using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Threading;
using Ips.Library.Basic;
using DevExpress.PerformanceTests.PerfomanceMonitor;

namespace Ips.Service.CapServer
{
    class FileMonitor
    {
        /// <summary>
        /// 磁盘可用空间百分比不足此数时开始清理数据
        /// </summary>
        float maxPercent = 0.2f;//
        /// <summary>
        /// 被监控目录
        /// </summary>
        string[] monitorPaths;
        /// <summary>
        /// 是否监控
        /// </summary>
        volatile bool isMonitor = false;

        public FileMonitor(string[] p, float maxPercent = 0.2f)
        {
            this.monitorPaths = p.Select(p => p.ToUpper()).Distinct().ToArray();
            this.maxPercent = maxPercent;
        }

        public void Stop()
        {
            isMonitor = false;
        }

        public void Start()
        {
            isMonitor = true;
            _ = DoMonitor();
        }

        private async Task DoMonitor()
        {
            while (isMonitor)
            {
                CheckAndClearDisk();
                await Task.Delay(1000 * 300);
            }
        }

        private void CheckAndClearDisk()
        {
            try
            {
                var driveFolders = monitorPaths.GroupBy(m => Path.GetPathRoot(m));
                foreach (var driveFolder in driveFolders)
                {
                    DriveInfo drive = new DriveInfo(driveFolder.Key);
                    DateTime prevClearTime = DateTime.MinValue;
                    while (drive.TotalFreeSpace / (drive.TotalSize * 1.0f) <= maxPercent)
                    {
                        IpsLogger.Info($"正在清理[{string.Join(";",driveFolder.ToList())}]中的数据...");
                        var fsList = driveFolder.Where(m => Directory.Exists(m))
                            .Select(m => new DirectoryInfo(m))
                            .SelectMany(m => m.EnumerateFiles("*", SearchOption.AllDirectories));
                        if (!fsList.Any())
                        {
                            IpsLogger.Warn($"{drive.ToString().Substring(0, 1)}盘空间不足，但要清理数据的目录为空，清理数据结束！");
                            Thread.Sleep(100);
                        }
                        else
                        {
                            //每次清理从上次清理结束时间开始，防止有些删不掉的文件阻止删除文件
                            var firstFs = fsList.Where(m => m.LastWriteTime > prevClearTime).OrderBy(m => m.LastWriteTime).FirstOrDefault();
                            var clearTime = firstFs.LastWriteTime.AddHours(1);
                            foreach (var fsItem in fsList.Where(m => m.LastWriteTime <= clearTime))
                            {
                                try
                                {
                                    fsItem.Delete();
                                    if (!fsItem.Directory.EnumerateFiles("*", SearchOption.AllDirectories).Any())
                                    {
                                        bool isAny = driveFolder.Any(s => s.Contains(fsItem.DirectoryName));
                                        if (isAny) continue;
                                        fsItem.Directory.Delete(true);
                                    }
                                }
                                catch (Exception ex)
                                {
                                    IpsLogger.Error($"{DateTime.Now:yyyy-MM-dd HH:mm:ss} 删除文件或目录出错", ex);
                                }
                            }
                            prevClearTime = clearTime;
                            IpsLogger.Info($"{DateTime.Now:yyyy-MM-dd HH:mm:ss} 清理数据结束！");
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                IpsLogger.Error($"清理数据异常", ex);
            }

        }
    }
}