New: Option to use Telegram topics for notifications

(cherry picked from commit c8933d812490ba375c6f7e07cd4355921dc513ac)

src/NzbDrone.Core/Notifications/Telegram/TelegramProxy.cs

@@ -39,6 +39,7 @@ namespace NzbDrone.Core.Notifications.Telegram
                                         .AddFormParameter("parse_mode", "HTML")
                                         .AddFormParameter("text", text)
                                         .AddFormParameter("disable_notification", settings.SendSilently)
+                                        .AddFormParameter("message_thread_id", settings.TopicId)
                                         .Build();
 
             _httpClient.Post(request);
@@ -64,7 +65,16 @@ namespace NzbDrone.Core.Notifications.Telegram
                 else if (ex is Common.Http.HttpException restException && restException.Response.StatusCode == HttpStatusCode.BadRequest)
                 {
                     var error = Json.Deserialize<TelegramError>(restException.Response.Content);
-                    var property = error.Description.ContainsIgnoreCase("chat not found") ? "ChatId" : "BotToken";
+                    var property = "BotToken";
+
+                    if (error.Description.ContainsIgnoreCase("chat not found") || error.Description.ContainsIgnoreCase("group chat was upgraded to a supergroup chat"))
+                    {
+                        property = "ChatId";
+                    }
+                    else if (error.Description.ContainsIgnoreCase("message thread not found"))
+                    {
+                        property = "TopicId";
+                    }
 
                     return new ValidationFailure(property, error.Description);
                 }

src/NzbDrone.Core/Notifications/Telegram/TelegramSettings.cs

@@ -11,6 +11,8 @@ namespace NzbDrone.Core.Notifications.Telegram
         {
             RuleFor(c => c.BotToken).NotEmpty();
             RuleFor(c => c.ChatId).NotEmpty();
+            RuleFor(c => c.TopicId).Must(topicId => !topicId.HasValue || topicId > 1)
+                                   .WithMessage("Topic ID must be greater than 1 or empty");
         }
     }
 
@@ -24,7 +26,10 @@ namespace NzbDrone.Core.Notifications.Telegram
         [FieldDefinition(1, Label = "Chat ID", HelpLink = "http://stackoverflow.com/a/37396871/882971", HelpText = "You must start a conversation with the bot or add it to your group to receive messages")]
         public string ChatId { get; set; }
 
-        [FieldDefinition(2, Label = "Send Silently", Type = FieldType.Checkbox, HelpText = "Sends the message silently. Users will receive a notification with no sound")]
+        [FieldDefinition(2, Label = "Topic ID", HelpLink = "https://stackoverflow.com/a/75178418", HelpText = "Specify a Topic ID to send notifications to that topic. Leave blank to use the general topic (Supergroups only)")]
+        public int? TopicId { get; set; }
+
+        [FieldDefinition(3, Label = "Send Silently", Type = FieldType.Checkbox, HelpText = "Sends the message silently. Users will receive a notification with no sound")]
         public bool SendSilently { get; set; }
 
         public NzbDroneValidationResult Validate()