/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.event.spi;

import java.io.Serializable;

import org.hibernate.AssertionFailure;
import org.hibernate.LockMode;
import org.hibernate.LockOptions;

 Defines an event class for the loading of an entity.
Author:
Steve Ebersole/**
 *  Defines an event class for the loading of an entity.
 *
 * @author Steve Ebersole
 */
public class LoadEvent extends AbstractEvent {
	public static final LockMode DEFAULT_LOCK_MODE = LockMode.NONE;
	//Performance hotspot: avoid allocating unneeded LockOptions
	public static final LockOptions DEFAULT_LOCK_OPTIONS = new LockOptions() {
		@Override
		public LockOptions setLockMode(LockMode lockMode) {
			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
		}
		@Override
		public LockOptions setAliasSpecificLockMode(String alias, LockMode lockMode) {
			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
		}
		@Override
		public LockOptions setTimeOut(int timeout) {
			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
		}
		@Override
		public LockOptions setScope(boolean scope) {
			throw new AssertionFailure( "Should not be invoked: DEFAULT_LOCK_OPTIONS needs to be treated as immutable." );
		}
	};

	private Serializable entityId;
	private String entityClassName;
	private Object instanceToLoad;
	private LockOptions lockOptions;
	private boolean isAssociationFetch;
	private Object result;

	public LoadEvent(Serializable entityId, Object instanceToLoad, EventSource source) {
		this( entityId, null, instanceToLoad, DEFAULT_LOCK_OPTIONS, false, source );
	}

	public LoadEvent(Serializable entityId, String entityClassName, LockMode lockMode, EventSource source) {
		this( entityId, entityClassName, null, lockMode, false, source );
	}

	public LoadEvent(Serializable entityId, String entityClassName, LockOptions lockOptions, EventSource source) {
		this( entityId, entityClassName, null, lockOptions, false, source );
	}

	public LoadEvent(Serializable entityId, String entityClassName, boolean isAssociationFetch, EventSource source) {
		this( entityId, entityClassName, null, DEFAULT_LOCK_OPTIONS, isAssociationFetch, source );
	}
	
	public boolean isAssociationFetch() {
		return isAssociationFetch;
	}

	private LoadEvent(
			Serializable entityId,
			String entityClassName,
			Object instanceToLoad,
			LockMode lockMode,
			boolean isAssociationFetch,
			EventSource source) {
		this( entityId, entityClassName, instanceToLoad,
				lockMode == DEFAULT_LOCK_MODE ? DEFAULT_LOCK_OPTIONS : new LockOptions().setLockMode( lockMode ),
				isAssociationFetch, source );
	}

	private LoadEvent(
			Serializable entityId,
			String entityClassName,
			Object instanceToLoad,
			LockOptions lockOptions,
			boolean isAssociationFetch,
			EventSource source) {

		super(source);

		if ( entityId == null ) {
			throw new IllegalArgumentException("id to load is required for loading");
		}

		if ( lockOptions.getLockMode() == LockMode.WRITE ) {
			throw new IllegalArgumentException("Invalid lock mode for loading");
		}
		else if ( lockOptions.getLockMode() == null ) {
			lockOptions.setLockMode(DEFAULT_LOCK_MODE);
		}

		this.entityId = entityId;
		this.entityClassName = entityClassName;
		this.instanceToLoad = instanceToLoad;
		this.lockOptions = lockOptions;
		this.isAssociationFetch = isAssociationFetch;
	}

	public Serializable getEntityId() {
		return entityId;
	}

	public void setEntityId(Serializable entityId) {
		this.entityId = entityId;
	}

	public String getEntityClassName() {
		return entityClassName;
	}

	public void setEntityClassName(String entityClassName) {
		this.entityClassName = entityClassName;
	}

	public Object getInstanceToLoad() {
		return instanceToLoad;
	}

	public void setInstanceToLoad(Object instanceToLoad) {
		this.instanceToLoad = instanceToLoad;
	}

	public LockOptions getLockOptions() {
		return lockOptions;
	}

	public LockMode getLockMode() {
		return lockOptions.getLockMode();
	}

	public void setLockMode(LockMode lockMode) {
		if ( lockMode != lockOptions.getLockMode() ) {
			writingOnLockOptions();
			this.lockOptions.setLockMode( lockMode );
		}
	}

	private void writingOnLockOptions() {
		if ( lockOptions == DEFAULT_LOCK_OPTIONS ) {
			this.lockOptions = new LockOptions();
		}
	}

	public void setLockTimeout(int timeout) {
		if ( timeout != lockOptions.getTimeOut() ) {
			writingOnLockOptions();
			this.lockOptions.setTimeOut( timeout );
		}
	}

	public int getLockTimeout() {
		return this.lockOptions.getTimeOut();
	}

	public void setLockScope(boolean cascade) {
		if ( lockOptions.getScope() != cascade ) {
			writingOnLockOptions();
			this.lockOptions.setScope( cascade );
		}
	}

	public boolean getLockScope() {
		return this.lockOptions.getScope();
	}

	public Object getResult() {
		return result;
	}

	public void setResult(Object result) {
		this.result = result;
	}
}