package fauxExchange;

import java.util.Iterator;

class MarketMarketRule implements Rule {
	public Trade processRule(OrderBook ob, Order lastOrder) throws TradeClosedException {
		//System.out.println("Matching on the Market-Market Rule");
//		lastOrder.print(null);
		
		
		Iterator orderIterator = null;
		Order tempOrder = null, matchedOrder = null;
		Trade aTrade = null;
		
		if (lastOrder instanceof SellOrder){
			orderIterator = ob.getBuyOrders();
		}
		else{
			orderIterator = ob.getSellOrders();
		}
		
		matchedOrder = (Order)orderIterator.next();
		tempOrder = matchedOrder;
		
		int size = matchedOrder.getSize();
		double price = ob.getLastPrice();

		while(orderIterator.hasNext()){
			tempOrder = (Order)orderIterator.next();
			if(!tempOrder.isMarket()){
				if ((lastOrder instanceof SellOrder && tempOrder.getPrice() > ob.getLastPrice())
					|| (lastOrder instanceof BuyOrder && tempOrder.getPrice() < ob.getLastPrice())){
					
					price = tempOrder.getPrice();
					
					break;
				}
			}
		}// end while

		if (matchedOrder.getSize() > lastOrder.getSize()){
			size = lastOrder.getSize();
		}
		
		aTrade = new Trade(lastOrder, matchedOrder, price, size);
		
		lastOrder.setSize(lastOrder.getSize() - size);
		matchedOrder.setSize(matchedOrder.getSize() - size);
		
		if (lastOrder.getSize() == 0) ob.deleteOrder(lastOrder);
		if (matchedOrder.getSize() == 0) ob.deleteOrder(matchedOrder);
		
		ob.setLastPrice(price);

		return aTrade;
	}// end ProcessRule
	
	/** 
	 * This method checks to see if a certain OrderBook-Order situation 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;
	}
	
}//end MarketMarketRule