AuthorBuddy/Services/OllamaService.cs

using AuthorBuddy.Web.Models;
using Ollama;

namespace AuthorBuddy.Web.Services;

public class OllamaService : IOllamaService, IDisposable
{
    private readonly OllamaSettings _settings;
    private OllamaApiClient? _client;
    private string _currentUrl = "http://localhost:11434";

    public OllamaService(OllamaSettings settings)
    {
        _settings = settings;
        _currentUrl = settings.OllamaUrl;
        _client = new OllamaApiClient(baseUri: new Uri(_currentUrl));
    }

    public Task ReconfigureAsync(string ollamaUrl)
    {
        if (_currentUrl != ollamaUrl)
        {
            _currentUrl = ollamaUrl;
            _client?.Dispose();
            _client = new OllamaApiClient(baseUri: new Uri(ollamaUrl));
        }
        return Task.CompletedTask;
    }

    private OllamaApiClient Client => _client ??= new OllamaApiClient(baseUri: new Uri(_currentUrl));

    public async Task<IEnumerable<Model>> GetLocalModelsAsync()
    {
        var models = await Client.Models.ListModelsAsync();
        return models.Models ?? Enumerable.Empty<Ollama.Model>();
    }

    public async Task PullModelAsync(string modelName, IProgress<ModelStatus> progress)
    {
        var p = new ModelStatus();
        await foreach (var response in Client.Models.PullModelAsync(modelName))
        {
            p.SetModelStatus(response);
            progress?.Report(p);
        }
    }

    public async Task<IList<double>> GetEmbeddingAsync(string text)
    {
        var response = await Client.Embeddings.GenerateEmbeddingAsync(
            model: _settings.EmbedModel,
            prompt: text);
        return response.Embedding ?? Array.Empty<double>();
    }

    public async Task<string> StreamStyleCheckAsync(string input)
    {
        var systemPrompt = _settings.LektorSystemPrompt;
        var chat = Client.Chat(_settings.ChatModel, systemPrompt);
        var message = await chat.SendAsync(input);
        return message.Content;
    }

    public async Task<string> AnswerBasedOnFactsAsync(string question, string facts)
    {
        var prompt = _settings.GetFactCheckPrompt(question, facts);
        var chat = Client.Chat(_settings.ChatModel);
        var message = await chat.SendAsync(prompt);
        return message.Content;
    }

    public async Task<string> QuickSpellCheckAsync(string text)
    {
        var systemPrompt = _settings.SpellingPrompt;
        var chat = Client.Chat(_settings.SpellingModel, systemPrompt);
        var message = await chat.SendAsync(text);
        return message.Content;
    }

    public void Dispose()
    {
        _client?.Dispose();
    }
}