Building the Session Manager in Ruby

Welcome back! In the previous lesson, we explored the importance of a robust system prompt and how it guides the behavior of our personal tutor. Now, we will delve into the next step of our journey: building the Session Manager. This lesson will focus on the model layer of the MVC (Model-View-Controller) architecture, which is crucial for organizing and managing data in a structured way. The SessionManager class will be the core component of our model layer, responsible for managing tutoring session data effectively. By the end of this lesson, you will understand how to create, manage, and retrieve session data using the SessionManager class.

The SessionManager class is designed to handle the storage and management of tutoring session data. It serves as the backbone of our tutor's data management system. We'll start by setting up the class and then gradually add methods to handle session creation, message addition, and conversation retrieval.

Let's begin by defining the SessionManager class and its initialize method. The initialize method sets up an empty hash, @sessions, which will eventually store all session data.

class SessionManager
  def initialize
    @sessions = {}  # This will hold all session data
  end
end

At this stage, @sessions is just an empty hash. As we add sessions, it will become a nested hash structure, where the first key is the student_id, and the second key is the session_id. This allows us to efficiently manage multiple tutoring sessions for different students.

Here’s an example of what the @sessions hash will look like after some sessions and messages have been added:

@sessions = {
  "student_001" => {
    "session_abc" => {
      system_prompt: "You are a helpful math tutor.",
      messages: [
        { role: "user", content: "What is 2 + 2?" },
        { role: "assistant", content: "2 + 2 equals 4." }
      ],
      last_active: Time.now
    }
  }
}

In this structure:

• The top-level keys are student_ids (e.g., "student_001").
• Each student_id maps to another hash, where the keys are session_ids (e.g., "session_abc").
• Each session_id maps to a hash containing:
  • system_prompt: The system prompt for the session.
  • messages: An array of message hashes, each with a role and content.
  • last_active: A timestamp for when the session was last active (optional, but useful for session management).

This nested structure makes it easy to organize and retrieve session data for any student and session combination.