// ***************************************************************** -*- C++ -*-

// mrwthumb.cpp

// Sample program to extract a Minolta thumbnail from the makernote

#include "error.hpp"

#include "exif.hpp"

#include "image.hpp"

#include <cassert>

#include <iostream>

int main(int argc, char* const argv[])

{

    Exiv2::XmpParser::initialize();

    ::atexit(Exiv2::XmpParser::terminate);

    try {

        if (argc != 2) {

            std::cout << "Usage: " << argv[0] << " file\n";

            return 1;

        }

        Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(argv[1]);

        assert(image.get() != 0);

        image->readMetadata();

        Exiv2::ExifData& exifData = image->exifData();

        if (exifData.empty()) {

            std::string error(argv[1]);

            error += ": No Exif data found in the file";

            throw Exiv2::Error(Exiv2::kerErrorMessage, error);

        }

        Exiv2::ExifKey key("Exif.Minolta.ThumbnailOffset");

        Exiv2::ExifData::const_iterator format = exifData.findKey(key);

        if (format != exifData.end()) {

            Exiv2::DataBuf buf = format->dataArea();

            // The first byte of the buffer needs to be patched

            buf.pData_[0] = 0xff;

            Exiv2::FileIo file("img_thumb.jpg");

            file.open("wb");

            file.write(buf.pData_, buf.size_);

            file.close();

        }

        return 0;

    } catch (Exiv2::AnyError& e) {

        std::cout << "Caught Exiv2 exception '" << e << "'\n";

        return -1;

    }

}