namespace BlogEngine.Core.Json

{

    using System;

    using System.Collections.Generic;

    using System.Linq;



    /// <summary>

    /// Comment type.

    /// </summary>

    public enum CommentType

    {

        /// <summary>

        ///     Pending Comment Type

        /// </summary>

        Pending,



        /// <summary>

        ///     Approved Comment Type

        /// </summary>

        Approved,



        /// <summary>

        ///     Pingbacks and trackbacks Comment Type

        /// </summary>

        Pingback,



        /// <summary>

        ///     Spam Comment Type

        /// </summary>

        Spam

    }



    /// <summary>

    /// List of comments

    /// </summary>

    public static class JsonComments

    {

        /// <summary>

        /// The current page.

        /// </summary>

        private static int currentPage = 1;    



        /// <summary>

        /// The comm cnt.

        /// </summary>

        private static int commCnt;



        /// <summary>

        /// List of comments based on type for a single page.

        /// </summary>

        /// <param name="commentType">

        /// The comment type.

        /// </param>

        /// <param name="page">

        /// The current page.

        /// </param>

        /// <returns>

        /// A list of JSON comments.

        /// </returns>

        public static List<JsonComment> GetComments(CommentType commentType, int page)

        {

            return GetComments(commentType, BlogSettings.Instance.CommentsPerPage, page);

        }



        /// <summary>

        /// List of comments based on type for a single page.

        /// </summary>

        /// <param name="commentType">

        /// The comment type.

        /// </param>

        /// <param name="pageSize">

        /// The number of comments per page.

        /// </param>

        /// <param name="page">

        /// The current page.

        /// </param>

        /// <returns>

        /// A list of JSON comments.

        /// </returns>

        public static List<JsonComment> GetComments(CommentType commentType, int pageSize, int page)

        {

            var cntTo = page * pageSize;

            var cntFrom = cntTo - pageSize;

            var cnt = 0;



            var allComments = new List<Comment>();

            var pageComments = new List<JsonComment>();



            foreach (var p in Post.Posts)

            {

                switch (commentType)

                {

                    case CommentType.Pending:

                        allComments.AddRange(p.NotApprovedComments);

                        break;

                    case CommentType.Pingback:

                        allComments.AddRange(p.Pingbacks);

                        break;

                    case CommentType.Spam:

                        allComments.AddRange(p.SpamComments);

                        break;

                    default:

                        allComments.AddRange(p.ApprovedComments);

                        break;

                }

            }



            allComments.Sort((x, y) => DateTime.Compare(y.DateCreated, x.DateCreated));



            // TODO: find a way to better handle deleting last comment on the last page

            // below is not working properly; after moving to the next page and deleting

            // another comment there, things get nasty

            if (allComments.Count > 0 && allComments.Count == cntFrom && page > 1)

            {

                // removed last comment(s) on the page

                // need to shift one page back



                //var context = System.Web.HttpContext.Current;

                //if (context.Request.Cookies["CommentPagerCurrentPage"] != null)

                //    context.Request.Cookies["CommentPagerCurrentPage"].Value = (page - 1).ToString();



                //return GetComments(commentType, page - 1);

            }



            foreach (var c in allComments)

            {

                cnt++;

                if (cnt <= cntFrom || cnt > cntTo)

                {

                    continue;

                }



                pageComments.Add(CreateJsonCommentFromComment(c));

            }



            currentPage = page;

            commCnt = cnt;



            return pageComments;

        }



        /// <summary>

        /// Single commnet by ID

        /// </summary>

        /// <param name="id">

        /// Comment id

        /// </param>

        /// <returns>

        /// A JSON Comment

        /// </returns>

        public static JsonComment GetComment(Guid id)

        {

            return (from p in Post.Posts

                    from c in p.AllComments

                    where c.Id == id

                    select CreateJsonCommentFromComment(c)).FirstOrDefault();

        }



        private static JsonComment CreateJsonCommentFromComment(Comment c)

        {

            var jc = new JsonComment

                {

                    Id = c.Id,

                    Email = c.Email,

                    Author = c.Author,

                    Title = c.Title,

                    Teaser = c.Teaser,

                    Website = c.Website == null ? "" : c.Website.ToString(),

                    AuthorAvatar = c.Avatar,

                    Content = c.Content,

                    Ip = c.IP,

                    Date = c.DateCreated.ToString("dd MMM yyyy"),

                    Time = c.DateCreated.ToString("t")

                };

            return jc;

        }



        /// <summary>

        /// Builds pager control for comments page

        /// </summary>

        /// <param name="page">

        /// Current page

        /// </param>

        /// <param name="srvs">

        /// The Srvs..

        /// </param>

        /// <returns>

        /// HTML with next and previous buttons

        /// </returns>

        public static string GetPager(int page)

        {

            if (commCnt == 0)

            {

                return string.Empty;

            }



            var prvLnk = string.Empty;

            var nxtLnk = string.Empty;

            var firstLnk = string.Empty;

            var lastLnk = string.Empty;



            const string linkFormat = "<a href=\"#\" id=\"{0}\" onclick=\"return LoadComments({1});\" class=\"{0}\"></a>";



            var PageSize = BlogSettings.Instance.CommentsPerPage;

            var pgs = Convert.ToDecimal(commCnt) / Convert.ToDecimal(PageSize);

            var p = pgs - (int)pgs;

            var lastPage = p > 0 ? (int)pgs + 1 : (int)pgs;



            var cntFrom = ((page * PageSize) - (PageSize - 1));

            var cntTo = (page * PageSize);

            

            // adjust for the last (or single) page

            if (commCnt < cntTo) cntTo = commCnt;



            // when last comment on the last page deleted

            // this will reset "from" counter

            if (cntFrom > cntTo) cntFrom = cntFrom - PageSize;



            if (commCnt > 0 && commCnt == cntFrom && page > 1)

            {

                // removed last comment(s) on the page

                // need to shift one page back

                //return GetPager(page - 1);

            }



            var currentScope = cntFrom + " - " + cntTo;



            var pageLink = string.Format("<span>Showing {0} of {1}</span>", currentScope, commCnt);



            if (currentPage > 1)

            {

                prvLnk = string.Format(linkFormat, "prevLink", currentPage - 1);

                firstLnk = string.Format(linkFormat, "firstLink", 1);

            }



            if (page < lastPage)

            {

                nxtLnk = string.Format(linkFormat, "nextLink", currentPage + 1);

                lastLnk = string.Format(linkFormat, "lastLink", lastPage);

            }



            return firstLnk + prvLnk + pageLink + nxtLnk + lastLnk;

        }

    }

}