/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.internal.xjc.util;

import java.text.ParseException;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

 * Utility class to parse a string

 *

 * @author Kohsuke Kawaguchi

 */

public final class StringCutter {

    private final String original;

    private String s;

    private boolean ignoreWhitespace;

    public StringCutter(String s, boolean ignoreWhitespace) {

        this.s = this.original = s;

        this.ignoreWhitespace = ignoreWhitespace;

    }

    public void skip(String regexp) throws ParseException {

        next(regexp);

    }

    public String next(String regexp) throws ParseException {

        trim();

        Pattern p = Pattern.compile(regexp);

        Matcher m = p.matcher(s);

        if(m.lookingAt()) {

            String r = m.group();

            s = s.substring(r.length());

            trim();

            return r;

        } else

            throw error();

    }

    private ParseException error() {

        return new ParseException(original,original.length()-s.length());

    }

    public String until(String regexp) throws ParseException {

        Pattern p = Pattern.compile(regexp);

        Matcher m = p.matcher(s);

        if(m.find()) {

            String r =  s.substring(0,m.start());

            s = s.substring(m.start());

            if(ignoreWhitespace)

                r = r.trim();

            return r;

        } else {

            // return everything left

            String r = s;

            s = "";

            return r;

        }

    }

    public char peek() {

        return s.charAt(0);

    }

    private void trim() {

        if(ignoreWhitespace)

            s = s.trim();

    }

    public int length() {

        return s.length();

    }

}