package fauxExchange;

import java.util.Iterator;

class MarketLimitRule implements Rule {
	
	/**
	 * Processes a rule in the attempt to find a trade
	 */
	public Trade processRule (OrderBook ob, Order lastOrder) throws TradeClosedException {
			//System.out.println("Matching on the Market-Limit Rule");
//			lastOrder.print(null);
		
		
			Iterator orderIterator;
			Order matchedOrder;
			Trade aTrade;
			if (lastOrder instanceof SellOrder){
				orderIterator = ob.getBuyOrders();
			}
			else{
				orderIterator = ob.getSellOrders();
			}
			
			matchedOrder = (Order) orderIterator.next();
			
			int size = matchedOrder.getSize();
			double price = matchedOrder.getPrice();
			
			if (matchedOrder.getSize() > lastOrder.getSize()){
				size = lastOrder.getSize();
			}
			
			matchedOrder.setSize(matchedOrder.getSize() - size);
			lastOrder.setSize(lastOrder.getSize() - size);
			
			if (matchedOrder.getSize() == 0) ob.deleteOrder(matchedOrder);
			if (lastOrder.getSize() == 0) ob.deleteOrder(lastOrder);
			
			aTrade = new Trade(matchedOrder, lastOrder, price, size);
			
			//System.out.print("POTENTIAL:");
//			aTrade.print(null);
			
			ob.setLastPrice(price);

			return aTrade;			
	}
	
	/** 
	 * This method checks whether a given order book condition applies
	 * to this rule
	 */
	public boolean fitsCriteria (OrderBook ob, Order o){
		boolean result = false;
		
		if (o.isMarket()){
			java.util.Iterator iter = null;
			if (o instanceof BuyOrder){
				iter = ob.getSellOrders();
			}else if (o instanceof SellOrder){
				iter = ob.getBuyOrders();
			}else{
				throw new IllegalArgumentException();
			}
			
			if (iter.hasNext()){
				Order tmp = (Order)iter.next();
				if (!tmp.isMarket()){
					result = true;
				}
			}else{
				result = false;
			}
		}
		
		return result;
	}
	
}