plugins/org.eclipse.ease/src/org/eclipse/ease/service/ScriptService.java - gerrit/ease/org.eclipse.ease.core - Git at Google

 /*******************************************************************************
  * Copyright (c) 2013 Christian Pontesegger and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * Contributors:
  *     Christian Pontesegger - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ease.service;

 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;

 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.InvalidRegistryObjectException;
 import org.eclipse.core.runtime.ListenerList;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.content.IContentDescription;
 import org.eclipse.core.runtime.content.IContentType;
 import org.eclipse.core.runtime.content.IContentTypeManager;
 import org.eclipse.ease.AbstractScriptEngine;
 import org.eclipse.ease.Activator;
 import org.eclipse.ease.ICodeFactory;
 import org.eclipse.ease.ICodeParser;
 import org.eclipse.ease.IExecutionListener;
 import org.eclipse.ease.IScriptEngine;
 import org.eclipse.ease.IScriptEngineLaunchExtension;
 import org.eclipse.ease.Logger;
 import org.eclipse.ease.Script;
 import org.eclipse.ease.ScriptResult;
 import org.eclipse.ease.modules.ModuleCategoryDefinition;
 import org.eclipse.ease.modules.ModuleDefinition;
 import org.eclipse.ease.tools.ResourceTools;
 import org.eclipse.ui.PlatformUI;
 import org.osgi.framework.BundleEvent;
 import org.osgi.framework.BundleListener;

 public final class ScriptService implements IScriptService, BundleListener, IExecutionListener {

 	private static final String ENGINE = "engine";

 	private static final String ENGINE_ID = "engineID";

 	private static final Object EXTENSION_MODULE = "module";

 	private static final Object EXTENSION_CATEGORY = "category";

 	private static final String EXTENSION_LANGUAGE_ID = "org.eclipse.ease.language";

 	private static final String EXTENSION_MODULES_ID = "org.eclipse.ease.modules";

 	private static final String EXTENSION_SCRIPTTYPE_ID = "org.eclipse.ease.scriptType";

 	private static final String SCRIPTTYPE_NAME = "name";

 	private static final String LAUNCH_EXTENSION = "launchExtension";

 	private static ScriptService fInstance = null;

 	public static IScriptService getService() {
 		try {
 			return PlatformUI.getWorkbench().getService(IScriptService.class);
 		} catch (final IllegalStateException e) {
 			// workbench has not been created yet, might be running in headless mode
 			return ScriptService.getInstance();
 		}
 	}

 	public static synchronized ScriptService getInstance() {
 		if (fInstance == null)
 			fInstance = new ScriptService();

 		return fInstance;
 	}

 	private Collection<ModuleDefinition> fAvailableModules = null;

 	private Map<String, EngineDescription> fEngineDescriptions = null;

 	private Map<String, ScriptType> fScriptTypes = null;

 	private Map<String, ModuleCategoryDefinition> fAvailableModuleCategories = null;

 	private final Collection<IScriptEngine> fRunningEngines = new ArrayList<>();

 	private final ListenerList<IScriptEngineLaunchExtension> fEngineListeners = new ListenerList<>();

 	private ScriptService() {
 		Activator.getDefault().getContext().addBundleListener(this);
 	}

 	@Override
 	public void addEngineListener(IScriptEngineLaunchExtension listener) {
 		if (listener != null)
 			fEngineListeners.add(listener);
 	}

 	@Override
 	public void removeEngineListener(IScriptEngineLaunchExtension listener) {
 		fEngineListeners.remove(listener);
 	}

 	@Override
 	public EngineDescription getEngineByID(final String engineID) {
 		return getEngineDescriptions().get(engineID);
 	}

 	@Override
 	public synchronized Collection<ModuleDefinition> getAvailableModules() {
 		if (fAvailableModules == null) {
 			fAvailableModules = new HashSet<>();
 			final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_MODULES_ID);
 			for (final IConfigurationElement e : config) {
 				if (e.getName().equals(EXTENSION_MODULE)) {
 					// module extension detected
 					final ModuleDefinition definition = new ModuleDefinition(e);
 					if (definition.getModuleClass() != null)
 						fAvailableModules.add(definition);

 					else
 						Logger.warning(Activator.PLUGIN_ID,
 								"Module <" + definition.getName() + "> in plugin <" + definition.getBundleID() + "> could not be located!");
 				}
 			}
 		}

 		return fAvailableModules;
 	}

 	@Override
 	public Collection<EngineDescription> getEngines() {
 		return getEngineDescriptions().values();
 	}

 	@Override
 	public List<EngineDescription> getEngines(final String scriptType) {
 		final List<EngineDescription> result = new ArrayList<>();

 		for (final EngineDescription description : getEngines()) {
 			if (description.supports(scriptType))
 				result.add(description);
 		}

 		// sort by priority
 		Collections.sort(result, (o1, o2) -> o2.getPriority() - o1.getPriority());

 		return result;
 	}

 	private synchronized Map<String, EngineDescription> getEngineDescriptions() {
 		if (fEngineDescriptions == null) {
 			fEngineDescriptions = new HashMap<>();
 			final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_LANGUAGE_ID);

 			for (final IConfigurationElement e : config) {
 				if (ENGINE.equals(e.getName())) {
 					final EngineDescription engine = new EngineDescription(e);
 					fEngineDescriptions.put(engine.getID(), engine);
 				}
 			}
 		}
 		return fEngineDescriptions;
 	}

 	@Override
 	public Collection<IScriptEngineLaunchExtension> getLaunchExtensions(final EngineDescription engineDescription) {
 		final String targetEngineID = engineDescription.getID();

 		final Collection<IScriptEngineLaunchExtension> extensions = new HashSet<>();
 		final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_LANGUAGE_ID);
 		for (final IConfigurationElement e : config) {
 			try {
 				if (LAUNCH_EXTENSION.equals(e.getName())) {
 					// Parse engine ID to backwards compatible regular expression
 					String engineID = e.getAttribute(ENGINE_ID);
 					if ((engineID == null) || engineID.matches("^\\*?$")) {
 						engineID = ".*";
 					}
 					if (!targetEngineID.matches(engineID)) {
 						continue;
 					}

 					// Check if script type given
 					final String scriptType = e.getAttribute("scriptType");
 					if ((scriptType != null) && !scriptType.isEmpty()) {
 						if (!engineDescription.supports(scriptType)) {
 							continue;
 						}
 					}

 					// Create IScriptEngineLaunchExtension based on given string
 					final Object extension = e.createExecutableExtension("class");
 					if (extension instanceof IScriptEngineLaunchExtension) {
 						extensions.add((IScriptEngineLaunchExtension) extension);
 					}
 				}
 			} catch (final InvalidRegistryObjectException e1) {
 			} catch (final CoreException e1) {
 			}
 		}

 		return extensions;
 	}

 	@Override
 	public synchronized Map<String, ScriptType> getAvailableScriptTypes() {
 		if (fScriptTypes == null) {
 			fScriptTypes = new HashMap<>();
 			final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_SCRIPTTYPE_ID);

 			for (final IConfigurationElement e : config) {
 				if ("scriptType".equals(e.getName()))
 					fScriptTypes.put(e.getAttribute(SCRIPTTYPE_NAME), new ScriptType(e));
 			}
 		}

 		return fScriptTypes;
 	}

 	@Override
 	public ScriptType getScriptType(final String location) {
 		if (location == null) {
 			return null;
 		}

 		final Object resource = ResourceTools.resolve(location);
 		try {
 			if (resource instanceof IFile) {
 				// try to resolve by content type
 				final IContentDescription description = ((IFile) resource).getContentDescription();
 				if (description != null) {
 					final IContentType contentType = description.getContentType();

 					for (final ScriptType scriptType : getAvailableScriptTypes().values()) {
 						if (scriptType.getContentTypes().contains(contentType.getId()))
 							return scriptType;
 					}
 				}
 			}
 		} catch (final CoreException e) {
 			// could not retrieve content type, continue using file extension
 		}

 		// try to resolve by extension
 		if (location != null) {
 			final int pos = location.lastIndexOf('.');
 			if (pos != -1) {
 				String extension = location.substring(pos + 1);

 				if (extension.contains("?"))
 					extension = extension.substring(0, extension.indexOf('?'));

 				for (final ScriptType scriptType : getAvailableScriptTypes().values()) {
 					if (scriptType.getDefaultExtension().equalsIgnoreCase(extension))
 						return scriptType;
 				}

 				// not found, verify content types
 				final IContentTypeManager contentTypeManager = Platform.getContentTypeManager();
 				final IContentType[] contentTypes = contentTypeManager.findContentTypesFor("foo." + extension);
 				if (contentTypes != null) {
 					for (final ScriptType scriptType : getAvailableScriptTypes().values()) {

 						// now lets see if one of the content types matches
 						for (final String contentTypeIdentifier : scriptType.getContentTypes()) {
 							for (final IContentType candidate : contentTypes) {
 								if (candidate.getId().equals(contentTypeIdentifier))
 									return scriptType;
 							}
 						}
 					}
 				}
 			}
 		}

 		return null;
 	}

 	@Override
 	public EngineDescription getEngine(final String scriptType) {
 		final List<EngineDescription> engines = getEngines(scriptType);
 		if (!engines.isEmpty())
 			return engines.get(0);

 		return null;
 	}

 	@Override
 	public synchronized Map<String, ModuleCategoryDefinition> getAvailableModuleCategories() {
 		if (fAvailableModuleCategories == null) {
 			fAvailableModuleCategories = new HashMap<>();
 			final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_MODULES_ID);
 			for (final IConfigurationElement e : config) {
 				if (e.getName().equals(EXTENSION_CATEGORY)) {
 					// module category detected
 					final ModuleCategoryDefinition definition = new ModuleCategoryDefinition(e);
 					fAvailableModuleCategories.put(definition.getId(), definition);
 				}
 			}
 		}
 		return fAvailableModuleCategories;
 	}

 	@Override
 	public ModuleDefinition getModuleDefinition(final String moduleId) {
 		for (final ModuleDefinition definition : getAvailableModules()) {
 			if (definition.getId().equals(moduleId))
 				return definition;
 		}

 		return null;
 	}

 	/**
 	 * Get the default {@link ICodeFactory} for a given script engine.
 	 *
 	 * @param engine
 	 *            script engine to look up
 	 * @return code factory or <code>null</code>
 	 */
 	public static ICodeFactory getCodeFactory(final IScriptEngine engine) {
 		final EngineDescription description = engine.getDescription();
 		if (description != null) {
 			final List<ScriptType> scriptTypes = description.getSupportedScriptTypes();
 			if (!scriptTypes.isEmpty())
 				return scriptTypes.get(0).getCodeFactory();
 		}

 		return null;
 	}

 	/**
 	 * Get the default {@link ICodeParser} for a given script engine.
 	 *
 	 * @param engine
 	 *            script engine to look up
 	 * @return code factory or <code>null</code>
 	 */
 	public static ICodeParser getCodeParser(final IScriptEngine engine) {
 		final EngineDescription description = engine.getDescription();
 		if (description != null) {
 			final List<ScriptType> scriptTypes = description.getSupportedScriptTypes();
 			if (!scriptTypes.isEmpty())
 				return scriptTypes.get(0).getCodeParser();
 		}

 		return null;
 	}

 	@Override
 	public void bundleChanged(BundleEvent event) {
 		final int type = event.getType();
 		if ((type == BundleEvent.RESOLVED) || (type == BundleEvent.STARTED) || (type == BundleEvent.STOPPED) || (type == BundleEvent.UPDATED)) {
 			synchronized (this) {
 				// clear cached entries
 				fAvailableModules = null;
 				fEngineDescriptions = null;
 				fScriptTypes = null;
 				fAvailableModuleCategories = null;
 			}
 		}
 	}

 	@Override
 	public Object executeScript(String scriptLocation, String engineID, String... arguments) throws Throwable {
 		// find script engine
 		EngineDescription engineDescription = null;
 		final IScriptService scriptService = ScriptService.getInstance();

 		if (engineID != null)
 			// locate engine by ID
 			engineDescription = scriptService.getEngineByID(engineID);

 		else {
 			// locate engine by file extension
 			final ScriptType scriptType = scriptService.getScriptType(scriptLocation);
 			if (scriptType != null)
 				engineDescription = scriptService.getEngine(scriptType.getName());
 		}

 		if (engineDescription != null) {
 			// create engine
 			final IScriptEngine engine = createEngine(engineDescription);
 			engine.setVariable("argv", arguments);

 			// TODO implement better URI handling - eg create URI and pass to script engine
 			Object scriptObject = ResourceTools.resolve(scriptLocation);
 			if (scriptObject == null)
 				// no file available, try to include to resolve URIs
 				scriptObject = "include(\"" + scriptLocation + "\")";

 			final ScriptResult scriptResult = engine.execute(scriptObject);
 			engine.schedule();

 			return scriptResult.get();
 		}

 		throw new IllegalArgumentException("Cannot locate a matching script engine");
 	}

 	@Override
 	public IScriptEngine createEngine(EngineDescription description) {
 		IScriptEngine engine;
 		try {
 			engine = description.createInstance();

 			// configure engine
 			if (engine instanceof AbstractScriptEngine)
 				((AbstractScriptEngine) engine).setEngineDescription(description);

 			// register engine locally
 			fRunningEngines.add(engine);
 			engine.addExecutionListener(this);

 			// inform listeners
 			for (final IScriptEngineLaunchExtension listener : fEngineListeners)
 				listener.createEngine(engine);

 			// engine loaded, now load launch extensions
 			for (final IScriptEngineLaunchExtension extension : getLaunchExtensions(description))
 				extension.createEngine(engine);

 			return engine;

 		} catch (final CoreException e) {
 			Logger.error(Activator.PLUGIN_ID, "Could not create script engine: " + description.getID(), e);
 		}

 		return null;
 	}

 	@Override
 	public Collection<IScriptEngine> getRunningEngines() {
 		return fRunningEngines;
 	}

 	@Override
 	public void notify(IScriptEngine engine, Script script, int status) {
 		if (status == IExecutionListener.ENGINE_END)
 			fRunningEngines.remove(engine);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2013 Christian Pontesegger and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* Contributors:
	* Christian Pontesegger - initial API and implementation
	*******************************************************************************/
	package org.eclipse.ease.service;

	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;

	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.InvalidRegistryObjectException;
	import org.eclipse.core.runtime.ListenerList;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.content.IContentDescription;
	import org.eclipse.core.runtime.content.IContentType;
	import org.eclipse.core.runtime.content.IContentTypeManager;
	import org.eclipse.ease.AbstractScriptEngine;
	import org.eclipse.ease.Activator;
	import org.eclipse.ease.ICodeFactory;
	import org.eclipse.ease.ICodeParser;
	import org.eclipse.ease.IExecutionListener;
	import org.eclipse.ease.IScriptEngine;
	import org.eclipse.ease.IScriptEngineLaunchExtension;
	import org.eclipse.ease.Logger;
	import org.eclipse.ease.Script;
	import org.eclipse.ease.ScriptResult;
	import org.eclipse.ease.modules.ModuleCategoryDefinition;
	import org.eclipse.ease.modules.ModuleDefinition;
	import org.eclipse.ease.tools.ResourceTools;
	import org.eclipse.ui.PlatformUI;
	import org.osgi.framework.BundleEvent;
	import org.osgi.framework.BundleListener;

	public final class ScriptService implements IScriptService, BundleListener, IExecutionListener {

	private static final String ENGINE = "engine";

	private static final String ENGINE_ID = "engineID";

	private static final Object EXTENSION_MODULE = "module";

	private static final Object EXTENSION_CATEGORY = "category";

	private static final String EXTENSION_LANGUAGE_ID = "org.eclipse.ease.language";

	private static final String EXTENSION_MODULES_ID = "org.eclipse.ease.modules";

	private static final String EXTENSION_SCRIPTTYPE_ID = "org.eclipse.ease.scriptType";

	private static final String SCRIPTTYPE_NAME = "name";

	private static final String LAUNCH_EXTENSION = "launchExtension";

	private static ScriptService fInstance = null;

	public static IScriptService getService() {
	try {
	return PlatformUI.getWorkbench().getService(IScriptService.class);
	} catch (final IllegalStateException e) {
	// workbench has not been created yet, might be running in headless mode
	return ScriptService.getInstance();
	}
	}

	public static synchronized ScriptService getInstance() {
	if (fInstance == null)
	fInstance = new ScriptService();

	return fInstance;
	}

	private Collection<ModuleDefinition> fAvailableModules = null;

	private Map<String, EngineDescription> fEngineDescriptions = null;

	private Map<String, ScriptType> fScriptTypes = null;

	private Map<String, ModuleCategoryDefinition> fAvailableModuleCategories = null;

	private final Collection<IScriptEngine> fRunningEngines = new ArrayList<>();

	private final ListenerList<IScriptEngineLaunchExtension> fEngineListeners = new ListenerList<>();

	private ScriptService() {
	Activator.getDefault().getContext().addBundleListener(this);
	}

	@Override
	public void addEngineListener(IScriptEngineLaunchExtension listener) {
	if (listener != null)
	fEngineListeners.add(listener);
	}

	@Override
	public void removeEngineListener(IScriptEngineLaunchExtension listener) {
	fEngineListeners.remove(listener);
	}

	@Override
	public EngineDescription getEngineByID(final String engineID) {
	return getEngineDescriptions().get(engineID);
	}

	@Override
	public synchronized Collection<ModuleDefinition> getAvailableModules() {
	if (fAvailableModules == null) {
	fAvailableModules = new HashSet<>();
	final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_MODULES_ID);
	for (final IConfigurationElement e : config) {
	if (e.getName().equals(EXTENSION_MODULE)) {
	// module extension detected
	final ModuleDefinition definition = new ModuleDefinition(e);
	if (definition.getModuleClass() != null)
	fAvailableModules.add(definition);

	else
	Logger.warning(Activator.PLUGIN_ID,
	"Module <" + definition.getName() + "> in plugin <" + definition.getBundleID() + "> could not be located!");
	}
	}
	}

	return fAvailableModules;
	}

	@Override
	public Collection<EngineDescription> getEngines() {
	return getEngineDescriptions().values();
	}

	@Override
	public List<EngineDescription> getEngines(final String scriptType) {
	final List<EngineDescription> result = new ArrayList<>();

	for (final EngineDescription description : getEngines()) {
	if (description.supports(scriptType))
	result.add(description);
	}

	// sort by priority
	Collections.sort(result, (o1, o2) -> o2.getPriority() - o1.getPriority());

	return result;
	}

	private synchronized Map<String, EngineDescription> getEngineDescriptions() {
	if (fEngineDescriptions == null) {
	fEngineDescriptions = new HashMap<>();
	final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_LANGUAGE_ID);

	for (final IConfigurationElement e : config) {
	if (ENGINE.equals(e.getName())) {
	final EngineDescription engine = new EngineDescription(e);
	fEngineDescriptions.put(engine.getID(), engine);
	}
	}
	}
	return fEngineDescriptions;
	}

	@Override
	public Collection<IScriptEngineLaunchExtension> getLaunchExtensions(final EngineDescription engineDescription) {
	final String targetEngineID = engineDescription.getID();

	final Collection<IScriptEngineLaunchExtension> extensions = new HashSet<>();
	final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_LANGUAGE_ID);
	for (final IConfigurationElement e : config) {
	try {
	if (LAUNCH_EXTENSION.equals(e.getName())) {
	// Parse engine ID to backwards compatible regular expression
	String engineID = e.getAttribute(ENGINE_ID);
	if ((engineID == null) \|\| engineID.matches("^\\*?$")) {
	engineID = ".*";
	}
	if (!targetEngineID.matches(engineID)) {
	continue;
	}

	// Check if script type given
	final String scriptType = e.getAttribute("scriptType");
	if ((scriptType != null) && !scriptType.isEmpty()) {
	if (!engineDescription.supports(scriptType)) {
	continue;
	}
	}

	// Create IScriptEngineLaunchExtension based on given string
	final Object extension = e.createExecutableExtension("class");
	if (extension instanceof IScriptEngineLaunchExtension) {
	extensions.add((IScriptEngineLaunchExtension) extension);
	}
	}
	} catch (final InvalidRegistryObjectException e1) {
	} catch (final CoreException e1) {
	}
	}

	return extensions;
	}

	@Override
	public synchronized Map<String, ScriptType> getAvailableScriptTypes() {
	if (fScriptTypes == null) {
	fScriptTypes = new HashMap<>();
	final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_SCRIPTTYPE_ID);

	for (final IConfigurationElement e : config) {
	if ("scriptType".equals(e.getName()))
	fScriptTypes.put(e.getAttribute(SCRIPTTYPE_NAME), new ScriptType(e));
	}
	}

	return fScriptTypes;
	}

	@Override
	public ScriptType getScriptType(final String location) {
	if (location == null) {
	return null;
	}

	final Object resource = ResourceTools.resolve(location);
	try {
	if (resource instanceof IFile) {
	// try to resolve by content type
	final IContentDescription description = ((IFile) resource).getContentDescription();
	if (description != null) {
	final IContentType contentType = description.getContentType();

	for (final ScriptType scriptType : getAvailableScriptTypes().values()) {
	if (scriptType.getContentTypes().contains(contentType.getId()))
	return scriptType;
	}
	}
	}
	} catch (final CoreException e) {
	// could not retrieve content type, continue using file extension
	}

	// try to resolve by extension
	if (location != null) {
	final int pos = location.lastIndexOf('.');
	if (pos != -1) {
	String extension = location.substring(pos + 1);

	if (extension.contains("?"))
	extension = extension.substring(0, extension.indexOf('?'));

	for (final ScriptType scriptType : getAvailableScriptTypes().values()) {
	if (scriptType.getDefaultExtension().equalsIgnoreCase(extension))
	return scriptType;
	}

	// not found, verify content types
	final IContentTypeManager contentTypeManager = Platform.getContentTypeManager();
	final IContentType[] contentTypes = contentTypeManager.findContentTypesFor("foo." + extension);
	if (contentTypes != null) {
	for (final ScriptType scriptType : getAvailableScriptTypes().values()) {

	// now lets see if one of the content types matches
	for (final String contentTypeIdentifier : scriptType.getContentTypes()) {
	for (final IContentType candidate : contentTypes) {
	if (candidate.getId().equals(contentTypeIdentifier))
	return scriptType;
	}
	}
	}
	}
	}
	}

	return null;
	}

	@Override
	public EngineDescription getEngine(final String scriptType) {
	final List<EngineDescription> engines = getEngines(scriptType);
	if (!engines.isEmpty())
	return engines.get(0);

	return null;
	}

	@Override
	public synchronized Map<String, ModuleCategoryDefinition> getAvailableModuleCategories() {
	if (fAvailableModuleCategories == null) {
	fAvailableModuleCategories = new HashMap<>();
	final IConfigurationElement[] config = Platform.getExtensionRegistry().getConfigurationElementsFor(EXTENSION_MODULES_ID);
	for (final IConfigurationElement e : config) {
	if (e.getName().equals(EXTENSION_CATEGORY)) {
	// module category detected
	final ModuleCategoryDefinition definition = new ModuleCategoryDefinition(e);
	fAvailableModuleCategories.put(definition.getId(), definition);
	}
	}
	}
	return fAvailableModuleCategories;
	}

	@Override
	public ModuleDefinition getModuleDefinition(final String moduleId) {
	for (final ModuleDefinition definition : getAvailableModules()) {
	if (definition.getId().equals(moduleId))
	return definition;
	}

	return null;
	}

	/**
	* Get the default {@link ICodeFactory} for a given script engine.
	*
	* @param engine
	* script engine to look up
	* @return code factory or <code>null</code>
	*/
	public static ICodeFactory getCodeFactory(final IScriptEngine engine) {
	final EngineDescription description = engine.getDescription();
	if (description != null) {
	final List<ScriptType> scriptTypes = description.getSupportedScriptTypes();
	if (!scriptTypes.isEmpty())
	return scriptTypes.get(0).getCodeFactory();
	}

	return null;
	}

	/**
	* Get the default {@link ICodeParser} for a given script engine.
	*
	* @param engine
	* script engine to look up
	* @return code factory or <code>null</code>
	*/
	public static ICodeParser getCodeParser(final IScriptEngine engine) {
	final EngineDescription description = engine.getDescription();
	if (description != null) {
	final List<ScriptType> scriptTypes = description.getSupportedScriptTypes();
	if (!scriptTypes.isEmpty())
	return scriptTypes.get(0).getCodeParser();
	}

	return null;
	}

	@Override
	public void bundleChanged(BundleEvent event) {
	final int type = event.getType();
	if ((type == BundleEvent.RESOLVED) \|\| (type == BundleEvent.STARTED) \|\| (type == BundleEvent.STOPPED) \|\| (type == BundleEvent.UPDATED)) {
	synchronized (this) {
	// clear cached entries
	fAvailableModules = null;
	fEngineDescriptions = null;
	fScriptTypes = null;
	fAvailableModuleCategories = null;
	}
	}
	}

	@Override
	public Object executeScript(String scriptLocation, String engineID, String... arguments) throws Throwable {
	// find script engine
	EngineDescription engineDescription = null;
	final IScriptService scriptService = ScriptService.getInstance();

	if (engineID != null)
	// locate engine by ID
	engineDescription = scriptService.getEngineByID(engineID);

	else {
	// locate engine by file extension
	final ScriptType scriptType = scriptService.getScriptType(scriptLocation);
	if (scriptType != null)
	engineDescription = scriptService.getEngine(scriptType.getName());
	}

	if (engineDescription != null) {
	// create engine
	final IScriptEngine engine = createEngine(engineDescription);
	engine.setVariable("argv", arguments);

	// TODO implement better URI handling - eg create URI and pass to script engine
	Object scriptObject = ResourceTools.resolve(scriptLocation);
	if (scriptObject == null)
	// no file available, try to include to resolve URIs
	scriptObject = "include(\"" + scriptLocation + "\")";

	final ScriptResult scriptResult = engine.execute(scriptObject);
	engine.schedule();

	return scriptResult.get();
	}

	throw new IllegalArgumentException("Cannot locate a matching script engine");
	}

	@Override
	public IScriptEngine createEngine(EngineDescription description) {
	IScriptEngine engine;
	try {
	engine = description.createInstance();

	// configure engine
	if (engine instanceof AbstractScriptEngine)
	((AbstractScriptEngine) engine).setEngineDescription(description);

	// register engine locally
	fRunningEngines.add(engine);
	engine.addExecutionListener(this);

	// inform listeners
	for (final IScriptEngineLaunchExtension listener : fEngineListeners)
	listener.createEngine(engine);

	// engine loaded, now load launch extensions
	for (final IScriptEngineLaunchExtension extension : getLaunchExtensions(description))
	extension.createEngine(engine);

	return engine;

	} catch (final CoreException e) {
	Logger.error(Activator.PLUGIN_ID, "Could not create script engine: " + description.getID(), e);
	}

	return null;
	}

	@Override
	public Collection<IScriptEngine> getRunningEngines() {
	return fRunningEngines;
	}

	@Override
	public void notify(IScriptEngine engine, Script script, int status) {
	if (status == IExecutionListener.ENGINE_END)
	fRunningEngines.remove(engine);
	}
	}