Copyright (c) 2004, 2013 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) 2004, 2013 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.core.internal.runtime;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import org.eclipse.core.runtime.*;
import org.eclipse.osgi.framework.log.FrameworkLog;
import org.eclipse.osgi.service.datalocation.Location;
import org.eclipse.osgi.service.debug.DebugOptions;
import org.eclipse.osgi.util.NLS;
import org.osgi.framework.Bundle;

This class can only be used if OSGi plugin is available
/**
 * This class can only be used if OSGi plugin is available
 */
public class DataArea {
	private static final String OPTION_DEBUG = "org.eclipse.equinox.common/debug"; //$NON-NLS-1$;
	private static final String REQUIRES_EXPLICIT_INIT = "osgi.dataAreaRequiresExplicitInit"; //$NON-NLS-1$;

	/* package */static final String F_META_AREA = ".metadata"; //$NON-NLS-1$
	/* package */static final String F_PLUGIN_DATA = ".plugins"; //$NON-NLS-1$
	/* package */static final String F_LOG = ".log"; //$NON-NLS-1$
	/* package */static final String F_TRACE = "trace.log"; //$NON-NLS-1$

	
Internal name of the preference storage file (value "pref_store.ini") in this plug-in's (read-write) state area.
/**
	 * Internal name of the preference storage file (value <code>"pref_store.ini"</code>) in this plug-in's (read-write) state area.
	 */
	/* package */static final String PREFERENCES_FILE_NAME = "pref_store.ini"; //$NON-NLS-1$

	private IPath location; //The location of the instance data
	private boolean initialized = false;

	protected synchronized void assertLocationInitialized() throws IllegalStateException {
		if (location != null && initialized)
			return;
		Activator activator = Activator.getDefault();
		if (activator == null)
			throw new IllegalStateException(CommonMessages.activator_not_available);
		Location service = activator.getInstanceLocation();
		if (service == null)
			throw new IllegalStateException(CommonMessages.meta_noDataModeSpecified);

		boolean explicitInitRequired = Boolean.valueOf(Activator.getContext().getProperty(REQUIRES_EXPLICIT_INIT));
		if (explicitInitRequired && !service.isSet()) {
			// See bug 514333: don't allow clients to initialize instance location if the instance area is not explicitly defined yet
			throw new IllegalStateException(CommonMessages.meta_instanceDataUnspecified);
		}

		try {
			// This will try to init url either from the specified location value or from service default
			URL url = service.getURL();
			if (url == null)
				throw new IllegalStateException(CommonMessages.meta_instanceDataUnspecified);
			// TODO assume the URL is a file: 
			// Use the new File technique to ensure that the resultant string is 
			// in the right format (e.g., leading / removed from /c:/foo etc)
			location = new Path(new File(url.getFile()).toString());
			initializeLocation();
		} catch (CoreException e) {
			throw new IllegalStateException(e.getMessage());
		}
	}

	public IPath getMetadataLocation() throws IllegalStateException {
		assertLocationInitialized();
		return location.append(F_META_AREA);
	}

	public IPath getInstanceDataLocation() throws IllegalStateException {
		assertLocationInitialized();
		return location;
	}

	
Returns the local file system path of the log file, or the default log location
if the log is not in the local file system.
/**
	 * Returns the local file system path of the log file, or the default log location
	 * if the log is not in the local file system.
	 */
	public IPath getLogLocation() throws IllegalStateException {
		//make sure the log location is initialized if the instance location is known
		if (isInstanceLocationSet())
			assertLocationInitialized();
		FrameworkLog log = Activator.getDefault().getFrameworkLog();
		if (log != null) {
			java.io.File file = log.getFile();
			if (file != null)
				return new Path(file.getAbsolutePath());
		}
		if (location == null)
			throw new IllegalStateException(CommonMessages.meta_instanceDataUnspecified);
		return location.append(F_META_AREA).append(F_LOG);
	}

	public IPath getTraceLocation() throws IllegalStateException {

		DebugOptions debugOptions = Activator.getDefault().getDebugOptions();
		if (debugOptions == null) {
			return null;
		}
		File file = debugOptions.getFile();
		if (file == null) {
			return null;
		}
		return new Path(file.getAbsolutePath());
	}

	
Returns true if the instance location has been set, and false otherwise.
/**
	 * Returns true if the instance location has been set, and <code>false</code> otherwise.
	 */
	private boolean isInstanceLocationSet() {
		Activator activator = Activator.getDefault();
		if (activator == null)
			return false;
		Location service = activator.getInstanceLocation();
		if (service == null)
			return false;
		return service.isSet();
	}

	
Returns the read/write location in which the given bundle can manage private state.
/**
	 * Returns the read/write location in which the given bundle can manage private state.
	 */
	public IPath getStateLocation(Bundle bundle) throws IllegalStateException {
		assertLocationInitialized();
		return getStateLocation(bundle.getSymbolicName());
	}

	public IPath getStateLocation(String bundleName) throws IllegalStateException {
		assertLocationInitialized();
		return getMetadataLocation().append(F_PLUGIN_DATA).append(bundleName);
	}

	public IPath getPreferenceLocation(String bundleName, boolean create) throws IllegalStateException {
		IPath result = getStateLocation(bundleName);
		if (create)
			result.toFile().mkdirs();
		return result.append(PREFERENCES_FILE_NAME);
	}

	private void initializeLocation() throws CoreException {
		// check if the location can be created
		if (location.toFile().exists()) {
			if (!location.toFile().isDirectory()) {
				String message = NLS.bind(CommonMessages.meta_notDir, location);
				throw new CoreException(new Status(IStatus.ERROR, IRuntimeConstants.PI_RUNTIME, IRuntimeConstants.FAILED_WRITE_METADATA, message, null));
			}
		}
		//try infer the device if there isn't one (windows)
		if (location.getDevice() == null)
			location = new Path(location.toFile().getAbsolutePath());
		createLocation();
		initialized = true;
	}

	private void createLocation() throws CoreException {
		// append on the metadata location so that the whole structure is created.  
		File file = location.append(F_META_AREA).toFile();
		try {
			file.mkdirs();
		} catch (Exception e) {
			String message = NLS.bind(CommonMessages.meta_couldNotCreate, file.getAbsolutePath());
			throw new CoreException(new Status(IStatus.ERROR, IRuntimeConstants.PI_RUNTIME, IRuntimeConstants.FAILED_WRITE_METADATA, message, e));
		}
		if (!file.canWrite()) {
			String message = NLS.bind(CommonMessages.meta_readonly, file.getAbsolutePath());
			throw new CoreException(new Status(IStatus.ERROR, IRuntimeConstants.PI_RUNTIME, IRuntimeConstants.FAILED_WRITE_METADATA, message, null));
		}
		// set the log file location now that we created the data area
		IPath logPath = location.append(F_META_AREA).append(F_LOG);
		try {
			Activator activator = Activator.getDefault();
			if (activator != null) {
				FrameworkLog log = activator.getFrameworkLog();
				if (log != null)
					log.setFile(logPath.toFile(), true);
				else if (debug())
					System.out.println("ERROR: Unable to acquire log service. Application will proceed, but logging will be disabled."); //$NON-NLS-1$
			}
		} catch (IOException e) {
			e.printStackTrace();
		}

		// set the trace file location now that we created the data area
		IPath tracePath = location.append(F_META_AREA).append(F_TRACE);
		Activator activator = Activator.getDefault();
		if (activator != null) {
			DebugOptions debugOptions = activator.getDebugOptions();
			if (debugOptions != null) {
				debugOptions.setFile(tracePath.toFile());
			} else {
				System.out.println("ERROR: Unable to acquire debug service. Application will proceed, but debugging will be disabled."); //$NON-NLS-1$
			}
		}
	}

	private boolean debug() {
		Activator activator = Activator.getDefault();
		if (activator == null)
			return false;
		DebugOptions debugOptions = activator.getDebugOptions();
		if (debugOptions == null)
			return false;
		return debugOptions.getBooleanOption(OPTION_DEBUG, false);
	}
}