/*
 * 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.io.File;
import java.text.ParseException;
import java.util.Locale;

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

/**
 * <pre>
 * Example *FILE/*MEM FTP entries, when the current
 * working directory is a file of file system QSYS:
 * ------------------------------------------------
 *
 * $ cwd /qsys.lib/rpgunit.lib/rpgunitc1.file
 *   250-NAMEFMT set to 1.
 *   250 "/QSYS.LIB/RPGUNIT.LIB/RPGUNITC1.FILE" is current directory.
 * $ dir
 *   227 Entering Passive Mode (10,200,36,33,40,249).
 *   125 List started.
 *   QPGMR          135168 22.06.13 13:18:19 *FILE
 *   QPGMR                                   *MEM       MKCMD.MBR
 *   QPGMR                                   *MEM       RUCALLTST.MBR
 *   QPGMR                                   *MEM       RUCMDHLP.MBR
 *   QPGMR                                   *MEM       RUCRTTST.MBR
 *   250 List completed.
 *
 *
 * Example *FILE entry of an OS/400 save file:
 * ---------------------------------------------------
 *
 * $ cwd /qsys.lib/rpgunit.lib
 *   250 "/QSYS.LIB/RPGUNIT.LIB" is current library.
 * $ dir rpgunit.file
 *   227 Entering Passive Mode (10,200,36,33,188,106).
 *   125 List started.
 *   QPGMR        16347136 29.06.13 15:45:09 *FILE      RPGUNIT.SAVF
 *   250 List completed.
 *
 *
 * Example *STMF/*DIR FTP entries, when the
 * current working directory is in file system "root":
 * ---------------------------------------------------
 *
 * $ cwd /home/raddatz
 *   250 "/home/raddatz" is current directory.
 * $ dir test*
 *   227 Entering Passive Mode (10,200,36,33,200,189).
 *   125 List started.
 *   RADDATZ           200 21.05.11 12:31:18 *STMF      TEST_RG_02_CRLF.properties
 *   RADDATZ           187 08.05.11 12:31:40 *STMF      TEST_RG_02_LF.properties
 *   RADDATZ           187 08.05.11 12:31:52 *STMF      TEST_RG_02_CR.properties
 *   RADDATZ          8192 04.07.13 09:04:14 *DIR       testDir1/
 *   RADDATZ          8192 04.07.13 09:04:17 *DIR       testDir2/
 *   250 List completed.
 *
 *
 * Example 1, using ANT to list specific members of a file:
 * --------------------------------------------------------
 *
 *      &lt;echo/&gt;
 *      &lt;echo&gt;Listing members of a file:&lt;/echo&gt;
 *
 *      &lt;ftp action="list"
 *           server="${ftp.server}"
 *           userid="${ftp.user}"
 *           password="${ftp.password}"
 *           binary="false"
 *           verbose="true"
 *           remotedir="/QSYS.LIB/RPGUNIT.LIB/RPGUNITY1.FILE"
 *           systemTypeKey="OS/400"
 *           listing="ftp-listing.txt"
 *           &gt;
 *          &lt;fileset dir="./i5-downloads-file" casesensitive="false"&gt;
 *              &lt;include name="run*.mbr" /&gt;
 *          &lt;/fileset&gt;
 *      &lt;/ftp&gt;
 *
 * Output:
 * -------
 *
 *   [echo] Listing members of a file:
 *    [ftp] listing files
 *    [ftp] listing RUN.MBR
 *    [ftp] listing RUNNER.MBR
 *    [ftp] listing RUNNERBND.MBR
 *    [ftp] 3 files listed
 *
 *
 * Example 2, using ANT to list specific members of all files of a library:
 * ------------------------------------------------------------------------
 *
 *      &lt;echo/&gt;
 *      &lt;echo&gt;Listing members of all files of a library:&lt;/echo&gt;
 *
 *      &lt;ftp action="list"
 *           server="${ftp.server}"
 *           userid="${ftp.user}"
 *           password="${ftp.password}"
 *           binary="false"
 *           verbose="true"
 *           remotedir="/QSYS.LIB/RPGUNIT.LIB"
 *           systemTypeKey="OS/400"
 *           listing="ftp-listing.txt"
 *           &gt;
 *          &lt;fileset dir="./i5-downloads-lib" casesensitive="false"&gt;
 *              &lt;include name="**\run*.mbr" /&gt;
 *          &lt;/fileset&gt;
 *      &lt;/ftp&gt;
 *
 * Output:
 * -------
 *
 *   [echo] Listing members of all files of a library:
 *    [ftp] listing files
 *    [ftp] listing RPGUNIT1.FILE\RUN.MBR
 *    [ftp] listing RPGUNIT1.FILE\RUNRMT.MBR
 *    [ftp] listing RPGUNITT1.FILE\RUNT.MBR
 *    [ftp] listing RPGUNITY1.FILE\RUN.MBR
 *    [ftp] listing RPGUNITY1.FILE\RUNNER.MBR
 *    [ftp] listing RPGUNITY1.FILE\RUNNERBND.MBR
 *    [ftp] 6 files listed
 *
 *
 * Example 3, using ANT to download specific members of a file:
 * ------------------------------------------------------------
 *
 *      &lt;echo/&gt;
 *      &lt;echo&gt;Downloading members of a file:&lt;/echo&gt;
 *
 *      &lt;ftp action="get"
 *           server="${ftp.server}"
 *           userid="${ftp.user}"
 *           password="${ftp.password}"
 *           binary="false"
 *           verbose="true"
 *           remotedir="/QSYS.LIB/RPGUNIT.LIB/RPGUNITY1.FILE"
 *           systemTypeKey="OS/400"
 *           &gt;
 *          &lt;fileset dir="./i5-downloads-file" casesensitive="false"&gt;
 *              &lt;include name="run*.mbr" /&gt;
 *          &lt;/fileset&gt;
 *      &lt;/ftp&gt;
 *
 * Output:
 * -------
 *
 *   [echo] Downloading members of a file:
 *    [ftp] getting files
 *    [ftp] transferring RUN.MBR to C:\workspaces\rdp_080\workspace\ANT - FTP\i5-downloads-file\RUN.MBR
 *    [ftp] transferring RUNNER.MBR to C:\workspaces\rdp_080\workspace\ANT - FTP\i5-downloads-file\RUNNER.MBR
 *    [ftp] transferring RUNNERBND.MBR to C:\workspaces\rdp_080\workspace\ANT - FTP\i5-downloads-file\RUNNERBND.MBR
 *    [ftp] 3 files retrieved
 *
 *
 * Example 4, using ANT to download specific members of all files of a library:
 * ----------------------------------------------------------------------------
 *
 *      &lt;echo/&gt;
 *      &lt;echo&gt;Downloading members of all files of a library:&lt;/echo&gt;
 *
 *      &lt;ftp action="get"
 *           server="${ftp.server}"
 *           userid="${ftp.user}"
 *           password="${ftp.password}"
 *           binary="false"
 *           verbose="true"
 *           remotedir="/QSYS.LIB/RPGUNIT.LIB"
 *           systemTypeKey="OS/400"
 *           &gt;
 *          &lt;fileset dir="./i5-downloads-lib" casesensitive="false"&gt;
 *              &lt;include name="**\run*.mbr" /&gt;
 *          &lt;/fileset&gt;
 *      &lt;/ftp&gt;
 *
 * Output:
 * -------
 *
 *   [echo] Downloading members of all files of a library:
 *    [ftp] getting files
 *    [ftp] transferring RPGUNIT1.FILE\RUN.MBR to C:\work\rdp_080\space\ANT - FTP\i5-downloads\RPGUNIT1.FILE\RUN.MBR
 *    [ftp] transferring RPGUNIT1.FILE\RUNRMT.MBR to C:\work\rdp_080\space\ANT - FTP\i5-downloads\RPGUNIT1.FILE\RUNRMT.MBR
 *    [ftp] transferring RPGUNITT1.FILE\RUNT.MBR to C:\work\rdp_080\space\ANT - FTP\i5-downloads\RPGUNITT1.FILE\RUNT.MBR
 *    [ftp] transferring RPGUNITY1.FILE\RUN.MBR to C:\work\rdp_080\space\ANT - FTP\i5-downloads\RPGUNITY1.FILE\RUN.MBR
 *    [ftp] transferring RPGUNITY1.FILE\RUNNER.MBR to C:\work\rdp_080\space\ANT - FTP\i5-downloads\RPGUNITY1.FILE\RUNNER.MBR
 *    [ftp] transferring RPGUNITY1.FILE\RUNNERBND.MBR to C:\work\rdp_080\space\ANT - FTP\i5-downloads\RPGUNITY1.FILE\RUNNERBND.MBR
 *    [ftp] 6 files retrieved
 *
 *
 * Example 5, using ANT to download a save file of a library:
 * ----------------------------------------------------------
 *
 *      &lt;ftp action="get"
 *           server="${ftp.server}"
 *           userid="${ftp.user}"
 *           password="${ftp.password}"
 *           binary="true"
 *           verbose="true"
 *           remotedir="/QSYS.LIB/RPGUNIT.LIB"
 *           systemTypeKey="OS/400"
 *           &gt;
 *        &lt;fileset dir="./i5-downloads-savf" casesensitive="false"&gt;
 *            &lt;include name="RPGUNIT.SAVF" /&gt;
 *        &lt;/fileset&gt;
 *      &lt;/ftp&gt;
 *
 * Output:
 * -------
 *   [echo] Downloading save file:
 *    [ftp] getting files
 *    [ftp] transferring RPGUNIT.SAVF to C:\workspaces\rdp_080\workspace\net-Test\i5-downloads-lib\RPGUNIT.SAVF
 *    [ftp] 1 files retrieved
 *
 * </pre>
 */
public class OS400FTPEntryParser extends ConfigurableFTPFileEntryParserImpl {
    private static final String DEFAULT_DATE_FORMAT = "yy/MM/dd HH:mm:ss"; // 01/11/09 12:30:24

    private static final String REGEX = "(\\S+)\\s+" // user
            + "(?:(\\d+)\\s+)?" // size, empty for members
            + "(?:(\\S+)\\s+(\\S+)\\s+)?" // date stuff, empty for members
            + "(\\*STMF|\\*DIR|\\*FILE|\\*MEM)\\s+" // *STMF/*DIR/*FILE/*MEM
            + "((\\S+\\s*)+)?"; // file name, missing, when CWD is a *FILE

    /**
     * The default constructor for a OS400FTPEntryParser object.
     *
     * @throws IllegalArgumentException Thrown if the regular expression is unparseable. Should not be seen under normal conditions. If it is seen, this is a
     *                                  sign that <code>REGEX</code> is not a valid regular expression.
     */
    public OS400FTPEntryParser() {
        this(null);
    }

    /**
     * This constructor allows the creation of an OS400FTPEntryParser 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. If it is seen, this is a
     *                                  sign that <code>REGEX</code> is not a valid regular expression.
     * @since 1.4
     */
    public OS400FTPEntryParser(final FTPClientConfig config) {
        super(REGEX);
        configure(config);
    }

    /**
     * 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_OS400, DEFAULT_DATE_FORMAT, null);
    }

    /**
     *
     * @param string String value that is checked for <code>null</code> or empty.
     * @return {@code true} for <code>null</code> or empty values, else {@code false}.
     */
    private boolean isNullOrEmpty(final String string) {
        return string == null || string.isEmpty();
    }

    @Override
    public FTPFile parseFTPEntry(final String entry) {

        final FTPFile file = new FTPFile();
        file.setRawListing(entry);
        final int type;

        if (matches(entry)) {
            final String usr = group(1);
            final String filesize = group(2);
            String datestr = "";
            if (!isNullOrEmpty(group(3)) || !isNullOrEmpty(group(4))) {
                datestr = group(3) + " " + group(4);
            }
            final String typeStr = group(5);
            String name = group(6);

            boolean mustScanForPathSeparator = true;

            try {
                file.setTimestamp(super.parseTimestamp(datestr));
            } catch (final ParseException e) {
                // intentionally do nothing
            }

            if (typeStr.equalsIgnoreCase("*STMF")) {
                type = FTPFile.FILE_TYPE;
                if (isNullOrEmpty(filesize) || isNullOrEmpty(name)) {
                    return null;
                }
            } else if (typeStr.equalsIgnoreCase("*DIR")) {
                type = FTPFile.DIRECTORY_TYPE;
                if (isNullOrEmpty(filesize) || isNullOrEmpty(name)) {
                    return null;
                }
            } else if (typeStr.equalsIgnoreCase("*FILE")) {
                // File, defines the structure of the data (columns of a row)
                // but the data is stored in one or more members. Typically, a
                // source file contains multiple members whereas it is
                // recommended (but not enforced) to use one member per data
                // file.
                // Save files are a special type of files which are used
                // to save objects, e.g. for backups.
                if ((name == null) || !name.toUpperCase(Locale.ROOT).endsWith(".SAVF")) {
                    return null;
                }
                mustScanForPathSeparator = false;
                type = FTPFile.FILE_TYPE;
            } else if (typeStr.equalsIgnoreCase("*MEM")) {
                mustScanForPathSeparator = false;
                type = FTPFile.FILE_TYPE;

                if (isNullOrEmpty(name)) {
                    return null;
                }
                if (!(isNullOrEmpty(filesize) && isNullOrEmpty(datestr))) {
                    return null;
                }

                // Quick and dirty bug fix to make SelectorUtils work.
                // Class SelectorUtils uses 'File.separator' to splitt
                // a given path into pieces. But actually it had to
                // use the separator of the FTP server, which is a forward
                // slash in case of an AS/400.
                name = name.replace('/', File.separatorChar);
            } else {
                type = FTPFile.UNKNOWN_TYPE;
            }

            file.setType(type);

            file.setUser(usr);

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

            if (name.endsWith("/")) {
                name = name.substring(0, name.length() - 1);
            }
            if (mustScanForPathSeparator) {
                final int pos = name.lastIndexOf('/');
                if (pos > -1) {
                    name = name.substring(pos + 1);
                }
            }

            file.setName(name);

            return file;
        }
        return null;
    }

}
