/***********************************************************************************
 *                                                                                 *
 * Voreen - The Volume Rendering Engine                                            *
 *                                                                                 *
 * Copyright (C) 2005-2012 University of Muenster, Germany.                        *
 * Visualization and Computer Graphics Group <http://viscg.uni-muenster.de>        *
 * For a list of authors please refer to the file "CREDITS.txt".                   *
 *                                                                                 *
 * This file is part of the Voreen software package. Voreen is free software:      *
 * you can redistribute it and/or modify it under the terms of the GNU General     *
 * Public License version 2 as published by the Free Software Foundation.          *
 *                                                                                 *
 * Voreen 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 in the file   *
 * "LICENSE.txt" along with this file. If not, see <http://www.gnu.org/licenses/>. *
 *                                                                                 *
 * For non-commercial academic use see the license exception specified in the file *
 * "LICENSE-academic.txt". To get information about commercial licensing please    *
 * contact the authors.                                                            *
 *                                                                                 *
 ***********************************************************************************/

#ifndef VRN_PPLEXER
#define VRN_PPLEXER

#include "voreen/core/utils/GLSLparser/lexer.h"

#include "voreen/core/utils/GLSLparser/glsl/glsltoken.h"
#include <deque>

namespace voreen {

namespace glslparser {

class PreprocessorLexer : public Lexer {
public:
    PreprocessorLexer(std::istream* const is, const std::map<std::string, Word>& keywords)
        throw (std::bad_alloc);

    PreprocessorLexer(const std::string& fileName, const std::map<std::string, Word>& keywords)
        throw (std::bad_alloc);

    virtual ~PreprocessorLexer();

    virtual Token* scan();

private:
    enum ScannerState {
        STATE_START,
        STATE_INSIDE_BLOCK_COMMENT,
        STATE_INSIDE_LINE_COMMENT,
        STATE_READING_DIRECTIVE,
        STATE_SKIPPING_WHITESPACE,
        STATE_END
    };

private:
    std::deque<Token*> scanDirective(const std::string& directive) const;
    ConstantToken* scanNumber(const std::string& input, size_t& end) const;
    Token* createTextToken(const std::streampos& start, const std::streampos& end);

private:
    ScannerState scanState_;
    std::deque<Token*> currentDirective_;
};

}   // namespace glslparser

}   // namespace voreen

#endif
