/*     _______________   ,----------------------------------------------------------------.
      //`````````````\\  \                                                                 \
     //~~~~~~~~~~~~~~~\\  \   by @ohsqueezy           &  @sleepin                           \ 
    //=================\\  \     [ohsqueezy.itch.io]     [sleepin.itch.io]                   \ 
   //                   \\  \                                                                 \ 
  //                     \\  \  code released under the zlib license [git.nugget.fun/pudding]  \ 
 //      ☆ GUNKISS ☆      \\  \                                                                 \
//_________________________\\  `---------------------------------------------------------------*/

#ifndef CAROUSEL_H_
#define CAROUSEL_H_

#include <cstdint>
#include <iterator>
#include "utility.hpp"

class Carousel
{

private:

    std::uint32_t offset = 0;

public:

    template<typename Container>
    auto current(Container& container) const
    {
        auto location = container.begin();
        if (location != container.end())
        {
            std::advance(location, offset);
            return location;
        }
        else
        {
            throw std::out_of_range("Container is empty");
        }
    }

    template<typename Container>
    void next(const Container& container)
    {
        offset = ++offset % container.size();
    }

    template<typename Container>
    void previous(const Container& container)
    {
        offset = sb::mod(--offset, container.size());
    }

    template<typename Container>
    void increment(const Container& container, int amount)
    {
        offset = sb::mod(offset + amount, container.size());
    }

    void beginning()
    {
        offset = 0;
    }

    template<typename Container>
    void end(const Container& container)
    {
        offset = container.size() - 1;
    }

    /* Return true if the carousel currently points to the location at the beginning of the container. */
    bool at_beginning() const
    {
        return offset == 0;
    }

    /* Return true if the carousel currently points to the location at the end of the container. */
    template<typename Container>
    bool at_end(const Container& container)
    {
        return offset >= container.size() - 1;
    }

};

#endif