Copyright (c) 2000, 2015 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
    Sergey Prigogin (Google) - use parameterized types (bug 442021)
/*******************************************************************************
 *  Copyright (c) 2000, 2015 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
 *     Sergey Prigogin (Google) - use parameterized types (bug 442021)
 *******************************************************************************/
package org.eclipse.core.internal.runtime;

import java.util.ArrayList;
import org.eclipse.core.runtime.*;
import org.eclipse.equinox.log.*;
import org.eclipse.osgi.framework.log.FrameworkLogEntry;
import org.osgi.framework.Bundle;
import org.osgi.service.log.LogEntry;
import org.osgi.service.log.LogService;
import org.osgi.service.packageadmin.PackageAdmin;

A log writer that writes log entries.  

Note that this class just provides a bridge from the old ILog interface
to the new extended log service
/**
 * A log writer that writes log entries.  
 * <p>
 * Note that this class just provides a bridge from the old ILog interface
 * to the new extended log service
 */
public class PlatformLogWriter implements SynchronousLogListener, LogFilter {
	public static final String EQUINOX_LOGGER_NAME = "org.eclipse.equinox.logger"; //$NON-NLS-1$
	private final ExtendedLogService logService;
	private final PackageAdmin packageAdmin;
	private final Bundle bundle;

	public PlatformLogWriter(ExtendedLogService logService, PackageAdmin packageAdmin, Bundle bundle) {
		this.logService = logService;
		this.packageAdmin = packageAdmin;
		this.bundle = bundle;
	}

	void logging(IStatus status) {
		Bundle b = getBundle(status);
		Logger equinoxLog = logService.getLogger(b, EQUINOX_LOGGER_NAME);
		equinoxLog.log(getLog(status), getLevel(status), status.getMessage(), status.getException());
	}

	public static int getLevel(IStatus status) {
		switch (status.getSeverity()) {
			case IStatus.ERROR :
				return LogService.LOG_ERROR;
			case IStatus.WARNING :
				return LogService.LOG_WARNING;
			case IStatus.INFO :
				return LogService.LOG_INFO;
			case IStatus.OK :
				return LogService.LOG_DEBUG;
			case IStatus.CANCEL :
			default :
				return 32; // unknown
		}
	}

	public static FrameworkLogEntry getLog(IStatus status) {
		Throwable t = status.getException();
		ArrayList<FrameworkLogEntry> childlist = new ArrayList<>();

		int stackCode = t instanceof CoreException ? 1 : 0;
		// ensure a substatus inside a CoreException is properly logged 
		if (stackCode == 1) {
			IStatus coreStatus = ((CoreException) t).getStatus();
			if (coreStatus != null) {
				childlist.add(getLog(coreStatus));
			}
		}

		if (status.isMultiStatus()) {
			IStatus[] children = status.getChildren();
			for (IStatus child : children) {
				childlist.add(getLog(child));
			}
		}

		FrameworkLogEntry[] children = childlist.size() == 0 ? null : childlist.toArray(new FrameworkLogEntry[childlist.size()]);

		return new FrameworkLogEntry(status, status.getPlugin(), status.getSeverity(), status.getCode(), status.getMessage(), stackCode, t, children);
	}

	private Bundle getBundle(IStatus status) {
		String pluginID = status.getPlugin();
		if (pluginID == null)
			return bundle;
		Bundle[] bundles = packageAdmin.getBundles(pluginID, null);
		return bundles == null || bundles.length == 0 ? bundle : bundles[0];
	}

	@Override
	public boolean isLoggable(Bundle bundle, String loggerName, int logLevel) {
		return EQUINOX_LOGGER_NAME.equals(loggerName) && RuntimeLog.hasListeners();
	}

	@Override
	public void logged(LogEntry entry) {
		RuntimeLog.logToListeners(convertToStatus(entry));
	}

	public static IStatus convertToStatus(LogEntry logEntry) {
		Object context = null;
		if (logEntry instanceof ExtendedLogEntry)
			context = ((ExtendedLogEntry) logEntry).getContext();
		if (context instanceof IStatus)
			return (IStatus) context;
		if (context instanceof FrameworkLogEntry) {
			FrameworkLogEntry fLogEntry = (FrameworkLogEntry) context;
			context = fLogEntry.getContext();
			if (context instanceof IStatus)
				return (IStatus) context;
			return convertToStatus(fLogEntry);
		}
		return convertRawEntryToStatus(logEntry);
	}

	private static IStatus convertToStatus(FrameworkLogEntry entry) {
		FrameworkLogEntry[] children = entry.getChildren();
		if (children != null) {
			IStatus[] statusChildren = new Status[children.length];
			for (int i = 0; i < statusChildren.length; i++)
				statusChildren[i] = convertToStatus(children[i]);
			return new MultiStatus(entry.getEntry(), entry.getBundleCode(), statusChildren, entry.getMessage(), entry.getThrowable());
		}
		return new Status(entry.getSeverity(), entry.getEntry(), entry.getBundleCode(), entry.getMessage(), entry.getThrowable());
	}

	private static IStatus convertRawEntryToStatus(LogEntry logEntry) {
		int severity;
		switch (logEntry.getLogLevel()) {
			case ERROR :
				severity = IStatus.ERROR;
				break;
			case WARN :
				severity = IStatus.WARNING;
				break;
			case INFO :
				severity = IStatus.INFO;
				break;
			case DEBUG :
			case TRACE :
			case AUDIT :
				severity = IStatus.OK;
				break;
			default :
				severity = -1;
				break;
		}
		Bundle bundle = logEntry.getBundle();
		return new Status(severity, bundle == null ? null : bundle.getSymbolicName(), logEntry.getMessage(), logEntry.getException());
	}
}