using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using Tango.Core.Commands;
using Tango.FileSystem;
using Tango.FSE.Common;
using Tango.FSE.Common.Connection;
using static Tango.SharedUI.Controls.NavigationControl;

namespace Tango.FSE.PPCConsole.ViewModels
{
    public class FileSystemViewVM : FSEViewModel, INavigationViewModel
    {
        private FileSystemItem _currentItem;
        public FileSystemItem CurrentItem
        {
            get { return _currentItem; }
            set { _currentItem = value; RaisePropertyChangedAuto(); OnCurrentItemChanged(); }
        }

        private String _currentPath;
        public String CurrentPath
        {
            get { return _currentPath; }
            set { _currentPath = value; RaisePropertyChangedAuto(); }
        }

        public RelayCommand NavigateCommand { get; set; }
        public RelayCommand<FileSystemItem> OpenItemCommand { get; set; }
        public RelayCommand BackCommand { get; set; }

        public FileSystemViewVM()
        {
            NavigateCommand = new RelayCommand(NavigateToCurrentPath);
            OpenItemCommand = new RelayCommand<FileSystemItem>(OpenFileSystemItem);
            BackCommand = new RelayCommand(NavigateBack, () => !(CurrentItem is FolderItem) || !(CurrentItem as FolderItem).IsRoot);
        }

        private async void NavigateBack()
        {
            if (CurrentItem.Path.Length == 3)
            {
                await Navigate(null);
            }
            else
            {
                String parent = Path.GetDirectoryName(CurrentItem.Path);
                await Navigate(parent);
            }
        }

        public override void OnApplicationStarted()
        {
            base.OnApplicationStarted();
            MachineProvider.MachineConnected += MachineProvider_MachineConnected;
        }

        public override void OnApplicationReady()
        {
            base.OnApplicationReady();
        }

        private async void MachineProvider_MachineConnected(object sender, MachineConnectedEventArgs e)
        {
            await Navigate(null);
        }

        private async void NavigateToCurrentPath()
        {
            await Navigate(CurrentPath);
        }

        private async void OpenFileSystemItem(FileSystemItem item)
        {
            if (item != null)
            {
                await Navigate(item.Path);
            }
        }

        private async Task Navigate(String path)
        {
            try
            {
                IsFree = false;

                Mouse.OverrideCursor = Cursors.AppStarting;

                if (path != null)
                {
                    CurrentItem = await FileSystemProvider.GetFolder(path) as FileSystemItem;
                }
                else
                {
                    CurrentItem = await FileSystemProvider.GetThisPC() as FileSystemItem;
                }
            }
            catch (Exception ex)
            {
                IsFree = true;
                Mouse.OverrideCursor = null;
                await NotificationProvider.ShowError($"Error navigating to the specified path.\n{ex.FlattenMessage()}");
            }
            finally
            {
                IsFree = true;
                Mouse.OverrideCursor = null;
            }
        }

        private void OnCurrentItemChanged()
        {
            CurrentPath = CurrentItem.Path;
            InvalidateRelayCommands();
        }
    }
}