LMS.service/LMS.Tools/MJPackage/TaskService.cs

using LMS.Common.Extensions;
using LMS.DAO;
using LMS.Repository.DB;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Net;
using System.Net.Sockets;
using System.Threading.Tasks;

namespace LMS.Tools.MJPackage
{
    public class TaskService(ITokenService tokenService, ILogger<TaskService> logger, ApplicationDbContext dbContext, ITaskConcurrencyManager taskConcurrencyManager) : ITaskService
    {
        private readonly ITokenService _tokenService = tokenService;
        private readonly ILogger<TaskService> _logger = logger;
        private readonly ApplicationDbContext _dbContext = dbContext;
        private readonly ITaskConcurrencyManager _taskConcurrencyManager = taskConcurrencyManager;

        public async Task<Dictionary<string, object>?> FetchTaskAsync(MJApiTasks mJApiTasks)
        {
            try
            {
                // 获取UseToken，先尝试 Token，再尝试 TokenId
                var tokenConfig = await _tokenService.GetTokenAsync(mJApiTasks.Token);
                string useToken = string.Empty;

                if (tokenConfig == null)
                {
                    // Token 没找到 尝试用 TokenId 查找
                    MJApiTokens? mJApiTokens = await _tokenService.GetMJapiTokenByIdAsync(mJApiTasks.TokenId);
                    if (mJApiTokens == null)
                    {
                        return null;
                    }
                    useToken = mJApiTokens.UseToken;
                }
                else
                {
                    useToken = tokenConfig.UseToken;
                }

                if (string.IsNullOrWhiteSpace(useToken))
                {
                    _logger.LogInformation($"Token is empty for task ID: {mJApiTasks.TaskId}");
                    return null;
                }

                // 尝试原始API
                var originResult = await TryOriginApiAsync(mJApiTasks.ThirdPartyTaskId);
                var properties = new Dictionary<string, object>();
                if (string.IsNullOrWhiteSpace(originResult))
                {
                    originResult = await TryBackupApiAsync(mJApiTasks.ThirdPartyTaskId, useToken);
                }

                if (string.IsNullOrWhiteSpace(originResult))
                {
                    // 没有找到数据 
                    _logger.LogInformation($"备用API没有返回数据，TaskId: {mJApiTasks.TaskId}");
                    return null;
                }

                try
                {
                    // 不为空 开始解析数据
                    properties = JsonConvert.DeserializeObject<Dictionary<string, object>>(originResult);
                }
                catch (JsonException ex)
                {
                    _logger.LogError($"解析API返回数据失败: {ex.Message}");
                    return null;
                }

                if (properties == null)
                {
                    _logger.LogInformation($"API返回数据为空，TaskId: {mJApiTasks.TaskId}");
                    return null;
                }
                return properties;
            }
            catch (Exception ex)
            {
                // 记录异常日志
                _logger.LogError($"Error fetching task: {ex.Message}");
                return null;
            }
        }

        private async Task<string?> TryOriginApiAsync(string id)
        {
            string originUrl = $"https://mjapi.bzu.cn/mj/task/{id}/fetch";

            // 判断 原始token 不存在 直接 返回空
            string orginToken = await _tokenService.GetOriginToken();
            if (string.IsNullOrWhiteSpace(orginToken))
            {
                return null;
            }

            try
            {
                using var client = new HttpClient();
                client.DefaultRequestHeaders.Add("Authorization", orginToken);
                client.Timeout = TimeSpan.FromSeconds(30);

                var response = await client.GetAsync(originUrl);
                var content = await response.Content.ReadAsStringAsync();
                // 判断是不是返回空
                if ((int)response.StatusCode == 204 || string.IsNullOrWhiteSpace(content))
                {
                    return string.Empty;
                }
                if (!response.IsSuccessStatusCode)
                {
                    _logger.LogWarning($"源API调用返回错误状态码，TaskId: {id}, StatusCode: {response.StatusCode}");
                    return null;
                }
                return content;
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex, "原始API调用失败，TaskId: {TaskId}，准备尝试备用API", id);
                return null;
            }
        }

        private async Task<string?> TryBackupApiAsync(string id, string useToken)
        {
            string mjAPIBasicUrl = await _tokenService.GetMJAPIBasicUrl();
            string backupUrl = $"{mjAPIBasicUrl}/mj/task/{id}/fetch";
            const int maxRetries = 3;
            const int baseDelayMs = 1000;

            using var client = new HttpClient();
            client.DefaultRequestHeaders.Add("Authorization", "sk-" + useToken);
            client.Timeout = TimeSpan.FromSeconds(30);


            for (int attempt = 1; attempt <= maxRetries; attempt++)
            {
                try
                {
                    var response = await client.GetAsync(backupUrl);
                    var content = await response.Content.ReadAsStringAsync();
                    // 判断请求是不是报错
                    if (!response.IsSuccessStatusCode)
                    {
                        _logger.LogWarning("备用API调用返回错误状态码，TaskId: {TaskId}, Attempt: {Attempt}, StatusCode: {StatusCode}",
                            id, attempt, response.StatusCode);
                        return null;
                    }
                    return content;
                }
                catch (Exception ex) when (IsRetriableException(ex))
                {
                    if (attempt < maxRetries)
                    {
                        var delay = baseDelayMs * (int)Math.Pow(2, attempt - 1);
                        _logger.LogWarning(ex, "备用API调用失败，TaskId: {TaskId}, Attempt: {Attempt}, 将在{Delay}ms后重试",
                            id, attempt, delay);
                        await Task.Delay(delay);
                    }
                    else
                    {
                        _logger.LogError(ex, "备用API调用最终失败，TaskId: {TaskId}, MaxAttempts: {MaxAttempts}",
                            id, maxRetries);
                    }
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex, "备用API调用发生不可重试异常，TaskId: {TaskId}, Attempt: {Attempt}",
                        id, attempt);
                    break;
                }
            }

            return null;
        }

        private static bool IsRetriableException(Exception ex)
        {
            return ex is HttpRequestException ||
                   ex is TaskCanceledException ||
                   ex is SocketException;
        }

    }
}