using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core.Commands;
using Tango.Core.DI;
using Tango.Core.IO;
using Tango.Integration.ExternalBridge;
using Tango.Integration.Storage;
using Tango.MachineStudio.Common;
using Tango.MachineStudio.Common.FirmwareUpgrade;
using Tango.MachineStudio.Common.Notifications;
using Tango.MachineStudio.Common.StudioApplication;
using Tango.MachineStudio.Storage.Models;

namespace Tango.MachineStudio.Storage.ViewModels
{
    public class MainViewVM : StudioViewModel
    {
        public event EventHandler CurrentFolderChanged;

        private IStudioApplicationManager _applicationManager;
        private INotificationProvider _notification;
        private IFirmwareUpgrader _firmwareUpgrader;
        private bool _machine_operator_changed = true;

        private StorageManager _storageManager;
        public StorageManager StorageManager
        {
            get { return _storageManager; }
            set { _storageManager = value; RaisePropertyChangedAuto(); }
        }

        private StorageItem _selectedStorageItem;
        public StorageItem SelectedStorageItem
        {
            get { return _selectedStorageItem; }
            set { _selectedStorageItem = value; RaisePropertyChangedAuto(); InvalidateRelayCommands(); }
        }

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

        public ObservableCollection<StorageFileHandlerModel> FileHandlers { get; set; }

        public RelayCommand BackCommand { get; set; }

        public RelayCommand RefreshCommand { get; set; }

        public RelayCommand GoCommand { get; set; }

        public RelayCommand<StorageFileHandlerModel> CancelFileHandlerCommand { get; set; }

        public RelayCommand<StorageFileHandlerModel> OpenFileHandlerCommand { get; set; }

        public RelayCommand<StorageFileHandlerModel> RemoveFileHandlerCommand { get; set; }

        public RelayCommand DownloadFileCommand { get; set; }

        public RelayCommand DeleteFileCommand { get; set; }

        public RelayCommand CreateFolderCommand { get; set; }

        public RelayCommand DeleteFolderCommand { get; set; }

        public RelayCommand UploadFileCommand { get; set; }

        public RelayCommand UploadVersionCommand { get; set; }

        public RelayCommand ValidateVersionCommand { get; set; }

        public RelayCommand ActivateVersionCommand { get; set; }

        public RelayCommand GenerateTfpCommand { get; set; }

        public MainViewVM()
        {

        }

        [TangoInject]
        public MainViewVM(IStudioApplicationManager applicationManager, INotificationProvider notificationProvider, IFirmwareUpgrader firmwareUpgrader)
        {
            _applicationManager = applicationManager;
            _notification = notificationProvider;
            _firmwareUpgrader = firmwareUpgrader;
            _applicationManager.ConnectedMachineChanged += _applicationManager_ConnectedMachineChanged;

            FileHandlers = new ObservableCollection<StorageFileHandlerModel>();

            GoCommand = new RelayCommand(() => NavigateToPath(CurrentPath), () => StorageManager != null);
            BackCommand = new RelayCommand(NavigateBack, () => StorageManager != null && StorageManager.CurrentFolder.Parent != null);
            CancelFileHandlerCommand = new RelayCommand<StorageFileHandlerModel>(CancelFileHandler);
            OpenFileHandlerCommand = new RelayCommand<StorageFileHandlerModel>(OpenFileHandler);
            RefreshCommand = new RelayCommand(Refresh, () => StorageManager != null);
            RemoveFileHandlerCommand = new RelayCommand<StorageFileHandlerModel>(RemoveFileHandler);
            DownloadFileCommand = new RelayCommand(DownloadFile, () => StorageManager != null && SelectedStorageItem != null && SelectedStorageItem is StorageFile);
            DeleteFileCommand = new RelayCommand(DeleteFile, () => StorageManager != null && SelectedStorageItem != null && SelectedStorageItem is StorageFile);
            CreateFolderCommand = new RelayCommand(CreateFolder, () => StorageManager != null && StorageManager.CurrentFolder != null);
            DeleteFolderCommand = new RelayCommand(DeleteFolder, () => StorageManager != null && SelectedStorageItem != null && SelectedStorageItem is StorageFolder);
            UploadFileCommand = new RelayCommand(UploadFile, () => StorageManager != null && StorageManager.CurrentFolder != null);
            UploadVersionCommand = new RelayCommand(UploadVersion, () => StorageManager != null && StorageManager.CurrentFolder != null);
            ValidateVersionCommand = new RelayCommand(ValidateVersion, () => StorageManager != null && StorageManager.CurrentFolder != null);
            ActivateVersionCommand = new RelayCommand(ActivateVersion, () => StorageManager != null && StorageManager.CurrentFolder != null);
            GenerateTfpCommand = new RelayCommand(GenerateTFP);
        }

        private void UploadFile()
        {
            OpenFileDialog dlg = new OpenFileDialog();
            dlg.Title = "Selected a file to upload";
            if (dlg.ShowDialog().Value)
            {
                UploadFile(dlg.FileName);
            }
        }

        private async void DeleteFolder()
        {
            if (SelectedStorageItem == null) return;

            if (_notification.ShowQuestion("Are you sure you want to delete the selected folder?"))
            {
                try
                {
                    IsFree = false;
                    await StorageManager.DeleteItem(SelectedStorageItem);
                    Refresh();
                }
                catch (Exception ex)
                {
                    _notification.ShowError($"Error deleting the selected folder.\n{ex.Message}");
                }

                IsFree = true;
            }
        }

        private async void CreateFolder()
        {
            try
            {
                var name = _notification.ShowTextInput("Enter Folder Name", "");

                if (!String.IsNullOrWhiteSpace(name))
                {
                    IsFree = false;
                    await StorageManager.CreateFolder(Path.Combine(StorageManager.CurrentPath, name));
                    Refresh();
                }
            }
            catch (Exception ex)
            {
                _notification.ShowError($"Error creating the new folder.\n{ex.Message}");
            }

            IsFree = true;
        }

        private async void DeleteFile()
        {
            if (SelectedStorageItem == null) return;

            if (_notification.ShowQuestion("Are you sure you want to delete the selected file?"))
            {
                try
                {
                    IsFree = false;
                    await StorageManager.DeleteItem(SelectedStorageItem);
                    Refresh();
                }
                catch (Exception ex)
                {
                    _notification.ShowError($"Error deleting the selected file.\n{ex.Message}");
                }

                IsFree = true;
            }
        }

        private void DownloadFile()
        {
            DownloadStorageItem(SelectedStorageItem as StorageFile);
        }

        private void OpenFileHandler(StorageFileHandlerModel handler)
        {
            ShowInExplorer(handler.FilePath);
        }

        private async void CancelFileHandler(StorageFileHandlerModel handler)
        {
            await handler.Handler.Cancel();
        }

        private void _applicationManager_ConnectedMachineChanged(object sender, IExternalBridgeClient e)
        {
            _machine_operator_changed = true;

            if (IsVisible)
            {
                Initialize();
            }
        }

        public override void OnApplicationReady()
        {

        }

        public override void OnNavigatedTo()
        {
            base.OnNavigatedTo();

            if (_machine_operator_changed)
            {
                _machine_operator_changed = false;
                Initialize();
            }
        }

        private async void NavigateToPath(String path, bool raiseEvent = true)
        {
            IsFree = false;

            try
            {
                await StorageManager.GetFolder(path);
                CurrentPath = StorageManager.CurrentPath;

                if (raiseEvent)
                {
                    CurrentFolderChanged?.Invoke(this, new EventArgs());
                }
            }
            catch (Exception ex)
            {
                _notification.ShowError($"Error navigating to the specified path.\n{ex.Message}");
            }

            IsFree = true;

            InvalidateRelayCommands();
        }

        private async void Initialize()
        {
            if (_applicationManager.ConnectedMachine != null)
            {
                try
                {
                    StorageManager = _applicationManager.ConnectedMachine.CreateStorageManager();
                    await StorageManager.GetStorageDrive();
                    await StorageManager.GetRootFolder();
                    CurrentPath = StorageManager.StorageDrive.Root;
                }
                catch (Exception ex)
                {
                    _notification.ShowError($"An error occurred while trying to initialize the storage manager.\n{ex.Message}");
                }

                InvalidateRelayCommands();
            }
        }

        public void OnStorageItemDoubleClicked(StorageItem storageItem)
        {
            if (storageItem is StorageFolder && storageItem != null)
            {
                NavigateToPath(storageItem.Path);
            }
            else
            {
                DownloadStorageItem(storageItem as StorageFile);
            }
        }

        private void NavigateBack()
        {
            NavigateToPath(StorageManager.CurrentFolder.Parent);
        }

        private void Refresh()
        {
            NavigateToPath(StorageManager.CurrentFolder.Path, false);
        }

        private async void DownloadStorageItem(StorageFile storageFile)
        {
            SaveFileDialog dlg = new SaveFileDialog();
            dlg.Title = "Select download location";
            dlg.DefaultExt = Path.GetExtension(storageFile.Path);
            dlg.FileName = storageFile.Name;
            if (dlg.ShowDialog().Value)
            {
                FileStream fs = new FileStream(dlg.FileName, FileMode.Create);
                var handler = await StorageManager.DownloadFile(storageFile, fs);
                handler.Completed += (_, __) =>
                {
                    fs.Dispose();
                };

                handler.Canceled += (_, __) =>
                {
                    fs.Dispose();
                    File.Delete(dlg.FileName);
                };

                handler.Failed += (_, __) =>
                {
                    fs.Dispose();
                    File.Delete(dlg.FileName);
                };

                FileHandlers.Insert(0, new StorageFileHandlerModel(handler, dlg.FileName, StorageFileHandlerType.Download));
            }
        }

        private async void UploadFile(String path)
        {
            FileStream fs = new FileStream(path, FileMode.Open);
            var handler = await StorageManager.UploadFile(Path.Combine(StorageManager.CurrentPath, Path.GetFileName(path)), fs);
            handler.Completed += (_, __) =>
            {
                fs.Dispose();
            };

            handler.Canceled += (_, __) =>
            {
                fs.Dispose();
            };

            handler.Failed += (_, __) =>
            {
                fs.Dispose();
            };

            FileHandlers.Insert(0, new StorageFileHandlerModel(handler, path, StorageFileHandlerType.Upload));
        }

        /// <summary>
        /// Shows the file in explorer.
        /// </summary>
        /// <param name="path">Name of the file/folder.</param>
        public static void ShowInExplorer(String path)
        {
            Process.Start("explorer.exe", string.Format("/select,\"{0}\"", path));
        }

        private void RemoveFileHandler(StorageFileHandlerModel handler)
        {
            if (handler.Handler.Status == StorageFileHandlerStatus.Active)
            {
                if (_notification.ShowQuestion("Are you sure you want to cancel this file operation?"))
                {
                    handler.Handler.Cancel();
                    FileHandlers.Remove(handler);
                }
            }
            else
            {
                FileHandlers.Remove(handler);
            }
        }

        private void UploadVersion()
        {
            _firmwareUpgrader.InvokeUpgradeUI();
        }

        private async void ValidateVersion()
        {
            using (_notification.PushTaskItem("Validating firmware version..."))
            {
                try
                {
                    await _applicationManager.ConnectedMachine.ValidateFirmwareVersion(StorageManager.CurrentPath);
                    _notification.ShowInfo($"Version validated successfully!");
                }
                catch (Exception ex)
                {
                    _notification.ShowError($"Error validating firmware version.\n{ex.FlattenMessage()}");
                }
            }
        }

        private async void ActivateVersion()
        {
            using (_notification.PushTaskItem("Activating firmware version..."))
            {
                try
                {
                    await _applicationManager.ConnectedMachine.ActivateFirmwareVersion(StorageManager.CurrentPath);
                    _notification.ShowInfo($"Version activated successfully!");
                }
                catch (Exception ex)
                {
                    _notification.ShowError($"Error activating firmware version.\n{ex.FlattenMessage()}");
                }
            }
        }

        private void GenerateTFP()
        {
            Tango.FirmwarePackageGenerator.MainWindow fWindow = new FirmwarePackageGenerator.MainWindow();
            fWindow.Topmost = true;
            fWindow.Show();
            _applicationManager.RegisterOpenedWindow(fWindow);
        }
    }
}