/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2020 Pelican Mapping
 * http://osgearth.org
 *
 * osgEarth is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */
#pragma once

#include <osgEarth/Common>
#include <vector>
#include <functional>
#include <string>

namespace osgEarth { namespace Util
{
    /**
     * Utility that reads GLSL source code and lexes it into chunks that
     * you can then perform operations on.
     */
    class OSGEARTH_EXPORT GLSLChunker
    {
    public:
        struct Chunk {
            enum Type { TYPE_STATEMENT, TYPE_DIRECTIVE, TYPE_FUNCTION, TYPE_COMMENT };
            Type type;
            std::string text;
            std::vector<std::string> tokens;
        };

        typedef std::vector<Chunk> Chunks;

    public:
        /** Read GLSL into chunks */
        void read(const std::string& input, Chunks& output) const;

        /** Write chunks (read using the read() method) back to GLSL */
        void write(const Chunks& input, std::string& output, bool reindent=true) const;

        /** Search and replace a string */
        void replace(Chunks& input, const std::string& target, const std::string& replacement) const;

        /** Dump chunks to notify (for debugging) */
        void dump(const std::string&, const Chunks&) const;

        /** Create a chunk from a line. */
        Chunk chunkLine(const std::string& line) const;
    };
} }