#pragma once

/*                          MOUNT CONTROL COMPONENTS LIBRARY                            */


/*                          IMPLEMENTATION OF TELEMETRY CLASS                           */


#include "mcc_defaults.h"

namespace mcc
{

static constexpr double mcc_sideral_to_UT1_ratio = 1.002737909350795;  // sideral/UT1


enum MccTelemetryErrorCode : int { ERROR_OK, ERROR_COORD_TRANSFROM, ERROR_PCM_COMP };

}  // namespace mcc

namespace std
{

template <>
class is_error_code_enum<mcc::MccTelemetryErrorCode> : public true_type
{
};

}  // namespace std


namespace mcc
{

/*  error category definition  */

// error category
struct MccTelemetryCategory : public std::error_category {
    MccTelemetryCategory() : std::error_category() {}

    const char* name() const noexcept
    {
        return "ALTITUDE-LIMIT-PZ";
    }

    std::string message(int ec) const
    {
        MccTelemetryErrorCode err = static_cast<MccTelemetryErrorCode>(ec);

        switch (err) {
            case MccTelemetryErrorCode::ERROR_OK:
                return "OK";
            case MccTelemetryErrorCode::ERROR_COORD_TRANSFROM:
                return "coordinate transformation error";
            case MccTelemetryErrorCode::ERROR_PCM_COMP:
                return "PCM computation error";
            default:
                return "UNKNOWN";
        }
    }

    static const MccTelemetryCategory& get()
    {
        static const MccTelemetryCategory constInst;
        return constInst;
    }
};


inline std::error_code make_error_code(MccTelemetryErrorCode ec)
{
    return std::error_code(static_cast<int>(ec), MccTelemetryCategory::get());
}


/*  TELEMETRY UPDATE POLICY  */

enum class MccTelemetryUpdatePolicy : int { TEMETRY_UPDATE_INNER, TEMETRY_UPDATE_EXTERNAL };


template <MccTelemetryUpdatePolicy UPDATE_POLICY = MccTelemetryUpdatePolicy::TEMETRY_UPDATE_INNER>
class MccTelemetry : public mcc_telemetry_interface_t<std::error_code>
{
public:
    static constexpr MccTelemetryUpdatePolicy updatePolicy = UPDATE_POLICY;

    typedef std::error_code error_t;


    MccTelemetry(mcc_ccte_c auto* ccte, mcc_PCM_c auto* pcm, mcc_hardware_c auto* hardware)
    {
        using ccte_t = std::remove_cvref_t<decltype(*ccte)>;
        using pcm_t = std::remove_cvref_t<decltype(*pcm)>;
        using hardware_t = std::remove_cvref_t<decltype(*hardware)>;

        _updateFunc = [ccte, pcm, hardware, this](MccTelemetryData* data) {
            typename hardware_t::axes_pos_t hw_pos;
            auto hw_err = hardware->getPos(&hw_pos);

            if (!hw_err) {
                data->time_point =
                    std::chrono::time_point_cast<typename decltype(data->time_point)::duration>(hw_pos.time_point);

                auto ccte_err = ccte->timepointToJulday(data->time_point, &data->JD);
                if (!ccte_err) {
                    ccte_err = ccte->timepointToAppSideral(data->time_point, &data->LST, true);
                    if (!ccte_err) {
                        data->speedX = (double)hw_pos.speedX;
                        data->speedY = (double)hw_pos.speedY;

                        struct {
                            double dx, dy;
                        } pcm_res;

                        auto pcm_err = pcm->computePCM(data, &pcm_res);
                        if (pcm_err) {
                            if constexpr (std::same_as<decltype(pcm_err), error_t>) {
                                return pcm_err;
                            } else {
                                return MccTelemetryErrorCode::ERROR_PCM_COMP;
                            }
                        }

                        MccCelestialPoint pt{.pair_kind = MccCoordPairKind::COORDS_KIND_AZALT,
                                             .time_point = data->time_point};

                        if constexpr (mccIsEquatorialMount(pcm_t::mountType)) {
                            data->HA = (double)hw_pos.X + pcm_res.dx;
                            data->DEC_APP = (double)hw_pos.Y + pcm_res.dy;

                            data->X = data->HA;
                            data->Y = data->DEC_APP;

                            data->pair_kind = MccCoordPairKind::COORDS_KIND_HADEC_APP;

                            ccte_err = ccte->transformCoordinates(*data, &pt);
                            if (!ccte_err) {
                                data->AZ = pt.X;
                                data->ALT = pt.Y;
                                data->ZD = std::numbers::pi / 2.0 - data->ALT;
                            }
                        } else if constexpr (mccIsAltAzMount(pcm_t::mountType)) {
                            data->AZ = (double)hw_pos.X + pcm_res.dx;
                            data->ALT = (double)hw_pos.Y + pcm_res.dy;
                            data->ZD = std::numbers::pi / 2.0 - data->ALT;

                            data->X = data->AZ;
                            data->Y = data->ALT;

                            data->pair_kind = MccCoordPairKind::COORDS_KIND_AZALT;

                            pt.pair_kind = MccCoordPairKind::COORDS_KIND_HADEC_APP;
                            ccte_err = ccte->transformCoordinates(*data, &pt);
                            if (!ccte) {
                                data->HA = pt.X;
                                data->DEC_APP = pt.Y;
                            }

                        } else {
                            static_assert(false, "UNKNOWN MOUNT TYPE!");
                        }
                    }
                }
            }
        };
    }


    error_t telemetryData(mcc_telemetry_data_c auto* data)
    {
        error_t ret = MccTelemetryErrorCode::ERROR_OK;

        // first, update mount coordinates



        return ret;
    }


    error_t setPointingTarget(mcc_celestial_point_c auto pt) {}

protected:
    std::function<error_t(MccTelemetryData*)> _updateFunc;
};

}  // namespace mcc