Learn.VideoAnalysis/VideoAnalysisCore/AICore/GPT/ChatGPT/ChatGPTClient.cs

using VideoAnalysisCore.Common;
using System.Net.Http.Headers;
using System.Text;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json.Linq;
using System.Net.Http;
using Newtonsoft.Json;
using System.Net.Http.Json;
using System.Net;
using VideoAnalysisCore.AICore.GPT.DeepSeek;
using VideoAnalysisCore.AICore.GPT;
using System.Text.Json;


namespace VideoAnalysisCore.AICore.GPT.ChatGPT
{

    public class ChatGPTClient
    {
        public static string Host = AppCommon.Config.ChatGpt.ChatGpt.Host;
        public static string ApiKey = AppCommon.Config.ChatGpt.ChatGpt.ApiKey;

        private readonly IHttpClientFactory _httpClientFactory;
        private readonly RedisManager redisManager;

        public ChatGPTClient(IHttpClientFactory httpClientFactory, RedisManager redisManager)
        {
            _httpClientFactory = httpClientFactory;
            this.redisManager = redisManager;
        }


        /// <summary>
        /// ChatSSE[流式传输 更稳定]
        /// </summary>
        /// <param name="chatReq"></param>
        /// <returns>Return HttpResponseMessage for SSE</returns>
        public async Task<(Usage u, string res)?> ChatSSE(ChatRequest chatReq)
        {
            var requestBody = chatReq.ToJson();
            PostJsonStream:
            var chatResp = await _httpClientFactory.PostJsonStreamAsync(Host+"v1/chat/completions", requestBody, ApiKey);
            if (!chatResp.IsSuccessStatusCode)
            {
                await redisManager.AddTaskLog(chatReq.taskId, "请求GPT服务器异常 " + chatResp?.StatusCode + await chatResp.Content.ReadAsStringAsync());
                goto PostJsonStream;
            }
            using var stream = chatResp.Content.ReadAsStream();
            using var reader = new StreamReader(stream, Encoding.UTF8);
            string line;
            var messageBuilder = new StringBuilder();
            var messageBuilder1 = new StringBuilder();
            var lastChat = new ChatResSSE();
            var splitCount = "data:".Length;
            var maxLoop = 60 * 100000;
            int threshold = 0;
            while (maxLoop > 0)
            {
                line = reader.ReadLine();
                if (line is null || string.IsNullOrEmpty(line) || line.StartsWith(": keep-alive"))
                {
                    Thread.Sleep(10);
                    maxLoop--;
                    continue;
                }
                else if (line.EndsWith("[DONE]"))
                {
                    // 表示一条消息结束
                    string message = messageBuilder.ToString();
                    string message2 = messageBuilder1.ToString();
                    messageBuilder.Clear();
                    messageBuilder1.Clear();
                    var u = lastChat?.usage;
                    if (u == null || string.IsNullOrEmpty(message))
                        return null;
                    return (u, message);
                    //return (u, message, message2);
                }
                else if (line.StartsWith("data:"))
                {
                    try
                    {
                        var data = System.Text.Json.JsonSerializer.Deserialize<ChatResSSE>(line.Substring(splitCount).Trim());
                        lastChat = data;
                        var delta = data?.choices.FirstOrDefault()?.delta;
                        var str = delta?.content;
                        var strReasoning = delta?.reasoning_content;
                        if (!string.IsNullOrEmpty(str))
                            messageBuilder.Append(str);
                        if (!string.IsNullOrEmpty(strReasoning))
                            messageBuilder1.Append(strReasoning);
                        var steamCount = messageBuilder.Length + messageBuilder1.Length;
                        if (++threshold % 30 == 0)
                            redisManager.SetTaskProgress(chatReq.taskId, "steam=>" + steamCount);
                    }
                    catch (Exception e)
                    {
                        await redisManager.AddTaskLog(chatReq.taskId, "异常 ChatSSE=>" + line + "\r\n" + e.Message + "\r\n" + e.StackTrace);
                    }
                }
            }
            await redisManager.AddTaskLog(chatReq.taskId, DateTime.Now + "=>AI请求超时 " + chatReq.taskId);
            return null;
        }

        /// <summary>
        /// 请求AI
        /// </summary>
        /// <typeparam name="T">返回JSON类型</typeparam>
        /// <param name="task">任务id</param>
        /// <param name="postMessages">提示词</param>
        /// <param name="title">任务类型</param>
        /// <param name="model">GPT版本</param>
        /// <param name="max_tokens">最大token <para>不设置默认最大值 16000/8000</para></param>
        /// <returns></returns>
        /// <exception cref="Exception"></exception>
        public async Task<T> ChatAsync<T>(string task, string postMessages, string title, string model =null, int max_tokens = -1)
        {
            Message[] messageArr = [
                    new Message(postMessages,"user"),
                ];
            messageArr = messageArr.Where(s => s != null).ToArray();
            var chatRep = new ChatRequest
            {
                taskId = task,
                model = model ?? ChatGPTType.GPT5_mini,
                max_tokens = 8000,
                stream = true,
                temperature = 0.2f,
                messages = messageArr
            };
            if (max_tokens != -1)
                chatRep.max_tokens = max_tokens;
            var tryCount = 10;
            while (tryCount-- > 0)
            {
                try
                {
                    var time = title + DateTime.Now.ToString("MMddHHmmss");
                    var redisCached = new object[2] { chatRep, null };
                    redisManager.SetTaskGPTCached(task, time, chatRep);
                    var chatResp = await Chat(chatRep);
                    var chatResContent = chatResp?.res;
                    if (string.IsNullOrEmpty(chatResContent))
                        throw new Exception("GPT返回message无效结果");
                    if (chatResp != null)
                    {
                        redisCached[1] = new object[] { chatResp.Value.res, chatResp.Value.u, chatResp.Value };
                        redisManager.SetTaskGPTCached(task, time, redisCached);
                    }
                    chatResContent = chatResContent?.ExtractJsonStrings()?.FirstOrDefault();
                    chatResContent = chatResContent?.Replace("\n", "");
                    chatResContent = chatResContent?.Replace("```json", "");
                    chatResContent = chatResContent?.Replace("```", "");
                    chatResContent = chatResContent?.Replace("}{", "},{");
                    chatResContent = chatResContent?.Replace("}|{", "},{");
                    chatResContent = chatResContent?.Trim();

                    if (string.IsNullOrEmpty(chatResContent))
                        throw new Exception("ChatGPT返回结果无有效JSON");
                    var startsStr = typeof(T).IsArray ? "[" : "{";
                    var endStr = typeof(T).IsArray ? "]" : "}";
                    if (!chatResContent.StartsWith(startsStr))
                        chatResContent = startsStr + chatResContent;
                    if (!chatResContent.EndsWith(endStr))
                        chatResContent = chatResContent + endStr;
                    var options = new JsonSerializerOptions
                    {
                        // 允许解析不严格符合 JSON 规范的字符串
                        AllowTrailingCommas = true,
                        // 处理不匹配的 JSON 字符
                        ReadCommentHandling = JsonCommentHandling.Skip
                    };
                    var questionRes = System.Text.Json.JsonSerializer.Deserialize<T>(chatResContent, options);
                    if (questionRes is null)
                        throw new Exception("ChatGPT返回无效结果");
                    return questionRes;
                }
                catch (Exception ex)
                {
                    await redisManager.AddTaskLog(task, $"ChatGPT结果解析错误 重试剩余{tryCount}" + ex.Message);
                }
            }
            throw new Exception(DateTime.Now + "=>ChatGPT请求失败次数过多!!!");
        }


        /// <summary>
        /// Chat
        /// </summary>
        /// <param name="chatReq"></param>
        /// <returns>Return HttpResponseMessage for SSE</returns>
        public async Task<(Usage u, string res)?> Chat(ChatRequest chatReq)
        {
            chatReq.modalities =null;
            chatReq.max_tokens = null;
            chatReq.top_p = null;
            if (chatReq.stream) return await ChatSSE(chatReq);

            var requestBody = chatReq.ToJson();
            var chatResp = await _httpClientFactory.PostJsonStreamAsync(Host+"v1/chat/completions", requestBody,ApiKey,true);
            var res = await chatResp.Content.ReadFromJsonAsync<ChatRes>();
            var chatResContent = res?.choices.FirstOrDefault()?.message.content.Trim();

            if (res is null || res.error != null)
                throw new Exception($" ChatGPT模型返回异常 返回参数: " +
                    $" {res?.ToJson()}");

            if (string.IsNullOrEmpty(chatResContent))
                return null;
            return (res.usage, chatResContent);
        }
    }
}