Copyright (c) 2005, 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) 2005, 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.storage.bundlefile;

import java.io.File;
import java.io.IOException;
import java.util.*;
import org.eclipse.osgi.internal.messages.Msg;
import org.eclipse.osgi.util.NLS;

A BundleFile that uses a directory as its base file.
/**
 * A BundleFile that uses a directory as its base file.
 */
public class DirBundleFile extends BundleFile {

	private static final String POINTER_SAME_DIRECTORY_1 = "/.";//$NON-NLS-1$
	private static final String POINTER_SAME_DIRECTORY_2 = "//";//$NON-NLS-1$
	private static final String POINTER_UPPER_DIRECTORY = "..";//$NON-NLS-1$

	private final boolean enableStrictBundleEntryPath;

	
Constructs a DirBundleFile
Params:
basefile – the base file
Throws:
IOException – /**
	 * Constructs a DirBundleFile
	 * @param basefile the base file
	 * @throws IOException
	 */
	public DirBundleFile(File basefile, boolean enableStrictBundleEntryPath) throws IOException {
		super(getBaseFile(basefile, enableStrictBundleEntryPath));
		if (!BundleFile.secureAction.exists(basefile) || !BundleFile.secureAction.isDirectory(basefile)) {
			throw new IOException(NLS.bind(Msg.ADAPTOR_DIRECTORY_EXCEPTION, basefile));
		}
		this.enableStrictBundleEntryPath = enableStrictBundleEntryPath;
	}

	private static File getBaseFile(File basefile, boolean enableStrictBundleEntryPath) throws IOException {
		return enableStrictBundleEntryPath ? secureAction.getCanonicalFile(basefile) : basefile;
	}

	@Override
	public File getFile(String path, boolean nativeCode) {
		final boolean checkInBundle = path != null && path.indexOf(POINTER_UPPER_DIRECTORY) >= 0;
		File file = new File(this.basefile, path);
		if (!BundleFile.secureAction.exists(file)) {
			return null;
		}

		if (!enableStrictBundleEntryPath) {
			// must do an extra check to make sure file is within the bundle (bug 320546)
			if (checkInBundle) {
				try {
					if (!BundleFile.secureAction.getCanonicalPath(file).startsWith(BundleFile.secureAction.getCanonicalPath(basefile)))
						return null;
				} catch (IOException e) {
					return null;
				}
			}
			return file;
		}
		boolean normalize = false;
		boolean isBundleRoot = false;
		if (path != null) {
			isBundleRoot = path.equals("/");//$NON-NLS-1$
			if (!isBundleRoot) {
				normalize = checkInBundle || path.indexOf(POINTER_SAME_DIRECTORY_1) >= 0 || path.indexOf(POINTER_SAME_DIRECTORY_2) >= 0;
			}
		}
		File canonicalFile;
		try {
			canonicalFile = BundleFile.secureAction.getCanonicalFile(file);
			if (!isBundleRoot) {
				File absoluteFile = BundleFile.secureAction.getAbsoluteFile(file);
				String canonicalPath;
				String absolutePath;
				if (normalize) {
					canonicalPath = canonicalFile.toURI().getPath();
					absolutePath = absoluteFile.toURI().normalize().getPath();
				} else {
					canonicalPath = canonicalFile.getPath();
					absolutePath = absoluteFile.getPath();
				}
				if (!canonicalPath.equals(absolutePath)) {
					return null;
				}
			}
			// must do an extra check to make sure file is within the bundle (bug 320546)
			if (checkInBundle) {
				if (!canonicalFile.getPath().startsWith(basefile.getPath()))
					return null;
			}
		} catch (IOException e) {
			return null;
		}

		return file;
	}

	@Override
	public BundleEntry getEntry(String path) {
		File filePath = getFile(path, false);
		if (filePath == null)
			return null;
		return new FileBundleEntry(filePath, path);
	}

	@Override
	public boolean containsDir(String dir) {
		File dirPath = getFile(dir, false);
		return dirPath != null && BundleFile.secureAction.isDirectory(dirPath);
	}

	@Override
	public Enumeration<String> getEntryPaths(String path, boolean recurse) {
		if (path.length() > 0 && path.charAt(0) == '/')
			path = path.substring(1);
		File pathFile = getFile(path, false);
		if (pathFile == null || !BundleFile.secureAction.isDirectory(pathFile))
			return null;
		String[] fileList = BundleFile.secureAction.list(pathFile);
		if (fileList == null || fileList.length == 0)
			return null;
		String dirPath = path.length() == 0 || path.charAt(path.length() - 1) == '/' ? path : path + '/';

		LinkedHashSet<String> entries = new LinkedHashSet<>();
		for (String s : fileList) {
			java.io.File childFile = new java.io.File(pathFile, s);
			StringBuilder sb = new StringBuilder(dirPath).append(s);
			if (BundleFile.secureAction.isDirectory(childFile)) {
				sb.append("/"); //$NON-NLS-1$
				if (recurse) {
					Enumeration<String> e = getEntryPaths(sb.toString(), true);
					if (e != null)
						entries.addAll(Collections.list(e));
				}
			}
			entries.add(sb.toString());
		}
		return Collections.enumeration(entries);
	}

	@Override
	public void close() {
		// nothing to do.
	}

	@Override
	public void open() {
		// nothing to do.
	}
}