package businessLogic;

import java.rmi.RemoteException;
import java.sql.Date;

import com.db4o.ObjectContainer;
import com.db4o.ObjectSet;

import dataAccess.DB4oManager;
import domain.Offer;
import domain.RuralHouse;
import exceptions.BadDates;
import exceptions.OverlappingOfferExists;

public final class OfferManager {

	private int offerNumber = 0;
	dataAccess.DB4oManager dbMngr;
	private static OfferManager theOfferManager;

	public OfferManager() {
		try {
			this.dbMngr = DB4oManager.getInstance();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static int getNumber() {
		ObjectContainer db=DB4oManager.getContainer();
		OfferManager o=getInstance();
		o.offerNumber++;
		db.store(o);
		db.commit();
		return o.offerNumber;
	}

	/**
	 * This method returns the instance of the OfferManager class 
	 * 
	 * @return the offer manager
	 */
	public static OfferManager getInstance()  {
		ObjectContainer db=DB4oManager.getContainer();
		OfferManager b = new OfferManager();
		ObjectSet<OfferManager> result = db.queryByExample(b);
		if (!result.hasNext()){
			theOfferManager = new OfferManager();
			db.store(theOfferManager);
			db.commit();
		} else theOfferManager=(OfferManager)result.next();
		return theOfferManager;
	}
	
	/**
	 * This method creates an offer with a house number, first day, last day and price
	 * 
	 * @param House
	 *            number, start day, last day and price
	 * @return the created offer, or null, or an exception
	 */
	public Offer createOffer(RuralHouse ruralHouse, Date firstDay, Date lastDay,
			float price) throws OverlappingOfferExists, BadDates, RemoteException, Exception {
		if (firstDay.after(lastDay)||firstDay==null||lastDay==null)
			throw new BadDates();

		boolean b = dbMngr.existsOverlappingOffer(ruralHouse,firstDay,lastDay); // The ruralHouse object in the client may not be updated
		if (!b) {
			ruralHouse.createOffer(offerNumber, firstDay, lastDay, price);
			return dbMngr.createOffer(ruralHouse,firstDay,lastDay,price);			
		}
		return null;
	}

	
	public void deleteOffer(RuralHouse rh, Offer o) throws RemoteException, Exception{
		rh.offers.removeElement(o);
		dbMngr.deleteOffer( o);
	}

}