package org.eclipse.remote.internal.proxy.protocol.core;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Plugin;
import org.eclipse.core.runtime.Status;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;

/**
 * The activator class controls the plug-in life cycle
 */
public class Activator extends Plugin {

	// The plug-in ID
	public static final String PLUGIN_ID = "org.eclipse.remote.proxy.protocol.core"; //$NON-NLS-1$

	// The shared instance
	private static Activator plugin;

	/**
	 * Returns the shared instance
	 * 
	 * @return the shared instance
	 */
	public static Activator getDefault() {
		return plugin;
	}

	/**
	 * Get unique identifier
	 * 
	 * @return
	 * @since 5.0
	 */
	public static String getUniqueIdentifier() {
		if (getDefault() == null) {
			return PLUGIN_ID;
		}
		return getDefault().getBundle().getSymbolicName();
	}

	/**
	 * Logs the specified status with this plug-in's log.
	 * 
	 * @param status
	 *            status to log
	 */
	public static void log(IStatus status) {
		getDefault().getLog().log(status);
	}

	/**
	 * Logs an internal error with the specified message.
	 * 
	 * @param message
	 *            the error message to log
	 */
	public static void log(String message) {
		log(new Status(IStatus.ERROR, getUniqueIdentifier(), IStatus.ERROR, message, null));
	}

	/**
	 * Logs an internal error with the specified throwable
	 * 
	 * @param e
	 *            the exception to be logged
	 */
	public static void log(Throwable e) {
		log(new Status(IStatus.ERROR, getUniqueIdentifier(), IStatus.ERROR, e.getMessage(), e));
	}


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

	/**
	 * Return the OSGi service with the given service interface.
	 * 
	 * @param service service interface
	 * @return the specified service or null if it's not registered
	 */
	public static <T> T getService(Class<T> service) {
		BundleContext context = plugin.getBundle().getBundleContext();
		ServiceReference<T> ref = context.getServiceReference(service);
		return ref != null ? context.getService(ref) : null;
	}

	@Override
	public void start(BundleContext context) throws Exception {
		super.start(context);
		plugin = this;
	}

	@Override
	public void stop(BundleContext context) throws Exception {
		plugin = null;
		super.stop(context);
	}
}