Responder for categories

app/models/ai_persona.rb

@@ -46,6 +46,10 @@ class AiPersona < ActiveRecord::Base
       .map(&:class_instance)
   end
 
+  def self.persona_class_by_id(id)
+    AiPersona.all_personas.find { |persona| persona.id == id } if id
+  end
+
   def self.persona_users(user: nil)
     persona_users =
       persona_cache[:persona_users] ||= AiPersona
@@ -72,6 +76,24 @@ class AiPersona < ActiveRecord::Base
     end
   end
 
+  def self.topic_responder_for(category_id:)
+    return nil if !category_id
+
+    all_responders =
+      persona_cache[:topic_responders] ||= AiPersona
+        .where(role: "topic_responder")
+        .where(enabled: true)
+        .pluck(:id, :role_category_ids)
+
+    id, _ = all_responders.find { |id, role_category_ids| role_category_ids.include?(category_id) }
+
+    if id
+      { id: id }
+    else
+      nil
+    end
+  end
+
   def self.message_responder_for(group_id: nil)
     return nil if !group_id
 

lib/ai_bot/playground.rb

@@ -29,7 +29,10 @@ module DiscourseAi
               .map { |group_id| AiPersona.message_responder_for(group_id: group_id) }
               .find { |found| !found.nil? }
 
-          AiPersona.all_personas.find { |persona| persona.id == info[:id] } if info && info[:id]
+          AiPersona.persona_class_by_id(info[:id]) if info && info[:id]
+        elsif post.post_number == 1 && post.topic && post.topic.archetype == Archetype.default
+          info = AiPersona.topic_responder_for(category_id: post.topic.category_id)
+          AiPersona.persona_class_by_id(info[:id]) if info && info[:id]
         end
       end
 
@@ -239,7 +242,7 @@ module DiscourseAi
           reply_user = User.find_by(id: bot.persona.class.user_id) || reply_user
         end
 
-        stream_reply = post.topic.private_message? && !bot.persona.role.include?("responder")
+        stream_reply = post.topic.private_message? && !bot.persona.class.role.include?("responder")
 
         # we need to ensure persona user is allowed to reply to the pm
         if post.topic.private_message?

spec/lib/modules/ai_bot/playground_spec.rb

@@ -531,6 +531,62 @@ RSpec.describe DiscourseAi::AiBot::Playground do
     end
   end
 
+  describe "topic_responder role" do
+    fab!(:category)
+    fab!(:tag)
+
+    it "can reply with a whisper to topics in a category" do
+      Jobs.run_immediately!
+
+      persona =
+        AiPersona.create!(
+          name: "Responder Persona",
+          description: "A responder",
+          system_prompt: "You are a responder",
+          enabled: true,
+          role: "topic_responder",
+          role_category_ids: [category.id],
+          role_whispers: true,
+          default_llm: "anthropic:claude-2",
+        )
+
+      persona.create_user!
+
+      post = nil
+      prompts = nil
+      DiscourseAi::Completions::Llm.with_prepared_responses(
+        ["An amazing post just for you"],
+      ) do |_, _, _prompts|
+        post =
+          create_post(title: "an amazing title", raw: "Howdy I need help!!", category: category)
+        prompts = _prompts
+      end
+
+      expect(prompts.length).to eq(1)
+      expect(prompts[0].messages[0][:content]).to eq("You are a responder")
+      expect(prompts[0].messages[1][:content]).to eq("# An amazing title\n\nHowdy I need help!!")
+
+      reply = post.topic.posts.find_by(post_number: 2)
+
+      expect(reply.post_type).to eq(Post.types[:whisper])
+      expect(reply.raw).to eq("An amazing post just for you")
+
+      # should be done responding at this point so llm will not be called
+      create_post(
+        raw: "should ignore posts that are not first on message",
+        topic: post.topic,
+        user: post.user,
+      )
+
+      # should not respond to topics in other categories
+      create_post(
+        title: "testing title 2",
+        raw: "should ignore posts that are not first on message",
+        user: post.user,
+      )
+    end
+  end
+
   describe "message_responder role" do
     fab!(:group) do
       Fabricate(:group, name: "test-group", messageable_level: Group::ALIAS_LEVELS[:everyone])
@@ -554,7 +610,6 @@ RSpec.describe DiscourseAi::AiBot::Playground do
       persona.create_user!
 
       post = nil
-
       prompts = nil
       DiscourseAi::Completions::Llm.with_prepared_responses(
         ["An amazing post just for you"],