/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2025 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
 *
 *****************************************************************************/

// mapnik
#include <mapnik/image.hpp>
#include <mapnik/image_scaling.hpp>
#include <mapnik/image_scaling_traits.hpp>
#include <mapnik/safe_cast.hpp>

#include <mapnik/warning.hpp>
MAPNIK_DISABLE_WARNING_PUSH
#include <mapnik/warning_ignore.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/bimap.hpp>
MAPNIK_DISABLE_WARNING_POP

#include <mapnik/warning.hpp>
MAPNIK_DISABLE_WARNING_PUSH
#include <mapnik/warning_ignore_agg.hpp>
#include "agg_image_accessors.h"
#include "agg_pixfmt_rgba.h"
#include "agg_pixfmt_gray.h"
#include "agg_color_rgba.h"
#include "agg_rasterizer_scanline_aa.h"
#include "agg_renderer_scanline.h"
#include "agg_rendering_buffer.h"
#include "agg_scanline_u.h"
#include "agg_span_allocator.h"
#include "agg_span_image_filter_gray.h"
#include "agg_span_image_filter_rgba.h"
#include "agg_span_interpolator_linear.h"
#include "agg_trans_affine.h"
#include "agg_image_filters.h"
MAPNIK_DISABLE_WARNING_POP

namespace mapnik {

using scaling_method_lookup_type = boost::bimap<scaling_method_e, std::string>;
static scaling_method_lookup_type const scaling_lookup =
  boost::assign::list_of<scaling_method_lookup_type::relation>(SCALING_NEAR, "near")(SCALING_BILINEAR, "bilinear")(
    SCALING_BICUBIC,
    "bicubic")(SCALING_SPLINE16, "spline16")(SCALING_SPLINE36, "spline36")(SCALING_HANNING, "hanning")(
    SCALING_HAMMING,
    "hamming")(SCALING_HERMITE, "hermite")(SCALING_KAISER, "kaiser")(SCALING_QUADRIC, "quadric")(
    SCALING_CATROM,
    "catrom")(SCALING_GAUSSIAN, "gaussian")(SCALING_BESSEL, "bessel")(SCALING_MITCHELL, "mitchell")(
    SCALING_SINC,
    "sinc")(SCALING_LANCZOS, "lanczos")(SCALING_BLACKMAN, "blackman");

std::optional<scaling_method_e> scaling_method_from_string(std::string const& name)
{
    scaling_method_lookup_type::right_const_iterator right_iter = scaling_lookup.right.find(name);
    if (right_iter != scaling_lookup.right.end())
    {
        return right_iter->second;
    }
    return std::nullopt;
}

std::optional<std::string> scaling_method_to_string(scaling_method_e scaling_method)
{
    scaling_method_lookup_type::left_const_iterator left_iter = scaling_lookup.left.find(scaling_method);
    if (left_iter != scaling_lookup.left.end())
    {
        return left_iter->second;
    }
    return std::nullopt;
}

template<typename T>
void scale_image_agg(T& target,
                     T const& source,
                     scaling_method_e scaling_method,
                     double image_ratio_x,
                     double image_ratio_y,
                     double x_off_f,
                     double y_off_f,
                     double filter_factor,
                     std::optional<double> const& nodata_value)
{
    // "the image filters should work namely in the premultiplied color space"
    // http://old.nabble.com/Re:--AGG--Basic-image-transformations-p1110665.html
    // "Yes, you need to use premultiplied images only. Only in this case the simple weighted averaging works correctly
    // in the image fitering." http://permalink.gmane.org/gmane.comp.graphics.agg/3443
    using image_type = T;
    using pixel_type = typename image_type::pixel_type;
    using pixfmt_pre = typename detail::agg_scaling_traits<image_type>::pixfmt_pre;
    using color_type = typename detail::agg_scaling_traits<image_type>::color_type;
    using img_src_type = typename detail::agg_scaling_traits<image_type>::img_src_type;
    using interpolator_type = typename detail::agg_scaling_traits<image_type>::interpolator_type;
    using renderer_base_pre = agg::renderer_base<pixfmt_pre>;
    constexpr std::size_t pixel_size = sizeof(pixel_type);

    // define some stuff we'll use soon
    agg::rasterizer_scanline_aa<> ras;
    agg::scanline_u8 sl;
    agg::span_allocator<color_type> sa;

    // initialize source AGG buffer
    agg::rendering_buffer rbuf_src(const_cast<unsigned char*>(source.bytes()),
                                   source.width(),
                                   source.height(),
                                   source.width() * pixel_size);
    pixfmt_pre pixf_src(rbuf_src);

    img_src_type img_src(pixf_src);

    // initialize destination AGG buffer (with transparency)
    agg::rendering_buffer rbuf_dst(target.bytes(), target.width(), target.height(), target.width() * pixel_size);
    pixfmt_pre pixf_dst(rbuf_dst);
    renderer_base_pre rb_dst_pre(pixf_dst);

    // create a scaling matrix
    agg::trans_affine img_mtx;
    img_mtx *= agg::trans_affine_translation(x_off_f, y_off_f);
    img_mtx /= agg::trans_affine_scaling(image_ratio_x, image_ratio_y);

    // create a linear interpolator for our scaling matrix
    interpolator_type interpolator(img_mtx);
    // draw an anticlockwise polygon to render our image into
    double scaled_width = target.width();
    double scaled_height = target.height();
    ras.reset();
    ras.move_to_d(0.0, 0.0);
    ras.line_to_d(scaled_width, 0.0);
    ras.line_to_d(scaled_width, scaled_height);
    ras.line_to_d(0.0, scaled_height);
    if (scaling_method == SCALING_NEAR)
    {
        using span_gen_type = typename detail::agg_scaling_traits<image_type>::span_image_filter;
        span_gen_type sg(img_src, interpolator);
        agg::render_scanlines_aa(ras, sl, rb_dst_pre, sa, sg);
    }
    else
    {
        using span_gen_type = typename detail::agg_scaling_traits<image_type>::span_image_resample_affine;
        agg::image_filter_lut filter;
        detail::set_scaling_method(filter, scaling_method, filter_factor);
        std::optional<typename span_gen_type::value_type> nodata;
        if (nodata_value.has_value())
        {
            nodata.emplace(safe_cast<typename span_gen_type::value_type>(*nodata_value));
        }
        span_gen_type sg(img_src, interpolator, filter, nodata);
        agg::render_scanlines_aa(ras, sl, rb_dst_pre, sa, sg);
    }
}

template MAPNIK_DECL void scale_image_agg(image_rgba8&,
                                          image_rgba8 const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray8&,
                                          image_gray8 const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray8s&,
                                          image_gray8s const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray16&,
                                          image_gray16 const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray16s&,
                                          image_gray16s const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray32&,
                                          image_gray32 const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray32s&,
                                          image_gray32s const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray32f&,
                                          image_gray32f const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray64&,
                                          image_gray64 const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray64s&,
                                          image_gray64s const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);

template MAPNIK_DECL void scale_image_agg(image_gray64f&,
                                          image_gray64f const&,
                                          scaling_method_e,
                                          double,
                                          double,
                                          double,
                                          double,
                                          double,
                                          std::optional<double> const&);
} // namespace mapnik
