package fauxExchange;

class LimitLimitRule implements Rule {
	
	/** Processes this rule to make a trade */
	public Trade processRule (OrderBook ob, Order lastOrder) throws TradeClosedException {
		//System.out.println("Matching on the Limit-Limit Rule");
		//System.out.print("==");
//		ob.outputBook(null);
		lastOrder.print(null);
		
		java.util.Iterator orderIterator;
		Order matchedOrder;
		Trade aTrade = null;
		
		if (lastOrder instanceof SellOrder){
			orderIterator = ob.getBuyOrders();
		}
		else{
			orderIterator = ob.getSellOrders();
		}
		matchedOrder = (Order) orderIterator.next();
		if ((lastOrder instanceof SellOrder && (matchedOrder.getPrice() >= lastOrder.getPrice())  )
			|| (lastOrder instanceof BuyOrder && (matchedOrder.getPrice() <= lastOrder.getPrice()) )){
				
			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;
	}
		
}