C# Pager On IEnumerable

C# Pager On IEnumerable.cs

using System;
using System.Collections.Generic;
using System.Linq;

public static class Pager
{

    /// <summary>
    /// Pages the specified items.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="items">The items.</param>
    /// <param name="numberOfResults">The number of results.</param>
    /// <param name="page">The page.</param>
    /// <returns></returns>
    public static PagedObject<T> Paging<T>(this IEnumerable<T> items, int numberOfResults, int page = 1, int pageNumbersCount = 10)
    {
        page = Math.Max(1, page);
        int itemCount = items.Count();
        float pages = numberOfResults >= itemCount || numberOfResults == 0 ? 1 : ((float)itemCount / (float)numberOfResults);
        int _pages = Convert.ToInt32(Math.Ceiling(pages));

        var _return = numberOfResults >= itemCount ? items : page > _pages ? items.Reverse().Take(numberOfResults).Reverse() : items.Skip(((page - 1) * numberOfResults)).Take(numberOfResults);

        return CreatePagedObjects(page, pageNumbersCount, itemCount, _pages, _return);

    }

    private static PagedObject<T> CreatePagedObjects<T>(int page, int pageNumbersCount, int itemCount, int pages, IEnumerable<T> result)
    {
        int _page = page;
        int _pageNumbersCount = pageNumbersCount;
        int _itemCount = itemCount;
        int _pages = pages;
        var _result = result.ToList();
        var _pageNumbers = GetPages(_pages, _page, _pageNumbersCount);
        int _lastPageNumber = _pageNumbers?.LastOrDefault()?.Page ?? _pages;
        int _firstPageNumber = _pageNumbers?.FirstOrDefault()?.Page ?? 1;

        return new PagedObject<T>
        {
            PagedResults = _result,
            Pages = _pages,
            PageNumbers = _pageNumbers,
            Next = _page < _pages ? (1 + _page) : _pages,
            HasNext = _page < _pages,
            Previous = (_pages > 1 && _page > 1) ? (-1 + _page) : 1,
            HasPrevious = (_pages > 1 && _page > 1),
            Last = _pages,
            HasLast = _lastPageNumber < _pages,
            First = 1,
            HasFirst = _firstPageNumber > 1,
            Total = _itemCount
        };
    }

    private static List<PagedObjectPages> GetPages(int pages, int current, int pageNumbersCount)
    {
        var _pages = new List<PagedObjectPages>();
        if (pages > 1)
        {
            int firstHalfPageNumbersCount = pageNumbersCount / 2;
            int secondHalfPageNumbersCount = pageNumbersCount - firstHalfPageNumbersCount - 1;

            int _start = Math.Max(1, (current - firstHalfPageNumbersCount));
            int _last = Math.Min(pages, (current + secondHalfPageNumbersCount));

            _start = Math.Max(1, (_start - (secondHalfPageNumbersCount - (_last - current))));

            for (int i = _start; i <= pages && _pages.Count < pageNumbersCount; i++)
                _pages.Add(new PagedObjectPages { Page = i, IsCurrent = current == i ? true : false });
        }

        return _pages;
    }

    public class PagedObjectPages
    {
        public bool IsCurrent { get; set; }
        public int Page { get; set; }
    }

    public class PagedObject<T>
    {
        public bool HasNext { get; set; }
        public bool HasPrevious { get; set; }
        public int Next { get; set; }
        public IEnumerable<T> PagedResults { get; set; }
        public List<PagedObjectPages> PageNumbers { get; set; }
        public int Pages { get; set; }
        public int Previous { get; set; }
        public int Total { get; set; }
        public int Last { get; set; }
        public int First { get; set; }
        public bool HasFirst { get; set; }
        public bool HasLast { get; set; }
    }
}