#include "common/GeoJson.h"

#include <vector>

namespace visione::geojson
{
namespace
{
struct Point
{
    double x;
    double y;
};
}  // namespace

bool pointInPolygon(double latitude, double longitude, const Json::Value &geojson)
{
    if (!geojson.isObject() || geojson["type"].asString() != "Polygon" ||
        !geojson["coordinates"].isArray() || geojson["coordinates"].empty())
    {
        return false;
    }

    const auto &ring = geojson["coordinates"][0];
    if (!ring.isArray() || ring.size() < 4)
    {
        return false;
    }

    std::vector<Point> points;
    points.reserve(ring.size());
    for (const auto &coordinate : ring)
    {
        if (!coordinate.isArray() || coordinate.size() < 2)
        {
            return false;
        }
        points.push_back({coordinate[0].asDouble(), coordinate[1].asDouble()});
    }

    const auto x = longitude;
    const auto y = latitude;
    bool inside = false;
    for (size_t i = 0, j = points.size() - 1; i < points.size(); j = i++)
    {
        const auto &pi = points[i];
        const auto &pj = points[j];
        const bool intersects =
            ((pi.y > y) != (pj.y > y)) &&
            (x < (pj.x - pi.x) * (y - pi.y) / (pj.y - pi.y) + pi.x);
        if (intersects)
        {
            inside = !inside;
        }
    }
    return inside;
}
}  // namespace visione::geojson