// Boost.Geometry (aka GGL, Generic Geometry Library)
// (Unit) Test

// Copyright (c) 2018 Barend Gehrels, Amsterdam, the Netherlands.

// Use, modification and distribution is subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

#include <boost/geometry.hpp>
#include <geometry_test_common.hpp>

#include <boost/foreach.hpp>

#include <iomanip>

#if defined(TEST_WITH_SVG)
#  include <boost/geometry/io/svg/svg_mapper.hpp>
#endif



template <typename MultiPolygon>
std::string read_from_file(std::string const& filename)
{
    MultiPolygon mp;
    std::ifstream in(filename.c_str());
    while (in.good())
    {
        std::string line;
        std::getline(in, line);
        if (! line.empty())
        {
            typename boost::range_value<MultiPolygon>::type pol;
            bg::read_wkt(line, pol);
            mp.push_back(pol);
        }
    }
    std::ostringstream out;
    if (! mp.empty())
    {
        out << std::fixed << std::setprecision(19) << bg::wkt(mp);
    }

    BOOST_CHECK(! out.str().empty());

    return out.str();
}


template <typename MultiPolygon>
void test_one(std::string const& caseid, std::string const& wkt,
              double distance_in_meters,
              double expected_area_ratio, double expected_perimeter_ratio)
{
    boost::ignore_unused(caseid);

    MultiPolygon geometry, simplified;
    bg::read_wkt(wkt, geometry);
    bg::correct(geometry);
    bg::simplify(geometry, simplified, distance_in_meters);

    double const area_ratio = bg::area(simplified) / bg::area(geometry);
    double const perimeter_ratio = bg::perimeter(simplified) / bg::perimeter(geometry);

    BOOST_CHECK_CLOSE(perimeter_ratio, expected_perimeter_ratio, 0.01);
    BOOST_CHECK_CLOSE(area_ratio, expected_area_ratio, 0.01);

//  To add new tests, this is convenient and write the test itself:
//    std::cout << "test_one<mp>(\"" << caseid << "\", " << caseid
//              << ", " << distance_in_meters
//              << std::setprecision(6)
//              << ", " << area_ratio
//              << ", " << perimeter_ratio
//              << ");"
//              << std::endl;

#if defined(TEST_WITH_SVG)
    {
        typedef typename boost::range_value<MultiPolygon>::type polygon;

        std::ostringstream filename;
        filename << "simplify_" << caseid << "_" << distance_in_meters << ".svg";

        std::ofstream svg(filename.str().c_str());

        bg::svg_mapper
            <
                typename bg::point_type<MultiPolygon>::type
            > mapper(svg, 1200, 800);
        mapper.add(geometry);
        mapper.add(simplified);

        mapper.map(geometry, "fill-opacity:0.5;fill:rgb(153,204,0);"
                "stroke:rgb(153,204,0);stroke-width:1");
        BOOST_FOREACH(polygon const& pol, simplified)
        {
            mapper.map(pol,
                       bg::area(pol) > 0 ? "fill:none;stroke:rgb(255,0,0);stroke-width:1"
                       : "fill:none;stroke:rgb(255,0,255);stroke-width:1");
        }
    }
#endif
}


template <bool Clockwise, typename P>
void test_all()
{
    typedef bg::model::polygon<P, Clockwise> polygon;
    typedef bg::model::multi_polygon<polygon> mp;

    // The unit test uses countries originally added for buffer unit test
    std::string base_folder = "buffer/data/";

    // Verify for Greece, Italy, Netherlands, Norway and UK
    std::string gr = read_from_file<mp>(base_folder + "gr.wkt");
    std::string it = read_from_file<mp>(base_folder + "it.wkt");
    std::string nl = read_from_file<mp>(base_folder + "nl.wkt");
    std::string no = read_from_file<mp>(base_folder + "no.wkt");
    std::string uk = read_from_file<mp>(base_folder + "uk.wkt");

    // Gradually simplify more aggresively. Perimeter ratio should decrease.
    // Area can increase or decrease
    test_one<mp>("gr", gr, 100, 0.999893, 0.999761);
    test_one<mp>("gr", gr, 200, 0.999727, 0.99889);
    test_one<mp>("gr", gr, 500, 0.999106, 0.995726);
    test_one<mp>("gr", gr, 1000, 0.997977, 0.991533);
    test_one<mp>("gr", gr, 2000, 0.994583, 0.977574);
    test_one<mp>("gr", gr, 5000, 0.979823, 0.912549);
    test_one<mp>("gr", gr, 10000, 0.97171, 0.783048);
    test_one<mp>("gr", gr, 20000, 0.947049, 0.600652);

    test_one<mp>("it", it, 100, 1.00001, 0.999815);
    test_one<mp>("it", it, 200, 1.00009, 0.9991);
    test_one<mp>("it", it, 500, 1.00021, 0.996903);
    test_one<mp>("it", it, 1000, 1.00059, 0.993098);
    test_one<mp>("it", it, 2000, 1.001, 0.985255);
    test_one<mp>("it", it, 5000, 1.00212, 0.929793);
    test_one<mp>("it", it, 10000, 1.01076, 0.878063);
    test_one<mp>("it", it, 20000, 1.01042, 0.829402);

    test_one<mp>("nl", nl, 100, 0.999894, 0.999817);
    test_one<mp>("nl", nl, 200, 0.999635, 0.99909);
    test_one<mp>("nl", nl, 500, 0.999015, 0.996253);
    test_one<mp>("nl", nl, 1000, 0.997958, 0.991893);
    test_one<mp>("nl", nl, 2000, 0.996671, 0.982696);
    test_one<mp>("nl", nl, 5000, 0.992621, 0.934318);
    test_one<mp>("nl", nl, 10000, 0.973356, 0.807464);
    test_one<mp>("nl", nl, 20000, 0.983277, 0.742468);

    test_one<mp>("no", no, 100, 0.999967, 0.999976);
    test_one<mp>("no", no, 200, 0.999821, 0.999731);
    test_one<mp>("no", no, 500, 0.999314, 0.998092);
    test_one<mp>("no", no, 1000, 0.998456, 0.994053);
    test_one<mp>("no", no, 2000, 0.996493, 0.985213);
    test_one<mp>("no", no, 5000, 0.99086, 0.965176);
    test_one<mp>("no", no, 10000, 0.976511, 0.909933);
    test_one<mp>("no", no, 20000, 0.9549, 0.785917);

    test_one<mp>("uk", uk, 100, 0.999948, 0.99988);
    test_one<mp>("uk", uk, 200, 0.999853, 0.999284);
    test_one<mp>("uk", uk, 500, 0.999551, 0.996887);
    test_one<mp>("uk", uk, 1000, 0.999096, 0.992345);
    test_one<mp>("uk", uk, 2000, 0.998076, 0.984032);
    test_one<mp>("uk", uk, 5000, 0.991446, 0.943896);
    test_one<mp>("uk", uk, 10000, 0.989576, 0.870631);
    test_one<mp>("uk", uk, 20000, 0.980135, 0.737608);
}

int test_main(int, char* [])
{
    test_all<true, bg::model::point<double, 2, bg::cs::cartesian> >();
    return 0;
}