using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Windows.Controls;
using Correlator.Model;
using Correlator.Util;
using HandyControl.Controls;
using HandyControl.Data;
using Prism.Commands;
using Prism.Mvvm;
using Prism.Services.Dialogs;

namespace Correlator.ViewModels
{
    public class PictureFileViewModel : BindableBase, IDialogAware
    {
        #region 属性绑定

        public string Title { get; private set; } = string.Empty;
        public event Action<IDialogResult> RequestClose;
        private List<ImageResultFile> _totalFiles;
        private List<ImageResultFile> _pictureFiles;

        public List<ImageResultFile> PictureFiles
        {
            get => _pictureFiles;
            set
            {
                _pictureFiles = value;
                RaisePropertyChanged();
            }
        }

        private int _pageIndex = 1;

        public int PageIndex
        {
            get => _pageIndex;
            set
            {
                _pageIndex = value;
                RaisePropertyChanged();
            }
        }

        private int _maxPage;

        public int MaxPage
        {
            get => _maxPage;
            set
            {
                _maxPage = value;
                RaisePropertyChanged();
            }
        }

        #endregion

        #region DelegateCommand

        public DelegateCommand GoBackCommand { get; set; }
        public DelegateCommand<DataGrid> ItemSelectedCommand { get; set; }
        public DelegateCommand ShowPictureCommand { get; set; }
        public DelegateCommand DeletePictureCommand { get; set; }
        public DelegateCommand<FunctionEventArgs<int>> PageUpdatedCmd { get; set; }

        #endregion

        private ImageResultFile _selectedFile;

        public PictureFileViewModel(IDialogService dialogService)
        {
            GoBackCommand = new DelegateCommand(delegate
            {
                RequestClose?.Invoke(new DialogResult(ButtonResult.Cancel));
            });

            ItemSelectedCommand = new DelegateCommand<DataGrid>(delegate(DataGrid dataGrid)
            {
                _selectedFile = (ImageResultFile)dataGrid.SelectedItem;
            });

            ShowPictureCommand = new DelegateCommand(delegate
            {
                if (_selectedFile == null)
                {
                    dialogService.ShowDialog(
                        "AlertMessageDialog",
                        new DialogParameters
                        {
                            { "AlertType", AlertType.Error }, { "Title", "温馨提示" }, { "Message", "图片文件路径错误，无法查看" }
                        },
                        delegate { }
                    );
                    return;
                }
                
                dialogService.ShowDialog("BigPictureView",
                    new DialogParameters { { "ImageFullPath", _selectedFile.FullPath } }, delegate { });
            });

            DeletePictureCommand = new DelegateCommand(() =>
            {
                if (_selectedFile == null)
                {
                    Growl.Error("删除失败");
                    return;
                }

                try
                {
                    File.Delete(_selectedFile.FullPath);

                    //刷新数据
                    _totalFiles = GetTotalPictureFiles();
                    MaxPage = _totalFiles.Count.GetPageSize();
                    PictureFiles = _totalFiles.Take(RuntimeCache.PerPageItemCount).ToList();
                }
                catch (IOException)
                {
                    Growl.Error("删除失败");
                }
            });

            PageUpdatedCmd = new DelegateCommand<FunctionEventArgs<int>>(args =>
            {
                PictureFiles = _totalFiles
                    .Skip((args.Info - 1) * RuntimeCache.PerPageItemCount)
                    .Take(RuntimeCache.PerPageItemCount)
                    .ToList();
            });
        }

        public bool CanCloseDialog()
        {
            return true;
        }

        public void OnDialogClosed()
        {
        }

        public void OnDialogOpened(IDialogParameters parameters)
        {
            _totalFiles = GetTotalPictureFiles();
            MaxPage = _totalFiles.Count.GetPageSize();
            PictureFiles = _totalFiles.Take(RuntimeCache.PerPageItemCount).ToList();
        }

        private static List<ImageResultFile> GetTotalPictureFiles()
        {
            var i = 1;
            return new DirectoryInfo(DirectoryManager.GetPictureDir()).GetFiles("*", SearchOption.AllDirectories)
                .Select(file => new ImageResultFile
                {
                    Order = i++,
                    FileName = file.Name,
                    PersonLiable = "",
                    FullPath = DirectoryManager.GetPictureDir() + "\\" + file.Name,
                    FileSize = file.Length.FormatFileSize(),
                    CreationTime = file.LastWriteTime.ToString("yyyy-MM-dd HH:mm:ss")
                }).ToList();
        }
    }
}