#include <algorithm>
#include <functional>
#include <iostream>
#include <random>
#include <ranges>

// #include <fitpack.h>
#include "../fitpack/fitpack.h"

int main()
{
    size_t nt = 30, np = 60, N = nt * np, i = 1;
    // size_t nt = 10, np = 20, N = nt * np, i = 1;
    double ts = std::numbers::pi / (nt + 1);
    double ps = 2.0 * std::numbers::pi / (np + 1);

    std::vector<double> tetha(N), phi(N), func(N);

    auto gen_func = [](double st, size_t& idx) {
        double v = st * idx;
        ++idx;

        return v;
    };

    auto print_func = [](const auto& r, std::string_view name) {
        std::cout << name << ": ";
        for (auto& el : r) {
            std::cout << el << " ";
        }
        std::cout << "\n";
    };


    // std::ranges::generate(tetha, std::bind(gen_func, ts, i));

    // i = 1;
    // std::ranges::generate(phi, std::bind(gen_func, ps, i));

    size_t k = 1;
    i = 0;
    for (size_t j = 0; j < nt; ++j) {
        std::ranges::fill_n(tetha.begin() + i * np, np, ts * (i + 1));
        std::ranges::generate(phi | std::views::drop(i * np) | std::views::take(np), std::bind(gen_func, ps, k));
        ++i;
        k = 1;
    }

    // std::uniform_real_distribution<double> distr{-0.1, 0.1};
    std::normal_distribution<double> distr{0.0, 1.0};
    std::random_device device;
    std::mt19937 engine{device()};

    std::ranges::generate(func, [ii = 0, &distr, &engine, &tetha, &phi]() mutable {
        double v = (5.0 + tetha[ii]) * 1.3 + (3.0 + phi[ii]) * 3.1 + distr(engine);
        ++ii;
        return v;
    });


    int ntk = 24, npk = 29, nf = (ntk + 4) * (npk + 4);
    // int ntk = 3, npk = 6, nf = (ntk + 4) * (npk + 4);
    std::vector<double> tk(ntk + 8), pk(npk + 8), coeffs(nf);
    ts = std::numbers::pi / (ntk + 1);
    ps = 2.0 * std::numbers::pi / (npk + 1);

    i = 1;
    std::ranges::generate(tk | std::views::drop(4) | std::views::take(ntk), std::bind(gen_func, ts, i));
    i = 1;
    std::ranges::generate(pk | std::views::drop(4) | std::views::take(npk), std::bind(gen_func, ps, i));


    double rs = 0.0;
    int ec = mcc::fitpack::fitpack_sphere_fit(tetha, phi, func, 1.0, tk, pk, coeffs, rs);

    std::cout << "FIT EC = " << ec << "\n";
    std::cout << "FIT RESI = " << rs << "\n";

    ntk += 8;
    npk += 8;
    std::ranges::fill(tk, -1);
    std::ranges::fill(pk, -1);
    ec = mcc::fitpack::fitpack_sphere_smooth(tetha, phi, func, 1.0, 1800.0, ntk, npk, tk, pk, coeffs, rs);

    std::cout << "FIT EC = " << ec << "\n";
    std::cout << "FIT RESI = " << rs << "\n";
    std::cout << "NKNOTS: " << ntk << ", " << npk << "\n";


    print_func(coeffs, "coeffs");

    // print_func(tetha, "tetha");
    // print_func(phi, "phi");
    print_func(tk, "tetha_knots");
    print_func(pk, "phi_knots");
    print_func(func, "func");

    std::cout << "\n\n";

    k = 1;
    ts = std::numbers::pi / (nt + 1);
    std::ranges::generate_n(tetha.begin(), nt, std::bind(gen_func, ts, k));

    std::vector<double> f_func;
    tetha.resize(nt);
    phi.resize(np);

    tk.resize(ntk);
    pk.resize(npk);

    print_func(tetha, "TETHA:");
    print_func(phi, "PHI:");

    ec = mcc::fitpack::fitpack_eval_spl2d(tk, pk, coeffs, tetha, phi, f_func);
    // ec = mcc::fitpack::fitpack_eval_spl2d(pk, tk, coeffs, phi, tetha, f_func);
    std::cout << "EVAL EC = " << ec << "\n";
    print_func(f_func, "func");

    std::cout << "\n\n";

    for (size_t l = 0; l < f_func.size(); ++l) {
        auto r = f_func[l] - func[l];
        std::cout << r << " ";
    }
    std::cout << "\n";

    return 0;
}