/*
 * 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.regex.Pattern;

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

/**
 * Implementation of FTPFileEntryParser and FTPFileListParser for NT Systems.
 *
 * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
 */
public class NTFTPEntryParser extends ConfigurableFTPFileEntryParserImpl {

    private static final String DEFAULT_DATE_FORMAT = "MM-dd-yy hh:mma"; // 11-09-01 12:30PM

    private static final String DEFAULT_DATE_FORMAT2 = "MM-dd-yy kk:mm"; // 11-09-01 18:30

    /**
     * this is the regular expression used by this parser.
     */
    private static final String REGEX = "(\\S+)\\s+(\\S+)\\s+" // MM-dd-yy whitespace hh:mma|kk:mm; swallow trailing spaces
            + "(?:(<DIR>)|([0-9]+))\\s+" // <DIR> or ddddd; swallow trailing spaces
            + "(\\S.*)"; // First non-space followed by rest of line (name)

    private final FTPTimestampParser timestampParser;

    /**
     * The sole constructor for an NTFTPEntryParser 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 NTFTPEntryParser() {
        this(null);
    }

    /**
     * This constructor allows the creation of an NTFTPEntryParser 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 NTFTPEntryParser(final FTPClientConfig config) {
        super(REGEX, Pattern.DOTALL);
        configure(config);
        final FTPClientConfig config2 = new FTPClientConfig(FTPClientConfig.SYST_NT, DEFAULT_DATE_FORMAT2, null);
        config2.setDefaultDateFormatStr(DEFAULT_DATE_FORMAT2);
        this.timestampParser = new FTPTimestampParserImpl();
        ((Configurable) this.timestampParser).configure(config2);
    }

    /**
     * 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
    public FTPClientConfig getDefaultConfiguration() {
        return new FTPClientConfig(FTPClientConfig.SYST_NT, DEFAULT_DATE_FORMAT, null);
    }

    /**
     * Parses a line of an NT 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 f = new FTPFile();
        f.setRawListing(entry);

        if (matches(entry)) {
            final String datestr = group(1) + " " + group(2);
            final String dirString = group(3);
            final String size = group(4);
            final String name = group(5);
            try {
                f.setTimestamp(super.parseTimestamp(datestr));
            } catch (final ParseException e) {
                // parsing fails, try the other date format
                try {
                    f.setTimestamp(timestampParser.parseTimestamp(datestr));
                } catch (final ParseException e2) {
                    // intentionally do nothing
                }
            }

            if (null == name || name.equals(".") || name.equals("..")) {
                return null;
            }
            f.setName(name);

            if ("<DIR>".equals(dirString)) {
                f.setType(FTPFile.DIRECTORY_TYPE);
                f.setSize(0);
            } else {
                f.setType(FTPFile.FILE_TYPE);
                if (null != size) {
                    f.setSize(Long.parseLong(size));
                }
            }
            return f;
        }
        return null;
    }

}
