ExtensionManager.java

/******************************************************************************
 * Copyright (c) 2008-2013, Linagora
 *
 * 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:
 * 		Linagora - initial API and implementation
 *******************************************************************************/
 
package com.ebmwebsourcing.petals.services.su.extensions;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;

import javax.xml.namespace.QName;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.ecore.util.BasicExtendedMetaData.EStructuralFeatureExtendedMetaData.Holder;
import org.eclipse.emf.ecore.util.FeatureMap;

import com.ebmwebsourcing.petals.common.generation.Mep;
import com.ebmwebsourcing.petals.common.internal.provisional.utils.StringUtils;
import com.ebmwebsourcing.petals.services.PetalsServicesPlugin;
import com.ebmwebsourcing.petals.services.su.wizards.AbstractServiceUnitWizard;
import com.ebmwebsourcing.petals.services.su.wizards.PetalsMode;
import com.sun.java.xml.ns.jbi.AbstractEndpoint;
import com.sun.java.xml.ns.jbi.Consumes;
import com.sun.java.xml.ns.jbi.Provides;

/**
 * The class in charge of getting the contributions made to the extension-point defined by this plug-in.
 * @author Vincent Zurczak - EBM WebSourcing
 * @author Mickael Istria - EBM WebSourcing
 */
public class ExtensionManager {

	/**
	 * The identifier of the extension used to register SU versions.
	 */
	private static final String EXTENSION_ID = "com.ebmwebsourcing.petals.services.componentExtension"; //$NON-NLS-1$

	/**
	 * The unique instance of RegisteredContributors.
	 */
	public static final ExtensionManager INSTANCE = new ExtensionManager ();

	/**
	 * The component descriptions.
	 */
	private final Map<String,List<ComponentVersionDescription>> namespaceToDescriptions;


	/**
	 * Constructor.
	 */
	private ExtensionManager() {

		this.namespaceToDescriptions = new HashMap<String,List<ComponentVersionDescription>> ();
		for (ComponentVersionDescription desc : findComponentVersionClass( "componentVersionDescription", ComponentVersionDescription.class )) {
			if( desc.getNamespace() == null )
				continue;

			List<ComponentVersionDescription> descriptions = this.namespaceToDescriptions.get( desc.getNamespace());
			if( descriptions == null )
				descriptions = new ArrayList<ComponentVersionDescription> ();

			descriptions.add( desc );
			this.namespaceToDescriptions.put( desc.getNamespace(), descriptions );
		}
	}


	/**
	 * Finds the wizard handlers.
	 * @return the wizard handlers (never null, possibly empty)
	 */
	public List<AbstractServiceUnitWizard> findComponentWizards( PetalsMode mode ) {
		String key = (mode == PetalsMode.provides ? "providesExtensionWizard" : "consumesExtensionWizard");
		return findComponentVersionClass( key, AbstractServiceUnitWizard.class );
	}


	/**
	 * Finds a class associated with a component version.
	 * @return the wizard handlers (never null, possibly empty)
	 */
	@SuppressWarnings( "unchecked" )
	private <T> List<T> findComponentVersionClass( String attributeName, Class<T> theClass ) {

		List<T> result = new ArrayList<T> ();
		IConfigurationElement[] extensions = Platform.getExtensionRegistry().getConfigurationElementsFor( EXTENSION_ID );
		for( IConfigurationElement elt : extensions ) {

			for( IConfigurationElement child : elt.getChildren( "ComponentVersionSupport" )) {
				String theClassName = child.getAttribute( attributeName );
				if( StringUtils.isEmpty( theClassName ))
					continue;

				try {
					Object o = child.createExecutableExtension( attributeName );
					if( theClass.isInstance( o ))
						result.add((T) o );
					else
						PetalsServicesPlugin.log( "Expected " + theClass + " but found " + o.getClass() + ".", IStatus.ERROR );

				} catch( CoreException e ) {
					PetalsServicesPlugin.log( e, IStatus.ERROR );
				}
			}
		}

		return result;
	}


	/**
	 * Finds the component alias (e.g. SOAP, FTP).
	 * @param componentName the component name
	 * @return the component alias, or null if it was not found
	 */
	public String findComponentAlias( String componentName ) {
		List<ComponentVersionDescription> descs = findDescriptionsByComponentName( componentName );
		return descs.isEmpty() ? null : descs.get( 0 ).getComponentAlias();
	}


	/**
	 * Finds the versions associated with this component.
	 * @param componentName the component name
	 * @return the associated versions (never null)
	 */
	public SortedSet<String> findComponentVersions( String componentName ) {

		SortedSet<String> result = new TreeSet<String> ();
		for( ComponentVersionDescription desc : findDescriptionsByComponentName( componentName )) {
			if( desc.getComponentName().equals( componentName ))
				result.add( desc.getComponentVersion());
		}

		return result;
	}


	/**
	 * Finds all the component names.
	 * @return a non-null collection of component names
	 */
	public Set<String> findAllComponentNames() {

		SortedSet<String> result = new TreeSet<String> ();
		for( List<ComponentVersionDescription> descriptions : this.namespaceToDescriptions.values())
			result.add( descriptions.get( 0 ).getComponentName());

		return result;
	}


	/**
	 * Finds the default operations for a component.
	 * @param componentName the component name
	 * @param componentVersion the component version
	 * @return a (never null) map with the default operations (key = operation name, value = MEP)
	 */
	public Map<QName,Mep> findDefaultOperations( String componentName, String componentVersion ) {
		ComponentVersionDescription desc = findDescriptionByComponentNameAndVersion( componentName, componentVersion );
		return desc != null ? desc.getDefaultOperations() : new HashMap<QName,Mep>( 0 );
	}


	/**
	 * Finds the component descriptions associated with a component name.
	 * @param componentName the component name
	 * @return a non-null list of component version descriptions
	 */
	public List<ComponentVersionDescription> findDescriptionsByComponentName( String componentName ) {

		List<ComponentVersionDescription> result = new ArrayList<ComponentVersionDescription> ();
		for( List<ComponentVersionDescription> descriptions : this.namespaceToDescriptions.values()) {
			for( ComponentVersionDescription desc : descriptions ) {
				if( desc.getComponentName().equals( componentName ))
					result.add( desc );
			}
		}

		return result;
	}


	/**
	 * Finds the component description associated with a given component name and version.
	 * @param componentName the component name
	 * @param componentVersion the component version (null to pick up the first found version)
	 * @return a component version's description, or null if none was found
	 */
	public ComponentVersionDescription findDescriptionByComponentNameAndVersion( String componentName, String componentVersion ) {

		ComponentVersionDescription result = null;
		for( ComponentVersionDescription desc : findDescriptionsByComponentName( componentName )) {
			if( desc.getComponentName().equals( componentName )) {
				if( componentVersion == null || desc.getComponentVersion().equals( componentVersion )) {
					result = desc;
					break;
				}
			}
		}

		return result;
	}


	/**
	 * @return
	 */
	public Collection<ComponentVersionDescription> findAllComponentVersionDescriptions() {
		Collection<ComponentVersionDescription> result = new ArrayList<ComponentVersionDescription> ();
		for( List<ComponentVersionDescription> descs : this.namespaceToDescriptions.values())
			result.addAll( descs );

				return result;
	}


	/**
	 * @param selectedEndpoint
	 * @return
	 */
	public ComponentVersionDescription findComponentDescription( AbstractEndpoint selectedEndpoint ) {

		for (FeatureMap.Entry entry : selectedEndpoint.getGroup()) {
			EStructuralFeature feature = entry.getEStructuralFeature();
			if (feature instanceof Holder) {
				String ns = ((Holder) feature).getExtendedMetaData().getNamespace();
				List<ComponentVersionDescription> exts = this.namespaceToDescriptions.get( ns );
				if( exts == null )
					continue;

				// We can pick up the first one (the name space is the key, not the version)
				ComponentVersionDescription used = exts.get( 0 );
				if (selectedEndpoint instanceof Provides
						&& (used.isProvide() || used.isProxy()))
					return used;

				else if (selectedEndpoint instanceof Consumes
						&& (used.isConsume() || used.isProxy()))
					return used;
			}
		}

		return null;
	}
}