/BlogEngine/BlogEngine.NET/App_Code/Extensions/TypePadFilter.cs

namespace App_Code.Extensions

{

    using BlogEngine.Core;

    using BlogEngine.Core.Web.Controls;

    using BlogEngine.Core.Web.Extensions;



    using Joel.Net;

    using System.Collections.Generic;

    using System;



    /// <summary>

    /// The type pad filter.

    /// </summary>

    [Extension("TypePad anti-spam comment filter (based on AkismetFilter)", "1.0", 

        "<a href=\"http://lucsiferre.net\">By Chris Nicola</a>")]

    public class TypePadFilter : ICustomFilter

    {

        #region Constants and Fields



        /// <summary>

        /// The sync root.

        /// </summary>

        private static readonly object syncRoot = new object();



        /// <summary>

        /// The Akismet api.

        /// </summary>

        private static Dictionary<Guid, Akismet> blogsApi = new Dictionary<Guid, Akismet>();



        /// <summary>

        /// The fall through.

        /// </summary>

        private bool fallThrough = true;



        /// <summary>

        /// The TypePad key.

        /// </summary>

        private static Dictionary<Guid, string> blogsKey = new Dictionary<Guid, string>();



        /// <summary>

        /// The settings.

        /// </summary>

        private static Dictionary<Guid, ExtensionSettings> blogsSettings = new Dictionary<Guid, ExtensionSettings>();



        /// <summary>

        /// The TypePad site.

        /// </summary>

        private static Dictionary<Guid, string> blogsSite = new Dictionary<Guid, string>();



        #endregion



        #region Constructors and Destructors



        /// <summary>

        /// Initializes a new instance of the <see cref="TypePadFilter"/> class.

        /// </summary>

        public TypePadFilter()

        {

            InitSettings();

        }



        #endregion



        #region Properties



        private static Akismet Api

        {

            get

            {

                Akismet akismet = null;

                blogsApi.TryGetValue(Blog.CurrentInstance.Id, out akismet);



                return akismet;

            }

            set

            {

                blogsApi[Blog.CurrentInstance.Id] = value;

            }

        }



        private static string Key

        {

            get

            {

                string key = null;

                blogsKey.TryGetValue(Blog.CurrentInstance.Id, out key);



                return key;

            }

            set

            {

                blogsKey[Blog.CurrentInstance.Id] = value;

            }

        }



        private static string Site

        {

            get

            {

                string key = null;

                blogsSite.TryGetValue(Blog.CurrentInstance.Id, out key);



                return key;

            }

            set

            {

                blogsSite[Blog.CurrentInstance.Id] = value;

            }

        }



        private static ExtensionSettings Settings

        {

            get

            {

                Guid blogId = Blog.CurrentInstance.Id;

                ExtensionSettings settings = null;

                blogsSettings.TryGetValue(blogId, out settings);



                if (settings == null)

                {

                    lock (syncRoot)

                    {

                        blogsSettings.TryGetValue(blogId, out settings);



                        if (settings == null)

                        {

                            var extensionSettings = new ExtensionSettings("TypePadFilter") { IsScalar = true };



                            extensionSettings.AddParameter("SiteURL", "Site URL");

                            extensionSettings.AddParameter("ApiKey", "API Key");



                            extensionSettings.AddValue("SiteURL", "http://example.com/blog");

                            extensionSettings.AddValue("ApiKey", "123456789");



                            blogsSettings[blogId] = ExtensionManager.InitSettings("TypePadFilter", extensionSettings);

                            ExtensionManager.SetStatus("TypePadFilter", false);

                        }

                    }

                }



                return settings;

            }

        }



        /// <summary>

        /// Gets a value indicating whether FallThrough.

        /// </summary>

        public bool FallThrough

        {

            get

            {

                return fallThrough;

            }

        }



        #endregion



        #region Implemented Interfaces



        #region ICustomFilter



        /// <summary>

        /// Check if comment is spam

        /// </summary>

        /// <param name="comment">BlogEngine comment</param>

        /// <returns>True if comment is spam</returns>

        public bool Check(Comment comment)

        {

            if (Api == null)

            {

                this.Initialize();

            }



            var typePadComment = GetAkismetComment(comment);

            var isspam = Api.CommentCheck(typePadComment);

            fallThrough = !isspam;

            return isspam;

        }



        /// <summary>

        /// Initializes anti-spam service

        /// </summary>

        /// <returns>

        /// True if service online and credentials validated

        /// </returns>

        public bool Initialize()

        {

            if (!ExtensionManager.ExtensionEnabled("TypePadFilter"))

            {

                return false;

            }



            Site = Settings.GetSingleValue("SiteURL");

            Key = Settings.GetSingleValue("ApiKey");

            Api = new Akismet(Key, Site, "BlogEngine.NET 1.5", "api.antispam.typepad.com");



            return Api.VerifyKey();

        }



        /// <summary>

        /// Report mistakes back to service

        /// </summary>

        /// <param name="comment">BlogEngine comment</param>

        public void Report(Comment comment)

        {

            if (Api == null)

            {

                this.Initialize();

            }



            var akismetComment = GetAkismetComment(comment);



            if (comment.IsApproved)

            {

                Utils.Log(string.Format("TypePad: Reporting NOT spam from \"{0}\" at \"{1}\"", comment.Author, comment.IP));

                Api.SubmitHam(akismetComment);

            }

            else

            {

                Utils.Log(string.Format("TypePad: Reporting SPAM from \"{0}\" at \"{1}\"", comment.Author, comment.IP));

                Api.SubmitSpam(akismetComment);

            }

        }



        #endregion



        #endregion



        #region Methods



        /// <summary>

        /// Gets the akismet comment.

        /// </summary>

        /// <param name="comment">The comment.</param>

        /// <returns>An Akismet Comment.</returns>

        private static AkismetComment GetAkismetComment(Comment comment)

        {

            var akismetComment = new AkismetComment

                {

                    Blog = Settings.GetSingleValue("SiteURL"),

                    UserIp = comment.IP,

                    CommentContent = comment.Content,

                    CommentAuthor = comment.Author,

                    CommentAuthorEmail = comment.Email

                };

            if (comment.Website != null)

            {

                akismetComment.CommentAuthorUrl = comment.Website.OriginalString;

            }



            return akismetComment;

        }



        public void InitSettings()

        {

            // call Settings getter so default settings are loaded on application start.

            var s = Settings;

        }



        #endregion

    }

}