/**
 * 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.jboss.migration.cli.commonscli;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

/**
 * The class PosixParser provides an implementation of the {@link Parser#flatten(Options,String[],boolean) flatten} method.
 *
 * @version $Id$
 * @deprecated since 1.3, use the {@link DefaultParser} instead
 */
@Deprecated
public class PosixParser extends Parser {
    /** holder for flattened tokens */
    private final List<String> tokens = new ArrayList<String>();

    /** specifies if bursting should continue */
    private boolean eatTheRest;

    /** holder for the current option */
    private Option currentOption;

    /** the command line Options */
    private Options options;

    /**
     * Resets the members to their original state i.e. remove all of <code>tokens</code> entries and set <code>eatTheRest</code>
     * to false.
     */
    private void init() {
        eatTheRest = false;
        tokens.clear();
    }

    /**
     * <p>
     * An implementation of {@link Parser}'s abstract {@link Parser#flatten(Options,String[],boolean) flatten} method.
     * </p>
     *
     * <p>
     * The following are the rules used by this flatten method.
     * </p>
     * <ol>
     * <li>if <code>stopAtNonOption</code> is <b>true</b> then do not burst anymore of <code>arguments</code> entries, just add
     * each successive entry without further processing. Otherwise, ignore <code>stopAtNonOption</code>.</li>
     * <li>if the current <code>arguments</code> entry is "<b>--</b>" just add the entry to the list of processed tokens</li>
     * <li>if the current <code>arguments</code> entry is "<b>-</b>" just add the entry to the list of processed tokens</li>
     * <li>if the current <code>arguments</code> entry is two characters in length and the first character is "<b>-</b>" then
     * check if this is a valid {@link Option} id. If it is a valid id, then add the entry to the list of processed tokens and
     * set the current {@link Option} member. If it is not a valid id and <code>stopAtNonOption</code> is true, then the
     * remaining entries are copied to the list of processed tokens. Otherwise, the current entry is ignored.</li>
     * <li>if the current <code>arguments</code> entry is more than two characters in length and the first character is
     * "<b>-</b>" then we need to burst the entry to determine its constituents. For more information on the bursting algorithm
     * see {@link PosixParser#burstToken(String, boolean) burstToken}.</li>
     * <li>if the current <code>arguments</code> entry is not handled by any of the previous rules, then the entry is added to
     * the list of processed tokens.</li>
     * </ol>
     *
     * @param options The command line {@link Options}
     * @param arguments The command line arguments to be parsed
     * @param stopAtNonOption Specifies whether to stop flattening when an non option is found.
     * @return The flattened <code>arguments</code> String array.
     */
    @Override
    protected String[] flatten(Options options, String[] arguments, boolean stopAtNonOption) throws ParseException {
        init();
        this.options = options;

        // an iterator for the command line tokens
        Iterator<String> iter = Arrays.asList(arguments).iterator();

        // process each command line token
        while (iter.hasNext()) {
            // get the next command line token
            String token = iter.next();

            // single or double hyphen
            if ("-".equals(token) || "--".equals(token)) {
                tokens.add(token);
            }

            // handle long option --foo or --foo=bar
            else if (token.startsWith("--")) {
                int pos = token.indexOf('=');
                String opt = pos == -1 ? token : token.substring(0, pos); // --foo

                List<String> matchingOpts = options.getMatchingOptions(opt);

                if (matchingOpts.isEmpty()) {
                    processNonOptionToken(token, stopAtNonOption);
                } else if (matchingOpts.size() > 1) {
                    throw new AmbiguousOptionException(opt, matchingOpts);
                } else {
                    currentOption = options.getOption(matchingOpts.get(0));

                    tokens.add("--" + currentOption.getLongOpt());
                    if (pos != -1) {
                        tokens.add(token.substring(pos + 1));
                    }
                }
            }

            else if (token.startsWith("-")) {
                if (token.length() == 2 || options.hasOption(token)) {
                    processOptionToken(token, stopAtNonOption);
                } else if (!options.getMatchingOptions(token).isEmpty()) {
                    List<String> matchingOpts = options.getMatchingOptions(token);
                    if (matchingOpts.size() > 1) {
                        throw new AmbiguousOptionException(token, matchingOpts);
                    }
                    Option opt = options.getOption(matchingOpts.get(0));
                    processOptionToken("-" + opt.getLongOpt(), stopAtNonOption);
                }
                // requires bursting
                else {
                    burstToken(token, stopAtNonOption);
                }
            } else {
                processNonOptionToken(token, stopAtNonOption);
            }

            gobble(iter);
        }

        return tokens.toArray(new String[tokens.size()]);
    }

    /**
     * Adds the remaining tokens to the processed tokens list.
     *
     * @param iter An iterator over the remaining tokens
     */
    private void gobble(Iterator<String> iter) {
        if (eatTheRest) {
            while (iter.hasNext()) {
                tokens.add(iter.next());
            }
        }
    }

    /**
     * Add the special token "<b>--</b>" and the current <code>value</code> to the processed tokens list. Then add all the
     * remaining <code>argument</code> values to the processed tokens list.
     *
     * @param value The current token
     */
    private void processNonOptionToken(String value, boolean stopAtNonOption) {
        if (stopAtNonOption && (currentOption == null || !currentOption.hasArg())) {
            eatTheRest = true;
            tokens.add("--");
        }

        tokens.add(value);
    }

    /**
     * <p>
     * If an {@link Option} exists for <code>token</code> then add the token to the processed list.
     * </p>
     *
     * <p>
     * If an {@link Option} does not exist and <code>stopAtNonOption</code> is set then add the remaining tokens to the
     * processed tokens list directly.
     * </p>
     *
     * @param token The current option token
     * @param stopAtNonOption Specifies whether flattening should halt at the first non option.
     */
    private void processOptionToken(String token, boolean stopAtNonOption) {
        if (stopAtNonOption && !options.hasOption(token)) {
            eatTheRest = true;
        }

        if (options.hasOption(token)) {
            currentOption = options.getOption(token);
        }

        tokens.add(token);
    }

    /**
     * Breaks <code>token</code> into its constituent parts using the following algorithm.
     *
     * <ul>
     * <li>ignore the first character ("<b>-</b>")</li>
     * <li>foreach remaining character check if an {@link Option} exists with that id.</li>
     * <li>if an {@link Option} does exist then add that character prepended with "<b>-</b>" to the list of processed
     * tokens.</li>
     * <li>if the {@link Option} can have an argument value and there are remaining characters in the token then add the
     * remaining characters as a token to the list of processed tokens.</li>
     * <li>if an {@link Option} does <b>NOT</b> exist <b>AND</b> <code>stopAtNonOption</code> <b>IS</b> set then add the special
     * token "<b>--</b>" followed by the remaining characters and also the remaining tokens directly to the processed tokens
     * list.</li>
     * <li>if an {@link Option} does <b>NOT</b> exist <b>AND</b> <code>stopAtNonOption</code> <b>IS NOT</b> set then add that
     * character prepended with "<b>-</b>".</li>
     * </ul>
     *
     * @param token The current token to be <b>burst</b>
     * @param stopAtNonOption Specifies whether to stop processing at the first non-Option encountered.
     */
    protected void burstToken(String token, boolean stopAtNonOption) {
        for (int i = 1; i < token.length(); i++) {
            String ch = String.valueOf(token.charAt(i));

            if (options.hasOption(ch)) {
                tokens.add("-" + ch);
                currentOption = options.getOption(ch);

                if (currentOption.hasArg() && token.length() != i + 1) {
                    tokens.add(token.substring(i + 1));

                    break;
                }
            } else if (stopAtNonOption) {
                processNonOptionToken(token.substring(i), true);
                break;
            } else {
                tokens.add(token);
                break;
            }
        }
    }
}
