#include "catch.hpp"

#include <mapnik/grid_vertex_converter.hpp>

TEST_CASE("spiral_iterator") {

SECTION("sprial 3x3") {

    mapnik::geometry::spiral_iterator si(3);
    const mapnik::geometry::point<int> points[] = {
        {  0, 0 }, { 1, 0 }, { 1, -1 },
        {  0, -1 }, { -1, -1 }, { -1, 0 },
        { -1, 1 }, { 0, 1 }, { 1, 1 } };

    const std::size_t points_size = std::extent<decltype(points)>::value;

    int x, y;
    std::size_t index = 0;

    while (si.vertex(&x, &y))
    {
        REQUIRE(index < points_size);

        CHECK(x == points[index].x);
        CHECK(y == points[index].y);

        index++;
    }

    CHECK(index == points_size);
}

}

TEST_CASE("grid_vertex_converter") {

SECTION("empty polygon") {

    mapnik::geometry::polygon<double> poly;
    using path_type = mapnik::geometry::polygon_vertex_adapter<double>;
    path_type path(poly);
    using converter_type = mapnik::geometry::grid_vertex_converter<path_type, double>;
    converter_type gvc(path, 10.0, 10.0, 1.0);

    double x, y;
    unsigned cmd = gvc.vertex(&x, &y);

    CHECK(cmd == mapnik::SEG_END);

}

SECTION("empty polygon exterior ring") {

    mapnik::geometry::polygon<double> poly;
    poly.emplace_back();

    using path_type = mapnik::geometry::polygon_vertex_adapter<double>;
    path_type path(poly);
    using converter_type = mapnik::geometry::grid_vertex_converter<path_type, double>;
    converter_type gvc(path, 10.0, 10.0, 1.0);

    double x, y;
    unsigned cmd = gvc.vertex(&x, &y);

    CHECK(cmd == mapnik::SEG_END);

}

SECTION("grid of a square") {

    mapnik::geometry::polygon<double> poly;
    poly.emplace_back();
    auto & exterior_ring = poly.front();
    exterior_ring.emplace_back(-10, -10);
    exterior_ring.emplace_back( 10, -10);
    exterior_ring.emplace_back( 10,  10);
    exterior_ring.emplace_back(-10,  10);
    exterior_ring.emplace_back(-10, -10);

    using path_type = mapnik::geometry::polygon_vertex_adapter<double>;
    path_type path(poly);
    using converter_type = mapnik::geometry::grid_vertex_converter<path_type, double>;
    converter_type gvc(path, 3.0, 3.0, 1.0);

    const mapnik::geometry::point<double> points[] = {
        { 0, 0 }, { 3, 0 }, { 3, 3 }, { 0, 3 },
        { -3, 3 }, { -3, 0 }, { -3, -3 }, { 0, -3 },
        { 3, -3 }, { 6, -3 }, { 6, 0 }, { 6, 3 },
        { 6, 6 }, { 3, 6 }, { 0, 6 }, { -3, 6 },
        { -6, 6 }, { -6, 3 }, { -6, 0 }, { -6, -3 },
        { -6, -6 }, { -3, -6 }, { 0, -6 }, { 3, -6 },
        { 6, -6 }, { 9, -6 }, { 9, -3 }, { 9, 0 },
        { 9, 3 }, { 9, 6 }, { 9, 9 }, { 6, 9 },
        { 3, 9 }, { 0, 9 }, { -3, 9 }, { -6, 9 },
        { -9, 9 }, { -9, 6 }, { -9, 3 }, { -9, 0 },
        { -9, -3 }, { -9, -6 }, { -9, -9 }, { -6, -9 },
        { -3, -9 }, { 0, -9 }, { 3, -9 }, { 6, -9 },
        { 9, -9 } };
    const std::size_t points_size = std::extent<decltype(points)>::value;

    double x, y;
    unsigned cmd = mapnik::SEG_END;
    std::size_t index = 0;

    while ((cmd = gvc.vertex(&x, &y)) != mapnik::SEG_END)
    {
        REQUIRE(index < points_size);

        CHECK(cmd == mapnik::SEG_MOVETO);
        CHECK(x == Approx(points[index].x));
        CHECK(y == Approx(points[index].y));

        index++;
    }

    CHECK(index == points_size);
    CHECK(cmd == mapnik::SEG_END);
}

}