In the previous lesson, we explored the SessionManager struct, which plays a crucial role in managing tutoring session data within our application. Now, we will take the next step by building the Tutor Service Layer in Go. This layer is essential for integrating the DeepSeek language model with tutoring sessions, allowing us to process student queries and generate tailored explanations. By the end of this lesson, you will understand how to set up the TutorService struct, create tutoring sessions, and process academic questions using DeepSeek models via the OpenAI Go SDK.

The service layer acts as a bridge between the model layer, where data is managed, and the AI model, which generates educational responses. It is responsible for orchestrating the flow of data and ensuring that student interactions are handled effectively. Let's dive into the details of setting up this important component.

The TutorService struct is the heart of our service layer. It is responsible for managing tutoring sessions and interacting with the DeepSeek model to generate educational responses. In Go, we use structs and associated methods instead of classes. To begin, we need to define the struct and its components.

First, we import the necessary packages, including the SessionManager from our previous lesson (now located at app/session/session_manager.go), the OpenAI Go SDK, and the UUID package for generating unique session IDs. Here is how the struct is defined and initialized:

In this setup, we instantiate SessionManager to manage tutoring data, initialize the OpenAI client for DeepSeek model access, and load the systemPrompt using the loadSystemPrompt function, which we'll discuss next.

The system prompt is a crucial component that guides the tutor AI's responses. It provides context and instructions for the AI, ensuring that it behaves like an effective educational assistant. In Go, we use file I/O functions such as os.ReadFile to load the prompt from a file and handle errors using Go's idiomatic error handling.

This function attempts to read the system prompt from a specified file path. If successful, it returns the prompt as a string. In case of an error, it logs an error message and returns a default prompt. This ensures that the application can continue functioning even if the file is missing or corrupted.

Creating a new tutoring session is a fundamental task of the TutorService. The CreateSession method is responsible for generating a unique session ID and initializing a tutoring session using the SessionManager. In Go, we use the github.com/google/uuid package to generate unique IDs.

In this method, we generate a unique sessionID using the UUID package. We then call the CreateSession method of SessionManager, passing the studentID, sessionID, and systemPrompt. This initializes a new tutoring session, which is ready to receive student queries.

The ProcessQuery method is where the educational magic happens. It processes student questions, interacts with the DeepSeek model to generate tutoring explanations, and updates the session history. Below, we outline the steps involved in this process, followed by the corresponding Go implementation:

1. Retrieve the session using GetSession, and return an error if the session is not found.
2. Add the student's query to the session history.
3. Get the conversation history from the session.
4. Convert the conversation to the OpenAI message format.
5. Send the conversation to the DeepSeek model to generate a response.
6. Extract the AI's response and add it to the session history.
7. Return the AI's response to the student.

Let's see the TutorService in action by simulating a tutoring session. We'll create a Go program to initialize a tutoring session and process a student's academic query.

In this example, we initialize the TutorService, simulate a student ID, and create a new tutoring session, printing the session ID. We then simulate sending an economics question and print the tutor's response, demonstrating the flow from student query to tutoring explanation and showcasing the functionality of the TutorService.

In this lesson, we explored the TutorService struct and its role in integrating the DeepSeek language model with tutoring sessions. We learned how to set up the struct, load the system prompt, create sessions, and process student queries. The service layer is a vital component of our personal tutor application, ensuring that student interactions are handled effectively and that educational content is delivered in a clear and engaging manner.

As you move on to the practice exercises, take the opportunity to experiment with the TutorService functionality. This hands-on practice will reinforce the concepts covered in this lesson and prepare you for the next steps in our course. Keep up the great work, and I look forward to seeing your progress!