Building the Session Manager in Ruby

Building the Session Manager

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.

Initializing the SessionManager

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. Rubyclass SessionManager def initialize @sessions = {} # This will hold all session data end endclass 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: Ruby@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 } } }@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.

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Implementing Session Management Methods

Next, we'll add the core methods to our SessionManager class: creating a session, retrieving a session, adding messages, and retrieving the full conversation.

Ruby

class SessionManager
  def initialize
    @sessions = {}
  end

  def create_session(student_id, session_id, system_prompt)
    # Create a new tutoring session for a student
    @sessions[student_id] ||= {}
    @sessions[student_id][session_id] = {
      system_prompt: system_prompt,
      messages: []
    }
  end

  def get_session(student_id, session_id)
    # Retrieve a tutoring session by student_id and session_id
    @sessions.dig(student_id, session_id)
  end

  def add_message(student_id, session_id, role, content)
    # Add a message to a tutoring session
    session = get_session(student_id, session_id)
    if session
      session[:messages] << { role: role, content: content }
    end
  end

  def get_conversation(student_id, session_id)
    # Retrieve the full tutoring conversation including the system prompt
    session = get_session(student_id, session_id)
    if session
      [{ role: "system", content: session[:system_prompt] }] + session[:messages]
    else
      []
    end
  end
end

class SessionManager
  def initialize
    @sessions = {}
  end

  def create_session(student_id, session_id, system_prompt)
    # Create a new tutoring session for a student
    @sessions[student_id] ||= {}
    @sessions[student_id][session_id] = {
      system_prompt: system_prompt,
      messages: []
    }
  end

  def get_session(student_id, session_id)
    # Retrieve a tutoring session by student_id and session_id
    @sessions.dig(student_id, session_id)
  end

  def add_message(student_id, session_id, role, content)
    # Add a message to a tutoring session
    session = get_session(student_id, session_id)
    if session
      session[:messages] << { role: role, content: content }
    end
  end

  def get_conversation(student_id, session_id)
    # Retrieve the full tutoring conversation including the system prompt
    session = get_session(student_id, session_id)
    if session
      [{ role: "system", content: session[:system_prompt] }] + session[:messages]
    else
      []
    end
  end
end

With these methods, we've built a fully functional SessionManager class that can create and manage tutoring sessions, add messages, and retrieve conversation histories.

Putting It All Together

Now, let's see how to use the SessionManager class in practice. We'll walk through creating a session, adding messages, and retrieving the conversation.

Ruby

def load_system_prompt
  # Load the tutor system prompt from file
  begin
    File.read('data/system_prompt.txt')
  rescue => e
    puts "Error loading system prompt: #{e}"
    "You are a helpful tutor."
  end
end

# Load the system prompt
system_prompt = load_system_prompt

# Initialize the session manager
manager = SessionManager.new

# Create a new tutoring session
student_id = "student_test"
session_id = "session_test"
manager.create_session(student_id, session_id, system_prompt)

# Add some messages to the session
manager.add_message(student_id, session_id, "user", "Hello, I need help with geometry.")
manager.add_message(student_id, session_id, "assistant", "Hi there! What specific geometry topic are you struggling with?")

# Retrieve the full conversation
conversation = manager.get_conversation(student_id, session_id)

# Display the session details
puts "Session ID: #{session_id}\n\n"
conversation.each do |message|
  puts "Role: #{message[:role]}"
  puts "Message:\n#{message[:content]}\n\n"
end

def load_system_prompt
  # Load the tutor system prompt from file
  begin
    File.read('data/system_prompt.txt')
  rescue => e
    puts "Error loading system prompt: #{e}"
    "You are a helpful tutor."
  end
end

# Load the system prompt
system_prompt = load_system_prompt

# Initialize the session manager
manager = SessionManager.new

# Create a new tutoring session
student_id = "student_test"
session_id = "session_test"
manager.create_session(student_id, session_id, system_prompt)

# Add some messages to the session
manager.add_message(student_id, session_id, "user", "Hello, I need help with geometry.")
manager.add_message(student_id, session_id, "assistant", "Hi there! What specific geometry topic are you struggling with?")

# Retrieve the full conversation
conversation = manager.get_conversation(student_id, session_id)

# Display the session details
puts "Session ID: #{session_id}\n\n"
conversation.each do |message|
  puts "Role: #{message[:role]}"
  puts "Message:\n#{message[:content]}\n\n"
end

In this example, we:

Load the system prompt.
Initialize a SessionManager instance.
Create a new tutoring session for a student.
Add a student message and an assistant response.
Retrieve and display the full conversation, including the system prompt and all messages.

This workflow demonstrates how the SessionManager class ties together session creation, message management, and conversation retrieval.

Building the Session Manager in Ruby