using iFileProxy.Config;
using iFileProxy.Helpers;
using iFileProxy.Models;
using Newtonsoft.Json;
using Serilog;

namespace iFileProxy.Services
{
    /// <summary>
    /// 本地缓存管理器
    /// </summary>
    public class LocalCacheManager
    {
        // 禁用空警告  因为初始化的时候就已经检查过相关的内容了
#pragma warning disable CS8601
        private readonly AppConfig _appConfig = AppConfig.GetCurrConfig();
        private readonly static Serilog.ILogger _logger = Log.Logger.ForContext<LocalCacheManager>();

        private readonly Timer _timer;
        private readonly DatabaseGateService _dbGateService;
        private readonly int CACHE_LIFETIME;

        /// <summary>
        /// 缓存管理器
        /// </summary>
        public LocalCacheManager(IServiceProvider serviceProvider)
        {
            _logger.Information("Initializing LocalCacheManager.");
            CACHE_LIFETIME = _appConfig.DownloadOptions.CacheLifetime;
            _dbGateService = serviceProvider.GetRequiredService<DatabaseGateService>();
            // 开始定时清理任务
            _timer = new Timer(CheckAndCleanCache, null, TimeSpan.FromSeconds(6), TimeSpan.FromSeconds(60));
            _logger.Information("succ.");
        }

        /// <summary>
        /// 检查并且清理缓存数据
        /// </summary>
        public void CheckAndCleanCache(object state)
        {
            // 初始化并打开一个MySQL连接 防止后续数据过多导致程序crush
            using var dbConn = _dbGateService.GetAndOpenDBConn(DbConfigName.iFileProxy);

            // 获取数据库中超出生命周期的缓存数据
            string result = _dbGateService.QueryTableData($"SELECT * FROM t_tasks_info WHERE  UNIX_TIMESTAMP(NOW()) - UNIX_TIMESTAMP(update_time) > {CACHE_LIFETIME} AND (tag <> 'CLEANED' OR tag IS NULL)", DbConfigName.iFileProxy);
            List<TaskInfo>? taskInfos = JsonConvert.DeserializeObject<List<TaskInfo>>(result);
            if (taskInfos != null)
            {
                foreach (TaskInfo taskInfo in taskInfos)
                {
                    string cacheFileName = Path.Combine(_appConfig.DownloadOptions.SavePath, taskInfo.FileName);
                    if (File.Exists(cacheFileName))
                    {
                        _logger.Information($"正在清理缓存文件: {cacheFileName}");
                        try
                        {
                            File.Delete(cacheFileName);
                        }
                        catch (Exception e)
                        {
                            _logger.Error("缓存文件删除失败: {e}", e);
                            throw;
                        }
                    }
                    _dbGateService.Query($"UPDATE t_tasks_info SET `tag` = \"CLEANED\" WHERE `tid` = '{taskInfo.TaskId}'", dbConn);
                    taskInfo.Status = TaskState.Cleaned;
                    _dbGateService.UpdateTaskStatus(taskInfo,dbConn);
                }
            }


        }

        /// <summary>
        /// 停止定时清理服务
        /// </summary>
        public void StopScheduledCleanupService()
        {
            _timer.Dispose();
        }

    }
}