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 System.Threading;
using System;
using System.IO;
using VideoAnalysisCore.AICore.GPT.ChatGPT;
using System.Threading.Tasks;
using System.Text.Json;

namespace VideoAnalysisCore.AICore.GPT
{
    public abstract class GPTClient
    {
        public virtual GptConfig Config { get; set; }

        private readonly IHttpClientFactory _httpClientFactory;
        private readonly RedisManager redisManager;


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

        /// <summary>
        /// Chat
        /// </summary>
        /// <param name="chatReq"></param>
        /// <returns>Return HttpResponseMessage for SSE</returns>
        public async Task<(Usage u, string res, string reasoning)?> Chat(ChatRequest chatReq)
        {
            //chatReq.model = "deepseek-r1";
            if (chatReq.stream) return await ChatSSE(chatReq);
            throw new NotImplementedException();

        }

        private (string m1, string m2) thinkMSG(Message? m)
        {
            var chatResContent = m?.content.Trim();
            var chatResReasoning = string.Empty;
            if (chatResContent.StartsWith("<think"))
            {
                chatResReasoning = chatResContent.Substring(7, chatResContent.IndexOf("</think") - 7);
                chatResContent = chatResContent
                    .Substring(chatResContent.IndexOf("</think>") + 8);
            }
            else
                chatResReasoning = m?.reasoning_content?.Trim();
            return (chatResContent, chatResReasoning);

        }

        /// <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, string reasoning)?> ChatSSE(ChatRequest chatReq)
        {
            var requestBody = chatReq.ToJson();
            var i = 5;
        PostJsonStream:
            var chatResp = await PostJsonStreamAsync(Config.Host + Config.Path, requestBody, Config.ApiKey);
            if (!chatResp.IsSuccessStatusCode)
            {
                await redisManager.AddTaskLog(chatReq.taskId, "=>请求GPT服务器异常 " + chatResp?.StatusCode + " " + await chatResp.Content.ReadAsStringAsync());
                if (--i < 0)
                {
                    throw new Exception("请求GPT服务器失败次数过多");
                }
        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 d = thinkMSG(new Message() { content = message, reasoning_content = message2 });
                    message = d.m1;
                    message2 = d.m2;
                    var u = lastChat?.usage;
                    if (u == null || string.IsNullOrEmpty(message))
                        return null;
                    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 = "deepseek-reasoner", 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,
                max_tokens = model == "deepseek-reasoner" ? 16000 : 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.reasoning };
                        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("GPT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("GPT返回无效结果");
                    return questionRes;
                }
                catch (Exception ex)
                {
                    await redisManager.AddTaskLog(task, $"=>GPT结果解析错误 重试剩余{tryCount} {ex.Message}");
                }
            }
            await redisManager.AddTaskLog(task, $"=>GPT请求失败次数过多!!!");
            throw new Exception(DateTime.Now + "=>GPT请求失败次数过多!!!");
        }

        public async Task<HttpResponseMessage> PostJsonStreamAsync(
            string path, string json, string apiKey, bool readAll = false)
        {
            var uriBuilder = new UriBuilder(path);
            var maxRestart = 4;
            var errorMSG = new Exception[maxRestart];
            for (int i = 0; i < maxRestart; i++)
            {
                try
                {
                    var client = _httpClientFactory.CreateClient();
                    client.DefaultRequestHeaders.Authorization =
                        new AuthenticationHeaderValue("Bearer", apiKey);
                    client.Timeout = TimeSpan.FromSeconds(60 * 20);//超时时间20分钟
                    client.DefaultRequestVersion = HttpVersion.Version20;
                    client.DefaultVersionPolicy = HttpVersionPolicy.RequestVersionOrLower;
                    client.DefaultRequestHeaders.ConnectionClose = true;

                    var request = new HttpRequestMessage(HttpMethod.Post, uriBuilder.Uri);
                    request.Content = new StringContent(json, Encoding.UTF8, "application/json");
                    if (readAll)
                        return await client.SendAsync(request);
                    return await client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
                }
                catch (Exception e)
                {
                    errorMSG[i] = e;
                    Console.WriteLine("====================[请求异常,重试]====================");
                    Console.WriteLine(uriBuilder.Uri);
                    Console.WriteLine(e.Message);
                    Console.WriteLine(e.StackTrace);
                    Console.WriteLine("==============================================");
                    Thread.Sleep(1000);
                }
            }
            throw errorMSG.Last(s => s != null);
        }
    }
}