Mini Kabibi Habibi

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DevExpress.Web.ASPxEditors;
using DevExpress.Web.ASPxClasses;

public partial class VideoView : System.Web.UI.UserControl {
    const string
        UserCommentsSessionKey = "398f9710-5213-4d77-b3eb-d2a022486bd2",
        InvalidNameErrorText = "Name must be non-empty and its length must not exceed 40 characters.",
        InvalidCommentErrorText = "Comment must be non-empty and its length must not exceed 5000 characters.";
    const int
        MaxUserNameLength = 40,
        MaxCommentLength = 5000;

    public string VideoTitle { get; set; }

    protected List<Comment> UserComments {
        get {
            if(Session[UserCommentsSessionKey] == null)
                Session[UserCommentsSessionKey] = new List<Comment>();
            return Session[UserCommentsSessionKey] as List<Comment>;
        }
    }

    protected void InitializeTagList(Video video) {
        rpTags.DataSource = video.TagVideoRelations
            .Select(r => new {
                Name = r.Tag.Name,
                UrlName = Server.UrlEncode(r.Tag.Name)
            })
            .AsQueryable();

        rpTags.DataBind();
    }

    protected void InitializeComments(Video video) {
        var persistentComments = video.Comments.AsQueryable();

        var userComments = UserComments
            .Where(c => c.VideoID == video.ID)
            .AsQueryable();

        rpComments.DataSource = persistentComments
            .Union(userComments)
            .OrderBy(c => c.AddedAt)
            .Select(c => new {
                UserName = c.UserName,
                UserAvatarID = c.UserAvatarID,
                AddedAt = string.Format("{0:d}", c.AddedAt),
                Text = c.Text
            });

        rpComments.DataBind();
    }

    protected void InitializeRelatedVideos(Video video) {
        var videoTagNames = video.TagVideoRelations
            .Select(r => r.Tag.Name)
            .ToList();

        rpRelatedVideos.DataSource = new VideoPortalDataContext().Videos
            .Where(v => v.ID != video.ID)
            //Map
             .SelectMany(v => v.TagVideoRelations, (v, r) => new {
                 Video = v,
                 TagName = r.Tag.Name
             })
             .Where(vt => videoTagNames.Contains(vt.TagName))
            //Reduce
             .GroupBy(vt => vt.Video.ID, vt => vt.Video, (i, vc) => new {
                 Video = vc.First(),
                 Relevance = vc.Count()
             })
            .OrderByDescending(vr => vr.Relevance)
            .AsEnumerable()
            .Select(vr => new {
                ID = vr.Video.ID,
                Title = vr.Video.Title,
                Url = ResolveUrl("~/Watch/" + Server.UrlEncode(vr.Video.Title))
            });


        rpRelatedVideos.DataBind();
    }

    protected override void OnInit(EventArgs e) {
        base.OnInit(e);
    }

    protected void Page_Load(object sender, EventArgs e) {
        var video = new VideoPortalDataContext().Videos
            .Where(v => v.Title == VideoTitle)
            .First();

        InitializeTagList(video);
        InitializeComments(video);
        InitializeRelatedVideos(video);

        videoPlaceholder.InnerHtml = video.EmbeddedCode;
        videoTitleControl.InnerText = VideoTitle;
        product.InnerHtml = video.Product;
        published.InnerHtml = string.Format("{0:d}", video.CreationDate);
        description.InnerHtml = video.Description;
        if(!cpComments.IsCallback) {
            commentEditor.Html = string.Empty;
            tbName.Text = string.Empty;
        }
    }

    protected bool ValidateComment(string userName, string text) {
        var valid = true;
        if(string.IsNullOrEmpty(userName) || userName.Length > MaxUserNameLength) {
            errorText.InnerText = InvalidNameErrorText;
            valid = false;
        }
        if(string.IsNullOrEmpty(text) || text.Length > MaxCommentLength) {
            if(!valid)
                errorText.InnerText += "\n";
            errorText.InnerText += InvalidCommentErrorText;
            valid = false;
        }
        
        errorFrame.Visible = !valid;
        return valid;
    }

    protected void cpComments_Callback(object sender, CallbackEventArgsBase e) {
        var video = new VideoPortalDataContext().Videos
            .Where(v => v.Title == VideoTitle)
            .First();

        var userName = tbName.Text.Trim();
        var text = e.Parameter.Trim();

        if(!ValidateComment(userName, text))
            return;

        Comment comment = new Comment() {
            VideoID = video.ID,
            UserAvatarID = 0,
            UserName = Server.HtmlEncode(userName),
            Text = commentEditor.Html,
            AddedAt = DateTime.Now
        };

        UserComments.Add(comment);
        InitializeComments(video);
        commentEditor.Html = string.Empty;
        tbName.Text = string.Empty;
    }
}