using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core.Commands;
using Tango.Integration.Operation;
using Tango.SharedUI;

namespace Tango.MachineStudio.UI.ViewModels
{
    public class FirmwareUpgradeViewVM : DialogViewVM
    {
        private IMachineOperator _operator;
        private FileStream _stream;

        private FirmwareUpgradeHandler _handler;
        public FirmwareUpgradeHandler Handler
        {
            get { return _handler; }
            set { _handler = value; RaisePropertyChangedAuto(); }
        }

        private String _selectedFile;
        public String SelectedFile
        {
            get { return _selectedFile; }
            set { _selectedFile = value; RaisePropertyChangedAuto(); }
        }

        private int _currentPage;
        public int CurrentPage
        {
            get { return _currentPage; }
            set { _currentPage = value; RaisePropertyChangedAuto(); }
        }

        public RelayCommand SelectCommand { get; set; }

        public RelayCommand UpgradeCommand { get; set; }

        public RelayCommand AbortCommand { get; set; }

        public FirmwareUpgradeViewVM(IMachineOperator machineOperator) : base()
        {
            _operator = machineOperator;
            SelectCommand = new RelayCommand(BrowseForFile);
            UpgradeCommand = new RelayCommand(StartUpgrade, () => SelectedFile != null);
            AbortCommand = new RelayCommand(AbortUpgrade, () => Handler != null && Handler.Status != FirmwareUpgradeStatus.Validating && Handler.Status != FirmwareUpgradeStatus.Activating);
        }

        private void BrowseForFile()
        {
            OpenFileDialog dlg = new OpenFileDialog();
            dlg.Title = "Select tango firmware package file";
            dlg.Filter = "Tango Firmware Package|*.tfp";
            if (dlg.ShowDialog().Value)
            {
                SelectedFile = dlg.FileName;
                InvalidateRelayCommands();
            }
        }

        private async void StartUpgrade()
        {
            CurrentPage = 1;

            _stream = new FileStream(SelectedFile, FileMode.Open);
            Handler = await _operator.UpgradeFirmware(_stream);
            Handler.Progress += (_, e) =>
            {
                InvokeUI(() =>
                {
                    AbortCommand.RaiseCanExecuteChanged();
                });
            };
            Handler.Completed += (_, __) => 
            {
                _stream.Dispose();
                CurrentPage = 2;
            };
            Handler.Canceled += (_, __) => 
            {
                _stream.Dispose();
            };
            Handler.Failed += (_, __) => 
            {
                _stream.Dispose();
            };

        }

        private async void AbortUpgrade()
        {
            await Handler.Cancel();
        }
    }
}