EDIT

// $Id$

/**

* Copyright (C) 2014 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.taxeditor.session;

import java.util.ArrayList;

import java.util.Collection;

import java.util.List;

import org.apache.poi.ss.formula.functions.T;

import eu.etaxonomy.cdm.model.common.CdmBase;

import eu.etaxonomy.cdm.model.common.ICdmBase;

import eu.etaxonomy.cdm.persistence.hibernate.CdmDataChangeEvent;

import eu.etaxonomy.cdm.persistence.hibernate.CdmDataChangeEvent.EventType;

import eu.etaxonomy.cdm.persistence.hibernate.CdmPostDataChangeObservableListener;

import eu.etaxonomy.taxeditor.remoting.cache.CdmTransientEntityCacher;

/**

 *

 * NOTE : It would be nice to have this class performing merge / delete operations

 * using services, but this is only possible if we can 'intelligently'

 * get from a model class to the correspoding service class

 * @author cmathew

 * @date 20 Oct 2014

 *

 */

public class CdmEntitySession implements ICdmEntitySession  {

	private final CdmEntitySessionManager cdmEntitySessionManager;

	private final ICdmEntitySessionEnabled sessionOwner;

	private final CdmTransientEntityCacher cdmTransientEntityCacher;

	private final List<ICdmEntitySessionEnabled> changeObservers;

	private final List<T> rootEntities;

	CdmEntitySession(ICdmEntitySessionEnabled sessionOwner, CdmEntitySessionManager cdmEntitySessionManager) {

		this.sessionOwner = sessionOwner;

		this.cdmTransientEntityCacher = new CdmTransientEntityCacher(sessionOwner, cdmEntitySessionManager);

		this.rootEntities = new ArrayList<T>();

		this.cdmEntitySessionManager = cdmEntitySessionManager;

		this.changeObservers = new ArrayList<ICdmEntitySessionEnabled>();

		cdmEntitySessionManager.addToOwnerSessionMap(sessionOwner, this);

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#load(T)

	 */

	@Override

	public <T extends Object> T load(T obj) {

		return cdmTransientEntityCacher.load(obj,true);

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#load(T)

	 */

	@Override

	public <T extends CdmBase> T load(T cdmBase) {

		return (T)cdmTransientEntityCacher.load(cdmBase,true);

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#load(java.util.Collection)

	 */

	@Override

	public <T extends CdmBase> Collection<T> load(Collection<T> cdmBaseList) {

		return cdmTransientEntityCacher.load(cdmBaseList,true);

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#setEntitiesAsLatest()

	 */

	@Override

	public void setEntitiesAsLatest() {

	    //FIXME:Remoting need to think more about whether we really need this

//		List<CdmBase> entities = cdmTransientEntityCacher.getAllEntities();

//		for(CdmBase entity : entities) {

//			cdmEntitySessionManager.setEntityAsLatest(entity);

//		}

	}

    /**

     * Register to get updated after any interaction with the datastore

     */

	@Override

    public void registerForDataStoreChanges(ICdmEntitySessionEnabled observer) {

        CdmPostDataChangeObservableListener.getDefault().register(observer);

    }

    /**

     * Register to get updated after any interaction with the datastore

     */

	@Override

    public void unregisterForDataStoreChanges(ICdmEntitySessionEnabled observer) {

        CdmPostDataChangeObservableListener.getDefault().unregister(observer);

    }

	@Override

	public void bind() {

	    cdmEntitySessionManager.bind(sessionOwner);

	}

	/* (non-Javadoc)

	 * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#dispose()

	 */

	@Override

	public void dispose() {

		rootEntities.clear();

		cdmTransientEntityCacher.dispose();

		for(ICdmEntitySessionEnabled observer : changeObservers) {

		    CdmPostDataChangeObservableListener.getDefault().unregister(observer);

		}

		changeObservers.clear();

	}

    /* (non-Javadoc)

     * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#commit()

     */

    @Override

    public void addEvent(ICdmBase cdmBase, EventType eventType) {

        CdmDataChangeEvent cdce = CdmDataChangeEvent.NewInstance((CdmBase)cdmBase, EventType.UPDATE);

        CdmPostDataChangeObservableListener.getDefault().notifyObservers(cdce);

    }

    /* (non-Javadoc)

     * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#notify(java.util.Collection, eu.etaxonomy.cdm.persistence.hibernate.CdmDataChangeEvent.EventType)

     */

    @Override

    public <T extends ICdmBase> void addEvent(Collection <T> cdmBases, EventType eventType) {

        for(ICdmBase cdmBase : cdmBases) {

            CdmDataChangeEvent cdce = CdmDataChangeEvent.NewInstance((CdmBase)cdmBase, EventType.UPDATE);

            CdmPostDataChangeObservableListener.getDefault().notifyObservers(cdce);

        }

    }

    /* (non-Javadoc)

     * @see eu.etaxonomy.taxeditor.session.ICdmEntitySession#commit()

     */

    @Override

    public void commit() {

        CdmPostDataChangeObservableListener.getDefault().delayedNotify();

    }

}