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

/**
 * Implementation FTPFileEntryParser and FTPFileListParser for pre MacOS-X Systems.
 *
 * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
 * @since 3.1
 */
public class MacOsPeterFTPEntryParser 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

    /**
     * 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
     */
    private static final String REGEX = "([bcdelfmpSs-])" // type (1)
            + "(((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-])))\\+?\\s+" // permission
            + "(" + "(folder\\s+)" + "|" + "((\\d+)\\s+(\\d+)\\s+)" // resource size & data size
            + ")" + "(\\d+)\\s+" // size
            /*
             * 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.
             */
            + "((?:\\d+[-/]\\d+[-/]\\d+)|(?:\\S{3}\\s+\\d{1,2})|(?:\\d{1,2}\\s+\\S{3}))\\s+"
            /*
             * year (for non-recent standard format) - yyyy or time (for numeric or recent standard format) [h]h:mm
             */
            + "(\\d+(?::\\d+)?)\\s+"

            + "(\\S*)(\\s*.*)"; // the rest

    /**
     * The default constructor for a UnixFTPEntryParser 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 MacOsPeterFTPEntryParser() {
        this(null);
    }

    /**
     * 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. If it is seen, this is a
     *                                  sign that <code>REGEX</code> is not a valid regular expression.
     * @since 1.4
     */
    public MacOsPeterFTPEntryParser(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_UNIX, DEFAULT_DATE_FORMAT, DEFAULT_RECENT_DATE_FORMAT);
    }

    /**
     * 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(final String entry) {
        final FTPFile file = new FTPFile();
        file.setRawListing(entry);
        final int type;
        boolean isDevice = false;

        if (matches(entry)) {
            final String typeStr = group(1);
            final String hardLinkCount = "0";
            final String filesize = group(20);
            final String datestr = group(21) + " " + group(22);
            String name = group(23);
            final String endtoken = group(24);

            try {
                file.setTimestamp(super.parseTimestamp(datestr));
            } catch (final 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("-"));

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

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

            file.setUser(null);
            file.setGroup(null);

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

            if (null == endtoken) {
                file.setName(name);
            } else {
                // oddball cases like symbolic links, file names
                // with spaces in them.
                name += endtoken;
                if (type == FTPFile.SYMBOLIC_LINK_TYPE) {

                    final 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;
    }

}