using LMS.Common.Extensions;
using LMS.DAO;
using LMS.Repository.DB;
using LMS.Repository.MJPackage;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using System.Collections.Concurrent;
using System.Text;

namespace LMS.Tools.MJPackage
{
    public class TaskConcurrencyManager : ITaskConcurrencyManager
    {
        private readonly ConcurrentDictionary<string, MJApiTasks> _activeTasks = new();
        private readonly ConcurrentDictionary<string, string> _thirdPartyTaskMap = new(); // ThirdPartyTaskId -> TaskId
        private readonly TokenUsageTracker _usageTracker;
        private readonly IServiceScopeFactory _scopeFactory;
        private readonly ILogger<TaskConcurrencyManager> _logger;
        private readonly ApplicationDbContext _dbContext;
        private readonly ITokenService _tokenService;

        public TaskConcurrencyManager(
            TokenUsageTracker usageTracker,
            IServiceScopeFactory scopeFactory,
            ILogger<TaskConcurrencyManager> logger,
            ApplicationDbContext dbContext,
            ITokenService tokenService)
        {
            _usageTracker = usageTracker;
            _scopeFactory = scopeFactory;
            _logger = logger;
            _dbContext = dbContext;
            _tokenService = tokenService;
        }

        /// <summary>
        /// 尝试开始新任务（获取并发许可）
        /// </summary>
        public async Task CreateTaskAsync(
            string token,
            string thirdPartyTaskId)
        {
            try
            {
                TokenCacheItem? tokenConfig = await _tokenService.GetTokenAsync(token);
                if (tokenConfig == null || string.IsNullOrWhiteSpace(tokenConfig.UseToken))
                {
                    _logger.LogWarning($"无效的Token: {token}");
                    return;
                }
                // 创建任务信息
                var taskId = Guid.NewGuid().ToString("N");
                var mJApiTasks = new MJApiTasks
                {
                    TaskId = taskId,
                    Token = token,
                    TokenId = tokenConfig.Id,
                    StartTime = BeijingTimeExtension.GetBeijingTime(),
                    Status = MJTaskStatus.NOT_START,
                    ThirdPartyTaskId = thirdPartyTaskId,
                    Properties = null
                };

                // 5. 持久化任务信息到数据库
                await SaveTaskToDatabase(mJApiTasks);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"开始任务时发生错误: Token={token}");
            }
        }


        /// <summary>
        /// 获取任务信息
        /// </summary>
        public async Task<MJApiTasks> GetTaskInfoAsync(string taskId)
        {
            if (_activeTasks.TryGetValue(taskId, out var taskInfo))
            {
                return taskInfo;
            }

            // 如果内存中没有，尝试从数据库加载
            return await LoadTaskFromDatabase(taskId);
        }

        /// <summary>
        /// 通过第三方ID获取数据
        /// </summary>
        /// <param name="thirdPartyId"></param>
        /// <returns></returns>
        public async Task<MJApiTasks> GetTaskInfoByThirdPartyIdAsync(string thirdPartyId)
        {
            if (string.IsNullOrWhiteSpace(thirdPartyId))
            {
                _logger.LogWarning("第三方任务ID为空");
                return null;
            }
            MJApiTasks? mJApiTasks = await _dbContext.MJApiTasks.FirstOrDefaultAsync(x => x.ThirdPartyTaskId == thirdPartyId);
            return mJApiTasks;
        }

        /// <summary>
        /// 获取运行中的任务列表
        /// </summary>
        public async Task<IEnumerable<MJApiTasks>> GetRunningTasksAsync(string token = null)
        {
            var runningTasks = _activeTasks.Values
                .Where(t => t.Status != MJTaskStatus.SUCCESS && t.Status != MJTaskStatus.FAILURE && t.Status != MJTaskStatus.CANCEL)
                .Where(t => string.IsNullOrEmpty(token) || t.Token == token)
                .OrderBy(t => t.StartTime)
                .ToList();

            _logger.LogDebug($"当前运行中的任务数: {runningTasks.Count}" + (string.IsNullOrEmpty(token) ? "" : $", Token={token}"));

            return await Task.FromResult(runningTasks);
        }

        /// <summary>
        /// 获取Token的并发状态
        /// </summary>
        public async Task<(int maxConcurrency, int running, int available)> GetConcurrencyStatusAsync(string token)
        {
            var status = _usageTracker.GetConcurrencyStatus(token);
            return await Task.FromResult((status.maxCount, status.currentlyExecuting, status.available));
        }

        /// <summary>
        /// 清理超时任务
        /// </summary>
        public async Task CleanupTimeoutTasksAsync(TimeSpan timeout)
        {
            _logger.LogInformation($"开始清理超时任务，超时阈值: {timeout.TotalMinutes}分钟");

            var cutoffTime = BeijingTimeExtension.GetBeijingTime() - timeout;
            var timeoutTasks = _activeTasks.Values
                .Where(t => t.StartTime < cutoffTime && t.Status != MJTaskStatus.SUCCESS && t.Status != MJTaskStatus.FAILURE && t.Status != MJTaskStatus.CANCEL)
                .ToList();

            _logger.LogInformation($"发现 {timeoutTasks.Count} 个超时任务");

            foreach (var task in timeoutTasks)
            {
                _logger.LogWarning($"清理超时任务: TaskId={task.TaskId}, Token={task.Token}, 开始时间={task.StartTime:yyyy-MM-dd HH:mm:ss}");
                _usageTracker.ReleaseConcurrencyPermit(task.Token);
            }
        }

        /// <summary>
        /// 保存任务到数据库
        /// </summary>
        private async Task SaveTaskToDatabase(MJApiTasks mJApiTasks)
        {
            try
            {
                await _dbContext.MJApiTasks.AddAsync(mJApiTasks);
                await _dbContext.SaveChangesAsync();
                _logger.LogInformation($"任务已保存到数据库: TaskId={mJApiTasks.TaskId}, Token={mJApiTasks.Token}");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"保存任务到数据库失败: TaskId={mJApiTasks.TaskId}");
            }
        }

        /// <summary>
        /// 更新数据库中的任务状态
        /// </summary>
        public async Task UpdateTaskInDatabase(MJApiTasks mJApiTasks)
        {
            try
            {
                MJApiTasks? apiTasks = await _dbContext.MJApiTasks.FirstOrDefaultAsync(x => x.ThirdPartyTaskId == mJApiTasks.ThirdPartyTaskId);
                if (apiTasks == null)
                {
                    _logger.LogWarning($"未找到任务: TaskId={mJApiTasks.TaskId}");
                    return;
                }
                apiTasks.Status = mJApiTasks.Status;
                apiTasks.EndTime = mJApiTasks.EndTime;
                apiTasks.Properties = mJApiTasks.Properties;
                _dbContext.MJApiTasks.Update(apiTasks);
                await _dbContext.SaveChangesAsync();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"更新任务状态到数据库失败: TaskId={mJApiTasks.TaskId}");
            }
        }

        /// <summary>
        /// 从数据库加载任务
        /// </summary>
        private async Task<MJApiTasks> LoadTaskFromDatabase(string taskId)
        {
            try
            {
                MJApiTasks? mJApiTasks = await _dbContext.MJApiTasks.FirstOrDefaultAsync(x => x.TaskId == taskId);
                if (mJApiTasks == null)
                {
                    _logger.LogWarning($"未找到任务: TaskId={taskId}");
                    return null;
                }

                return mJApiTasks;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"从数据库加载任务失败: TaskId={taskId}");
                return null;
            }
        }
    }
}