Copyright (c) 2013, 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
    Chris McGee (IBM) - Bug 380325 - Release filesystem fragment providing Java 7 NIO2 support
    Sergey Prigogin (Google) - ongoing development
/*******************************************************************************
 * Copyright (c) 2013, 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
 *     Chris McGee (IBM) - Bug 380325 - Release filesystem fragment providing Java 7 NIO2 support
 *     Sergey Prigogin (Google) - ongoing development
 *******************************************************************************/
package org.eclipse.core.internal.filesystem.local.nio;

import java.io.IOException;
import java.nio.file.*;
import java.nio.file.attribute.*;
import java.util.HashSet;
import java.util.Set;
import org.eclipse.core.filesystem.EFS;
import org.eclipse.core.filesystem.IFileInfo;
import org.eclipse.core.filesystem.provider.FileInfo;
import org.eclipse.core.internal.filesystem.local.NativeHandler;

NativeHandler for POSIX using only Java 7 API's. It can be used for any
file system supporting POSIX family of standards.
/**
 * NativeHandler for POSIX using only Java 7 API's. It can be used for any
 * file system supporting POSIX family of standards.
 */
public class PosixHandler extends NativeHandler {
	private static final int ATTRIBUTES = EFS.ATTRIBUTE_SYMLINK | EFS.ATTRIBUTE_LINK_TARGET // symbolic link support
			| EFS.ATTRIBUTE_READ_ONLY | EFS.ATTRIBUTE_EXECUTABLE // mapped to owner read and owner execute via FileInfo implementation
			| EFS.ATTRIBUTE_OWNER_READ | EFS.ATTRIBUTE_OWNER_WRITE | EFS.ATTRIBUTE_OWNER_EXECUTE // owner
			| EFS.ATTRIBUTE_GROUP_READ | EFS.ATTRIBUTE_GROUP_WRITE | EFS.ATTRIBUTE_GROUP_EXECUTE // group
			| EFS.ATTRIBUTE_OTHER_READ | EFS.ATTRIBUTE_OTHER_WRITE | EFS.ATTRIBUTE_OTHER_EXECUTE; // other

	@Override
	public FileInfo fetchFileInfo(String fileName) {
		Path path = Paths.get(fileName);
		FileInfo info = new FileInfo();

		// Fill in the name of the file.
		// If the file system is case insensitive, we don't know the real name of the file.
		// Since obtaining the real name in such situation is pretty expensive, we use the name
		// passed as a parameter, which may differ by case from the real name of the file
		// if the file system is case insensitive.
		Path fileNamePath = path.getFileName();
		info.setName(fileNamePath == null ? "" : fileNamePath.toString()); //$NON-NLS-1$

		try {
			PosixFileAttributes attrs = Files.readAttributes(path, PosixFileAttributes.class, LinkOption.NOFOLLOW_LINKS);

			if (attrs.isSymbolicLink()) {
				info.setAttribute(EFS.ATTRIBUTE_SYMLINK, true);
				info.setStringAttribute(EFS.ATTRIBUTE_LINK_TARGET, Files.readSymbolicLink(path).toString());
				attrs = Files.readAttributes(path, PosixFileAttributes.class);
			}

			info.setExists(true);
			info.setLastModified(attrs.lastModifiedTime().toMillis());
			info.setLength(attrs.size());
			info.setDirectory(attrs.isDirectory());

			Set<PosixFilePermission> perms = attrs.permissions();
			info.setAttribute(EFS.ATTRIBUTE_OWNER_READ, perms.contains(PosixFilePermission.OWNER_READ));
			info.setAttribute(EFS.ATTRIBUTE_OWNER_WRITE, perms.contains(PosixFilePermission.OWNER_WRITE));
			info.setAttribute(EFS.ATTRIBUTE_OWNER_EXECUTE, perms.contains(PosixFilePermission.OWNER_EXECUTE));
			info.setAttribute(EFS.ATTRIBUTE_GROUP_READ, perms.contains(PosixFilePermission.GROUP_READ));
			info.setAttribute(EFS.ATTRIBUTE_GROUP_WRITE, perms.contains(PosixFilePermission.GROUP_WRITE));
			info.setAttribute(EFS.ATTRIBUTE_GROUP_EXECUTE, perms.contains(PosixFilePermission.GROUP_EXECUTE));
			info.setAttribute(EFS.ATTRIBUTE_OTHER_READ, perms.contains(PosixFilePermission.OTHERS_READ));
			info.setAttribute(EFS.ATTRIBUTE_OTHER_WRITE, perms.contains(PosixFilePermission.OTHERS_WRITE));
			info.setAttribute(EFS.ATTRIBUTE_OTHER_EXECUTE, perms.contains(PosixFilePermission.OTHERS_EXECUTE));
		} catch (NoSuchFileException e) {
			// A non-existing file is not considered an error.
		} catch (IOException e) {
			// Leave alone and continue.
			info.setError(IFileInfo.IO_ERROR);
		}
		return info;
	}

	@Override
	public int getSupportedAttributes() {
		return ATTRIBUTES;
	}

	@Override
	public boolean putFileInfo(String fileName, IFileInfo info, int options) {
		Path path = Paths.get(fileName);
		Set<PosixFilePermission> perms = new HashSet<>();

		if (info.getAttribute(EFS.ATTRIBUTE_OWNER_READ))
			perms.add(PosixFilePermission.OWNER_READ);
		if (info.getAttribute(EFS.ATTRIBUTE_OWNER_WRITE))
			perms.add(PosixFilePermission.OWNER_WRITE);
		if (info.getAttribute(EFS.ATTRIBUTE_OWNER_EXECUTE))
			perms.add(PosixFilePermission.OWNER_EXECUTE);
		if (info.getAttribute(EFS.ATTRIBUTE_GROUP_READ))
			perms.add(PosixFilePermission.GROUP_READ);
		if (info.getAttribute(EFS.ATTRIBUTE_GROUP_WRITE))
			perms.add(PosixFilePermission.GROUP_WRITE);
		if (info.getAttribute(EFS.ATTRIBUTE_GROUP_EXECUTE))
			perms.add(PosixFilePermission.GROUP_EXECUTE);
		if (info.getAttribute(EFS.ATTRIBUTE_OTHER_READ))
			perms.add(PosixFilePermission.OTHERS_READ);
		if (info.getAttribute(EFS.ATTRIBUTE_OTHER_WRITE))
			perms.add(PosixFilePermission.OTHERS_WRITE);
		if (info.getAttribute(EFS.ATTRIBUTE_OTHER_EXECUTE))
			perms.add(PosixFilePermission.OTHERS_EXECUTE);

		PosixFileAttributeView view = Files.getFileAttributeView(path, PosixFileAttributeView.class);
		try {
			view.setPermissions(perms);
		} catch (IOException e) {
			return false;
		}
		return true;
	}
}