Yi.Framework/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Application/Services/AiChatService.cs

using System.Collections.Concurrent;
using System.Text;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using Microsoft.Identity.Client;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using OpenAI.Chat;
using Volo.Abp.Application.Services;
using Volo.Abp.Users;
using Yi.Framework.AiHub.Application.Contracts.Dtos;
using Yi.Framework.AiHub.Application.Contracts.Options;
using Yi.Framework.AiHub.Domain.Managers;
using Yi.Framework.Rbac.Application.Contracts.IServices;
using Yi.Framework.Rbac.Domain.Shared.Dtos;

namespace Yi.Framework.AiHub.Application.Services;

/// <summary>
/// ai服务
/// </summary>
public class AiChatService : ApplicationService
{
    private readonly AiGateWayOptions _options;
    private readonly IHttpContextAccessor _httpContextAccessor;
    private readonly AiMessageManager _aiMessageManager;

    public AiChatService(IOptions<AiGateWayOptions> options, IHttpContextAccessor httpContextAccessor,
        AiMessageManager aiMessageManager)
    {
        _options = options.Value;
        this._httpContextAccessor = httpContextAccessor;
        _aiMessageManager = aiMessageManager;
    }


    /// <summary>
    /// 查询已登录的账户信息
    /// </summary>
    /// <returns></returns>
    [Route("ai-chat/account")]
    [Authorize]
    public async Task<UserRoleMenuDto> GetAsync()
    {
        var accountService = LazyServiceProvider.GetRequiredService<IAccountService>();
        var output = await accountService.GetAsync();
        return output;
    }

    /// <summary>
    /// 获取模型列表
    /// </summary>
    /// <returns></returns>
    public async Task<List<ModelGetListOutput>> GetModelAsync()
    {
        var output = _options.Chats.SelectMany(x => x.Value.ModelIds)
            .Select(x => new ModelGetListOutput()
            {
                Id = 001,
                Category = "chat",
                ModelName = x,
                ModelDescribe = "这是一个直连模型",
                ModelPrice = 4,
                ModelType = "1",
                ModelShow = "0",
                Remark = "直连模型"
            }).ToList();
        return output;
    }


    /// <summary>
    /// 发送消息
    /// </summary>
    /// <param name="input"></param>
    /// <param name="cancellationToken"></param>
    public async Task PostSendAsync(SendMessageInput input, CancellationToken cancellationToken)
    {
        var httpContext = this._httpContextAccessor.HttpContext;
        var response = httpContext.Response;
        // 设置响应头，声明是 SSE 流
        response.ContentType = "text/event-stream";
        response.Headers.Append("Cache-Control", "no-cache");
        response.Headers.Append("Connection", "keep-alive");


        var history = new List<ChatMessage>();
        foreach (var aiChatContextDto in input.Messages)
        {
            if (aiChatContextDto.Role == "system")
            {
                history.Add(ChatMessage.CreateAssistantMessage(aiChatContextDto.Content));
            }
            else if (aiChatContextDto.Role == "user")
            {
                history.Add(ChatMessage.CreateUserMessage(aiChatContextDto.Content));
            }
        }

        var gateWay = LazyServiceProvider.GetRequiredService<AiGateWayManager>();
        var completeChatResponse = gateWay.CompleteChatAsync(input.Model, history, cancellationToken);
        await using var writer = new StreamWriter(response.Body, Encoding.UTF8, leaveOpen: true);


        //缓存队列算法

        // 创建一个队列来缓存消息
        var messageQueue = new ConcurrentQueue<string>();
        // 设置输出速率（例如每50毫秒输出一次）
        var outputInterval = TimeSpan.FromMilliseconds(100);
        // 标记是否完成接收
        var isComplete = false;
        // 启动一个后台任务来消费队列
        var outputTask = Task.Run(async () =>
        {
            while (!(isComplete&&messageQueue.IsEmpty))
            {
                if (messageQueue.TryDequeue(out var message))
                {
                    await writer.WriteLineAsync(message);
                    await writer.FlushAsync(cancellationToken);
                }

                if (!isComplete)
                {
                    // 如果没有完成，才等待，已完成，全部输出
                    await Task.Delay(outputInterval, cancellationToken);
                }
            }
        }, cancellationToken);


        await foreach (var data in completeChatResponse)
        {
            var model = MapToMessage(input.Model, data);
            var message = JsonConvert.SerializeObject(model, new JsonSerializerSettings
            {
                ContractResolver = new CamelCasePropertyNamesContractResolver()
            });

            // 将消息加入队列而不是直接写入
            messageQueue.Enqueue($"data: {message}\n");
        }

        // 标记完成并发送结束标记
        isComplete = true;
        //断开连接
        messageQueue.Enqueue("data: done\n");

        await outputTask;
        if (CurrentUser.IsAuthenticated && input.SessionId.HasValue)
        {
            // 等待接入token
            // await _aiMessageManager.CreateMessageAsync(CurrentUser.GetId(), input.SessionId.Value, new MessageInputDto
            // {
            //     Content = null,
            //     Role = null,
            //     DeductCost = 0,
            //     TotalTokens = 0,
            //     ModelId = null,
            //     Remark = null
            // });
        }
    }


    private SendMessageOutputDto MapToMessage(string modelId, string content)
    {
        var output = new SendMessageOutputDto
        {
            Id = 001,
            Object = "chat.completion.chunk",
            Created = 1750336171,
            Model = modelId,
            Choices = new()
            {
                new Choice
                {
                    Index = 0,
                    Delta = new Delta
                    {
                        Content = content,
                        Role = "assistant"
                    },
                    FinishReason = null,
                    ContentFilterResults = new()
                    {
                        Hate = new()
                        {
                            Filtered = false,
                            Detected = null
                        },
                        SelfHarm = new()
                        {
                            Filtered = false,
                            Detected = null
                        },
                        Sexual = new()
                        {
                            Filtered = false,
                            Detected = null
                        },
                        Violence = new()
                        {
                            Filtered = false,
                            Detected = null
                        },
                        Jailbreak = new()
                        {
                            Filtered = false,
                            Detected = false
                        },
                        Profanity = new()
                        {
                            Filtered = false,
                            Detected = false
                        },
                    }
                }
            },
            SystemFingerprint = "",
            Usage = new Usage
            {
                PromptTokens = 75,
                CompletionTokens = 25,
                TotalTokens = 100,
                PromptTokensDetails = new()
                {
                    AudioTokens = 0,
                    CachedTokens = 0
                },
                CompletionTokensDetails = new()
                {
                    AudioTokens = 0,
                    ReasoningTokens = 0,
                    AcceptedPredictionTokens = 0,
                    RejectedPredictionTokens = 0
                }
            }
        };

        return output;
    }
}