package com.dumbhippo.server.impl;



import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;



import javax.ejb.EJB;

import javax.ejb.Stateless;

import javax.persistence.EntityManager;

import javax.persistence.PersistenceContext;



import org.slf4j.Logger;



import com.dumbhippo.GlobalSetup;

import com.dumbhippo.TypeUtils;

import com.dumbhippo.identity20.Guid;

import com.dumbhippo.identity20.Guid.ParseException;

import com.dumbhippo.persistence.ExternalAccount;

import com.dumbhippo.persistence.ExternalAccountType;

import com.dumbhippo.persistence.FacebookAccount;

import com.dumbhippo.persistence.FacebookEvent;

import com.dumbhippo.persistence.FacebookEventType;

import com.dumbhippo.persistence.User;

import com.dumbhippo.server.Configuration;

import com.dumbhippo.server.ExternalAccountSystem;

import com.dumbhippo.server.FacebookSystem;

import com.dumbhippo.server.HippoProperty;

import com.dumbhippo.server.NotFoundException;

import com.dumbhippo.server.Configuration.PropertyNotFoundException;

import com.dumbhippo.server.util.EJBUtil;

import com.dumbhippo.server.views.Viewpoint;



@Stateless

public class FacebookSystemBean implements FacebookSystem {

	static private final Logger logger = GlobalSetup.getLogger(FacebookSystemBean.class);

	

	@PersistenceContext(unitName = "dumbhippo")

	private EntityManager em; 

	

	@EJB

	private ExternalAccountSystem externalAccounts;

	

	@EJB

	private Configuration config;

	

	public List<FacebookAccount> getAllAccounts() {

		List list = em.createQuery("SELECT fa FROM FacebookAccount fa").getResultList();

		return TypeUtils.castList(FacebookAccount.class, list);

	}

	

	public FacebookAccount lookupFacebookAccount(Viewpoint viewpoint, String userId) throws ParseException, NotFoundException {

        User user = EJBUtil.lookupGuid(em, User.class, new Guid(userId));

        return lookupFacebookAccount(viewpoint, user);

	}

	

	public FacebookAccount lookupFacebookAccount(Viewpoint viewpoint, User user) throws NotFoundException {

		if (!em.contains(user.getAccount()))

			throw new RuntimeException("detached account in lookupExternalAccount()");

	

		ExternalAccount externalAccount = externalAccounts.lookupExternalAccount(viewpoint, user, ExternalAccountType.FACEBOOK);



        return lookupFacebookAccount(externalAccount);

	}

	

	private FacebookAccount lookupFacebookAccount(ExternalAccount externalAccount) throws NotFoundException {

		FacebookAccount facebookAccount;

		if (externalAccount.getExtra() == null) {

			throw new NotFoundException("No facebook account details for user " + externalAccount.getAccount().getOwner());

		} else {

			facebookAccount = em.find(FacebookAccount.class, Long.parseLong(externalAccount.getExtra()));

			if (facebookAccount == null)

				throw new RuntimeException("Invalid FacebookAccount id " + externalAccount.getExtra() + " is stored in externalAccount " + externalAccount);

		}	

		

		return facebookAccount;

	}

	

	public FacebookEvent lookupFacebookEvent(Viewpoint viewpoint, long eventId) throws NotFoundException {

		FacebookEvent facebookEvent = em.find(FacebookEvent.class, eventId);

		

		// before we implement getting info about one's friends and network, we can only show

		// facebook blocks to their owners; later we can return it if the viewpoint is for someone

		// who is the owner's facebook friend or is in the same network with the owner and

		// facebookEvent.getEventType().getDisplayToOthers() is true

		if (viewpoint.isOfUser(facebookEvent.getFacebookAccount().getExternalAccount().getAccount().getOwner())) {

			return facebookEvent;

		} else {

			throw new NotFoundException("Viewpoint " + viewpoint + " can't view facebook event " + facebookEvent);

		}

	}

	

	public List<FacebookEvent> getLatestEvents(Viewpoint viewpoint, FacebookAccount facebookAccount, int eventsCount) {

		ArrayList<FacebookEvent> list = new ArrayList<FacebookEvent>();

		

		boolean viewpointIsOfOwner = viewpoint.isOfUser(facebookAccount.getExternalAccount().getAccount().getOwner());

		

		for (FacebookEvent event : facebookAccount.getFacebookEvents()) {

			if (event.getEventType().shouldDisplay(viewpointIsOfOwner)) {

                list.add(event);

			}

		}

		

		if (FacebookEventType.UNREAD_MESSAGES_UPDATE.shouldDisplay(viewpointIsOfOwner) &&

			facebookAccount.getMessageCountTimestampAsLong() > 0) {

	        list.add(new FacebookEvent(facebookAccount, FacebookEventType.UNREAD_MESSAGES_UPDATE, 

	      		                       facebookAccount.getUnreadMessageCount(), facebookAccount.getMessageCountTimestampAsLong()));

		}

		

		if (FacebookEventType.UNSEEN_POKES_UPDATE.shouldDisplay(viewpointIsOfOwner) &&

			facebookAccount.getPokeCountTimestampAsLong() > 0) {

	        list.add(new FacebookEvent(facebookAccount, FacebookEventType.UNSEEN_POKES_UPDATE, 

        		                       facebookAccount.getUnseenPokeCount(), facebookAccount.getPokeCountTimestampAsLong()));		

		}

		

		// we want newer(greater) timestamps to be in the front of the list

		Collections.sort(list, new Comparator<FacebookEvent>() {

			public int compare (FacebookEvent fe1, FacebookEvent fe2) {

				if (fe1.getEventTimestampAsLong() < fe2.getEventTimestampAsLong())

					return 1;

				else if (fe1.getEventTimestampAsLong() > fe2.getEventTimestampAsLong())

					return -1;

				else

					return 0;

			}

		});

		

		return list.subList(0, Math.min(eventsCount, list.size()));

	}

	

	public String getProfileLink(ExternalAccount externalAccount) {

		try {

		    FacebookAccount facebookAccount = lookupFacebookAccount(externalAccount);

		    return "http://www.facebook.com/profile.php?uid=" 

		           + facebookAccount.getFacebookUserId() + "&api_key=" + getApiKey();

		} catch (NotFoundException e) {

			throw new RuntimeException("An ExternalAccount passed to getProfileLink() was not associated with a valid FacebookAccount.", e);

		}

	}

	

	public String getEventLink(FacebookEvent facebookEvent) {

        if ((facebookEvent.getEventType() == FacebookEventType.LOGIN_STATUS_EVENT) && (facebookEvent.getCount() == 0)) {		

	        return "http://api.facebook.com/login.php?api_key=" + getApiKey() + "&next=/";

	    } else {

		    return "http://www.facebook.com/" + facebookEvent.getEventType().getPageName() +  ".php?uid=" 

	               + facebookEvent.getFacebookAccount().getFacebookUserId() + "&api_key=" + getApiKey();

	    }

	}

	

	public String getApiKey() {

    	String apiKey;

		try {

			apiKey = config.getPropertyNoDefault(HippoProperty.FACEBOOK_API_KEY).trim();

			if (apiKey.length() == 0)

				apiKey = null;	

		} catch (PropertyNotFoundException e) {

			apiKey = null;

		}

		

		if (apiKey == null)

			logger.warn("Facebook API key is not set, we can't use Facebook web services.");

		

		return apiKey;

	}

	

}