Pagination Made Easy

public class Pagination<PaginatedType> : IEnumerable<Pagination<PaginatedType>.Page>
{
	private readonly IList<Page> pages = new List<Page>();
	private readonly Page currentPage;
	private readonly IEnumerable<PaginatedType> paginatedCollection;
	private readonly int maximumCount;

	public Pagination(IEnumerable<PaginatedType> paginatedCollection, int maxCount, Page currentPage)
	{
		this.maximumCount = maxCount;
		this.paginatedCollection = paginatedCollection;
		var pageSize = currentPage.PageSize();
		for (var i = 1; i < maxCount; i+=pageSize)
		{
			pages.Add(new Page {StartingAt = i, EndingAt = i+pageSize-1});
		}
		this.currentPage = currentPage;
	}

	public IEnumerable<PaginatedType> PaginatedCollection
	{
		get { return paginatedCollection; }
	}

	public int MaximumCount
	{
		get { return maximumCount; }
	}

	public Page CurrentPage
	{
		get { return currentPage; }
	}

	public bool IsTheCurrentPage(Page page)
	{
		return currentPage.Equals(page);
	}

	public IEnumerator<Page> GetEnumerator()
	{
		return pages.GetEnumerator();
	}

	IEnumerator IEnumerable.GetEnumerator()
	{
		return GetEnumerator();
	}

	public struct Page
	{
		public int StartingAt;
		public int EndingAt;

		public string Name()
		{
			return string.Format("{0}-{1}", StartingAt,EndingAt);
		}
		public int PageSize()
		{
			return EndingAt - StartingAt + 1;
		}
		public bool IsValid()
		{
			return StartingAt <= EndingAt &amp;&amp; StartingAt > 0;
		}
	}
}

public interface IWillFindYouTreasures
{
	Pagination<Treasure> FindTreasuresFor(Pagination<Treasure>.Page page);
	Pagination<Treasure>.Page FirstPage();
}

public class PaginatedTreasureFinder : IWillFindYouTreasures
{
	private readonly IPropertyStore propertyStore;
	public PaginatedTreasureFinder(IPropertyStore propertyStore)
	{
		this.propertyStore = propertyStore;
	}

	public Pagination<Treasure> FindTreasureFor(Pagination<Treasure>.Page page)
	{
		if (!page.IsValid())
		{
			return new Pagination<Treasure>(new Treasure[] {}, Treasure.Count, FirstPage());
		}

		var criteria = DetachedCriteria.For<Treasure>()			
			.SetFirstResult(page.StartingAt-1)
			.SetMaxResults(page.PageSize());

		var treasures = ActiveRecordMediator<Treasure>.FindAll(criteria);
		return new Pagination<Treasure>(treasures, Treasures.Count, page);
	}

	public Pagination<Treasure>.Page FirstPage()
	{
		var endingAt = propertyStore.Get(ApplicationProperty.FirstPageEndingAt).AsIntOr(1);
		return new Pagination<Treasure>.Page {StartingAt = 1, EndingAt = endingAt};
	}
}

public class TreasureController : Controller
{
	private readonly IWillFindYouTreasures treasureFinder;

	public TreasureController(IWillFindYouTreasures treasureFinder)
	{
		this.treasureFinder = treasureFinder;
	}

	[AcceptVerbs(HttpVerbs.Get)]
	public ActionResult Show(int id, int startingAt, int endingAt)
	{
		var page = new Pagination<Treasure>.Page {StartingAt = startingAt, EndingAt = endingAt};
		var treasures = treasureFinder.FindTreasureFor(page);
		ViewData["Pages"] = treasures;
		return View("Show");
	}
}