package fauxExchange;

	class LimitMarketRule implements Rule {
		
		/** 
		 * This method processes the rule 
		 */
		public Trade processRule(OrderBook ob, Order lastOrder) throws TradeClosedException {
			//System.out.println("Matching on the Limit-Market Rule");
//			lastOrder.print(null);		
			
			java.util.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;
	
			//initialize price to the lastOrder's price
			double price = lastOrder.getPrice();
			int size = matchedOrder.getSize();
			
			while(orderIterator.hasNext()){
				tempOrder = (Order)orderIterator.next();
				if(!tempOrder.isMarket()){
					if ((lastOrder instanceof SellOrder && (tempOrder.getPrice() > lastOrder.getPrice()))
						|| (lastOrder instanceof BuyOrder && (tempOrder.getPrice() < lastOrder.getPrice()))){

						price = tempOrder.getPrice();
						
						break; // leave the while loop
					}
				}
			}// end while
			
			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 (lastOrder, matchedOrder, price, size);
			ob.setLastPrice(price);
			
			return aTrade;
		}// end ProcessRule
		
	/** 
	 * 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;
	}
		
}//end MarketMarketRule