using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using DH.Commons.Helper;

namespace DH.Commons.Enums
{
    public class ImageSaveHelper
    {
        public event Action<DateTime, string> OnImageSaveExceptionRaised;

        //private string baseDirectory = "";
        //public string BaseDirectory
        //{
        //    get => baseDirectory;
        //    set
        //    {
        //        baseDirectory = value;
        //        if (string.IsNullOrWhiteSpace(baseDirectory) || !Path.IsPathRooted(baseDirectory))
        //        {
        //            baseDirectory = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Images");
        //        }
        //    }
        //}
        public bool EnableImageSave { get; set; } = true;

        public ImageSaveHelper() { }
        public ImageSaveHelper(bool enableImageSave = true)
        {
            EnableImageSave = enableImageSave;
        }


        object lockObj = new object();
        ////耗时操作从 _taskFactory分配线程
        //public TaskFactory _taskFactory = new TaskFactory(TaskCreationOptions.LongRunning, TaskContinuationOptions.LongRunning);
        readonly ConcurrentQueue<ImageSaveSet> _imageQueue = new ConcurrentQueue<ImageSaveSet>();
        Task _saveTask = null;
        readonly object _saveLock = new object();

        public async void ImageSaveAsync(ImageSaveSet set)
        {
            if (!EnableImageSave)
                return;

            await Task.Run(() =>
            {
                _imageQueue.Enqueue(set);

                lock (_saveLock)
                {
                    if (_saveTask == null)
                    {
                        _saveTask = Task.Run(async () =>
                        {
                            try
                            {
                                while (true)
                                {
                                    while (_imageQueue.Count > 0)
                                    {
                                        if (_imageQueue.TryDequeue(out ImageSaveSet saveSet))
                                        {
                                            if (!Directory.Exists(Path.GetDirectoryName(saveSet.FullName)))
                                            {
                                                Directory.CreateDirectory(Path.GetDirectoryName(saveSet.FullName));
                                            }
                                            if (saveSet.SaveImage != null)
                                            {
                                                saveSet.SaveImage.Save(saveSet.FullName, saveSet.ImageFormat);
                                                saveSet.SaveImage.Dispose();
                                            }
                                            saveSet = null;
                                        }
                                    }

                                    await Task.Delay(2000);
                                }
                            }
                            catch (Exception ex)
                            {
                                OnImageSaveExceptionRaised?.Invoke(DateTime.Now, $"图片保存异常：{ex.GetExceptionMessage()}");
                            }
                        });
                    }
                }
            });
        }
    }

    public class ImageSaveSet
    {
        public string FullName { get; set; }//带后缀 全路径

        public Bitmap SaveImage { get; set; }

        public ImageFormat ImageFormat { get; set; } = ImageFormat.Jpeg;
    }
}