#pragma once

#if !defined(BAD_APPLE_OS_ALGORITHM_INCLUDED)
#define BAD_APPLE_OS_ALGORITHM_INCLUDED

#include <cstddef>
#include <iterator>
#include <utility>

namespace std
{
template<typename T>
constexpr const T& min(const T& left, const T& right)
{
    return right < left ? right : left;
}

template<typename T>
constexpr const T& max(const T& left, const T& right)
{
    return right > left ? right : left;
}

template<typename RandomIt, class Compare>
constexpr void sort(RandomIt first, RandomIt last, Compare comp)
{
    // TODO: be smarter
    const size_t size = last - first;
    size_t sorted = 1;
    while (sorted < size)
    {
        // find insertion pos
        size_t pos = 0;
        while (pos < sorted)
        {
            if (comp(*(first + sorted), *(first + pos)))
            {
                break;
            }
            ++pos;
        }
        // bail if already sorted
        if (pos == sorted)
        {
            ++sorted;
            continue;
        }
        // insert at pos
        for (size_t idx = pos; idx < sorted; ++idx)
        {
            swap(*(first + idx), *(first + sorted));
        }
        ++sorted;
    }
}

template<typename RandomIt>
constexpr void sort(RandomIt first, RandomIt last)
{
    sort(first, last, [](auto left, auto right) { return left < right; });
}

template<typename ForwardIt, typename UnaryPredicate>
constexpr ForwardIt find_if(ForwardIt first, ForwardIt last, UnaryPredicate pred)
{
    for (auto it = first; it != last; ++it)
    {
        if (pred(*it))
        {
            return it;
        }
    }
    return last;
}

template<typename ForwardIt, typename UnaryPredicate>
constexpr ForwardIt remove_if(ForwardIt first, ForwardIt last, UnaryPredicate pred)
{
    auto found = find_if(first, last, pred);
    if (found != last)
    {
        for (auto tomove = next(found); tomove != last; ++tomove)
        {
            if (!pred(*tomove))
            {
                *found = move(*tomove);
                ++found;
            }
        }
    }
    return found;
}
}

#endif // !defined(BAD_APPLE_OS_ALGORITHM_INCLUDED)