/*******************************************************************************
 *  Copyright (c) 2006, 2007 Oracle. All rights reserved. This
 *  program and the accompanying materials are made available under the terms of
 *  the Eclipse Public License v1.0 which accompanies this distribution, and is
 *  available at http://www.eclipse.org/legal/epl-v10.html
 *  
 *  Contributors: Oracle. - initial API and implementation
 *  
 *******************************************************************************/
package org.eclipse.jpt.core.internal.synch;

import java.io.IOException;
import java.util.Iterator;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jdt.core.IType;
import org.eclipse.jem.java.JavaClass;
import org.eclipse.jem.java.JavaRefFactory;
import org.eclipse.jpt.core.internal.IJpaFile;
import org.eclipse.jpt.core.internal.IJpaProject;
import org.eclipse.jpt.core.internal.IMappingKeys;
import org.eclipse.jpt.core.internal.IPersistentType;
import org.eclipse.jpt.core.internal.JptCoreMessages;
import org.eclipse.jpt.core.internal.JptCorePlugin;
import org.eclipse.jpt.core.internal.content.java.JpaCompilationUnit;
import org.eclipse.jpt.core.internal.content.orm.EntityMappingsInternal;
import org.eclipse.jpt.core.internal.content.orm.XmlRootContentNode;
import org.eclipse.jpt.core.internal.content.persistence.JavaClassRef;
import org.eclipse.jpt.core.internal.content.persistence.MappingFileRef;
import org.eclipse.jpt.core.internal.content.persistence.Persistence;
import org.eclipse.jpt.core.internal.content.persistence.PersistenceFactory;
import org.eclipse.jpt.core.internal.content.persistence.PersistenceUnit;
import org.eclipse.jpt.core.internal.content.persistence.PersistenceXmlRootContentNode;
import org.eclipse.jpt.core.internal.content.persistence.resource.PersistenceResource;
import org.eclipse.jpt.utility.internal.CollectionTools;
import org.eclipse.jpt.utility.internal.Filter;
import org.eclipse.jpt.utility.internal.iterators.FilteringIterator;
import org.eclipse.jpt.utility.internal.iterators.TransformationIterator;

/**
 * Synchronizes the lists of persistent classes in a persistence unit and a 
 * persistence project.
 */
public class SynchronizeClassesJob extends Job
{
	private IFile persistenceXmlFile;
	
	
	public SynchronizeClassesJob(IFile file) {
		super(JptCoreMessages.SYNCHRONIZE_CLASSES_JOB);
		persistenceXmlFile = file;
	}
	
	protected IStatus run(IProgressMonitor monitor) {
		IProject project = persistenceXmlFile.getProject();
		
		monitor.beginTask(JptCoreMessages.SYNCHRONIZING_CLASSES_TASK, 150);
		
		if (monitor.isCanceled()) {
			return Status.CANCEL_STATUS;
		}
		
		IJpaFile jpaFile = JptCorePlugin.getJpaFile(persistenceXmlFile);
		PersistenceXmlRootContentNode root;
		try {
			root = (PersistenceXmlRootContentNode) jpaFile.getContent();
		}
		catch (ClassCastException cce) {
			return new Status(Status.ERROR, JptCorePlugin.PLUGIN_ID, JptCoreMessages.INVALID_PERSISTENCE_XML_CONTENT);
		}
		
		Persistence persistence = root.getPersistence();
		
		if (persistence == null) {
			persistence = PersistenceFactory.eINSTANCE.createPersistence();
			root.setPersistence(persistence);
		}
		
		PersistenceUnit persistenceUnit;
		
		if (persistence.getPersistenceUnits().size() > 0) {
			persistenceUnit = persistence.getPersistenceUnits().get(0);
		}
		else {
			persistenceUnit = PersistenceFactory.eINSTANCE.createPersistenceUnit();
			persistenceUnit.setName(persistenceXmlFile.getProject().getName());
			persistence.getPersistenceUnits().add(persistenceUnit);
		}
		
		PersistenceResource resource = (PersistenceResource) persistenceUnit.eResource();
		
		persistenceUnit.getClasses().clear();
		for (Iterator<String> stream = mappedTypeNames(persistenceUnit); stream.hasNext(); ) {
			String typeName = stream.next();
			JavaClassRef classRef = PersistenceFactory.eINSTANCE.createJavaClassRef();
			JavaClass javaClass = (JavaClass) JavaRefFactory.eINSTANCE.reflectType(typeName, resource.getResourceSet());
			classRef.setJavaClass(javaClass);
			persistenceUnit.getClasses().add(classRef);
		}
		
		monitor.worked(50);
		
		try {
			resource.save(null);
		}
		catch (IOException ioe) {
			return new Status(Status.ERROR, JptCorePlugin.PLUGIN_ID, JptCoreMessages.ERROR_WRITING_FILE, ioe);
		}
		
		return Status.OK_STATUS;
	}
	
	private Iterator<String> mappedTypeNames(PersistenceUnit persistenceUnit) {
		return CollectionTools.sort(
			new TransformationIterator<IPersistentType, String>(mappedTypes(persistenceUnit)) {
				@Override
				protected String transform(IPersistentType next) {
					return next.findJdtType().getFullyQualifiedName();
				}
			}
		);
	}
	
	private Iterator<IPersistentType> mappedTypes(PersistenceUnit persistenceUnit) {
		return new FilteringIterator<IPersistentType>(allJavaTypes(persistenceUnit.getJpaProject()), filter(persistenceUnit));
	}
	
	private Iterator<IPersistentType> allJavaTypes(IJpaProject jpaProject) {
		return new TransformationIterator<IJpaFile, IPersistentType>(jpaProject.jpaFiles(JptCorePlugin.JAVA_CONTENT_TYPE).iterator()) {
			@Override
			protected IPersistentType transform(IJpaFile next) {
				JpaCompilationUnit jcu = (JpaCompilationUnit) next.getContent();
				return (jcu.getTypes().isEmpty()) ? null : jcu.getTypes().get(0);
			}
		};
	}
	
	private Filter<IPersistentType> filter(final PersistenceUnit persistenceUnit) {
		return new Filter<IPersistentType>() {
			public boolean accept(IPersistentType o) {
				if (o == null) {
					return false;
				}
				if (o.getMappingKey() == IMappingKeys.NULL_TYPE_MAPPING_KEY) {
					return false;
				}
				IType jdtType = o.findJdtType();
				if (jdtType == null) {
					return false;
				}
				for (MappingFileRef mappingFileRef : persistenceUnit.getMappingFiles()) {
					if (containsType(mappingFileRef, jdtType)) {
						return false;
					}
				}
				return true;
			}
		};
	}
	
	private boolean containsType(MappingFileRef mappingFileRef, IType jdtType) {
		IJpaFile mappingFile = mappingFileRef.getMappingFile();
		if (mappingFile == null) {
			return false;
		}
		
		XmlRootContentNode root;
		try {
			root = (XmlRootContentNode) mappingFile.getContent();
		}
		catch (ClassCastException cce) {
			return false;
		}
		
		EntityMappingsInternal entityMappings = root.getEntityMappings();
		
		if (entityMappings == null) {
			return false;
		}
		
		for (IPersistentType persistentType : entityMappings.getPersistentTypes()) {
			IType otherJdtType = persistentType.findJdtType();
			if (otherJdtType != null && otherJdtType.equals(jdtType)) {
				return true;
			}
		}
		
		return false;
	}
}