A simple wrapper around the OpenAI API

AiModel.cs

internal class AiModel
{
    HttpClient httpClient = new HttpClient();
    List<GptMessage> Messages = new List<GptMessage>();

    public AiModel()
    {
        httpClient.DefaultRequestHeaders.Add("api-key", "APIKEY");
        httpClient.DefaultRequestHeaders.Add("Authorization", "Bearer APIKEY");

        Messages.Add(new GptMessage()
        {
            role = "system",
            content = AiPrompts.SupportPrompt
        });
    }

    /// <summary>
    /// Generates a reply given the current prompt and context
    /// </summary>
    /// <param name="message"></param>
    /// <returns></returns>
    public string GenerateReply(string message)
    {
        Messages.Add(new GptMessage()
        {
            role = "user",
            content = message
        });

        string completion = RequestCompletion();

        Messages.Add(new GptMessage()
        {
            role = "assistant",
            content = completion
        });

        return completion;
    }

    /// <summary>
    /// Requests a completion with the current messages to the OpenAI API
    /// </summary>
    /// <returns></returns>
    string RequestCompletion()
    {
        GptData gptData = new GptData()
        {
            model = "gpt-3.5-turbo",
            messages = Messages,
            stream = false
        };

        HttpContent content = new StringContent(JsonConvert.SerializeObject(gptData), Encoding.UTF8, "application/json");
        HttpResponseMessage response = httpClient.PostAsync("https://api.openai.com/v1/chat/completions", content).GetAwaiter().GetResult();

        ChatCompletion chatCompletion = JsonConvert.DeserializeObject<ChatCompletion>(response.Content.ReadAsStringAsync().Result);

        return chatCompletion.Choices[0].Message.Content;
    }

    /// <summary>
    /// A message that will be sendt to GPT
    /// </summary>
    public class GptMessage
    {
        /// <summary>
        /// <para>system = a system message to explain the behaviour of the AI</para>
        /// <para>user = a reference message from the user</para>
        /// <para>assistant = a reference message from the AI</para>
        /// </summary>
        public string role { get; set; }

        /// <summary>
        /// The content of the message
        /// </summary>
        public string content { get; set; }
    }
    
     public class GptData
    {
        public string model { get; set; }
        public List<GptMessage> messages { get; set; }
        public bool stream { get; set; }
    }

    public class ChatCompletion
    {
        public string Id { get; set; }
        public string Object { get; set; }
        public long Created { get; set; }
        public string Model { get; set; }
        public List<Choice> Choices { get; set; }
        public Usage Usage { get; set; }
    }

    public class Choice
    {
        public int Index { get; set; }
        public Message Message { get; set; }
        public FinishReason FinishReason { get; set; }
    }

    public enum FinishReason
    {
        Stop,
        Timeout,
        Error
    }

    public class Message
    {
        public string Role { get; set; }
        public string Content { get; set; }
    }
}