/// Copyright 2010 Sedo Technologies, LLC (http://sedotech.com/)
/// @author Sayed Ibrahim Hashimi
namespace InlineTasks.Common.ViewHelpers.HtmlView
{
    using System;
    using System.Web;
    using System.Web.Mvc;

    // This uses the files from http://mvcviewhelpers.codeplex.com/
    // based on http://weblogs.asp.net/gunnarpeipman/archive/2010/02/21/simple-pager-for-asp-net-mvc.aspx
    public class Pager : AbstractHtmlViewObject
    {
        public Pager(IViewRequestContext requestContext, string name,
            int currentPage, int currentPageSize, long totalRecords, string urlPrefix)
            : base(requestContext, name)
        {
            if (urlPrefix == null) { throw new ArgumentNullException("urlPrefix"); }

            if (currentPage <= 0)
            { currentPage = 1; }

            if (currentPageSize <= 0)
            {
                throw new ArgumentException("Must be greater than zero", "currentPageSize");
            }

            this.CurrentPage = currentPage;
            this.CurrentPageSize = currentPageSize;
            this.TotalRecords = totalRecords;
            this.UrlPrefix = urlPrefix;
        }

        protected virtual int CurrentPage
        { get; set; }

        protected virtual int CurrentPageSize
        { get; set; }

        protected virtual long TotalRecords
        { get; set; }

        protected virtual string UrlPrefix
        { get; set; }

        public override void StartView()
        {
            HttpResponseBase httpResponse = this.RequestContext.HttpResponse;
            FluentTagBuilder container =
                new FluentTagBuilder("span")
                .AddCssClass("pager");

            httpResponse.Write(container.ToString(TagRenderMode.StartTag));

            int pageCount = (int)Math.Ceiling((double)this.TotalRecords / (double)CurrentPageSize);

            if (CurrentPage > 1)
            {
                FluentTagBuilder startTag =
                    new FluentTagBuilder("a")
                    .AddAttribute("href", string.Format("{0}/{1}", this.UrlPrefix, 1))
                    .SetInnerText("<<")
                    .AddAttribute("title", "first page");

                httpResponse.Write(startTag.ToString(TagRenderMode.Normal));

                FluentTagBuilder previous =
                    new FluentTagBuilder("a")
                    .AddAttribute("href", string.Format("{0}/{1}", this.UrlPrefix, this.CurrentPage - 1))
                    .SetInnerText("<")
                    .AddAttribute("title", "previous page");

                httpResponse.Write(previous.ToString(TagRenderMode.Normal));
            }
            int startPage = Math.Max(CurrentPage - 2, 1);
            int endPage = Math.Min(pageCount, CurrentPage + 2);

            for (int i = startPage; i < endPage; i++)
            {
                FluentTagBuilder link =
                    new FluentTagBuilder("a")
                    .AddAttribute("href", string.Format("{0}/{1}", this.UrlPrefix, i + 1))
                    .SetInnerText((i + 1).ToString());
                if (i == CurrentPage)
                {
                    link.AddCssClass("pagerCurrent");
                }
                httpResponse.Write(link.ToString(TagRenderMode.Normal));
            }

            if (CurrentPage < pageCount)
            {
                FluentTagBuilder nextTag =
                    new FluentTagBuilder("a")
                    .AddAttribute("href", string.Format("{0}/{1}", this.UrlPrefix, this.CurrentPage + 1))
                    .SetInnerText(">")
                    .AddAttribute("title", "next page");

                httpResponse.Write(nextTag.ToString(TagRenderMode.Normal));

                FluentTagBuilder lastTag =
                    new FluentTagBuilder("a")
                    .AddAttribute("href", string.Format("{0}/{1}", this.UrlPrefix, pageCount))
                    .AddAttribute("title", "last page")
                    .SetInnerText(">>");

                httpResponse.Write(lastTag.ToString(TagRenderMode.Normal));
            }

            httpResponse.Write(container.ToString(TagRenderMode.EndTag));
        }

        public override void EndView()
        {
            // nothing to do here
        }
    }
}