/****************************************************************************
 * Copyright (c) 2004 Composent, Inc. and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * Contributors: Composent, Inc. - initial API and implementation
 *
 * SPDX-License-Identifier: EPL-2.0
 *****************************************************************************/
package org.eclipse.ecf.internal.core.identity;

import org.eclipse.core.runtime.*;
import org.eclipse.ecf.core.identity.*;
import org.eclipse.ecf.core.util.*;
import org.eclipse.osgi.service.debug.DebugOptions;
import org.osgi.framework.*;
import org.osgi.service.log.LogService;
import org.osgi.util.tracker.ServiceTracker;
import org.osgi.util.tracker.ServiceTrackerCustomizer;

/**
 * The activator class controls the plug-in life cycle
 */
public class Activator implements BundleActivator {

	// The plug-in ID
	public static final String PLUGIN_ID = "org.eclipse.ecf.identity"; //$NON-NLS-1$

	private static final String NAMESPACE_NAME = "namespace"; //$NON-NLS-1$

	private static final String NAMESPACE_EPOINT = PLUGIN_ID + "." //$NON-NLS-1$
			+ NAMESPACE_NAME;

	private static final String NAME_ATTRIBUTE = "name"; //$NON-NLS-1$

	private static final String CLASS_ATTRIBUTE = "class"; //$NON-NLS-1$

	private static final int FACTORY_NAME_COLLISION_ERRORCODE = 200;

	private static final String DESCRIPTION_ATTRIBUTE = "description"; //$NON-NLS-1$

	// The shared instance
	private static Activator plugin;

	private BundleContext context;

	@SuppressWarnings("rawtypes")
	private ServiceRegistration idFactoryServiceRegistration;

	@SuppressWarnings("rawtypes")
	private ServiceTracker debugOptionsTracker;

	@SuppressWarnings("rawtypes")
	private ServiceTracker logServiceTracker;

	private LogService logService;

	private AdapterManagerTracker adapterManagerTracker;

	@SuppressWarnings("rawtypes")
	private ServiceTracker namespacesTracker;

	// This is object rather than typed to avoid referencing the
	// IRegistryChangedListener class directly
	private Object registryManager;

	public synchronized IAdapterManager getAdapterManager() {
		if (this.context == null)
			return null;
		// First, try to get the adapter manager via
		if (adapterManagerTracker == null) {
			adapterManagerTracker = new AdapterManagerTracker(this.context);
			adapterManagerTracker.open();
		}
		return adapterManagerTracker.getAdapterManager();
	}

	/**
	 * The constructor
	 */
	public Activator() {
		// public null constructor
	}

	@SuppressWarnings({ "unchecked", "rawtypes" })
	public synchronized DebugOptions getDebugOptions() {
		if (context == null)
			return null;
		if (debugOptionsTracker == null) {
			debugOptionsTracker = new ServiceTracker(context, DebugOptions.class.getName(), null);
			debugOptionsTracker.open();
		}
		return (DebugOptions) debugOptionsTracker.getService();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.runtime.Plugins#start(org.osgi.framework.BundleContext)
	 */
	@SuppressWarnings({ "unchecked", "rawtypes" })
	public void start(BundleContext ctxt) throws Exception {
		plugin = this;
		this.context = ctxt;
		BundleStarter.startDependents(this.context, new String[] { "org.eclipse.equinox.common",
				"org.eclipse.core.jobs", "org.eclipse.equinox.concurrent" }, Bundle.STARTING | Bundle.RESOLVED);

		// Register IIDFactory service
		idFactoryServiceRegistration = context.registerService(IIDFactory.class.getName(), IDFactory.getDefault(),
				null);

		namespacesTracker = new ServiceTracker(context, Namespace.class.getName(), new ServiceTrackerCustomizer() {

			public Object addingService(ServiceReference reference) {
				Namespace ns = (Namespace) context.getService(reference);
				if (ns != null && ns.getName() != null)
					IDFactory.addNamespace0(ns);
				return ns;
			}

			public void modifiedService(ServiceReference reference, Object service) {
			}

			public void removedService(ServiceReference reference, Object service) {
				IDFactory.removeNamespace0((Namespace) service);
			}
		});
		namespacesTracker.open();

		SafeRunner.run(new ExtensionRegistryRunnable(ctxt) {
			protected void runWithRegistry(IExtensionRegistry registry) throws Exception {
				if (registry != null) {
					registryManager = new IRegistryChangeListener() {
						public void registryChanged(IRegistryChangeEvent event) {
							final IExtensionDelta delta[] = event.getExtensionDeltas(PLUGIN_ID, NAMESPACE_NAME);
							for (IExtensionDelta d : delta) {
								switch (d.getKind()) {
									case IExtensionDelta.ADDED:
										addNamespaceExtensions(d.getExtension().getConfigurationElements());
										break;
									case IExtensionDelta.REMOVED:
										IConfigurationElement[] members = d.getExtension().getConfigurationElements();
										for (IConfigurationElement member : members) {
											String name = null;
											try {
												name = member.getAttribute(NAME_ATTRIBUTE);
												if (name == null) {
													name = member.getAttribute(CLASS_ATTRIBUTE);
												}
												if (name == null)
													continue;
												final IIDFactory factory = IDFactory.getDefault();
												final Namespace n = factory.getNamespaceByName(name);
												if (n == null || !factory.containsNamespace(n)) {
													continue;
												}
												// remove
												factory.removeNamespace(n);
											} catch (final Exception e) {
												getDefault().log(new Status(IStatus.ERROR, Activator.PLUGIN_ID,
														IStatus.ERROR, "Exception removing namespace", e)); //$NON-NLS-1$
											}
										}
										break;
								}
							}
						}
					};
					registry.addRegistryChangeListener((IRegistryChangeListener) registryManager);
				}
			}
		});
	}

	public BundleContext getBundleContext() {
		return context;
	}

	Bundle getBundle() {
		if (context == null)
			return null;
		return context.getBundle();
	}

	@SuppressWarnings({ "rawtypes", "unchecked" })
	synchronized LogService getLogService() {
		if (context == null) {
			if (logService == null)
				logService = new SystemLogService(PLUGIN_ID);
			return logService;
		}
		if (logServiceTracker == null) {
			logServiceTracker = new ServiceTracker(this.context, LogService.class.getName(), null);
			logServiceTracker.open();
		}
		logService = (LogService) logServiceTracker.getService();
		if (logService == null)
			logService = new SystemLogService(PLUGIN_ID);
		return logService;
	}

	public void log(IStatus status) {
		if (logService == null)
			logService = getLogService();

		if (logService != null)
			logService.log(LogHelper.getLogCode(status), LogHelper.getLogMessage(status), status.getException());
	}

	/**
	 * Add identity namespace extension point extensions
	 * 
	 * @param members
	 *            the members to add
	 */
	void addNamespaceExtensions(IConfigurationElement[] members) {
		final String bundleName = getDefault().getBundle().getSymbolicName();
		for (IConfigurationElement member : members) {
			// Get the label of the extender plugin and the ID of the
			// extension.
			final IExtension extension = member.getDeclaringExtension();
			String nsName = null;
			try {
				final Namespace ns = (Namespace) member.createExecutableExtension(CLASS_ATTRIBUTE);
				final String clazz = ns.getClass().getName();
				nsName = member.getAttribute(NAME_ATTRIBUTE);
				if (nsName == null) {
					nsName = clazz;
				}
				final String nsDescription = member.getAttribute(DESCRIPTION_ATTRIBUTE);
				ns.initialize(nsName, nsDescription);
				// Check to see if we have a namespace name collision
				if (!IDFactory.containsNamespace0(ns)) {
					// Now add to known namespaces
					IDFactory.addNamespace0(ns);
				}
			} catch (final CoreException e) {
				getDefault().log(e.getStatus());
			} catch (final Exception e) {
				getDefault().log(new Status(IStatus.ERROR, bundleName, FACTORY_NAME_COLLISION_ERRORCODE, "name=" //$NON-NLS-1$
						+ nsName + ";extension point id=" //$NON-NLS-1$
						+ extension.getExtensionPointUniqueIdentifier(), null));
			}
		}
	}

	/**
	 * Setup identity namespace extension point
	 * 
	 */
	public void setupNamespaceExtensionPoint() {
		SafeRunner.run(new ExtensionRegistryRunnable(context) {
			protected void runWithRegistry(IExtensionRegistry registry) throws Exception {
				if (registry != null) {
					final IExtensionPoint extensionPoint = registry.getExtensionPoint(NAMESPACE_EPOINT);
					if (extensionPoint == null)
						return;
					addNamespaceExtensions(extensionPoint.getConfigurationElements());
				}
			}
		});
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.runtime.Plugin#stop(org.osgi.framework.BundleContext)
	 */
	public void stop(BundleContext ctxt) throws Exception {
		SafeRunner.run(new ExtensionRegistryRunnable(ctxt) {
			protected void runWithRegistry(IExtensionRegistry registry) throws Exception {
				if (registry != null)
					registry.removeRegistryChangeListener((IRegistryChangeListener) registryManager);
			}
		});
		if (namespacesTracker != null) {
			namespacesTracker.close();
			namespacesTracker = null;
		}
		registryManager = null;
		if (logServiceTracker != null) {
			logServiceTracker.close();
			logServiceTracker = null;
			logService = null;
		}
		if (debugOptionsTracker != null) {
			debugOptionsTracker.close();
			debugOptionsTracker = null;
		}
		if (idFactoryServiceRegistration != null) {
			idFactoryServiceRegistration.unregister();
			idFactoryServiceRegistration = null;
		}
		if (adapterManagerTracker != null) {
			adapterManagerTracker.close();
			adapterManagerTracker = null;
		}
		context = null;
		plugin = null;
	}

	/**
	 * Returns the shared instance
	 * 
	 * @return the shared instance
	 */
	public synchronized static Activator getDefault() {
		if (plugin == null)
			plugin = new Activator();
		return plugin;
	}

}