feat: Introduce the concept of tool registry within Captain (#11516)

This PR introduces the concept of a tool registry. The implementation is
straightforward: you can define a tool by creating a class with a
function name. The function name gets registered in the registry and can
be referenced during LLM calls. When the LLM invokes a tool using the
registered name, the registry locates and executes the appropriate tool.
If the LLM calls an unregistered tool, the registry returns an error
indicating that the tool is not defined.

enterprise/app/helpers/captain/chat_helper.rb

@@ -1,24 +1,4 @@
 module Captain::ChatHelper
-  def search_documentation_tool
-    {
-      type: 'function',
-      function: {
-        name: 'search_documentation',
-        description: "Use this function to get documentation on functionalities you don't know about.",
-        parameters: {
-          type: 'object',
-          properties: {
-            search_query: {
-              type: 'string',
-              description: 'The search query to look up in the documentation.'
-            }
-          },
-          required: ['search_query']
-        }
-      }
-    }
-  end
-
   def request_chat_completion
     Rails.logger.debug { "[CAPTAIN][ChatCompletion] #{@messages}" }
 
@@ -26,13 +6,12 @@ module Captain::ChatHelper
       parameters: {
         model: @model,
         messages: @messages,
-        tools: [search_documentation_tool],
+        tools: @tool_registry&.registered_tools || [],
         response_format: { type: 'json_object' }
       }
     )
 
     handle_response(response)
-    @response
   end
 
   def handle_response(response)
@@ -41,7 +20,7 @@ module Captain::ChatHelper
     if message['tool_calls']
       process_tool_calls(message['tool_calls'])
     else
-      @response = JSON.parse(message['content'].strip)
+      JSON.parse(message['content'].strip)
     end
   end
 
@@ -54,38 +33,20 @@ module Captain::ChatHelper
   end
 
   def process_tool_call(tool_call)
+    arguments = JSON.parse(tool_call['function']['arguments'])
+    function_name = tool_call['function']['name']
     tool_call_id = tool_call['id']
 
-    if tool_call['function']['name'] == 'search_documentation'
-      query = JSON.parse(tool_call['function']['arguments'])['search_query']
-      sections = fetch_documentation(query)
-      append_tool_response(sections, tool_call_id)
+    if @tool_registry.respond_to?(function_name)
+      execute_tool(function_name, arguments, tool_call_id)
     else
-      append_tool_response('', tool_call_id)
+      process_invalid_tool_call(tool_call_id)
     end
   end
 
-  def fetch_documentation(query)
-    Rails.logger.debug { "[CAPTAIN][DocumentationSearch] #{query}" }
-    @assistant
-      .responses
-      .approved
-      .search(query)
-      .map { |response| format_response(response) }.join
-  end
-
-  def format_response(response)
-    formatted_response = "
-    Question: #{response.question}
-    Answer: #{response.answer}
-    "
-    if response.documentable.present? && response.documentable.try(:external_link)
-      formatted_response += "
-      Source: #{response.documentable.external_link}
-      "
-    end
-
-    formatted_response
+  def execute_tool(function_name, arguments, tool_call_id)
+    result = @tool_registry.send(function_name, arguments)
+    append_tool_response(result, tool_call_id)
   end
 
   def append_tool_calls(tool_calls)
@@ -95,11 +56,15 @@ module Captain::ChatHelper
     }
   end
 
-  def append_tool_response(sections, tool_call_id)
+  def process_invalid_tool_call(tool_call_id)
+    append_tool_response('Tool not available', tool_call_id)
+  end
+
+  def append_tool_response(content, tool_call_id)
     @messages << {
       role: 'tool',
       tool_call_id: tool_call_id,
-      content: "Found the following FAQs in the documentation:\n #{sections}"
+      content: content
     }
   end
 end