/*******************************************************************************
 * Copyright (c) 2006, 2009 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;

import javax.xml.parsers.SAXParserFactory;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.ProjectScope;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Plugin;
import org.eclipse.core.runtime.QualifiedName;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.content.IContentType;
import org.eclipse.core.runtime.preferences.DefaultScope;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.core.runtime.preferences.IScopeContext;
import org.eclipse.core.runtime.preferences.InstanceScope;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jpt.core.internal.JpaModelManager;
import org.eclipse.jpt.core.internal.platform.GenericJpaPlatformProvider;
import org.eclipse.jpt.core.internal.platform.JpaPlatformRegistry;
import org.eclipse.jpt.utility.internal.StringTools;
import org.eclipse.jst.j2ee.internal.J2EEConstants;
import org.eclipse.wst.common.componentcore.ComponentCore;
import org.eclipse.wst.common.componentcore.internal.util.IModuleConstants;
import org.eclipse.wst.common.componentcore.resources.IVirtualFile;
import org.eclipse.wst.common.project.facet.core.FacetedProjectFramework;
import org.osgi.framework.BundleContext;
import org.osgi.service.prefs.BackingStoreException;
import org.osgi.service.prefs.Preferences;
import org.osgi.util.tracker.ServiceTracker;

/**
 * The JPT plug-in lifecycle implementation.
 * A number of globally-available constants and methods.
 * 
 * Provisional API: This class is part of an interim API that is still
 * under development and expected to change significantly before reaching
 * stability. It is available at this early stage to solicit feedback from
 * pioneering adopters on the understanding that any code that uses this API
 * will almost certainly be broken (repeatedly) as the API evolves.
 */
// TODO keep preferences in synch with the JPA project
// (connection profile name, "discover" flag)
// use listeners?
public class JptCorePlugin extends Plugin {

	// ********** public constants **********

	/**
	 * The plug-in identifier of the persistence support
	 * (value <code>"org.eclipse.jpt.core"</code>).
	 */
	public static final String PLUGIN_ID = "org.eclipse.jpt.core";  //$NON-NLS-1$
	public static final String PLUGIN_ID_ = PLUGIN_ID + '.';

	/**
	 * The identifier for the JPA facet
	 * (value <code>"jpt.jpa"</code>).
	 */
	public static final String FACET_ID = "jpt.jpa";  //$NON-NLS-1$

	/**
	 * The key for storing a JPA project's platform ID in the Eclipse
	 * project's preferences.
	 */
	private static final String JPA_PLATFORM_PREF_KEY = PLUGIN_ID_ + "platform";  //$NON-NLS-1$

	/**
	 * The key for storing the default JPA platform ID in the workspace
	 * preferences.
	 */
	private static final String DEFAULT_JPA_PLATFORM_PREF_KEY = "defaultJpaPlatform"; //$NON-NLS-1$

	/**
	 * The key for storing a JPA project's "discover" flag in the Eclipse
	 * project's preferences.
	 */
	public static final String DISCOVER_ANNOTATED_CLASSES = PLUGIN_ID_ + "discoverAnnotatedClasses";  //$NON-NLS-1$

	/**
	 * The key for storing a JPA project's data source connection profile name
	 * in the Eclipse project's persistent properties.
	 */
	public static final QualifiedName DATA_SOURCE_CONNECTION_PROFILE_NAME = 
			new QualifiedName(PLUGIN_ID, "dataSource.connectionProfileName");  //$NON-NLS-1$

	/**
	 * The key for storing a JPA project's user overridden default catalog name
	 * in the Eclipse project's persistent properties.
	 */
	public static final QualifiedName USER_OVERRIDE_DEFAULT_CATALOG = 
		new QualifiedName(PLUGIN_ID, "userOverrideDefaultCatalogName");  //$NON-NLS-1$

	/**
	 * The key for storing a JPA project's user overridden default schema name
	 * in the Eclipse project's persistent properties.
	 */
	public static final QualifiedName USER_OVERRIDE_DEFAULT_SCHEMA = 
			new QualifiedName(PLUGIN_ID, "userOverrideDefaultSchemaName");  //$NON-NLS-1$

	/**
	 * The identifier for the JPA validator
	 * (value <code>"org.eclipse.jpt.core.jpaValidator"</code>).
	 */
	public static final String VALIDATOR_ID = PLUGIN_ID_ + "jpaValidator";  //$NON-NLS-1$

	/**
	 * The content type for Java source code files.
	 */
	public static final IContentType JAVA_SOURCE_CONTENT_TYPE = getContentType(JavaCore.JAVA_SOURCE_CONTENT_TYPE);

	/**
	 * The base content type for all persistence.xml files.
	 */
	public static final IContentType PERSISTENCE_FILE_CONTENT_TYPE = getJpaContentType("persistenceFile"); //$NON-NLS-1$

	/**
	 * The content type for persistence.xml 1.0 (based on the persistence 1.0 schema) files.
	 */
	public static final IContentType PERSISTENCE_XML_CONTENT_TYPE = getJpaContentType("persistence"); //$NON-NLS-1$

	/**
	 * The content type for persistence.xml 2.0 (based on the persistence 2.0 schema) files.
	 */
	public static final IContentType PERSISTENCE2_0_XML_CONTENT_TYPE = getJpaContentType("persistence2_0"); //$NON-NLS-1$

	/**
	 * The base content type for all mapping files.
	 */
	public static final IContentType MAPPING_FILE_CONTENT_TYPE = getJpaContentType("mappingFile"); //$NON-NLS-1$

	/**
	 * The content type for orm.xml 1.0 (based on the orm 1.0 schema) mapping files.
	 */
	public static final IContentType ORM_XML_CONTENT_TYPE = getJpaContentType("orm"); //$NON-NLS-1$

	/**
	 * The content type for orm.xml 2.0 (based on the orm 2.0 schema) mapping files.
	 */
	public static final IContentType ORM2_0_XML_CONTENT_TYPE = getJpaContentType("orm2_0"); //$NON-NLS-1$

	/**
	 * The content type for Java archives (JARs).
	 */
	public static final IContentType JAR_CONTENT_TYPE = getJpaContentType("jar"); //$NON-NLS-1$

	/**
	 * Web projects have some special exceptions.
	 */
	public static final String WEB_PROJECT_FACET_ID = IModuleConstants.JST_WEB_MODULE;

	/**
	 * Web projects have some special exceptions.
	 */
	public static final String WEB_PROJECT_DEPLOY_PREFIX = J2EEConstants.WEB_INF_CLASSES;

	public static final String DEFAULT_PERSISTENCE_XML_FILE_PATH = "META-INF/persistence.xml"; //$NON-NLS-1$

	public static final String DEFAULT_ORM_XML_FILE_PATH = "META-INF/orm.xml"; //$NON-NLS-1$

	private static IContentType getJpaContentType(String jpaContentType) {
		return getContentType(CONTENT_PREFIX_ + jpaContentType);
	}
	public static final String CONTENT_PREFIX = PLUGIN_ID_ + "content"; //$NON-NLS-1$
	public static final String CONTENT_PREFIX_ = CONTENT_PREFIX + '.';

	private static IContentType getContentType(String contentType) {
		return Platform.getContentTypeManager().getContentType(contentType);
	}

	private ServiceTracker parserTracker;

	// ********** singleton **********

	private static JptCorePlugin INSTANCE;

	/**
	 * Return the singleton JPT plug-in.
	 */
	public static JptCorePlugin instance() {
		return INSTANCE;
	}


	// ********** public static methods **********

	/**
	 * Return the singular JPA model corresponding to the current workspace.
	 */
	public static JpaModel getJpaModel() {
		return JpaModelManager.instance().getJpaModel();
	}

	/**
	 * Return the JPA project corresponding to the specified Eclipse project,
	 * or null if unable to associate the specified project with a
	 * JPA project.
	 */
	public static JpaProject getJpaProject(IProject project) {
		try {
			return JpaModelManager.instance().getJpaProject(project);
		} catch (CoreException ex) {
			log(ex);
			return null;
		}
	}

	/**
	 * Return the JPA file corresponding to the specified Eclipse file,
	 * or null if unable to associate the specified file with a JPA file.
	 */
	public static JpaFile getJpaFile(IFile file) {
		try {
			return JpaModelManager.instance().getJpaFile(file);
		} catch (CoreException ex) {
			log(ex);
			return null;
		}
	}

	/**
	 * Return whether the specified Eclipse project has a JPA facet.
	 */
	public static boolean projectHasJpaFacet(IProject project) {
		return projectHasFacet(project, FACET_ID);
	}

	/**
	 * Return whether the specified Eclipse project has a JPA facet.
	 */
	public static boolean projectHasWebFacet(IProject project) {
		return projectHasFacet(project, WEB_PROJECT_FACET_ID);
	}

	/**
	 * Checked exceptions bite.
	 */
	private static boolean projectHasFacet(IProject project, String facetId) {
		try {
			return FacetedProjectFramework.hasProjectFacet(project, facetId);
		} catch (CoreException ex) {
			log(ex);  // problems reading the project metadata - assume facet doesn't exist - return 'false'
			return false;
		}
	}

	/**
	 * Return the persistence.xml (specified as "META-INF/persistence.xml")
	 * deployment URI for the specified project.
	 */
	public static String getPersistenceXmlDeploymentURI(IProject project) {
		return getDeploymentURI(project, DEFAULT_PERSISTENCE_XML_FILE_PATH);
	}

	/**
	 * Return the default mapping file (specified as "META-INF/orm.xml")
	 * deployment URI for the specified project.
	 */
	public static String getDefaultOrmXmlDeploymentURI(IProject project) {
		return getDeploymentURI(project, DEFAULT_ORM_XML_FILE_PATH);
	}

	/**
	 * Return the mapping file (specified as "META-INF/<mappingFileName>")
	 * deployment URI for the specified project.
	 */
	public static String getOrmXmlDeploymentURI(IProject project, String mappingFileName) {
		return getDeploymentURI(project, mappingFileName);
	}

	/**
	 * Tweak the specified deployment URI if the specified project
	 * has a web facet.
	 */
	public static String getDeploymentURI(IProject project, String defaultURI) {
		return projectHasWebFacet(project) ?
				WEB_PROJECT_DEPLOY_PREFIX + '/' + defaultURI
			:
				defaultURI;
	}

	/**
	 * Return the deployment path to which jars are relatively specified for 
	 * the given project
	 * (Web projects have a different deployment structure than non-web projects)
	 */
	public static IPath getJarDeploymentRootPath(IProject project) {
		return new Path(getJarDeploymentRootPathName(project));
	}

	private static String getJarDeploymentRootPathName(IProject project) {
		return projectHasWebFacet(project) ? ("/" + J2EEConstants.WEB_INF) : "/"; //$NON-NLS-1$ //$NON-NLS-2$
	}

	public static IFile getPlatformFile(IProject project, String defaultURI) {
		IPath deploymentPath = new Path(getDeploymentURI(project, defaultURI));
		IVirtualFile vFile = ComponentCore.createFile(project, deploymentPath);
		return vFile.getUnderlyingFile();

	}

	public static JpaFile getJpaFile(IProject project, String defaultURI) {
		IFile xmlFile = getPlatformFile(project, defaultURI);
		return xmlFile.exists() ? getJpaFile(xmlFile) : null;
	}

	public static void initializeDefaultPreferences() {
		IEclipsePreferences node = getDefaultPreferences();

		// default JPA platform
		String defaultPlatformId = JpaPlatformRegistry.instance().getDefaultJpaPlatformId();
		if (StringTools.stringIsEmpty(defaultPlatformId)) {
			defaultPlatformId = GenericJpaPlatformProvider.ID;
		}
		node.put(DEFAULT_JPA_PLATFORM_PREF_KEY, defaultPlatformId);
	}

	/**
	 * Return the default Dali preferences
	 * @see JpaPreferenceInitializer
	 */
	public static IEclipsePreferences getDefaultPreferences() {
		return getPreferences(new DefaultScope());
	}

	/**
	 * Return the Dali preferences for the current workspace instance.
	 */
	public static IEclipsePreferences getWorkspacePreferences() {
		return getPreferences(new InstanceScope());
	}

	/**
	 * Return the Dali preferences for the specified Eclipse project.
	 */
	public static IEclipsePreferences getProjectPreferences(IProject project) {
		return getPreferences(new ProjectScope(project));
	}

	/**
	 * Return the Dali preferences for the specified context.
	 */
	private static IEclipsePreferences getPreferences(IScopeContext context) {
		return context.getNode(PLUGIN_ID);
	}

	/**
	 * Return the default JPA Platform ID for new JPA projects.
	 */
	public static String getDefaultJpaPlatformId() {
		String platformId = getDefaultJpaPlatformId(getWorkspacePreferences(), getDefaultPreferences());
		if (jpaPlatformIdIsValid(platformId)) {
			return platformId;
		}
		// if the platform ID stored in the workspace prefs is invalid, look in the default prefs
		platformId = getDefaultJpaPlatformId(getDefaultPreferences());
		if (jpaPlatformIdIsValid(platformId)) {
			return platformId;
		}
		// if the platform ID stored in the default prefs is invalid, use the Generic platform ID
		return GenericJpaPlatformProvider.ID;
	}

	private static String getDefaultJpaPlatformId(Preferences... nodes) {
		return Platform.getPreferencesService().get(DEFAULT_JPA_PLATFORM_PREF_KEY, GenericJpaPlatformProvider.ID, nodes);
	}

	private static boolean jpaPlatformIdIsValid(String platformId) {
		return JpaPlatformRegistry.instance().containsPlatform(platformId);
	}

	/**
	 * Set the default JPA platform ID for creating new JPA projects
	 */
	public static void setDefaultJpaPlatformId(String platformId) {
		IEclipsePreferences prefs = getWorkspacePreferences();
		prefs.put(DEFAULT_JPA_PLATFORM_PREF_KEY, platformId);
		flush(prefs);
	}

	/**
	 * Return the JPA platform associated with the specified Eclipse project.
	 */
	public static JpaPlatform getJpaPlatform(IProject project) {
		return JpaPlatformRegistry.instance().getJpaPlatform(project);
	}

	/**
	 * Return the JPA platform ID associated with the specified Eclipse project.
	 */
	public static String getJpaPlatformId(IProject project) {
		return getProjectPreferences(project).get(JPA_PLATFORM_PREF_KEY, GenericJpaPlatformProvider.ID);
	}

	/**
	 * Set the JPA platform ID associated with the specified Eclipse project.
	 */
	public static void setJpaPlatformId(IProject project, String jpaPlatformId) {
		IEclipsePreferences prefs = getProjectPreferences(project);
		prefs.put(JPA_PLATFORM_PREF_KEY, jpaPlatformId);
		flush(prefs);
	}

	/**
	 * Return the preferences key used to look up an Eclipse project's
	 * JPA platform ID.
	 */
	public static String getJpaPlatformIdPrefKey() {
		return JPA_PLATFORM_PREF_KEY;
	}

	/**
	 * Return the JPA "discover" flag associated with the specified
	 * Eclipse project.
	 */
	public static boolean discoverAnnotatedClasses(IProject project) {
		return getProjectPreferences(project).getBoolean(DISCOVER_ANNOTATED_CLASSES, false);
	}

	/**
	 * Set the JPA "discover" flag associated with the specified
	 * Eclipse project.
	 */
	public static void setDiscoverAnnotatedClasses(IProject project, boolean discoverAnnotatedClasses) {
		IEclipsePreferences prefs = getProjectPreferences(project);
		prefs.putBoolean(DISCOVER_ANNOTATED_CLASSES, discoverAnnotatedClasses);
		flush(prefs);
	}

	/**
	 * checked exceptions bite
	 */
	private static void flush(IEclipsePreferences prefs) {
		try {
			prefs.flush();
		} catch(BackingStoreException ex) {
			log(ex);
		}
	}

	/**
	 * Return the name of the connection profile associated with the specified
	 * Eclipse project.
	 */
	public static String getConnectionProfileName(IProject project) {
		try {
			return project.getPersistentProperty(DATA_SOURCE_CONNECTION_PROFILE_NAME);
		} catch (CoreException ex) {
			log(ex);
			return null;
		}
	}

	/**
	 * Set the name of the connection profile associated with the specified
	 * Eclipse project.
	 */
	public static void setConnectionProfileName(IProject project, String connectionProfileName) {
		try {
			project.setPersistentProperty(DATA_SOURCE_CONNECTION_PROFILE_NAME, connectionProfileName);
		} catch (CoreException ex) {
			log(ex);
		}
	}

	/**
	 * Return the default catalog (identifier) associated with the specified Eclipse project.
	 * @see JpaProject#getUserOverrideDefaultCatalog()
	 */
	public static String getUserOverrideDefaultCatalog(IProject project) {
		try {
			return project.getPersistentProperty(USER_OVERRIDE_DEFAULT_CATALOG);
		} catch (CoreException ex) {
			log(ex);
			return null;
		}
	}

	/**
	 * Set the default catalog (identifier) associated with the specified Eclipse project.
	 * @see JpaProject#setUserOverrideDefaultCatalog(String)
	 */
	public static void setUserOverrideDefaultCatalog(IProject project, String defaultCatalog) {
		try {
			project.setPersistentProperty(USER_OVERRIDE_DEFAULT_CATALOG, defaultCatalog);
		} catch (CoreException ex) {
			log(ex);
		}
	}

	/**
	 * Return the default schema (identifier) associated with the specified Eclipse project.
	 * @see JpaProject#getUserOverrideDefaultSchema()
	 */
	public static String getUserOverrideDefaultSchema(IProject project) {
		try {
			return project.getPersistentProperty(USER_OVERRIDE_DEFAULT_SCHEMA);
		} catch (CoreException ex) {
			log(ex);
			return null;
		}
	}

	/**
	 * Set the default schema (identifier) associated with the specified Eclipse project.
	 * @see JpaProject#setUserOverrideDefaultSchema(String)
	 */
	public static void setUserOverrideDefaultSchema(IProject project, String defaultSchema) {
		try {
			project.setPersistentProperty(USER_OVERRIDE_DEFAULT_SCHEMA, defaultSchema);
		} catch (CoreException ex) {
			log(ex);
		}
	}

	/**
	 * Log the specified status.
	 */
	public static void log(IStatus status) {
        INSTANCE.getLog().log(status);
    }

	/**
	 * Log the specified message.
	 */
	public static void log(String msg) {
        log(new Status(IStatus.ERROR, PLUGIN_ID, IStatus.OK, msg, null));
    }

	/**
	 * Log the specified exception or error.
	 */
	public static void log(Throwable throwable) {
		log(new Status(IStatus.ERROR, PLUGIN_ID, IStatus.OK, throwable.getLocalizedMessage(), throwable));
	}


	// ********** plug-in implementation **********

	public JptCorePlugin() {
		super();
		if (INSTANCE != null) {
			throw new IllegalStateException();
		}
		// this convention is *wack*...  ~bjv
		INSTANCE = this;
	}


	@Override
	public void start(BundleContext context) throws Exception {
		super.start(context);
		JpaModelManager.instance().start();
	}

	@Override
	public void stop(BundleContext context) throws Exception {
		try {
			JpaModelManager.instance().stop();
			if (this.parserTracker != null) {
				this.parserTracker.close();
				this.parserTracker = null;
			}
		} finally {
			super.stop(context);
		}
	}

	public synchronized SAXParserFactory getSAXParserFactory() {
		SAXParserFactory factory = (SAXParserFactory) this.getParserTracker().getService();
		if (factory != null) {
			factory.setNamespaceAware(true);
		}
		return factory;
	}

	private ServiceTracker getParserTracker() {
		if (this.parserTracker == null) {
			this.parserTracker = this.buildParserTracker();
			this.parserTracker.open();
		}
		return this.parserTracker;
	}

	private ServiceTracker buildParserTracker() {
		return new ServiceTracker(this.getBundle().getBundleContext(), "javax.xml.parsers.SAXParserFactory", null); //$NON-NLS-1$
	}

}