPrice : askPrice;
    sellPrice = sellPrice + N;
    if (askPrice <= lastBuyPrice) {
      sellPrice = lastBuyPrice;
      trader.log('lastBuyPrice <= askPrice, askPrice:' + askPrice + ', lastBuyPrice:' + lastBuyPrice);
    }
  }

  trader.sell(sellCount, sellPrice);
  timeSell = trader.get("Time");
}

function buyFunc() {
  var buyPrice;
  var buyCount = sumCount();
  if (buyCount < 0.1) return;
  if (priceBuy > 0) {
    buyPrice = priceBuy - N;
  } else {
    var bidPrice = trader.get("BidPrice");
    buyPrice = lastPrice < bidPrice ? lastPrice : bidPrice;
    buyPrice = buyPrice - N;
    lastBuyPrice = buyPrice;
  }

  trader.buy(buyCount.toFixed(3), buyPrice);
  timeBuy = trader.get("Time");
}