/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 Artem Pavlenko
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

//$Id: tiff_reader.cpp 17 2005-03-08 23:58:43Z pavlenko $
// stl
#include <iostream>
#include <boost/filesystem/operations.hpp>
// mapnik
#include <mapnik/image_reader.hpp>

extern "C" 
{
   #include <tiffio.h>    
}

namespace mapnik 
{

    using std::min;
    using std::max;

    class TiffReader : public ImageReader
    {
    private:
        std::string file_name_;
        int read_method_;
        unsigned width_;
        unsigned height_;
        int rows_per_strip_;
        int tile_width_;
        int tile_height_;
    public:
        enum {
            generic=1,
            stripped,
            tiled
        };
        explicit TiffReader(const std::string& file_name);
        virtual ~TiffReader();
        unsigned width() const;
        unsigned height() const;
        void read(unsigned x,unsigned y,ImageData32& image);
    private:
        TiffReader(const TiffReader&);
        TiffReader& operator=(const TiffReader&);
        void init();
        void read_generic(unsigned x,unsigned y,ImageData32& image);
        void read_stripped(unsigned x,unsigned y,ImageData32& image);
        void read_tiled(unsigned x,unsigned y,ImageData32& image);
        TIFF* load_if_exists(const std::string& filename);
    };

    namespace
    {
        ImageReader* createTiffReader(const std::string& file)
        {
            return new TiffReader(file);
        }

        const bool registered = register_image_reader("tiff",createTiffReader);
    }

    TiffReader::TiffReader(const std::string& file_name)
        : file_name_(file_name),
          read_method_(generic),
          width_(0),
          height_(0),
          rows_per_strip_(0),
          tile_width_(0),
          tile_height_(0)
    {
        try
        {
            init();
        }
        catch (ImageReaderException& ex)
        {
            std::clog<<ex.what()<<std::endl;
            throw;
        }
    }


    void TiffReader::init()
    {
	TIFF* tif = load_if_exists(file_name_);
        if (!tif) return;
	
        char msg[1024];

        if (TIFFRGBAImageOK(tif,msg))
        {
            TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &width_);
            TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &height_);
            if (TIFFIsTiled(tif))
            {
                TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tile_width_);
                TIFFGetField(tif, TIFFTAG_TILELENGTH, &tile_height_);
                read_method_=tiled;
            }
            else if (TIFFGetField(tif,TIFFTAG_ROWSPERSTRIP,&rows_per_strip_)!=0)
            {
                read_method_=stripped;
            }
            TIFFClose(tif);
        }
        else
        {
            TIFFClose(tif);
            throw ImageReaderException(msg);
        }
    }


    TiffReader::~TiffReader()
    {
        //
    }


    unsigned TiffReader::width() const
    {
        return width_;
    }


    unsigned TiffReader::height() const
    {
        return height_;
    }


    void TiffReader::read(unsigned x,unsigned y,ImageData32& image)
    {    
        if (read_method_==stripped)
        {
            read_stripped(x,y,image);
        }
        else if (read_method_==tiled)
        {
            read_tiled(x,y,image);
        }
        else
        {
            read_generic(x,y,image);
        }
    }


    void TiffReader::read_generic(unsigned x,unsigned y,ImageData32& image)
    {
	TIFF* tif = load_if_exists(file_name_);
        if (tif)
        {
            std::clog<<"TODO:tiff is not stripped or tiled\n";
            TIFFClose(tif);
        }
    }


    void TiffReader::read_tiled(unsigned x0,unsigned y0,ImageData32& image)
    {
	TIFF* tif = load_if_exists(file_name_);
        if (tif)
        {
            uint32* buf = (uint32*)_TIFFmalloc(tile_width_*tile_height_*sizeof(uint32));
            int width=image.width();
            int height=image.height();

            int start_y=(y0/tile_height_)*tile_height_;
            int end_y=((y0+height)/tile_height_+1)*tile_height_;

            int start_x=(x0/tile_width_)*tile_width_;
            int end_x=((x0+width)/tile_width_+1)*tile_width_;
            int row,tx0,tx1,ty0,ty1;

            for (int y=start_y;y<end_y;y+=tile_height_)
            {
                ty0 = max(y0,(unsigned)y) - y;
                ty1 = min(height+y0,(unsigned)(y+tile_height_)) - y;

                int n0=tile_height_-ty1;
                int n1=tile_height_-ty0-1;

                for (int x=start_x;x<end_x;x+=tile_width_)
                {

                    if (!TIFFReadRGBATile(tif,x,y,buf)) break;

                    tx0=max(x0,(unsigned)x);
                    tx1=min(width+x0,(unsigned)(x+tile_width_));
                    row=y+ty0-y0;
                    for (int n=n1;n>=n0;--n)
                    {
                        image.setRow(row,tx0-x0,tx1-x0,(const unsigned*)&buf[n*tile_width_+tx0-x]);
                        ++row;
                    }
                }
            }
            _TIFFfree(buf);
            TIFFClose(tif);
        }
    }


    void TiffReader::read_stripped(unsigned x0,unsigned y0,ImageData32& image)
    {
	TIFF* tif = load_if_exists(file_name_);
        if (tif)
        {
            uint32* buf = (uint32*)_TIFFmalloc(width_*rows_per_strip_*sizeof(uint32));

            int width=image.width();
            int height=image.height();

            unsigned start_y=(y0/rows_per_strip_)*rows_per_strip_;
            unsigned end_y=((y0+height)/rows_per_strip_+1)*rows_per_strip_;
            bool laststrip=((unsigned)end_y > height_)?true:false;
            int row,tx0,tx1,ty0,ty1;

            tx0=x0;
            tx1=min(width+x0,(unsigned)width_);

            for (unsigned y=start_y; y < end_y; y+=rows_per_strip_)
            {
                ty0 = max(y0,y)-y;
                ty1 = min(height+y0,y+rows_per_strip_)-y;

                if (!TIFFReadRGBAStrip(tif,y,buf)) break;

                row=y+ty0-y0;

                int n0=laststrip ? 0:(rows_per_strip_-ty1);
                int n1=laststrip ? (ty1-ty0-1):(rows_per_strip_-ty0-1);
                for (int n=n1;n>=n0;--n)
                {
                    image.setRow(row,tx0-x0,tx1-x0,(const unsigned*)&buf[n*width_+tx0]);
                    ++row;
                }
            }
            _TIFFfree(buf);
            TIFFClose(tif);
        }
    }
    
    TIFF* TiffReader::load_if_exists(const std::string& filename)
    {
        TIFF* tif = 0;
        boost::filesystem::path path(file_name_);
        if (exists(path) && is_regular(path)) {
            // File path is a full file path and does exist
            tif = TIFFOpen(filename.c_str(), "rb");
        } else {
            return 0;
        }
        if (!tif) {
            throw ImageReaderException("cannot open "+file_name_);
        }
        return tif;
    }
}