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

namespace System.Web.Mvc {
    public interface IPagedList {
        int ItemCount {
            get;
            set;
        }

        int PageCount {
            get;
            set;
        }

        int PageIndex {
            get;
            set;
        }

        int PageSize {
            get;
            set;
        }

        bool IsPreviousPage {
            get;
        }

        bool IsNextPage {
            get;
        }
    }

    public interface IPagedList<T> : IList<T>, IPagedList {
    }

    public class PagedList<T> : List<T>, IPagedList<T> {
        public PagedList(IQueryable<T> source, int index, int pageSize) {
            this.ItemCount = source.Count();
            this.PageSize = pageSize;
            this.PageIndex = index;
            this.AddRange(source.Skip(index * pageSize).Take(pageSize).ToList());
            this.PageCount = (int)Math.Ceiling((double)this.ItemCount / this.PageSize);
        }

        public PagedList(List<T> source, int index, int pageSize) {
            this.ItemCount = source.Count();
            this.PageSize = pageSize;
            this.PageIndex = index;
            this.AddRange(source.Skip(index * pageSize).Take(pageSize).ToList());
        }

        public int ItemCount {
            get;
            set;
        }

        public int PageCount {
            get;
            set;
        }

        public int PageIndex {
            get;
            set;
        }

        public int PageSize {
            get;
            set;
        }

        public bool IsPreviousPage {
            get {
                return (PageIndex > 0);
            }
        }

        public bool IsNextPage {
            get {
                return (PageIndex+1) * PageSize <= ItemCount;
            }
        }
    }

    public static class Pagination {
        public static PagedList<T> ToPagedList<T>(this IQueryable<T> source, int index, int pageSize) {
            return new PagedList<T>(source, index, pageSize);
        }

        public static PagedList<T> ToPagedList<T>(this IQueryable<T> source, int index) {
            return new PagedList<T>(source, index, 10);
        }
    }
}