/*
 * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
 * 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.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * The MIT License
 *
 * Copyright (c) 2004-2014 Paul R. Holser, Jr.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package jdk.internal.joptsimple;

import java.util.NoSuchElementException;

import static jdk.internal.joptsimple.ParserRules.*;

/**
 * Tokenizes a short option specification string.
 *
 * @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a>
 */
class OptionSpecTokenizer {
    private static final char POSIXLY_CORRECT_MARKER = '+';
    private static final char HELP_MARKER = '*';

    private String specification;
    private int index;

    OptionSpecTokenizer( String specification ) {
        if ( specification == null )
            throw new NullPointerException( "null option specification" );

        this.specification = specification;
    }

    boolean hasMore() {
        return index < specification.length();
    }

    AbstractOptionSpec<?> next() {
        if ( !hasMore() )
            throw new NoSuchElementException();


        String optionCandidate = String.valueOf( specification.charAt( index ) );
        index++;

        AbstractOptionSpec<?> spec;
        if ( RESERVED_FOR_EXTENSIONS.equals( optionCandidate ) ) {
            spec = handleReservedForExtensionsToken();

            if ( spec != null )
                return spec;
        }

        ensureLegalOption( optionCandidate );

        if ( hasMore() ) {
            boolean forHelp = false;
            if ( specification.charAt( index ) == HELP_MARKER ) {
                forHelp = true;
                ++index;
            }
            spec = hasMore() && specification.charAt( index ) == ':'
                ? handleArgumentAcceptingOption( optionCandidate )
                : new NoArgumentOptionSpec( optionCandidate );
            if ( forHelp )
                spec.forHelp();
        } else
            spec = new NoArgumentOptionSpec( optionCandidate );

        return spec;
    }

    void configure( OptionParser parser ) {
        adjustForPosixlyCorrect( parser );

        while ( hasMore() )
            parser.recognize( next() );
    }

    private void adjustForPosixlyCorrect( OptionParser parser ) {
        if ( POSIXLY_CORRECT_MARKER == specification.charAt( 0 ) ) {
            parser.posixlyCorrect( true );
            specification = specification.substring( 1 );
        }
    }

    private AbstractOptionSpec<?> handleReservedForExtensionsToken() {
        if ( !hasMore() )
            return new NoArgumentOptionSpec( RESERVED_FOR_EXTENSIONS );

        if ( specification.charAt( index ) == ';' ) {
            ++index;
            return new AlternativeLongOptionSpec();
        }

        return null;
    }

    private AbstractOptionSpec<?> handleArgumentAcceptingOption( String candidate ) {
        index++;

        if ( hasMore() && specification.charAt( index ) == ':' ) {
            index++;
            return new OptionalArgumentOptionSpec<String>( candidate );
        }

        return new RequiredArgumentOptionSpec<String>( candidate );
    }
}