Copyright (c) 2003, 2016 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2003, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.osgi.internal.debug;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import org.eclipse.osgi.internal.framework.EquinoxConfiguration;
import org.eclipse.osgi.internal.location.LocationHelper;
import org.eclipse.osgi.service.debug.DebugOptions;
import org.eclipse.osgi.service.debug.DebugOptionsListener;
import org.eclipse.osgi.service.debug.DebugTrace;
import org.osgi.framework.BundleContext;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.util.tracker.ServiceTracker;
import org.osgi.util.tracker.ServiceTrackerCustomizer;

The DebugOptions implementation class that allows accessing the list of debug options specified for the application as well as creating DebugTrace objects for the purpose of having dynamic enablement of debug tracing. 
Since:
3.1/**
 * The DebugOptions implementation class that allows accessing the list of debug options specified
 * for the application as well as creating {@link DebugTrace} objects for the purpose of having
 * dynamic enablement of debug tracing.
 * 
 * @since 3.1
 */
public class FrameworkDebugOptions implements DebugOptions, ServiceTrackerCustomizer<DebugOptionsListener, DebugOptionsListener> {

	private static final String OSGI_DEBUG = "osgi.debug"; //$NON-NLS-1$
	private static final String OSGI_DEBUG_VERBOSE = "osgi.debug.verbose"; //$NON-NLS-1$
	public static final String PROP_TRACEFILE = "osgi.tracefile"; //$NON-NLS-1$
	
The default name of the .options file if loading when the -debug command-line argument is used /** The default name of the .options file if loading when the -debug command-line argument is used */
	private static final String OPTIONS = ".options"; //$NON-NLS-1$

	
A lock object used to synchronize access to the trace file /** A lock object used to synchronize access to the trace file */
	private final static Object writeLock = new Object();
	
monitor used to lock the options maps /** monitor used to lock the options maps */
	private final Object lock = new Object();
	
A current map of all the options with values set /** A current map of all the options with values set */
	private Properties options = null;
	
A map of all the disabled options with values set at the time debug was disabled /** A map of all the disabled options with values set at the time debug was disabled */
	private Properties disabledOptions = null;
	
A cache of all of the bundles DebugTrace in the format  -->  /** A cache of all of the bundles <code>DebugTrace</code> in the format <key,value> --> <bundle name, DebugTrace> */
	protected final Map<String, DebugTrace> debugTraceCache = new HashMap<>();
	
The File object to store messages.  This value may be null. /** The File object to store messages.  This value may be null. */
	protected File outFile = null;
	
Is verbose debugging enabled?  Changing this value causes a new tracing session to start. /** Is verbose debugging enabled?  Changing this value causes a new tracing session to start. */
	protected boolean verboseDebug = true;
	
A flag to determine if the message being written is done to a new file (i.e. should the header information be written) /** A flag to determine if the message being written is done to a new file (i.e. should the header information be written) */
	private boolean newSession = true;
	private final EquinoxConfiguration environmentInfo;
	private volatile BundleContext context;
	private volatile ServiceTracker<DebugOptionsListener, DebugOptionsListener> listenerTracker;

	public FrameworkDebugOptions(EquinoxConfiguration environmentInfo) {
		this.environmentInfo = environmentInfo;
		// check if verbose debugging was set during initialization.  This needs to be set even if debugging is disabled
		this.verboseDebug = Boolean.valueOf(environmentInfo.getConfiguration(OSGI_DEBUG_VERBOSE, Boolean.TRUE.toString())).booleanValue();
		// if no debug option was specified, don't even bother to try.
		// Must ensure that the options slot is null as this is the signal to the
		// platform that debugging is not enabled.
		String debugOptionsFilename = environmentInfo.getConfiguration(OSGI_DEBUG);
		if (debugOptionsFilename == null)
			return;
		options = new Properties();
		URL optionsFile;
		if (debugOptionsFilename.length() == 0) {
			// default options location is user.dir (install location may be r/o so
			// is not a good candidate for a trace options that need to be updatable by
			// by the user)
			String userDir = System.getProperty("user.dir").replace(File.separatorChar, '/'); //$NON-NLS-1$
			if (!userDir.endsWith("/")) //$NON-NLS-1$
				userDir += "/"; //$NON-NLS-1$
			debugOptionsFilename = new File(userDir, OPTIONS).toString();
		}
		optionsFile = LocationHelper.buildURL(debugOptionsFilename, false);
		if (optionsFile == null) {
			System.out.println("Unable to construct URL for options file: " + debugOptionsFilename); //$NON-NLS-1$
			return;
		}
		System.out.print("Debug options:\n    " + optionsFile.toExternalForm()); //$NON-NLS-1$
		try {
			InputStream input = LocationHelper.getStream(optionsFile);
			try {
				options.load(input);
				System.out.println(" loaded"); //$NON-NLS-1$
			} finally {
				input.close();
			}
		} catch (FileNotFoundException e) {
			System.out.println(" not found"); //$NON-NLS-1$
		} catch (IOException e) {
			System.out.println(" did not parse"); //$NON-NLS-1$
			e.printStackTrace(System.out);
		}
		// trim off all the blanks since properties files don't do that.
		for (Object key : options.keySet()) {
			options.put(key, ((String) options.get(key)).trim());
		}
	}

	public void start(BundleContext bc) {
		this.context = bc;
		listenerTracker = new ServiceTracker<>(bc, DebugOptionsListener.class.getName(), this);
		listenerTracker.open();
	}

	public void stop(BundleContext bc) {
		listenerTracker.close();
		listenerTracker = null;
		this.context = null;
	}

	
See Also:
getBooleanOption.getBooleanOption(String, boolean)/**
	 * @see DebugOptions#getBooleanOption(String, boolean)
	 */
	@Override
	public boolean getBooleanOption(String option, boolean defaultValue) {
		String optionValue = getOption(option);
		return optionValue != null ? optionValue.equalsIgnoreCase("true") : defaultValue; //$NON-NLS-1$
	}

	
See Also:
getOption.getOption(String)/**
	 * @see DebugOptions#getOption(String)
	 */
	@Override
	public String getOption(String option) {
		return getOption(option, null);
	}

	
See Also:
getOption.getOption(String, String)/**
	 * @see DebugOptions#getOption(String, String)
	 */
	@Override
	public String getOption(String option, String defaultValue) {
		synchronized (lock) {
			if (options != null) {
				return options.getProperty(option, defaultValue);
			}
		}
		return defaultValue;
	}

	
See Also:
getIntegerOption.getIntegerOption(String, int)/**
	 * @see DebugOptions#getIntegerOption(String, int)
	 */
	@Override
	public int getIntegerOption(String option, int defaultValue) {
		String value = getOption(option);
		try {
			return value == null ? defaultValue : Integer.parseInt(value);
		} catch (NumberFormatException e) {
			return defaultValue;
		}
	}

	@SuppressWarnings({"unchecked", "rawtypes"})
	@Override
	public Map<String, String> getOptions() {
		Map<String, String> snapShot = new HashMap<>();
		synchronized (lock) {
			if (options != null)
				snapShot.putAll((Map) options);
			else if (disabledOptions != null)
				snapShot.putAll((Map) disabledOptions);
		}
		return snapShot;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#getAllOptions()
	 */
	String[] getAllOptions() {

		String[] optionsArray = null;
		synchronized (lock) {
			if (options != null) {
				optionsArray = new String[options.size()];
				final Iterator<Map.Entry<Object, Object>> entrySetIterator = options.entrySet().iterator();
				int i = 0;
				while (entrySetIterator.hasNext()) {
					Map.Entry<Object, Object> entry = entrySetIterator.next();
					optionsArray[i] = ((String) entry.getKey()) + "=" + ((String) entry.getValue()); //$NON-NLS-1$
					i++;
				}
			}
		}
		if (optionsArray == null) {
			optionsArray = new String[1]; // TODO this is strange; null is the only element so we can print null in writeSession
		}
		return optionsArray;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#removeOption(java.lang.String)
	 */
	@Override
	public void removeOption(String option) {
		if (option == null)
			return;
		String fireChangedEvent = null;
		synchronized (lock) {
			if (options != null && options.remove(option) != null) {
				fireChangedEvent = getSymbolicName(option);
			}
		}
		// Send the options change event outside the sync block
		if (fireChangedEvent != null) {
			optionsChanged(fireChangedEvent);
		}
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#setOption(java.lang.String, java.lang.String)
	 */
	@Override
	public void setOption(String option, String value) {

		if (option == null || value == null) {
			throw new IllegalArgumentException("The option and value must not be null."); //$NON-NLS-1$
		}
		String fireChangedEvent = null;
		value = value != null ? value.trim() : null;
		synchronized (lock) {
			if (options != null) {
				// get the current value
				String currentValue = options.getProperty(option);

				if (currentValue != null) {
					if (!currentValue.equals(value)) {
						fireChangedEvent = getSymbolicName(option);
					}
				} else {
					if (value != null) {
						fireChangedEvent = getSymbolicName(option);
					}
				}
				if (fireChangedEvent != null) {
					options.put(option, value);
				}
			}
		}
		// Send the options change event outside the sync block
		if (fireChangedEvent != null) {
			optionsChanged(fireChangedEvent);
		}
	}

	private String getSymbolicName(String option) {
		int firstSlashIndex = option.indexOf('/');
		if (firstSlashIndex > 0)
			return option.substring(0, firstSlashIndex);
		return null;
	}

	@SuppressWarnings("cast")
	@Override
	public void setOptions(Map<String, String> ops) {
		if (ops == null)
			throw new IllegalArgumentException("The options must not be null."); //$NON-NLS-1$
		Properties newOptions = new Properties();
		for (Map.Entry<String, String> entry : ops.entrySet()) {
			if (!(entry.getKey() instanceof String) || !(entry.getValue() instanceof String))
				throw new IllegalArgumentException("Option keys and values must be of type String: " + entry.getKey() + "=" + entry.getValue()); //$NON-NLS-1$ //$NON-NLS-2$
			newOptions.put(entry.getKey(), entry.getValue().trim());
		}
		Set<String> fireChangesTo = null;

		synchronized (lock) {
			if (options == null) {
				disabledOptions = newOptions;
				// no events to fire
				return;
			}
			fireChangesTo = new HashSet<>();
			// first check for removals
			for (Iterator<Object> keys = options.keySet().iterator(); keys.hasNext();) {
				String key = (String) keys.next();
				if (!newOptions.containsKey(key)) {
					String symbolicName = getSymbolicName(key);
					if (symbolicName != null)
						fireChangesTo.add(symbolicName);
				}
			}
			// now check for changes to existing values
			for (Map.Entry<Object, Object> entry : newOptions.entrySet()) {
				String existingValue = (String) options.get(entry.getKey());
				if (!entry.getValue().equals(existingValue)) {
					String symbolicName = getSymbolicName((String) entry.getKey());
					if (symbolicName != null)
						fireChangesTo.add(symbolicName);
				}
			}
			// finally set the actual options
			options = newOptions;
		}
		if (fireChangesTo != null)
			for (Iterator<String> iChanges = fireChangesTo.iterator(); iChanges.hasNext();)
				optionsChanged(iChanges.next());
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#isDebugEnabled()
	 */
	@Override
	public boolean isDebugEnabled() {
		synchronized (lock) {
			return options != null;
		}
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#setDebugEnabled()
	 */
	@Override
	public void setDebugEnabled(boolean enabled) {
		boolean fireChangedEvent = false;
		synchronized (lock) {
			if (enabled) {
				if (options != null)
					return;
				// notify the trace that a new session is started
				this.newSession = true;

				// enable platform debugging - there is no .options file
				environmentInfo.setConfiguration(OSGI_DEBUG, ""); //$NON-NLS-1$
				if (disabledOptions != null) {
					options = disabledOptions;
					disabledOptions = null;
					// fire changed event to indicate some options were re-enabled
					fireChangedEvent = true;
				} else {
					options = new Properties();
				}
			} else {
				if (options == null)
					return;
				// disable platform debugging.
				environmentInfo.clearConfiguration(OSGI_DEBUG);
				if (options.size() > 0) {
					// Save the current options off in case debug is re-enabled
					disabledOptions = options;
					// fire changed event to indicate some options were disabled
					fireChangedEvent = true;
				}
				options = null;
			}
		}
		if (fireChangedEvent) {
			// (Bug 300911) need to fire event to listeners that options have been disabled
			optionsChanged("*"); //$NON-NLS-1$
		}
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#createTrace(java.lang.String)
	 */
	@Override
	public final DebugTrace newDebugTrace(String bundleSymbolicName) {

		return this.newDebugTrace(bundleSymbolicName, null);
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#createTrace(java.lang.String, java.lang.Class)
	 */
	@Override
	public final DebugTrace newDebugTrace(String bundleSymbolicName, Class<?> traceEntryClass) {

		DebugTrace debugTrace = null;
		synchronized (debugTraceCache) {
			debugTrace = debugTraceCache.get(bundleSymbolicName);
			if (debugTrace == null) {
				debugTrace = new EclipseDebugTrace(bundleSymbolicName, this, traceEntryClass);
				debugTraceCache.put(bundleSymbolicName, debugTrace);
			}
		}
		return debugTrace;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#getFile()
	 */
	@Override
	public final File getFile() {

		return this.outFile;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#setFile(java.io.File)
	 */
	@Override
	public void setFile(final File traceFile) {
		synchronized (lock) {
			this.outFile = traceFile;
			if (this.outFile != null)
				environmentInfo.setConfiguration(PROP_TRACEFILE, this.outFile.getAbsolutePath());
			else
				environmentInfo.clearConfiguration(PROP_TRACEFILE);
			// the file changed so start a new session
			this.newSession = true;
		}
	}

	boolean newSession() {
		synchronized (lock) {
			if (newSession) {
				this.newSession = false;
				return true;
			}
			return false;
		}
	}

	Object getWriteLock() {
		return writeLock;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#getVerbose()
	 */
	boolean isVerbose() {

		return this.verboseDebug;
	}

	EquinoxConfiguration getConfiguration() {
		return this.environmentInfo;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.service.debug.DebugOptions#setVerbose(boolean)
	 */
	public void setVerbose(final boolean verbose) {
		synchronized (lock) {
			this.verboseDebug = verbose;
			// the verbose flag changed so start a new session
			this.newSession = true;
		}
	}

	
Notifies the trace listener for the specified bundle that its option-path has changed.
Params:
bundleSymbolicName – The bundle of the owning trace listener to notify./**
	 * Notifies the trace listener for the specified bundle that its option-path has changed.
	 * @param bundleSymbolicName The bundle of the owning trace listener to notify.
	 */
	private void optionsChanged(String bundleSymbolicName) {
		// use osgi services to get the listeners
		BundleContext bc = context;
		if (bc == null)
			return;
		// do not use the service tracker because that is only used to call all listeners initially when they are registered
		// here we only want the services with the specified name.
		ServiceReference<?>[] listenerRefs = null;
		try {
			listenerRefs = bc.getServiceReferences(DebugOptionsListener.class.getName(), "(" + DebugOptions.LISTENER_SYMBOLICNAME + "=" + bundleSymbolicName + ")"); //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
		} catch (InvalidSyntaxException e) {
			// consider logging; should not happen
		}
		if (listenerRefs == null)
			return;
		for (ServiceReference<?> listenerRef : listenerRefs) {
			DebugOptionsListener service = (DebugOptionsListener) bc.getService(listenerRef);
			if (service == null)
				continue;
			try {
				service.optionsChanged(this);
			}catch (Throwable t) {
				// TODO consider logging
			} finally {
				bc.ungetService(listenerRef);
			}
		}
	}

	@Override
	public DebugOptionsListener addingService(ServiceReference<DebugOptionsListener> reference) {
		DebugOptionsListener listener = context.getService(reference);
		listener.optionsChanged(this);
		return listener;
	}

	@Override
	public void modifiedService(ServiceReference<DebugOptionsListener> reference, DebugOptionsListener service) {
		// nothing
	}

	@Override
	public void removedService(ServiceReference<DebugOptionsListener> reference, DebugOptionsListener service) {
		context.ungetService(reference);
	}
}