feat: Migrate ruby llm captain (#12981)

Co-authored-by: aakashb95 <aakash@chatwoot.com>
Co-authored-by: Shivam Mishra <scm.mymail@gmail.com>

enterprise/app/services/llm/base_ai_service.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# Base service for LLM operations using RubyLLM.
+# New features should inherit from this class.
+class Llm::BaseAiService
+  DEFAULT_MODEL = Llm::Config::DEFAULT_MODEL
+  DEFAULT_TEMPERATURE = 1.0
+
+  attr_reader :model, :temperature
+
+  def initialize
+    Llm::Config.initialize!
+    setup_model
+    setup_temperature
+  end
+
+  # Returns a configured RubyLLM chat instance.
+  # Subclasses can override model/temperature via instance variables or pass them explicitly.
+  def chat(model: @model, temperature: @temperature)
+    RubyLLM.chat(model: model).with_temperature(temperature)
+  end
+
+  private
+
+  def setup_model
+    config_value = InstallationConfig.find_by(name: 'CAPTAIN_OPEN_AI_MODEL')&.value
+    @model = (config_value.presence || DEFAULT_MODEL)
+  end
+
+  def setup_temperature
+    @temperature = DEFAULT_TEMPERATURE
+  end
+end

enterprise/app/services/llm/legacy_base_open_ai_service.rb

@@ -1,5 +1,11 @@
-class Llm::BaseOpenAiService
-  DEFAULT_MODEL = 'gpt-4o-mini'.freeze
+# frozen_string_literal: true
+
+# DEPRECATED: This class uses the legacy OpenAI Ruby gem directly.
+# New features should use Llm::BaseAiService with RubyLLM instead.
+# This class will be removed once all services are migrated to RubyLLM.
+class Llm::LegacyBaseOpenAiService
+  DEFAULT_MODEL = 'gpt-4o-mini'
+
   attr_reader :client, :model
 
   def initialize