Copyright (c) 2013, 2017 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) 2013, 2017 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.storage;

import java.io.*;
import java.net.URL;
import java.util.Enumeration;
import java.util.Map;
import org.eclipse.osgi.framework.util.CaseInsensitiveDictionaryMap;
import org.eclipse.osgi.storage.bundlefile.BundleEntry;
import org.eclipse.osgi.storage.bundlefile.BundleFile;
import org.eclipse.osgi.util.ManifestElement;
import org.osgi.framework.BundleException;

public class SystemBundleFile extends BundleFile {

	public SystemBundleFile() {
		super(null);
	}

	@Override
	public File getFile(String path, boolean nativeCode) {
		return null;
	}

	@Override
	public BundleEntry getEntry(String path) {
		if (BundleInfo.OSGI_BUNDLE_MANIFEST.equals(path)) {
			return new BundleEntry() {

				@Override
				public InputStream getInputStream() throws IOException {
					return getManifestURL().openStream();
				}

				@Override
				public long getSize() {
					return 0;
				}

				@Override
				public String getName() {
					return BundleInfo.OSGI_BUNDLE_MANIFEST;
				}

				@Override
				public long getTime() {
					return 0;
				}

				@Override
				public URL getLocalURL() {
					return getManifestURL();
				}

				@Override
				public URL getFileURL() {
					return null;
				}
			};
		}
		return null;
	}

	@Override
	public Enumeration<String> getEntryPaths(String path, boolean recurse) {
		return null;
	}

	@Override
	public void close() throws IOException {
		// nothing
	}

	@Override
	public void open() throws IOException {
		// nothing
	}

	@Override
	public boolean containsDir(String dir) {
		return false;
	}

	URL getManifestURL() {
		ClassLoader cl = getClass().getClassLoader();
		try {
			// get all manifests in your classloader delegation
			Enumeration<URL> manifests = cl != null ? cl.getResources(BundleInfo.OSGI_BUNDLE_MANIFEST) : ClassLoader.getSystemResources(BundleInfo.OSGI_BUNDLE_MANIFEST);
			while (manifests.hasMoreElements()) {
				URL url = manifests.nextElement();
				try {
					// check each manifest until we find one with the Eclipse-SystemBundle: true header
					Map<String, String> headers = ManifestElement.parseBundleManifest(url.openStream(), new CaseInsensitiveDictionaryMap<String, String>());
					if ("true".equals(headers.get(Storage.ECLIPSE_SYSTEMBUNDLE))) //$NON-NLS-1$
						return url;
				} catch (BundleException e) {
					// ignore and continue to next URL
				}
			}
		} catch (IOException e) {
			// ignore and return null
		}
		return null;
	}
}