/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification
 *             of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.util;

import java.util.*;


/**
 * This class provides some utility methods for working with
 * <code>java.util.List</code> objects.
 *
 * @author Eric Lafortune
 */
public class ListUtil
{
    /**
     * Creates a comma-separated String from the given List of String objects.
     */
    public static String commaSeparatedString(List list, boolean quoteStrings)
    {
        if (list == null)
        {
            return null;
        }

        StringBuffer buffer = new StringBuffer();

        for (int index = 0; index < list.size(); index++)
        {
            if (index > 0)
            {
                buffer.append(',');
            }

            String string = (String)list.get(index);

            if (quoteStrings)
            {
                string = quotedString(string);
            }

            buffer.append(string);
        }

        return buffer.toString();
    }


    /**
     * Creates a List of String objects from the given comma-separated String.
     */
    public static List commaSeparatedList(String string)
    {
        if (string == null)
        {
            return null;
        }

        List list = new ArrayList();
        int index = 0;
        while ((index = skipWhitespace(string, index)) < string.length())
        {
            int nextIndex;

            // Do we have an opening quote?
            if (string.charAt(index) == '\'')
            {
                // Parse a quoted string.
                nextIndex = string.indexOf('\'', index + 1);
                if (nextIndex < 0)
                {
                    nextIndex = string.length();
                }

                list.add(string.substring(index + 1, nextIndex));
            }
            else
            {
                // Parse a non-quoted string.
                nextIndex = string.indexOf(',', index);
                if (nextIndex < 0)
                {
                    nextIndex = string.length();
                }

                String substring = string.substring(index, nextIndex).trim();
                if (substring.length() > 0)
                {
                    list.add(substring);
                }
            }

            index = nextIndex + 1;
        }

        return list;
    }


    /**
     * Skips any whitespace characters.
     */
    private static int skipWhitespace(String string, int index)
    {
        while (index < string.length() &&
               Character.isWhitespace(string.charAt(index)))
        {
            index++;
        }
        return index;
    }


    /**
     * Returns a quoted version of the given string, if necessary.
     */
    private static String quotedString(String string)
    {
        return string.length()     == 0 ||
               string.indexOf(' ') >= 0 ||
               string.indexOf('@') >= 0 ||
               string.indexOf('{') >= 0 ||
               string.indexOf('}') >= 0 ||
               string.indexOf('(') >= 0 ||
               string.indexOf(')') >= 0 ||
               string.indexOf(':') >= 0 ||
               string.indexOf(';') >= 0 ||
               string.indexOf(',') >= 0  ? ("'" + string + "'") :
                                           (      string      );
    }


    public static void main(String[] args)
    {
        if (args.length == 1)
        {
            System.out.println("Input string: ["+args[0]+"]");

            List list = commaSeparatedList(args[0]);

            System.out.println("Resulting list:");
            for (int index = 0; index < list.size(); index++)
            {
                System.out.println("["+list.get(index)+"]");
            }
        }
        else
        {
            List list = Arrays.asList(args);

            System.out.println("Input list:");
            for (int index = 0; index < list.size(); index++)
            {
                System.out.println("["+list.get(index)+"]");
            }

            String string = commaSeparatedString(list, true);

            System.out.println("Resulting string: ["+string+"]");
        }
    }
}
