/*
 * 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.Calendar;

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


 This abstract class implements the common timestamp parsing algorithm for all the concrete parsers. Classes derived from this one will parse file listings via a supplied regular expression that pulls out the date portion as a separate string which is passed to the underlying delegate to handle parsing of the file timestamp. 
 This class also implements the Configurable interface to allow the parser to be configured from the outside. 
Since:
1.4/**
 * <p>
 * This abstract class implements the common timestamp parsing
 * algorithm for all the concrete parsers.  Classes derived from
 * this one will parse file listings via a supplied regular expression
 * that pulls out the date portion as a separate string which is
 * passed to the underlying {@link FTPTimestampParser delegate} to
 * handle parsing of the file timestamp.
 * <p>
 * This class also implements the {@link Configurable Configurable}
 * interface to allow the parser to be configured from the outside.
 *
 * @since 1.4
 */
public abstract class ConfigurableFTPFileEntryParserImpl
extends RegexFTPFileEntryParserImpl
implements Configurable
{

    private final FTPTimestampParser timestampParser;

    
constructor for this abstract class.
Params:
regex –  Regular expression used main parsing of the
file listing./**
     * constructor for this abstract class.
     * @param regex  Regular expression used main parsing of the
     * file listing.
     */
    public ConfigurableFTPFileEntryParserImpl(String regex)
    {
        super(regex);
        this.timestampParser = new FTPTimestampParserImpl();
    }

    
constructor for this abstract class.
Params:
regex –  Regular expression used main parsing of the
file listing.
flags – the flags to apply, see Pattern#compile(String, int). Use 0 for none.
Since:
3.4/**
     * constructor for this abstract class.
     * @param regex  Regular expression used main parsing of the
     * file listing.
     * @param flags the flags to apply, see
     * {@link java.util.regex.Pattern#compile(String, int) Pattern#compile(String, int)}. Use 0 for none.
     * @since 3.4
     */
    public ConfigurableFTPFileEntryParserImpl(String regex, int flags)
    {
        super(regex, flags);
        this.timestampParser = new FTPTimestampParserImpl();
    }

    
This method is called by the concrete parsers to delegate
timestamp parsing to the timestamp parser.
Params:
timestampStr – the timestamp string pulled from the
file listing by the regular expression parser, to be submitted
to the timestampParser for extracting the timestamp.
Throws:
ParseException – on parse error
Returns:
a java.util.Calendar containing results of the
timestamp parse./**
     * This method is called by the concrete parsers to delegate
     * timestamp parsing to the timestamp parser.
     *
     * @param timestampStr the timestamp string pulled from the
     * file listing by the regular expression parser, to be submitted
     * to the <code>timestampParser</code> for extracting the timestamp.
     * @return a <code>java.util.Calendar</code> containing results of the
     * timestamp parse.
     * @throws ParseException on parse error
     */
    public Calendar parseTimestamp(String timestampStr) throws ParseException {
        return this.timestampParser.parseTimestamp(timestampStr);
    }


    
Implementation of the  Configurable interface. Configures this parser by delegating to the underlying Configurable FTPTimestampParser implementation, ' passing it the supplied FTPClientConfig if that is non-null or a default configuration defined by each concrete subclass. 
Params:
config – the configuration to be used to configure this parser.
If it is null, a default configuration defined by
each concrete subclass is used instead./**
     * Implementation of the {@link  Configurable  Configurable}
     * interface. Configures this parser by delegating to the
     * underlying Configurable FTPTimestampParser implementation, '
     * passing it the supplied {@link  FTPClientConfig FTPClientConfig}
     * if that is non-null or a default configuration defined by
     * each concrete subclass.
     *
     * @param config the configuration to be used to configure this parser.
     * If it is null, a default configuration defined by
     * each concrete subclass is used instead.
     */
    @Override
    public void configure(FTPClientConfig config)
    {
        if (this.timestampParser instanceof Configurable) {
            FTPClientConfig defaultCfg = getDefaultConfiguration();
            if (config != null) {
                if (null == config.getDefaultDateFormatStr()) {
                    config.setDefaultDateFormatStr(defaultCfg.getDefaultDateFormatStr());
                }
                if (null == config.getRecentDateFormatStr()) {
                    config.setRecentDateFormatStr(defaultCfg.getRecentDateFormatStr());
                }
                ((Configurable)this.timestampParser).configure(config);
            } else {
                ((Configurable)this.timestampParser).configure(defaultCfg);
            }
        }
    }

    
Each concrete subclass must define this member to create a default configuration to be used when that subclass is instantiated without a  FTPClientConfig parameter being specified. 
Returns:
the default configuration for the subclass./**
     * Each concrete subclass must define this member to create
     * a default configuration to be used when that subclass is
     * instantiated without a {@link  FTPClientConfig  FTPClientConfig}
     * parameter being specified.
     * @return the default configuration for the subclass.
     */
    protected abstract FTPClientConfig getDefaultConfiguration();
}