/******************************************************************************
 * Copyright (c) 2002, 2005 IBM Corporation and others.
 * 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:
 *    IBM Corporation - initial API and implementation 
 ****************************************************************************/

package org.eclipse.gmf.runtime.common.core.util;

import org.eclipse.core.runtime.ILog;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Plugin;
import org.eclipse.core.runtime.Status;

import org.eclipse.gmf.runtime.common.core.internal.CommonCoreDebugOptions;
import org.eclipse.gmf.runtime.common.core.internal.CommonCorePlugin;
import org.eclipse.gmf.runtime.common.core.internal.CommonCoreStatusCodes;

/**
 * A utility for logging errors, warnings, and information. Provides a simple
 * interface for generating logs based on status objects.
 * 
 * @author khussey
 */
public class Log {

	/**
	 * private constructor for the static class.
	 */
	protected Log() {
		super();
	}
	
	/**
	 * The default log listener for this log utility.
	 */
	private static final ILog fLog = CommonCorePlugin.getDefault().getLog();

	/**
	 * Retrieves the default log listener for this log utility.
	 * 
	 * @return The default log listener for this log utility.
	 */
	protected static ILog getDefault() {
		return fLog;
	}
	
	/**
	 * Responds to a log request for the specified plug-in based on the
	 * specified status object. Statuses with severity of error or warning
	 * result in the generation of a platform log for the specified plug-in; all
	 * log requests are forward to the default log listener.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param status
	 *            The status object on which to base the log.
	 *  
	 */
	public static void log(Plugin plugin, IStatus status) {
		switch (status.getSeverity()) {
			case IStatus.ERROR:
			case IStatus.WARNING:
				getDefault().log(status);
				break;
			default:
				/*
				 * The Eclipse logging facility does not have the concept of
				 * logging levels. Anything logged to the plugins logger will
				 * automatically be logged to the .log file. The Common Logging
				 * implementation provides the common log file
				 * (CommonBaseEvents.log) with the associated extension point
				 * and preference page but is not related to the .log file.
				 * Since we do not want to Eclipse log poluted with "plug-in
				 * started" messages, we do not log these.
				 * 
				 * getDefault().log(status);
				 */
				break;
		}
	}

	/**
	 * Generates a log for the specified plug-in, with the specified severity,
	 * status code, and message.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param severity
	 *            The severity of the log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 *  
	 */
	public static void log(Plugin plugin, int severity, int code, String message) {

		log(plugin, severity, code, message, null);
	}

	/**
	 * Generates a log for the specified plug-in, with the specified severity,
	 * status code, message, and throwable.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param severity
	 *            The severity of the log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 * @param throwable
	 *            The throwable for the log.
	 *  
	 */
	public static void log(Plugin plugin, int severity, int code,
			String message, Throwable throwable) {

		//
		// Status ctor requires a non-null message
		String msg = message == null ? "" //$NON-NLS-1$
			: message;

		try {
			log(plugin, new Status(severity, plugin.getBundle()
				.getSymbolicName(), code, msg, throwable));
		} catch (IllegalArgumentException iae) {
			Trace.catching(CommonCorePlugin.getDefault(),
				CommonCoreDebugOptions.EXCEPTIONS_CATCHING, Log.getDefault()
					.getClass(), "log", iae); //$NON-NLS-1$
			Log.error(CommonCorePlugin.getDefault(),
				CommonCoreStatusCodes.SERVICE_FAILURE, "log", iae); //$NON-NLS-1$
		}
	}

	/**
	 * Generates an error log for the specified plug-in, with the specified
	 * status code and message.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 *  
	 */
	public static void error(Plugin plugin, int code, String message) {
		error(plugin, code, message, null);
	}
	
	/**
	 * Generates an error log for the specified plug-in, with the specified
	 * status code, message, and throwable.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 * @param throwable
	 *            The throwable for the log.
	 *  
	 */
	public static void error(Plugin plugin, int code, String message,
			Throwable throwable) {

		log(plugin, IStatus.ERROR, code, message, throwable);
	}

	/**
	 * Generates a warning log for the specified plug-in, with the specified
	 * status code and message.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 *  
	 */
	public static void warning(Plugin plugin, int code, String message) {
		warning(plugin, code, message, null);
	}

	/**
	 * Generates a warning log for the specified plug-in, with the specified
	 * status code, message, and throwable.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 * @param throwable
	 *            The throwable for the log.
	 *  
	 */
	public static void warning(Plugin plugin, int code, String message,
			Throwable throwable) {

		log(plugin, IStatus.WARNING, code, message, throwable);
	}

	/**
	 * Generates an information log for the specified plug-in, with the
	 * specified status code and message.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 *  
	 */
	public static void info(Plugin plugin, int code, String message) {
		info(plugin, code, message, null);
	}

	/**
	 * Generates an information log for the specified plug-in, with the
	 * specified status code, message, and throwable.
	 * 
	 * @param plugin
	 *            The plug-in for which to generate a log.
	 * @param code
	 *            The status code for the log.
	 * @param message
	 *            The message for the log.
	 * @param throwable
	 *            The throwable for the log.
	 *  
	 */
	public static void info(Plugin plugin, int code, String message,
			Throwable throwable) {

		log(plugin, IStatus.INFO, code, message, throwable);
	}
}