UTM for links on posts

modules/RichSiteSummary/Data/Post.cs

@@ -6,6 +6,8 @@
 using System;
 using System.ComponentModel.DataAnnotations;
 using System.Text;
+using System.Web;
+using Kruzya.TelegramBot.RichSiteSummary.UrchinTrackingModule;
 using Telegram.Bot.Types.Enums;
 
 namespace Kruzya.TelegramBot.RichSiteSummary.Data
@@ -28,8 +30,15 @@ namespace Kruzya.TelegramBot.RichSiteSummary.Data
 
         protected override string ViewableUrl
         {
-            get => Url;
+            get => UtmUtility.ApplyParameters(Url, new UtmParameters()
+            {
+                Source = "telegram",
+                Type = "rss_post",
+                Campaign = "subscriber",
+                Content = PostId.ToString()
+            });
         }
+
         #endregion
 
         /// <summary>

modules/RichSiteSummary/Handler/FeedList.cs

@@ -92,7 +92,7 @@ namespace Kruzya.TelegramBot.RichSiteSummary.Handler
             }
         }
 
-        [Command("feed_subscriptions")]
+        [Command("rss_subscriptions")]
         public async Task Subscriptions()
         {
             if (!(await GenerateMenu(":sub")))

modules/RichSiteSummary/UrchinTrackingModule/UtmParameters.cs

@@ -0,0 +1,11 @@
+namespace Kruzya.TelegramBot.RichSiteSummary.UrchinTrackingModule
+{
+    public struct UtmParameters
+    {
+        public string Source;
+        public string Type;
+        public string Campaign;
+        public string Term;
+        public string Content;
+    }
+}

modules/RichSiteSummary/UrchinTrackingModule/UtmUtility.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.Web;
+using Microsoft.EntityFrameworkCore.Internal;
+
+namespace Kruzya.TelegramBot.RichSiteSummary.UrchinTrackingModule
+{
+    public class UtmUtility
+    {
+        public static string ApplyParameters(string url, UtmParameters parameters)
+        {
+            var uri = new Uri(url);
+            var query = HttpUtility.ParseQueryString(uri.Query);
+            
+            SetIfNotNull(query, "utm_source", parameters.Source);
+            SetIfNotNull(query, "utm_medium", parameters.Type);
+            SetIfNotNull(query, "utm_campaign", parameters.Campaign);
+            SetIfNotNull(query, "utm_term", parameters.Term);
+            SetIfNotNull(query, "utm_content", parameters.Content);
+            
+            var uriBuilder = new UriBuilder(uri);
+            uriBuilder.Query = BuildQueryString(query);
+            return uriBuilder.ToString();
+        }
+
+        protected static string BuildQueryString(NameValueCollection query)
+        {
+            var queryParameters = new List<string>();
+
+            foreach (var keyName in query.AllKeys)
+            {
+                var value = query[keyName];
+                queryParameters.Add($"{HttpUtility.UrlEncode(keyName)}={HttpUtility.UrlEncode(value)}");
+            }
+
+            return String.Join('&', queryParameters);
+        }
+        
+        protected static void SetIfNotNull(NameValueCollection queryParameteters, string key, string value)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                return;
+            }
+            
+            queryParameteters.Set(key, value);
+        }
+    }
+}