GOA/LLMApi/Services/ChatGpt3_5.cs

using LLMApi.Data.Contracts.ChatGpt3_5;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;

namespace LLMApi.Services;

public class ChatGpt3_5Service : ILlmApiService
{
    private readonly HttpClient _client;
    private static readonly JsonSerializerSettings jsonSerializerSettings = new()
    {
        ContractResolver = new DefaultContractResolver()
        {
            NamingStrategy = new SnakeCaseNamingStrategy()
        }
    };
    private const string API_TOKEN = "";
    private const string VERSION_IDENTIFIER = "gpt-3.5-turbo";

    public ChatGpt3_5Service(HttpClient client)
    {
        _client = client;
        _client.BaseAddress = new Uri("https://api.openai.com");
        // _client.DefaultRequestHeaders.Add("Content-Type", "application/json");
        _client.DefaultRequestHeaders.Add("Authorization", $"Bearer {API_TOKEN}");
    }

    public async Task<string> GetAnswerToPrompt(string prompt)
    {
        var requestContract = new ChatCompletionRequest(VERSION_IDENTIFIER, 
            new Message[] 
            { 
                new("system", "You are a helpful assistant."), 
                new("user", "Hello!"), 
            });

        var response = await _client.PostAsJsonAsync("/v1/chat/completions", requestContract);
        
        var content = await response.Content.ReadAsStringAsync();

        var obj = JsonConvert.DeserializeObject<ChatCompletionResponse>(content, jsonSerializerSettings);

        return obj!.ToString() + Environment.NewLine + string.Join(", ", obj!.Choices.Select(c => c.ToString()));
        
    }
}