#ifndef MBGL_UTIL_GEO
#define MBGL_UTIL_GEO

#include <mbgl/util/vec.hpp>

#include <cmath>

namespace mbgl {

class TileID;

using PrecisionPoint = vec2<double>;

struct LatLng {
    double latitude = 0;
    double longitude = 0;

    inline LatLng(double lat = 0, double lon = 0)
        : latitude(lat), longitude(lon) {}

    inline operator bool() const {
        return !(std::isnan(latitude) || std::isnan(longitude));
    }

    // Constructs a LatLng object with the top left position of the specified tile.
    LatLng(const TileID& id);

    PrecisionPoint project() const;
};

struct ProjectedMeters {
    double northing = 0;
    double easting = 0;

    inline ProjectedMeters(double n = 0, double e = 0)
        : northing(n), easting(e) {}

    inline operator bool() const {
        return !(std::isnan(northing) || std::isnan(easting));
    }
};

struct LatLngBounds {
    LatLng sw = {-90, -180};
    LatLng ne = {90, 180};

    inline LatLngBounds() {}

    inline LatLngBounds(const LatLng& sw_, const LatLng& ne_)
        : sw(sw_), ne(ne_) {}

    static inline LatLngBounds getExtendable() {
        LatLngBounds bounds;
        return { bounds.ne, bounds.sw };
    }

    inline operator bool() const {
        return sw && ne;
    }

    // Constructs a LatLngBounds object with the tile's exact boundaries.
    LatLngBounds(const TileID& id);

    inline void extend(const LatLng& point) {
        if (point.latitude < sw.latitude) sw.latitude = point.latitude;
        if (point.latitude > ne.latitude) ne.latitude = point.latitude;
        if (point.longitude < sw.longitude) sw.longitude = point.longitude;
        if (point.longitude > ne.longitude) ne.longitude = point.longitude;
    }

    inline void extend(const LatLngBounds& bounds) {
        extend(bounds.sw);
        extend(bounds.ne);
    }

    inline bool contains(const LatLng& point) const {
        return (point.latitude  >= sw.latitude  &&
                point.latitude  <= ne.latitude  &&
                point.longitude >= sw.longitude &&
                point.longitude <= ne.longitude);
    }

    inline bool intersects(const LatLngBounds area) const {
        return (area.ne.latitude  > sw.latitude  &&
                area.sw.latitude  < ne.latitude  &&
                area.ne.longitude > sw.longitude &&
                area.sw.longitude < ne.longitude);
    }
};

struct MetersBounds {
    ProjectedMeters sw;
    ProjectedMeters ne;

    inline MetersBounds(const ProjectedMeters& sw_, const ProjectedMeters& ne_)
        : sw(sw_), ne(ne_) {}

    inline operator bool() const {
        return sw && ne;
    }
};

// Determines the orientation of the map.
enum class NorthOrientation : uint8_t {
    Upwards, // Default
    Rightwards,
    Downwards,
    Leftwards,
};

/// The distance on each side between a rectangle and a rectangle within.
struct EdgeInsets {
    double top = 0;     ///< Number of pixels inset from the top edge.
    double left = 0;    ///< Number of pixels inset from the left edge.
    double bottom = 0;  ///< Number of pixels inset from the bottom edge.
    double right = 0;   ///< Number of pixels inset from the right edge.
    
    inline EdgeInsets() {}
    
    inline EdgeInsets(const double t, const double l, const double b, const double r)
        : top(t), left(l), bottom(b), right(r) {}
    
    inline operator bool() const {
        return top || left || bottom || right;
    }
    
    inline void operator+=(const EdgeInsets& o) {
        top += o.top;
        left += o.left;
        bottom += o.bottom;
        right += o.right;
    }

    inline EdgeInsets operator+(const EdgeInsets& o) const {
        return {
            top + o.top, left + o.left, bottom + o.bottom, right + o.right,
        };
    }
    
    PrecisionPoint getCenter(uint16_t width, uint16_t height) const;
};

} // namespace mbgl

#endif