ChatWithAI_Server/Services/LmStudioService.cs - master - ilyakos/ChatWithAI

ChatWithAI_Server/Services/LmStudioService.cs
108 строк4 KB
ilyakos
новые энд поинты
15 июн 2026, 20:32
15 июн 2026, 20:3215ab71c
using System.Net.Http.Json;
using System.Text.Json;
using System.Text.Json.Serialization;
using ChatWithAI.Database.Models;

namespace ChatWithAI_Server.Services;

/// <summary>
/// Реализация сервиса LM Studio на основе OpenAI-совместимого HTTP API.
/// Отправляет запросы на эндпоинт <c>/chat/completions</c> с полной историей диалога.
/// </summary>
public class LmStudioService(HttpClient httpClient, IConfiguration config) : ILmStudioService
{
    private static readonly JsonSerializerOptions SerializerOptions = new()
    {
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
    };

    /// <inheritdoc/>
    public async Task<string> CompleteChatAsync(
        string systemPrompt,
        IEnumerable<Message> history,
        string userText,
        string? userImageBase64 = null)
    {
        var apiMessages = new List<LmMessage>
        {
            new("system", systemPrompt)
        };

        foreach (var msg in history)
        {
            apiMessages.Add(new LmMessage(
                msg.IsUser ? "user" : "assistant",
                BuildContent(msg.Text, msg.ImageBase64)));
        }

        apiMessages.Add(new LmMessage("user", BuildContent(userText, userImageBase64)));

        var model = config["LmStudio:Model"] ?? "local-model";
        var maxTokens = int.Parse(config["LmStudio:MaxTokens"] ?? "2048");

        var requestBody = new LmChatRequest(model, apiMessages, maxTokens);

        var response = await httpClient.PostAsJsonAsync("chat/completions", requestBody, SerializerOptions);
        response.EnsureSuccessStatusCode();

        var result = await response.Content.ReadFromJsonAsync<LmChatResponse>()
            ?? throw new InvalidOperationException("LM Studio вернул пустой ответ.");

        if (result.Choices is not { Count: > 0 })
            throw new InvalidOperationException("LM Studio не вернул ни одного варианта ответа.");

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

    /// <summary>
    /// Формирует содержимое сообщения: строку для текстовых, массив частей для мультимодальных.
    /// </summary>
    private static object BuildContent(string? text, string? imageBase64)
    {
        if (imageBase64 is null)
            return text ?? string.Empty;

        var parts = new List<LmContentPart>();
        if (text is not null)
            parts.Add(new LmContentPart("text", text, null));
        parts.Add(new LmContentPart("image_url", null, new LmImageUrl($"data:image/jpeg;base64,{imageBase64}")));
        return parts;
    }

    // --- Внутренние модели для OpenAI-совместимого API ---

    private record LmChatRequest(
        [property: JsonPropertyName("model")] string Model,
        [property: JsonPropertyName("messages")] List<LmMessage> Messages,
        [property: JsonPropertyName("max_tokens")] int MaxTokens,
        [property: JsonPropertyName("stream")] bool Stream = false
    );

    private record LmMessage(
        [property: JsonPropertyName("role")] string Role,
        [property: JsonPropertyName("content")] object Content
    );

    private record LmContentPart(
        [property: JsonPropertyName("type")] string Type,
        [property: JsonPropertyName("text")] string? Text,
        [property: JsonPropertyName("image_url")] LmImageUrl? ImageUrl
    );

    private record LmImageUrl(
        [property: JsonPropertyName("url")] string Url
    );

    private record LmChatResponse(
        [property: JsonPropertyName("choices")] List<LmChoice> Choices
    );

    private record LmChoice(
        [property: JsonPropertyName("message")] LmAssistantMessage Message
    );

    private record LmAssistantMessage(
        [property: JsonPropertyName("role")] string Role,
        [property: JsonPropertyName("content")] string Content
    );
}