Allow telegram to send notifications to ‘broadcast channels’

lib/discourse_chat/provider/telegram/telegram_command_controller.rb

@@ -27,6 +27,23 @@ module DiscourseChat::Provider::TelegramProvider
 
         DiscourseChat::Provider::TelegramProvider.sendMessage(message)
 
+      elsif params.key?('channel_post') and params['channel_post']['text'].include? '/getchatid'
+        chat_id = params['channel_post']['chat']['id']
+
+        message_text = I18n.t(
+          "chat_integration.provider.telegram.unknown_chat",
+          site_title: CGI::escapeHTML(SiteSetting.title),
+          chat_id: chat_id,
+        )
+
+        message = {
+          chat_id: chat_id,
+          text: message_text,
+          parse_mode: "html",
+          disable_web_page_preview: true,
+        }
+
+        DiscourseChat::Provider::TelegramProvider.sendMessage(message)
       end
 
     	# Always give telegram a success message, otherwise we'll stop receiving webhooks

spec/lib/discourse_chat/provider/telegram/telegram_command_controller_spec.rb

@@ -101,6 +101,18 @@ describe 'Telegram Command Controller', type: :request do
           end
         end
       end
+
+      it "should respond only to a specific command in a broadcast channel" do
+        post '/chat-integration/telegram/command/shhh.json', channel_post: {chat: {id:123}, text: "something" }
+
+        expect(response.status).to eq(200)
+        expect(stub).to have_been_requested.times(0)
+
+        post '/chat-integration/telegram/command/shhh.json', channel_post: {chat: {id:123}, text: "/getchatid" }
+
+        expect(response.status).to eq(200)
+        expect(stub).to have_been_requested.times(1)
+      end
     end
   end
 end