using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.BL.Entities;
using Tango.Core.Commands;
using Tango.FSE.BL;
using Tango.FSE.Common;
using Tango.FSE.Common.RemoteUpgrade;

namespace Tango.FSE.Upgrade.ViewModels
{
    public class FirmwareUpgradeViewVM : RemoteUpgradeViewModel
    {
        private List<TangoVersion> _tangoVersions;
        public List<TangoVersion> TangoVersions
        {
            get { return _tangoVersions; }
            set { _tangoVersions = value; RaisePropertyChangedAuto(); }
        }

        private TangoVersion _selectedVersion;
        public TangoVersion SelectedVersion
        {
            get { return _selectedVersion; }
            set { _selectedVersion = value; RaisePropertyChangedAuto(); InvalidateRelayCommands(); }
        }

        private bool _useExistingTfpFile;
        public bool UseExistingTfpFile
        {
            get { return _useExistingTfpFile; }
            set { _useExistingTfpFile = value; RaisePropertyChangedAuto(); InvalidateRelayCommands(); }
        }

        private String _existingTfpFileLocation;
        public String ExistingTfpFileLocation
        {
            get { return _existingTfpFileLocation; }
            set { _existingTfpFileLocation = value; RaisePropertyChangedAuto(); InvalidateRelayCommands(); }
        }

        private String _existingTfpFileVersion;
        public String ExistingTfpFileVersion
        {
            get { return _existingTfpFileVersion; }
            set { _existingTfpFileVersion = value; RaisePropertyChangedAuto(); }
        }


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

        public RelayCommand SelectExistingTfpFileLocationCommand { get; set; }

        public RelayCommand GeneratePackageCommand { get; set; }

        public RelayCommand ContinueCommand { get; set; }

        public FirmwareUpgradeViewVM()
        {
            SelectExistingTfpFileLocationCommand = new RelayCommand(SelectExistingTfpFileLocation);
            GeneratePackageCommand = new RelayCommand(GeneratePackage, () => SelectedVersion != null);
            ContinueCommand = new RelayCommand(ContinueWithExistingTfpFile, () => ExistingTfpFileLocation != null);
        }

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

            if (UseExistingTfpFile && !MachineProvider.IsConnected)
            {
                UseExistingTfpFile = false;
            }

            Handler = new RemoteUpgradeHandler("Ready");
        }

        private async void SelectExistingTfpFileLocation()
        {
            var result = await StorageProvider.OpenFile("Select existing firmware package file", "Tango Firmware Package|*.tfp");
            if (result)
            {
                try
                {
                    LogManager.Log("Validating firmware package file...");
                    using (FileStream s = File.OpenRead(result.SelectedItem))
                    {
                        var package = MachineProvider.MachineOperator.GetFirmwarePackageInfo(s).Result;
                        package.Validate();
                        ExistingTfpFileVersion = package.GetMcuVersion().ToString();
                    }
                }
                catch (Exception ex)
                {
                    await NotificationProvider.ShowError($"Error loading the selected tfp file.\n{ex.FlattenMessage()}");
                    return;
                }

                ExistingTfpFileLocation = result.SelectedItem;
            }
        }

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

            if (TangoVersions == null)
            {
                try
                {
                    TangoVersions = (await Services.TangoVersionsService.GetAllTangoVersions()).DistinctBy(x => x.FirmwareVersion).Take(10).ToList();
                    SelectedVersion = TangoVersions.FirstOrDefault();
                }
                catch (Exception ex)
                {
                    LogManager.Log(ex, "Error retrieving tango versions.");
                    await NotificationProvider.ShowError($"Error retrieving Tango versions.\n{ex.FlattenMessage()}");
                }
            }
        }

        private async void GeneratePackage()
        {
            try
            {
                IsFree = false;
                var tempTfpFile = TemporaryManager.CreateImaginaryFile(".tfp");
                Handler = await RemoteUpgradeManager.CreateTfpFile(SelectedVersion, tempTfpFile);
                await Handler.WaitForCompletion();
                await ModularNavigationManager.NavigateTo<FirmwareUpgradeGeneratedViewVM.NavigationObject>(Navigation.RemoteUpgradeView.FirmwareUpgradeGeneratedView, new FirmwareUpgradeGeneratedViewVM.NavigationObject()
                {
                    IsExistingTfpFile = false,
                    TfpFileLocation = tempTfpFile,
                    SelectedVersion = SelectedVersion,
                }, false);
            }
            catch (OperationCanceledException)
            {
                //Aborted...
            }
            catch (AuthorizationException ex)
            {
                await NotificationProvider.ShowError(ex.Message);
            }
            catch (Exception ex)
            {
                LogManager.Log(ex, "Error generating remote firmware upgrade package.");
            }
            finally
            {
                IsFree = true;
            }
        }

        private async void ContinueWithExistingTfpFile()
        {
            await ModularNavigationManager.NavigateTo<FirmwareUpgradeGeneratedViewVM.NavigationObject>(Navigation.RemoteUpgradeView.FirmwareUpgradeGeneratedView, new FirmwareUpgradeGeneratedViewVM.NavigationObject()
            {
                IsExistingTfpFile = true,
                TfpFileLocation = ExistingTfpFileLocation,
            }, false);
        }
    }
}