/*-----------------------------------------------------------------------
    * SKiES - Solver of Kinetic Equation for Solids
    * 
    * (C) 2025 Galtsov Ilya, Fokin Vladimir, Minakov Dmitry, Levashov Pavel (JIHT RAS)
    *
    * SKiES may only be utilized for non-profit research.
    * Citing appropriate sources is required when using SKiES.
    * 
    * Distribution of this file is permitted by the GNU General Public License.
    * Examine the `LICENSE' file located in the current distribution's root directory.
------------------------------------------------------------------------- */
#include <cmath>
#include <cassert>
#include <regex>

#include <skies/common/alg.h>

#include <iostream>

namespace skies {

std::vector<std::string>
custom_split_regex(const std::string& str, const std::string& separator)
{
    std::vector<std::string> strings;
    std::regex rgx(separator);
    std::sregex_token_iterator iter(str.begin(), str.end(), rgx, -1);
    std::sregex_token_iterator end;
    if (*iter == "") ++iter;
    for (; iter != end; ++iter)
        strings.push_back(*iter);
    return strings;
}

std::vector<std::string>
custom_split(const std::string& str, const char separator)
{
    // if white space, any number is assumed
    if (separator == ' ')
        return custom_split_regex(str, "\\s+");
    return custom_split_regex(str, std::string(1, separator));
}

std::vector<std::string>
custom_split(const std::string& str, const std::string& separator)
{
    if (separator.empty())
        throw std::runtime_error("A null-separator given!\n");
    if (separator.find(" ") != std::string::npos)
        throw std::runtime_error("A separator must not contain white spaces!\n");
    return custom_split_regex(str, separator);
}

double find_root_bisect(std::function<double(double)> f, double a, double b, double crit)
{
    int Nit{ 0 };
    while ((b - a) / std::pow(2, Nit) > crit)
    {
        assert((f(a) <= 0) && (f(b) >= 0));
        Nit++;
        f((a + b) / 2) > 0 ? b = (a + b) / 2 : a = (a + b) / 2;
    }
    return (a + b) / 2;
}

} // skies