/*
 * 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.commons.net.ftp.parser;
import java.text.ParseException;
import java.util.List;
import java.util.ListIterator;

import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;

Implementation FTPFileEntryParser and FTPFileListParser for standard
Unix Systems.
This class is based on the logic of Daniel Savarese's
DefaultFTPListParser, but adapted to use regular expressions and to fit the
new FTPFileEntryParser interface.
See Also:
FTPFileEntryParser (for usage instructions)
Version:
$Id: UnixFTPEntryParser.java 1781925 2017-02-06 16:43:40Z sebb $/**
 * Implementation FTPFileEntryParser and FTPFileListParser for standard
 * Unix Systems.
 *
 * This class is based on the logic of Daniel Savarese's
 * DefaultFTPListParser, but adapted to use regular expressions and to fit the
 * new FTPFileEntryParser interface.
 * @version $Id: UnixFTPEntryParser.java 1781925 2017-02-06 16:43:40Z sebb $
 * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
 */
public class UnixFTPEntryParser extends ConfigurableFTPFileEntryParserImpl
{

    static final String DEFAULT_DATE_FORMAT
        = "MMM d yyyy"; //Nov 9 2001

    static final String DEFAULT_RECENT_DATE_FORMAT
        = "MMM d HH:mm"; //Nov 9 20:06

    static final String NUMERIC_DATE_FORMAT
        = "yyyy-MM-dd HH:mm"; //2001-11-09 20:06

    // Suffixes used in Japanese listings after the numeric values
    private static final String JA_MONTH = "\u6708";
    private static final String JA_DAY   = "\u65e5";
    private static final String JA_YEAR  = "\u5e74";

    private static final String DEFAULT_DATE_FORMAT_JA
        = "M'" + JA_MONTH + "' d'" + JA_DAY + "' yyyy'" + JA_YEAR + "'"; //6月 3日 2003年

    private static final String DEFAULT_RECENT_DATE_FORMAT_JA
        = "M'" + JA_MONTH + "' d'" + JA_DAY + "' HH:mm"; //8月 17日 20:10

    
Some Linux distributions are now shipping an FTP server which formats
file listing dates in an all-numeric format:
"yyyy-MM-dd HH:mm.
This is a very welcome development,  and hopefully it will soon become
the standard.  However, since it is so new, for now, and possibly
forever, we merely accomodate it, but do not make it the default.

For now end users may specify this format only via
UnixFTPEntryParser(FTPClientConfig).
Steve Cohen - 2005-04-17
/**
     * Some Linux distributions are now shipping an FTP server which formats
     * file listing dates in an all-numeric format:
     * <code>"yyyy-MM-dd HH:mm</code>.
     * This is a very welcome development,  and hopefully it will soon become
     * the standard.  However, since it is so new, for now, and possibly
     * forever, we merely accomodate it, but do not make it the default.
     * <p>
     * For now end users may specify this format only via
     * <code>UnixFTPEntryParser(FTPClientConfig)</code>.
     * Steve Cohen - 2005-04-17
     */
    public static final FTPClientConfig NUMERIC_DATE_CONFIG =
        new FTPClientConfig(
                FTPClientConfig.SYST_UNIX,
                NUMERIC_DATE_FORMAT,
                null);

    
this is the regular expression used by this parser. Permissions: r the file is readable w the file is writable x the file is executable - the indicated permission is not granted L mandatory locking occurs during access (the set-group-ID bit is on and the group execution bit is off) s the set-user-ID or set-group-ID bit is on, and the corresponding user or group execution bit is also on S undefined bit-state (the set-user-ID bit is on and the user execution bit is off) t the 1000 (octal) bit, or sticky bit, is on [see chmod(1)], and execution is on T the 1000 bit is turned on, and execution is off (undefined bit- state) e z/OS external link bit Final letter may be appended: + file has extended security attributes (e.g. ACL) Note: local listings on MacOSX also use '@'; this is not allowed for here as does not appear to be shown by FTP servers @ file has extended attributes /**
     * this is the regular expression used by this parser.
     *
     * Permissions:
     *    r   the file is readable
     *    w   the file is writable
     *    x   the file is executable
     *    -   the indicated permission is not granted
     *    L   mandatory locking occurs during access (the set-group-ID bit is
     *        on and the group execution bit is off)
     *    s   the set-user-ID or set-group-ID bit is on, and the corresponding
     *        user or group execution bit is also on
     *    S   undefined bit-state (the set-user-ID bit is on and the user
     *        execution bit is off)
     *    t   the 1000 (octal) bit, or sticky bit, is on [see chmod(1)], and
     *        execution is on
     *    T   the 1000 bit is turned on, and execution is off (undefined bit-
     *        state)
     *    e   z/OS external link bit
     *    Final letter may be appended:
     *    +   file has extended security attributes (e.g. ACL)
     *    Note: local listings on MacOSX also use '@';
     *    this is not allowed for here as does not appear to be shown by FTP servers
     *    {@code @}   file has extended attributes
     */
    private static final String REGEX =
        "([bcdelfmpSs-])" // file type
        +"(((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-])))\\+?" // permissions

        + "\\s*"                                        // separator TODO why allow it to be omitted??

        + "(\\d+)"                                      // link count

        + "\\s+" // separator

        + "(?:(\\S+(?:\\s\\S+)*?)\\s+)?"                // owner name (optional spaces)
        + "(?:(\\S+(?:\\s\\S+)*)\\s+)?"                 // group name (optional spaces)
        + "(\\d+(?:,\\s*\\d+)?)"                        // size or n,m

        + "\\s+" // separator

        /*
         * numeric or standard format date:
         *   yyyy-mm-dd (expecting hh:mm to follow)
         *   MMM [d]d
         *   [d]d MMM
         *   N.B. use non-space for MMM to allow for languages such as German which use
         *   diacritics (e.g. umlaut) in some abbreviations.
         *   Japanese uses numeric day and month with suffixes to distinguish them
         *   [d]dXX [d]dZZ
        */
        + "("+
            "(?:\\d+[-/]\\d+[-/]\\d+)" + // yyyy-mm-dd
            "|(?:\\S{3}\\s+\\d{1,2})" +  // MMM [d]d
            "|(?:\\d{1,2}\\s+\\S{3})" + // [d]d MMM
            "|(?:\\d{1,2}" + JA_MONTH + "\\s+\\d{1,2}" + JA_DAY + ")"+
           ")"

        + "\\s+" // separator

        /*
           year (for non-recent standard format) - yyyy
           or time (for numeric or recent standard format) [h]h:mm
           or Japanese year - yyyyXX
        */
        + "((?:\\d+(?::\\d+)?)|(?:\\d{4}" + JA_YEAR + "))" // (20)

        + "\\s" // separator

        + "(.*)"; // the rest (21)


    // if true, leading spaces are trimmed from file names
    // this was the case for the original implementation
    final boolean trimLeadingSpaces; // package protected for access from test code

    
The default constructor for a UnixFTPEntryParser object.
Throws:
IllegalArgumentException – 
Thrown if the regular expression is unparseable.  Should not be seen
under normal conditions.  It it is seen, this is a sign that
REGEX is  not a valid regular expression./**
     * The default constructor for a UnixFTPEntryParser object.
     *
     * @throws IllegalArgumentException
     * Thrown if the regular expression is unparseable.  Should not be seen
     * under normal conditions.  It it is seen, this is a sign that
     * <code>REGEX</code> is  not a valid regular expression.
     */
    public UnixFTPEntryParser()
    {
        this(null);
    }

    
This constructor allows the creation of a UnixFTPEntryParser object with
something other than the default configuration.
Params:
config – The configuration object used to configure this parser.
Throws:
IllegalArgumentException – 
Thrown if the regular expression is unparseable.  Should not be seen
under normal conditions.  It it is seen, this is a sign that
REGEX is  not a valid regular expression.
Since:
1.4/**
     * This constructor allows the creation of a UnixFTPEntryParser object with
     * something other than the default configuration.
     *
     * @param config The {@link FTPClientConfig configuration} object used to
     * configure this parser.
     * @throws IllegalArgumentException
     * Thrown if the regular expression is unparseable.  Should not be seen
     * under normal conditions.  It it is seen, this is a sign that
     * <code>REGEX</code> is  not a valid regular expression.
     * @since 1.4
     */
    public UnixFTPEntryParser(FTPClientConfig config)
    {
        this(config, false);
    }

    
This constructor allows the creation of a UnixFTPEntryParser object with
something other than the default configuration.
Params:
config – The configuration object used to configure this parser.
trimLeadingSpaces – if true, trim leading spaces from file names
Throws:
IllegalArgumentException – 
Thrown if the regular expression is unparseable.  Should not be seen
under normal conditions.  It it is seen, this is a sign that
REGEX is  not a valid regular expression.
Since:
3.4/**
     * This constructor allows the creation of a UnixFTPEntryParser object with
     * something other than the default configuration.
     *
     * @param config The {@link FTPClientConfig configuration} object used to
     * configure this parser.
     * @param trimLeadingSpaces if {@code true}, trim leading spaces from file names
     * @throws IllegalArgumentException
     * Thrown if the regular expression is unparseable.  Should not be seen
     * under normal conditions.  It it is seen, this is a sign that
     * <code>REGEX</code> is  not a valid regular expression.
     * @since 3.4
     */
    public UnixFTPEntryParser(FTPClientConfig config, boolean trimLeadingSpaces)
    {
        super(REGEX);
        configure(config);
        this.trimLeadingSpaces = trimLeadingSpaces;
    }

    
Preparse the list to discard "total nnn" lines
/**
     * Preparse the list to discard "total nnn" lines
     */
    @Override
    public List<String> preParse(List<String> original) {
        ListIterator<String> iter = original.listIterator();
        while (iter.hasNext()) {
            String entry = iter.next();
            if (entry.matches("^total \\d+$")) { // NET-389
                iter.remove();
            }
        }
        return original;
    }

    
Parses a line of a unix (standard) FTP server file listing and converts
it into a usable format in the form of an  FTPFile 
instance.  If the file listing line doesn't describe a file,
 null  is returned, otherwise a  FTPFile 
instance representing the files in the directory is returned.
Params:
entry – A line of text from the file listing
Returns:
An FTPFile instance corresponding to the supplied entry/**
     * Parses a line of a unix (standard) FTP server file listing and converts
     * it into a usable format in the form of an <code> FTPFile </code>
     * instance.  If the file listing line doesn't describe a file,
     * <code> null </code> is returned, otherwise a <code> FTPFile </code>
     * instance representing the files in the directory is returned.
     *
     * @param entry A line of text from the file listing
     * @return An FTPFile instance corresponding to the supplied entry
     */
    @Override
    public FTPFile parseFTPEntry(String entry) {
        FTPFile file = new FTPFile();
        file.setRawListing(entry);
        int type;
        boolean isDevice = false;

        if (matches(entry))
        {
            String typeStr = group(1);
            String hardLinkCount = group(15);
            String usr = group(16);
            String grp = group(17);
            String filesize = group(18);
            String datestr = group(19) + " " + group(20);
            String name = group(21);
            if (trimLeadingSpaces) {
                name = name.replaceFirst("^\\s+", "");
            }

            try
            {
                if (group(19).contains(JA_MONTH)) { // special processing for Japanese format
                    FTPTimestampParserImpl jaParser = new FTPTimestampParserImpl();
                    jaParser.configure(new FTPClientConfig(
                            FTPClientConfig.SYST_UNIX, DEFAULT_DATE_FORMAT_JA, DEFAULT_RECENT_DATE_FORMAT_JA));
                    file.setTimestamp(jaParser.parseTimestamp(datestr));
                } else {
                    file.setTimestamp(super.parseTimestamp(datestr));
                }
            }
            catch (ParseException e)
            {
                 // intentionally do nothing
            }

            // A 'whiteout' file is an ARTIFICIAL entry in any of several types of
            // 'translucent' filesystems, of which a 'union' filesystem is one.

            // bcdelfmpSs-
            switch (typeStr.charAt(0))
            {
            case 'd':
                type = FTPFile.DIRECTORY_TYPE;
                break;
            case 'e': // NET-39 => z/OS external link
                type = FTPFile.SYMBOLIC_LINK_TYPE;
                break;
            case 'l':
                type = FTPFile.SYMBOLIC_LINK_TYPE;
                break;
            case 'b':
            case 'c':
                isDevice = true;
                type = FTPFile.FILE_TYPE; // TODO change this if DEVICE_TYPE implemented
                break;
            case 'f':
            case '-':
                type = FTPFile.FILE_TYPE;
                break;
            default: // e.g. ? and w = whiteout
                type = FTPFile.UNKNOWN_TYPE;
            }

            file.setType(type);

            int g = 4;
            for (int access = 0; access < 3; access++, g += 4)
            {
                // Use != '-' to avoid having to check for suid and sticky bits
                file.setPermission(access, FTPFile.READ_PERMISSION,
                                   (!group(g).equals("-")));
                file.setPermission(access, FTPFile.WRITE_PERMISSION,
                                   (!group(g + 1).equals("-")));

                String execPerm = group(g + 2);
                if (!execPerm.equals("-") && !Character.isUpperCase(execPerm.charAt(0)))
                {
                    file.setPermission(access, FTPFile.EXECUTE_PERMISSION, true);
                }
                else
                {
                    file.setPermission(access, FTPFile.EXECUTE_PERMISSION, false);
                }
            }

            if (!isDevice)
            {
                try
                {
                    file.setHardLinkCount(Integer.parseInt(hardLinkCount));
                }
                catch (NumberFormatException e)
                {
                    // intentionally do nothing
                }
            }

            file.setUser(usr);
            file.setGroup(grp);

            try
            {
                file.setSize(Long.parseLong(filesize));
            }
            catch (NumberFormatException e)
            {
                // intentionally do nothing
            }

            // oddball cases like symbolic links, file names
            // with spaces in them.
            if (type == FTPFile.SYMBOLIC_LINK_TYPE)
            {

                int end = name.indexOf(" -> ");
                // Give up if no link indicator is present
                if (end == -1)
                {
                    file.setName(name);
                }
                else
                {
                    file.setName(name.substring(0, end));
                    file.setLink(name.substring(end + 4));
                }

            }
            else
            {
                file.setName(name);
            }
            return file;
        }
        return null;
    }

    
Defines a default configuration to be used when this class is instantiated without a  FTPClientConfig parameter being specified. 
Returns:
the default configuration for this parser./**
     * Defines a default configuration to be used when this class is
     * instantiated without a {@link  FTPClientConfig  FTPClientConfig}
     * parameter being specified.
     * @return the default configuration for this parser.
     */
    @Override
    protected FTPClientConfig getDefaultConfiguration() {
        return new FTPClientConfig(
                FTPClientConfig.SYST_UNIX,
                DEFAULT_DATE_FORMAT,
                DEFAULT_RECENT_DATE_FORMAT);
    }

}