#include "slider.hpp"
#include <cmath>

namespace options {

slider_value::slider_value(double cur, double min, double max) :
    cur_(cur),
    min_(min),
    max_(max)
{
    if (min_ > max_)
        min_ = max_;
    if (cur_ > max_)
        cur_ = max;
    if (cur_ < min_)
        cur_ = min_;
}

slider_value::slider_value(const slider_value& v) : slider_value(v.cur(), v.min(), v.max())
{
}

slider_value::slider_value() : slider_value(0, 0, 0)
{
}

slider_value& slider_value::operator=(const slider_value& v)
{
    cur_ = v.cur_;

    min_ = v.min_;
    max_ = v.max_;

    return *this;
}

bool slider_value::operator==(const slider_value& v) const
{
    using std::fabs;

    static constexpr double eps = 1e-3;

    return (fabs(v.cur_ - cur_) < eps &&
            fabs(v.min_ - min_) < eps &&
            fabs(v.max_ - max_) < eps);
}

slider_value slider_value::update_from_slider(int pos, int q_min, int q_max) const
{
    slider_value v(*this);

    const int q_diff = q_max - q_min;
    const double sv_pos = q_diff == 0
                          ? -1e6
                          : (((pos - q_min) * (v.max() - v.min())) / q_diff + v.min());

    if (sv_pos < v.min())
        v = slider_value(v.min(), v.min(), v.max());
    else if (sv_pos > v.max())
        v = slider_value(v.max(), v.min(), v.max());
    else
        v = slider_value(sv_pos, v.min(), v.max());
    return v;
}

int slider_value::to_slider_pos(int q_min, int q_max) const
{
    const int q_diff = q_max - q_min;

    return int(std::round(((cur() - min() * q_diff) / (max() - min())) + q_min));
}

} // end ns options