// SPDX-License-Identifier: LGPL-2.1-or-later
/*****************************************************************************
 *
 * This file is part of Mapnik Vector Tile Plugin
 *
 * Copyright (C) 2023 Geofabrik GmbH
 * 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
 *
 *****************************************************************************/

#include "mvt_io.hpp"
#include "vector_tile_geometry_decoder.hpp"
#include <mapnik/feature_factory.hpp>
#include <mapnik/well_known_srs.hpp>
#include <stdexcept>
#include <cmath>

mvt_io::mvt_layer::mvt_layer(mvt_io& io)
    : keys_(),
      values_(),
      io_(io)
{}

void mvt_io::mvt_layer::add_feature(protozero::data_view const& feature)
{
    features_.emplace_back(feature);
}

bool mvt_io::mvt_layer::has_features() const
{
    return !features_.empty();
}

void mvt_io::mvt_layer::add_key(std::string&& key)
{
    keys_.push_back(key);
}

void mvt_io::mvt_layer::add_value(pbf_attr_value_type value)
{
    values_.push_back(value);
}

void mvt_io::mvt_layer::set_name(std::string&& name)
{
    name_ = name;
}

void mvt_io::mvt_layer::set_extent(uint32_t extent)
{
    extent_ = extent;
}

uint32_t mvt_io::mvt_layer::extent() const
{
    return extent_;
}

void mvt_io::mvt_layer::finish_reading()
{
    num_keys_ = keys_.size();
    num_values_ = values_.size();
    scale_ = static_cast<double>(extent_ / io_.resolution_);
}

mapnik::feature_ptr mvt_io::mvt_layer::next_feature()
{
    while (feature_index_ < features_.size())
    {
        protozero::data_view const d(features_.at(feature_index_));
        protozero::pbf_reader f(d);
        mapnik::feature_ptr feature = mapnik::feature_factory::create(io_.context_, feature_index_);
        ++feature_index_;
        mvt_message::geom_type geometry_type = mvt_message::geom_type::unknown;
        bool has_geometry = false;
        bool has_geometry_type = false;
        mapnik::vector_tile_impl::GeometryPBF::pbf_itr geom_itr;
        while (f.next())
        {
            switch (f.tag())
            {
                case static_cast<uint32_t>(mvt_message::feature::id):
                    feature->set_id(f.get_uint64());
                    break;
                case static_cast<uint32_t>(mvt_message::feature::tags): {
                    auto tag_iterator = f.get_packed_uint32();
                    for (auto _i = tag_iterator.begin(); _i != tag_iterator.end();)
                    {
                        std::size_t key_name = *(_i++);
                        if (_i == tag_iterator.end())
                        {
                            throw std::runtime_error(
                              "Vector Tile has a feature with an odd number of tags, therefore the tile is invalid.");
                        }
                        std::size_t key_value = *(_i++);
                        if (key_name < num_keys_ && key_value < num_values_)
                        {
                            std::string const& name = keys_.at(key_name);
                            if (feature->has_key(name))
                            {
                                pbf_attr_value_type val = values_.at(key_value);
                                value_visitor vv(io_.tr_, feature, name);
                                mapnik::util::apply_visitor(vv, val);
                            }
                        }
                    }
                    break;
                }
                case static_cast<uint32_t>(mvt_message::feature::type):
                    has_geometry_type = true;
                    geometry_type = static_cast<mvt_message::geom_type>(f.get_enum());
                    switch (geometry_type)
                    {
                        case mvt_message::geom_type::point:
                        case mvt_message::geom_type::linestring:
                        case mvt_message::geom_type::polygon:
                            break;
                        default:
                            throw std::runtime_error(
                              "Vector tile has an unknown geometry type " +
                              std::to_string(static_cast<protozero::pbf_tag_type>(geometry_type)) + " in feature");
                    }
                    break;
                case static_cast<uint32_t>(mvt_message::feature::geometry):
                    if (has_geometry)
                    {
                        throw std::runtime_error(
                          "Vector Tile has a feature with multiple geometry fields, it must have only one of them");
                    }
                    has_geometry = true;
                    geom_itr = f.get_packed_uint32();
                    break;
                default:
                    throw std::runtime_error("Vector Tile contains unknown field type " +
                                             std::to_string(static_cast<protozero::pbf_tag_type>(f.tag())) +
                                             " in feature");
            }
        }
        if (has_geometry)
        {
            if (!has_geometry_type)
            {
                throw std::runtime_error("Vector Tile has a feature that does not define the required geometry type.");
            }
            mapnik::vector_tile_impl::GeometryPBF geoms(geom_itr);
            mapnik::geometry::geometry<double> geom =
              mapnik::vector_tile_impl::decode_geometry<double>(geoms,
                                                                static_cast<std::int32_t>(geometry_type),
                                                                1,
                                                                io_.bbox().minx(),
                                                                io_.bbox().maxy(),
                                                                scale_,
                                                                -1.0 * scale_);
            if (geom.is<mapnik::geometry::geometry_empty>())
            {
                continue;
            }
            feature->set_geometry(std::move(geom));
            return feature;
        }
    }
    return mapnik::feature_ptr();
}

bool mvt_io::read_layer(protozero::pbf_message<mvt_message::layer>& pbf_layer)
{
    layer_.reset(new mvt_layer(*this));
    bool ignore_layer = false;
    while (pbf_layer.next())
    {
        if (ignore_layer)
        {
            pbf_layer.skip();
            continue;
        }
        switch (pbf_layer.tag())
        {
            case mvt_message::layer::name: {
                std::string name = pbf_layer.get_string();
                if (name != layer_name_)
                {
                    ignore_layer = true;
                }
                layer_->set_name(std::move(name));
                break;
            }
            case mvt_message::layer::extent:
                layer_->set_extent(pbf_layer.get_uint32());
                if (layer_->extent() == 0)
                {
                    throw std::runtime_error{"Vector tile layer has extent 0."};
                }
                break;
            case mvt_message::layer::keys:
                layer_->add_key(pbf_layer.get_string());
                break;
            case mvt_message::layer::values: {
                auto const data_view(pbf_layer.get_view());
                protozero::pbf_reader val_msg(data_view);
                while (val_msg.next())
                {
                    switch (val_msg.tag())
                    {
                        case static_cast<uint32_t>(mvt_message::value::string_value):
                            layer_->add_value(val_msg.get_string());
                            break;
                        case static_cast<uint32_t>(mvt_message::value::float_value):
                            layer_->add_value(val_msg.get_float());
                            break;
                        case static_cast<uint32_t>(mvt_message::value::double_value):
                            layer_->add_value(val_msg.get_double());
                            break;
                        case static_cast<uint32_t>(mvt_message::value::int_value):
                            layer_->add_value(val_msg.get_int64());
                            break;
                        case static_cast<uint32_t>(mvt_message::value::uint_value):
                            layer_->add_value(val_msg.get_uint64());
                            break;
                        case static_cast<uint32_t>(mvt_message::value::sint_value):
                            layer_->add_value(val_msg.get_sint64());
                            break;
                        case static_cast<uint32_t>(mvt_message::value::bool_value):
                            layer_->add_value(val_msg.get_bool());
                            break;
                        default:
                            val_msg.skip();
                            throw std::runtime_error("unknown Value type " +
                                                     std::to_string(static_cast<int>(val_msg.tag())) +
                                                     " in layer->values");
                    }
                }
                break;
            }
            case mvt_message::layer::features: {
                auto const data_view(pbf_layer.get_view());
                layer_->add_feature(data_view);
                break;
            }
            case mvt_message::layer::version: {
                uint32_t version = pbf_layer.get_uint32();
                if (version != 2)
                {
                    throw std::runtime_error("Vector tile does not have major version 2.");
                }
                break;
            }
            default:
                std::string msg = "Unsupported tag " + std::to_string(static_cast<uint32_t>(pbf_layer.tag())) +
                                  " found in layer message.";
                throw std::runtime_error(msg);
                pbf_layer.skip();
        }
    }
    layer_->finish_reading();
    return !ignore_layer;
}

mapnik::feature_ptr mvt_io::next()
{
    if (!layer_ || !layer_->has_features())
    {
        return mapnik::feature_ptr();
    }
    return layer_->next_feature();
}

mvt_io::mvt_io(std::string&& data,
               mapnik::context_ptr const& ctx,
               uint32_t const x,
               uint32_t const y,
               uint32_t const zoom,
               std::string layer_name)
    : reader_(data),
      context_(ctx),
      layer_name_(layer_name),
      tr_("utf-8")
{
    resolution_ = mapnik::EARTH_CIRCUMFERENCE / (1 << zoom);
    double x0 = -0.5 * mapnik::EARTH_CIRCUMFERENCE + x * resolution_;
    double y0 = 0.5 * mapnik::EARTH_CIRCUMFERENCE - y * resolution_;
    double x1 = -0.5 * mapnik::EARTH_CIRCUMFERENCE + (x + 1) * resolution_;
    double y1 = 0.5 * mapnik::EARTH_CIRCUMFERENCE - (y + 1) * resolution_;

    bbox_.init(x0, y0, x1, y1);

    while (reader_.next(static_cast<uint32_t>(mvt_message::tile::layer)))
    {
        auto const data_view(reader_.get_view());
        protozero::pbf_message<mvt_message::layer> msg_layer(data_view);
        if (read_layer(msg_layer))
        {
            break;
        }
    }
}

mapnik::box2d<double> const& mvt_io::bbox() const
{
    return bbox_;
}