/// @file
/// @brief Task3: tests

#include "task3.hpp"

#include "iue-io/csv.hpp"

#include <cassert>    // assert
#include <cmath>      // std::sin
#include <filesystem> // std::filesystem::remove
#include <iostream>   // std::cout|endl
#include <numbers>    // std::numbers::pi

int main() {

  {
    auto f = [](double x) { return cos(x); };
    auto df = [](double x) { return -sin(x); };
    auto F = [](double x) { return sin(x) - (sin(0)); };
    std::filesystem::path filename = "test.task3.cos.csv";

    std::filesystem::remove(filename);
    sample_to_csv(filename, ';', '#', f, 0, 2 * std::numbers::pi, 18);
    auto table = iue::io::loadtxt(filename, ';', '#');

    assert(table.size() == 18);

    for (unsigned int r = 0; r != table.size(); ++r) {
      assert(table[r].size() == 4);
      assert(std::abs(f(table[r][0]) - table[r][1]) < 0.2);
      assert(std::abs(F(table[r][0]) - table[r][2]) < 0.2);
      assert(std::abs(df(table[r][0]) - table[r][3]) < 0.2);
    }
  }

  {
    auto f = [](double x) { return sin(x); };
    auto df = [](double x) { return cos(x); };
    auto F = [](double x) { return -cos(x) - (-cos(0)); };
    std::filesystem::path filename = "test.task3.sin.csv";

    std::filesystem::remove(filename);
    sample_to_csv(filename, ';', '#', f, 0, 2 * std::numbers::pi, 360);
    auto table = iue::io::loadtxt(filename, ';', '#');

    assert(table.size() == 360);

    for (unsigned int r = 0; r != table.size(); ++r) {
      assert(table[r].size() == 4);
      assert(std::abs(f(table[r][0]) - table[r][1]) < 0.01);
      assert(std::abs(F(table[r][0]) - table[r][2]) < 0.01);
      assert(std::abs(df(table[r][0]) - table[r][3]) < 0.01);
    }
  }

  std::cout << "task3.test.cpp: all asserts passed" << std::endl;

  return 0;
}