#include <format>
#include <fstream>
#include <print>
#include <ranges>

#include <cxxopts.hpp>

#include <mcc/mcc_coordinate.h>
#include <mcc/mcc_pcm_fit.h>

#include "asibfm700_configfile.h"

// static constexpr mcc::MccMountType MOUNT_TYPE{mcc::MccMountType::CROSSAXIS_TYPE};

int main(int argc, char* argv[])
{
    /*  COMMANDLINE OPTS  */
    cxxopts::Options options(argv[0], "Astrosib (c) FM700 mount PCM fitter\n");

    options.allow_unrecognised_options();

    options.add_options()("h,help", "Print usage");

    options.add_options()("v,verbose", "Verbose output");

    options.add_options()("input_file", "Input encoder-celestial coordinate pairs file",
                          cxxopts::value<std::vector<std::string>>()->default_value(""));

    options.add_options()("niter", "Max number of iterations for robust linear regression method",
                          cxxopts::value<size_t>()->default_value("100"));

    // options.positional_help("[input_encoder-celestial_pair_filename]");
    options.positional_help("mount-server-config-filename input-pcm-data-filename results-filename");
    options.parse_positional({"input_file"});

    mcc::impl::MccPCMFitter<asibfm700::asibfm700MountType> pcm_fitter;
    mcc::impl::MccPCMFitter<asibfm700::asibfm700MountType>::compute_params_t comp_pars;

    asibfm700::Asibfm700MountConfig mount_cfg;

    try {
        auto opt_result = options.parse(argc, argv);

        auto pos_args = opt_result["input_file"].as<std::vector<std::string>>();

        if (opt_result["help"].count() || argc == 1 || (pos_args.size() < 3)) {
            std::println("{}", options.help());

            std::println(
                "\tmount-server-config-filename - filename of the ASIB FM-700 mount server configuration\n"
                "\tinput-pcm-data-filename - filename of the input encoder-celestial coordinate pairs data\n"
                "\tresults-filename - filename of the fitting results\n");

            // std::println(
            //     "[input_encoder-celestial_pair_filename] - Input encoder-celestial coordinate pairs filename. "
            //     "It must be in the format: ENCODER_HA ENCODER_DEC ENCODER_EPOCH RA_ICRS DEC_ICRS TEMP(C)
            //     PRESSURE(hPa) " "HUMIDITY([0-1])", options.help());

            return 0;
        }

        std::string cfg_fname = pos_args[0];
        std::string pcm_data_fname = pos_args[1];
        std::string result_fname = pos_args[2];

        bool verbose = false;
        if (opt_result["verbose"].count()) {
            verbose = true;
        }

        auto l_err = mount_cfg.load(cfg_fname);
        if (l_err) {
            std::println("Cannot load mount config: {}", l_err.message());
            return 2;
        }

        asibfm700::Asibfm700PCM::pcm_data_t pcm_data = mount_cfg.pcmData();

        std::ifstream fst;

        fst.open(pcm_data_fname);
        if (!fst.is_open()) {
            std::println("Cannot open input file {}", pcm_data_fname);
            return 2;
        }

        size_t sz;
        double temp, press, humi;
        std::optional<double> num;
        std::string str;
        std::string fmt_head;

        std::string_view delim{"  "};

        std::string_view sv;
        std::array<std::string_view, 8> tokens;

        mcc::impl::MccCelestialCoordEpoch ep;
        mcc::impl::MccAngleX enc_ha;
        mcc::impl::MccAngleY enc_dec;
        mcc::impl::MccAngleRA_ICRS ra;
        mcc::impl::MccAngleDEC_ICRS dec;

        mcc::impl::MccSkyPoint sp;
        mcc::impl::MccError err;

        if (verbose) {
            std::format_to(std::back_inserter(fmt_head), "{:^12}{}{:^12}{}{:^11}{}{:^11}{}{:^12}{}{:^6}{}{:^7}{}{:^4}",
                           "ENC_HA", delim, "ENC_DEC", delim, "ENC_MJD", delim, "RA_ICRS", delim, "DEC_ICRS", delim,
                           "TEMP", delim, "PRESS", delim, "HUMI");

            str = std::string(fmt_head.size(), '*');
            std::println("{}", str);

            auto fmt = std::format("*{{:^{}}}*", fmt_head.size() - 2);
            std::println("{}", std::vformat(std::string_view(fmt.begin(), fmt.end()),
                                            std::make_format_args(" INPUT HARDWARE-CELESTIAL COORDINATE PAIRS ")));

            fmt = std::format("*{{:<{}}}*", fmt_head.size() - 2);
            auto fmt_sv = std::string_view(fmt.begin(), fmt.end());
            std::println("{}", std::vformat(fmt_sv, std::make_format_args("")));
            auto s = std::format("{} {}", "  SITE LAT:", mount_cfg.siteLatitude().sexagesimal());
            std::println("{}", std::vformat(fmt_sv, std::make_format_args(s)));
            s = std::format("{} {}", "  SITE LON:", mount_cfg.siteLongitude().sexagesimal());
            std::println("{}", std::vformat(fmt_sv, std::make_format_args(s)));
            s = std::format("{} {} meters", "  SITE ELEV:", mount_cfg.siteElevation());
            std::println("{}", std::vformat(fmt_sv, std::make_format_args(s)));

            s = std::format("{} {} ", "  PCM TYPE:", mcc::impl::mccDefaultPCMTypeString(pcm_data.type));
            std::println("{}", std::vformat(fmt_sv, std::make_format_args(s)));

            std::println("{}", str);
            std::println("{}", fmt_head);
            std::println("{}", std::string(fmt_head.size(), '-'));
        }

        while (std::getline(fst, str)) {
            // while (!fst.eof()) {
            //     std::getline(fst, str);

            sv = mcc::utils::trimSpaces(str);
            if (!sv.size()) {  // an empty string
                continue;
            }
            if (sv[0] == '#') {  // comment
                continue;
            }

            auto toks = std::views::split(sv, std::string_view(" ")) |
                        std::views::filter([](auto const& r) { return std::ranges::size(r); });

            sz = std::ranges::distance(toks.begin(), toks.end());
            if (sz < 8) {
                std::println("Invalid input file format! Number of tokens must be at least 8: {}", str);
                return 3;
            }

            size_t i = 0;
            for (auto const& t : toks) {
                tokens[i++] = {t.begin(), t.end()};
            }

            // degrees or sexagesimal hours representations
            enc_ha = {tokens[0], mcc::impl::mcc_hms};

            // degrees or sexagesimal degrees representations
            enc_dec = {tokens[1]};

            if (!ep.fromCharRange(tokens[2])) {
                std::println("Invalid input file format! Invalid encoder coordinates epoch representation: {}",
                             tokens[2]);
                return 4;
            }

            // degrees or sexagesimal hours representations
            ra = {tokens[3], mcc::impl::mcc_hms};

            // degrees or sexagesimal degrees representations
            dec = {tokens[4]};

            num = mcc::utils::numFromStr<double>(tokens[5]);
            if (!num) {
                std::println("Invalid input file format! Non-numeric representation of temperature: {}", tokens[5]);
                return 5;
            }
            temp = num.value();

            num = mcc::utils::numFromStr<double>(tokens[6]);
            if (!num) {
                std::println("Invalid input file format! Non-numeric representation of pressure: {}", tokens[6]);
                return 6;
            }
            press = num.value();

            num = mcc::utils::numFromStr<double>(tokens[7]);
            if (!num) {
                std::println("Invalid input file format! Non-numeric representation of humidity: {}", tokens[7]);
                return 7;
            }
            humi = num.value();

            // update meteo parameters here
            mcc::impl::MccSkyPoint::cctEngine.updateMeteoERFA(
                {.temperature = temp, .humidity = humi, .pressure = press});

            sp.from(mcc::impl::MccSkyRADEC_ICRS{ra, dec});

            // astrometric transformations are here (and it needs meteo updated above!!!)
            err = pcm_fitter.addPoint(sp, mcc::impl::MccGenXY{enc_ha, enc_dec, ep});
            if (err) {
                std::println("An error occured: {}", err.message());
                return 8;
            }

            if (verbose) {
                std::println("{:>12}{}{:>12}{}{:>11.5f}{}{:>11}{}{:>12}{}{:>5.1f}{}{:>7.2f}{}{:>4.2f}",
                             enc_ha.sexagesimal(true), delim, enc_dec.sexagesimal(), delim, ep.MJD(), delim,
                             ra.sexagesimal(true), delim, dec.sexagesimal(), delim, temp, delim, press, delim, humi);
            }
        }

        fst.close();

        // fitting

        if (verbose) {
            std::println("\n");

            fmt_head.clear();
            std::format_to(std::back_inserter(fmt_head), "{:^12}{}{:^12}{}{:^12}{}{:^12}{}{:^14}{}{:^14}", "ENC_HA",
                           delim, "ENC_DEC", delim, "OBS_HA", delim, "OBS_DEC", delim, "dHA(OBS-ENC)", delim,
                           "dDEC(OBS-ENC)");

            str = std::string(fmt_head.size(), '*');
            std::println("{}", str);

            auto fmt = std::format("*{{:^{}}}*", fmt_head.size() - 2);
            std::println("{}", std::vformat(std::string_view(fmt.begin(), fmt.end()),
                                            std::make_format_args(" FITTED HARDWARE-CELESTIAL COORDINATE PAIRS ")));

            std::println("{}", str);

            std::println("{}", fmt_head);
            std::println("{}", std::string(fmt_head.size(), '-'));


            fmt = std::format("*{{:<{}}}*", fmt_head.size() - 2);

            auto tab = pcm_fitter.getPCMTable();

            for (auto const& el : tab) {
                std::println("{:>12}{}{:>12}{}{:>12}{}{:>12}{}{:>14}{}{:>14}", el.hw.x().sexagesimal(true), delim,
                             el.hw.y().sexagesimal(), delim, el.target.x().sexagesimal(true), delim,
                             el.target.y().sexagesimal(), delim, mcc::impl::MccAngleFancyString(el.res.x()), delim,
                             mcc::impl::MccAngleFancyString(el.res.y()));
            }
        }

        return 0;

        if (pcm_data.type == mcc::impl::MccDefaultPCMType::PCM_TYPE_GEOMETRY ||
            pcm_data.type == mcc::impl::MccDefaultPCMType::PCM_TYPE_GEOMETRY_BSPLINE) {
            if (opt_result["niter"].count()) {
                comp_pars.max_iter = opt_result["niter"].as<size_t>() ? opt_result["niter"].as<size_t>() : 100;
            }
        }

        auto comp_result = pcm_fitter.computeModel(pcm_data, comp_pars);

        if (comp_result.error) {
            std::println("An error occured while fit PCM data: {}", comp_result.error.message());
            return 200;
        }


    } catch (cxxopts::exceptions::parsing& ex) {
        std::println("An error occured while parsing input options: {}", ex.what());

        return 1;
    } catch (std::exception& ex) {
        std::println("An exception occured: {}", ex.what());

        return 10;

    } catch (...) {
        std::println("An unhandled exception occured!");

        return 100;
    }

    return 0;
}