mountcontrol/cxx/mcc_mount_pz.h

#pragma once

/*  MOUNT CONTROL COMPONENTS LIBRARY  */

/*  PROHIBITED ZONE IMPLEMENTATION  */

#include <chrono>
#include <string_view>

#include "mcc_mount_coord.h"
#include "mcc_traits.h"

namespace mcc
{

class MccProhibitedZone
{
public:
    static constexpr MccCoordPairKind preferedCoordKind = MccCoordPairKind::COORDS_KIND_AZALT;


    // floating-point time duration (seconds)
    typedef std::chrono::duration<double> pz_duration_t;


    struct pz_request_t {
        bool in_zone{false};           // true if given coordinates are within the zone
        pz_duration_t time_to{0.0};    // a time duration to reach the zone
        pz_duration_t time_from{0.0};  // a time duration to exit the zone
    };


    virtual ~MccProhibitedZone() = default;

    std::string_view name() const
    {
        return _name;
    }

    // check if given position (x,y) in the zone
    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    bool inZone(this auto&& self,
                const XT& x,
                const YT& y,
                traits::mcc_systime_c auto const& utc = std::chrono::system_clock::now())
    {
        return std::forward<decltype(self)>(self).inZoneImpl(x, y, utc);
    }

    // returns a time duration to reach the zone
    // 0 - if already within
    // Inf - if it never reaches the zone
    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    pz_duration_t timeTo(this auto&& self,
                         const XT& x,
                         const YT& y,
                         traits::mcc_systime_c auto const& utc = std::chrono::system_clock::now())
    {
        return std::forward<decltype(self)>(self).timeToImpl(x, y, utc);
    }

    // returns a time duration to exit from the zone
    // 0 - if given position (x,y) is out of the zone
    // Inf - if (x,y) is always within the zone
    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    pz_duration_t timeFrom(this auto&& self,
                           const XT& x,
                           const YT& y,
                           traits::mcc_systime_c auto const& utc = std::chrono::system_clock::now())
    {
        return std::forward<decltype(self)>(self).timeFromImpl(x, y, utc);
    }


    // all-in-one request (call three methods above)
    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    pz_request_t request(const XT& x,
                         const YT& y,
                         traits::mcc_systime_c auto const& utc = std::chrono::system_clock::now())
    {
        pz_request_t res{.in_zone = false, .time_to = pz_duration_t{0.0}, .time_from{0.0}};

        res.in_zone = inZone(x, y, utc);

        if (res.in_zone) {
            res.time_from = timeFrom(x, y, utc);
        } else {
            res.time_to = timeFrom(x, y, utc);
        }

        return res;
    }

protected:
    MccProhibitedZone(std::string_view name) : _name(name) {}

    std::string_view _name;


    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    bool inZoneImpl(const XT&, const YT&, traits::mcc_systime_c auto const&)
    {
        return false;
    }


    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    pz_duration_t timeToImpl(const XT&, const YT&, traits::mcc_systime_c auto const&)
    {
        return pz_duration_t{std::numeric_limits<double>::infinity()};
    }


    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    pz_duration_t timeFromImpl(const XT&, const YT&, traits::mcc_systime_c auto const&)
    {
        return pz_duration_t{0.0};
    }
};


/*  SOME PROHIBITED ZONE IMPLEMENTATIONS  */


// minimal or maximal altitude prohibited zones

enum class MccAltLimitKind { MIN_ALT_LIMIT, MAX_ALT_LIMIT };

template <MccAltLimitKind KIND = MccAltLimitKind::MIN_ALT_LIMIT>
class MccAltLimitPZ : public MccProhibitedZone
{
public:
    static constexpr MccAltLimitKind altLimitKind = KIND;

    MccAltLimitPZ(const MccAngle& alt_limit)
        : MccProhibitedZone(KIND == MccAltLimitKind::MIN_ALT_LIMIT   ? "MINALT-ZONE"
                            : KIND == MccAltLimitKind::MAX_ALT_LIMIT ? "MAXALT-ZONE"
                                                                     : "ALTLIMIT-UNKNOWN"),
          _altLimit(alt_limit)
    {
        _altLimit.normalize<MccAngle::NORM_KIND_90_90>();
    }

private:
    MccAngle _altLimit;

    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    bool inZoneImpl(const XT& x, const YT& y, traits::mcc_systime_c auto const& utc)
    {
        static constexpr MccCoordPairKind coord_kind = traits::mcc_type_pair_hash<XT, YT>();

        if constexpr (coord_kind == MccCoordPairKind::COORDS_KIND_AZALT) {  // trivial case
            if constexpr (KIND == MccAltLimitKind::MIN_ALT_LIMIT) {
                return y <= _altLimit;
            } else if constexpr (KIND == MccAltLimitKind::MAX_ALT_LIMIT) {
                return y >= _altLimit;
            }
        } else if constexpr (coord_kind == MccCoordPairKind::COORDS_KIND_AZZD) {  // trivial case
            return inZoneImpl(x, MccAngleALT(std::numbers::pi / 2 - (double)y), utc);
        } else if constexpr (coord_kind == MccCoordPairKind::COORDS_KIND_HADEC_APP) {
            // implementation ...
            return false;
        } else if constexpr (coord_kind == MccCoordPairKind::COORDS_KIND_RADEC_APP) {
            // implementation ...
            return false;
        } else {
            throw std::system_error(std::make_error_code(std::errc::operation_not_supported));
        }

        return false;
    }


    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    pz_duration_t timeToImpl(const XT&, const YT&, traits::mcc_systime_c auto const&)
    {
        return pz_duration_t{std::numeric_limits<double>::infinity()};
    }


    template <std::derived_from<MccAngle> XT, std::derived_from<MccAngle> YT>
    pz_duration_t timeFromImpl(const XT&, const YT&, traits::mcc_systime_c auto const&)
    {
        return pz_duration_t{0.0};
    }
};

}  // namespace mcc