Support for Spam Filtering Using Akismet. #599.

source/DasBlog All.sln

@@ -28,6 +28,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DasBlog.Test.Integration",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DasBlog.CLI", "DasBlog.CLI\DasBlog.CLI.csproj", "{3DEF6C9E-293A-4E41-9CEC-3466E3EEC754}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Subtext.Akismet", "Subtext.Akismet\Subtext.Akismet.csproj", "{3937987F-789E-4AB9-BAC8-8773ADCC5ED9}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug - All|Any CPU = Debug - All|Any CPU

source/DasBlog.Services/ConfigFile/SiteConfig.cs

@@ -177,7 +177,19 @@ public SiteConfig() { }
         public string SpamBlockingServiceApiKey { get; set; }
 
 		[XmlIgnore]
-        public ISpamBlockingService SpamBlockingService { get; set; }
+        public ISpamBlockingService SpamBlockingService 
+        {
+            get
+            {
+                //TODO: this may eventually be configurable, if Akismet alternatives show up
+                if (! EnableSpamBlockingService|| SpamBlockingServiceApiKey.Length == 0)
+                {
+                    return null;
+                }
+                return new AkismetSpamBlockingService(this.SpamBlockingServiceApiKey, this.Root);
+            }
+            set {}
+        }
         public bool EnableSpamModeration { get; set; }
         public int EntriesPerPage { get; set; }
         public bool EnableDailyReportEmail { get; set; }

source/DasBlog.Services/DasBlog.Services.csproj

@@ -6,6 +6,7 @@
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\DasBlog.Web.Core\DasBlog.Core.csproj" />
+    <ProjectReference Include="..\Subtext.Akismet\Subtext.Akismet.csproj" />
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Kveer.XmlRPC" Version="1.2.0" />

source/DasBlog.Services/SpamBlocking/AkismetSpamBlockingService.cs

@@ -0,0 +1,77 @@
+using System;
+using newtelligence.DasBlog.Runtime;
+using Subtext.Akismet;
+using AkismetComment = Subtext.Akismet.Comment;
+
+namespace DasBlog.Services
+{
+	/// <summary>
+	/// Uses the Akismet service to determine if a comment is SPAM
+	/// </summary>
+	/// <remarks>http://akismet.com/</remarks>
+	public class AkismetSpamBlockingService : ISpamBlockingService
+	{
+		AkismetClient akismetClient;
+
+		public AkismetSpamBlockingService(string apiKey, string blogUrl)
+		{
+			akismetClient = new AkismetClient(apiKey, new Uri(blogUrl));	
+		}
+
+		public bool IsSpam(IFeedback feedback)
+		{
+			IComment akismetFormattedComment = ConvertToAkismetComment(feedback);
+			return akismetClient.CheckCommentForSpam(akismetFormattedComment);
+		}
+
+		public void ReportSpam(IFeedback feedback)
+		{
+			IComment akismetFormattedComment = ConvertToAkismetComment(feedback);
+			akismetClient.SubmitSpam(akismetFormattedComment);
+		}
+
+		public void ReportNotSpam(IFeedback feedback)
+		{
+			IComment akismetFormattedComment = ConvertToAkismetComment(feedback);
+			akismetClient.SubmitHam(akismetFormattedComment);
+		}
+
+		private AkismetComment ConvertToAkismetComment(IFeedback feedback)
+		{
+			System.Net.IPAddress ipAddress = System.Net.IPAddress.None;
+			if (feedback.AuthorIPAddress != null)
+			{
+				try 
+				{
+					ipAddress = System.Net.IPAddress.Parse(feedback.AuthorIPAddress);
+				}
+				catch(FormatException){}
+			}
+			AkismetComment comment = new AkismetComment(ipAddress, feedback.AuthorUserAgent);
+			comment.Author = feedback.Author;
+			comment.AuthorEmail = feedback.AuthorEmail;
+			if (feedback.AuthorHomepage != null && feedback.AuthorHomepage.Length > 0)
+			{
+				try 
+				{
+					comment.AuthorUrl = new Uri(feedback.AuthorHomepage);
+				}
+				catch(UriFormatException){}			
+			}
+			comment.Content = feedback.Content;
+			comment.Referer = feedback.Referer;
+			if (feedback.TargetEntryId != null & feedback.TargetEntryId.Trim().Length > 0)
+			{
+				try 
+				{
+					//TODO: comeback
+					//comment.Permalink = new Uri(SiteUtilities.GetPermaLinkUrl(feedback.TargetEntryId));
+				}
+				catch(UriFormatException){}
+			}
+			comment.CommentType = feedback.FeedbackType;
+			return comment;
+		}
+
+	}
+}

source/DasBlog.Web.UI/Controllers/BlogPostController.cs

@@ -19,6 +19,7 @@
 using System.Linq;
 using System.Net;
 using reCAPTCHA.AspNetCore;
+using DasBlog.Services.ConfigFile.Interfaces;
 
 namespace DasBlog.Web.Controllers
 {
@@ -434,18 +435,29 @@ public IActionResult AddComment(AddCommentViewModel addcomment)
                 }
             }
 
-			if (errors.Count > 0)
-			{
-				return CommentError(addcomment, errors);
-			}
-
 			var commt = mapper.Map<NBR.Comment>(addcomment);
 			commt.AuthorIPAddress = HttpContext.Connection.RemoteIpAddress.ToString();
 			commt.AuthorUserAgent = HttpContext.Request.Headers["User-Agent"].ToString();
 			commt.EntryId = Guid.NewGuid().ToString();
 			commt.IsPublic = !dasBlogSettings.SiteConfiguration.CommentsRequireApproval;
 			commt.CreatedUtc = commt.ModifiedUtc = DateTime.Now.ToUniversalTime();
-
+			if (dasBlogSettings.SiteConfiguration.EnableSpamBlockingService)
+			{
+				commt = CheckForSpam(commt, dasBlogSettings.SiteConfiguration);
+				// Spam Moderation is Disabled and the comment is spam. Let's show an error!
+				// TODO: Discuss what are the pros and cons of showing error vs just silently deleting the 
+				// comment.
+				if (!dasBlogSettings.SiteConfiguration.EnableSpamModeration && commt.SpamState == NBR.SpamState.Spam)
+				{
+					errors.Add("Spam Comment Detected. Please enter a legitimate comment that is not spam to post it.");
+				}
+			}
+
+			if (errors.Count > 0)
+			{
+				return CommentError(addcomment, errors);
+			}
+
 			logger.LogInformation(new EventDataItem(EventCodes.CommentAdded, null, "Comment CONTENT DUMP", commt.Content));
 
 			var state = blogManager.AddComment(addcomment.TargetEntryId, commt);
@@ -484,6 +496,28 @@ public IActionResult AddComment(AddCommentViewModel addcomment)
 			return Comment(addcomment.TargetEntryId);
 		}
 
+		private NBR.Comment CheckForSpam(NBR.Comment commt, ISiteConfig siteConfiguration)
+		{
+			try 
+			{
+				if (siteConfiguration.SpamBlockingService.IsSpam(commt))
+				{
+						commt.SpamState = NBR.SpamState.Spam;
+						commt.IsPublic = false;
+				}
+				else
+				{
+					commt.SpamState = NBR.SpamState.NotSpam;
+					commt.IsPublic = true;
+				}
+			}
+			catch (Exception ex)
+			{
+				logger.LogError(new EventDataItem(EventCodes.Error, null, String.Format("The external spam blocking service failed for comment {0}. Original exception: {1}", commt.EntryId, ex)));
+			}
+			return commt;
+		}
+
 		[HttpDelete("post/{postid:guid}/comments/{commentid:guid}")]
 		public IActionResult DeleteComment(Guid postid, Guid commentid)
 		{
@@ -586,7 +620,7 @@ private IActionResult HandleNewCategory(PostViewModel post)
 			var newCategory = post.NewCategory?.Trim();
 			var newCategoryDisplayName = newCategory;
 			var newCategoryUrl = NBR.Entry.InternalCompressTitle(newCategory);
-					// Category names should not include special characters #200
+			// Category names should not include special characters #200
 			if (post.AllCategories.Any(c => c.CategoryUrl == newCategoryUrl))
 			{
 				ModelState.AddModelError(nameof(post.NewCategory), $"The category, {post.NewCategory}, already exists");

source/DasBlog.Web.UI/Models/AdminViewModels/SiteViewModel.cs

@@ -355,9 +355,19 @@ public class SiteViewModel
 		public string CommentsGravatarRating { get; set; }
 		public bool CommentsAllowHtml { get; set; }
 		public bool EnableCoComment { get; set; }
+
+		[DisplayName("Enable Spam Blocking Service")]
+		[Description("Enable Akismet Spam Blocking Service.")]
 		public bool EnableSpamBlockingService { get; set; }
+
+		[DisplayName("Akismet API Key")]
+		[Description("API Key for Spam Blocking Service")]
 		public string SpamBlockingServiceApiKey { get; set; }
 		//public ISpamBlockingService SpamBlockingService { get; set; }
+
+
+		[DisplayName("Enable Spam Moderation")]
+		[Description("Allow Manual Moderation of Spam")]
 		public bool EnableSpamModeration { get; set; }
 		public bool EnableDailyReportEmail { get; set; }
 		public bool EnableGoogleMaps { get; set; }

source/DasBlog.Web.UI/Views/Admin/Settings.cshtml

@@ -304,6 +304,36 @@
 
     </div>
 
+
+    <div class="form-check row mb-3">
+        <div class="col-sm-10 offset-sm-2">
+            <div class="col-sm-2">
+                @Html.CheckBoxFor(m => @Model.SiteConfig.EnableSpamBlockingService, new { @class = "form-check-input form-check-input" })
+            </div>
+            @Html.LabelFor(m => @Model.SiteConfig.EnableSpamBlockingService, null, new { @class = "col-check-label col-sm-10" })
+        </div>
+    </div>
+
+    <div class="form-check row mb-3">
+        <div class="col-sm-10 offset-sm-2">
+            <div class="col-sm-2">
+                @Html.CheckBoxFor(m => @Model.SiteConfig.EnableSpamModeration, new { @class = "form-check-input form-check-input" })
+            </div>
+            @Html.LabelFor(m => @Model.SiteConfig.EnableSpamModeration, null, new { @class = "col-check-label col-sm-10" })
+        </div>
+    </div>
+
+    <div class="form-group row mb-3">
+
+        @Html.LabelFor(m => @Model.SiteConfig.SpamBlockingServiceApiKey, null, new { @class = "col-form-label col-sm-2" })
+        <div class="col-sm-10">
+            @Html.TextBoxFor(m => @Model.SiteConfig.SpamBlockingServiceApiKey, null, new { @class = "form-control sm-10" })
+        </div>
+        @Html.ValidationMessageFor(m => m.SiteConfig.SpamBlockingServiceApiKey, null, new { @class = "text-danger" })
+
+    </div>
+
+
     <div class="form-check row mb-3">
         <div class="col-sm-10 offset-sm-2">
             <div class="col-sm-2">
@@ -779,10 +809,6 @@
     @Html.HiddenFor(@m => m.SiteConfig.CommentsGravatarRating)
     @Html.HiddenFor(@m => m.SiteConfig.EnableCoComment)
 
-    @Html.HiddenFor(@m => m.SiteConfig.EnableSpamBlockingService)
-    @Html.HiddenFor(@m => m.SiteConfig.SpamBlockingServiceApiKey)
-    @Html.HiddenFor(@m => m.SiteConfig.EnableSpamModeration)
-
     @Html.HiddenFor(@m => m.SiteConfig.EnableDailyReportEmail)
 
     @Html.HiddenFor(@m => m.SiteConfig.EnableGoogleMaps)