/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.karaf.shell.ssh;

import org.apache.sshd.server.FileSystemView;
import org.apache.sshd.server.SshFile;
import org.apache.sshd.server.filesystem.NativeSshFile;

import java.io.File;

/**
 * Karaf file system view reduced to the KARAF_BASE location
 */
public class KarafFileSystemView implements FileSystemView {

    private String location;

    public KarafFileSystemView() {
        location = System.getProperty("karaf.base");
    }

    public SshFile getFile(String file) {
        return getFile(location, file);
    }

    public SshFile getFile(SshFile baseDir, String file) {
        return getFile(baseDir.getAbsolutePath(), file);
    }

    protected SshFile getFile(String dir, String file) {
        // get actual file object
        String physicalName = NativeSshFile.getPhysicalName("/", dir, file, false);

        if (!physicalName.startsWith(location)) {
            throw new IllegalArgumentException("The path is not relative to KARAF_BASE. For security reason, it's not allowed.");
        }

        File fileObj = new File(physicalName);

        // strip the root directory and return
        String karafFileName = physicalName.substring("/".length() - 1);
        return new KarafSshFile(karafFileName, fileObj);
    }

}