Building the Session Manager in JavaScript

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 constructor. The constructor initializes an empty object, this.sessions, which will store all session data.

class SessionManager {
    constructor() {
        this.sessions = {}; // studentId -> sessionId -> sessionData
    }
}

In this setup, this.sessions is a nested object where the first key is the studentId, and the second key is the sessionId. This structure allows us to efficiently manage multiple tutoring sessions for different students.

Next, we'll add the createSession method. This method is responsible for creating a new session entry for a student. It takes three parameters: studentId, sessionId, and systemPrompt.

class SessionManager {
    constructor() {
        this.sessions = {};
    }

    createSession(studentId, sessionId, systemPrompt) {
        // Create a new tutoring session for a student
        if (!this.sessions[studentId]) {
            this.sessions[studentId] = {};
        }

        this.sessions[studentId][sessionId] = {
            systemPrompt: systemPrompt,
            messages: []
        };
    }
}

The createSession method checks if the studentId exists in this.sessions. If not, it creates a new entry. Then, it initializes the session with the provided systemPrompt and an empty array for messages.