using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core.Commands;
using Tango.Emulations.ExternalBridge;
using Tango.Integration.ExternalBridge;
using Tango.MachineStudio.Common;
using Tango.MachineStudio.Common.Notifications;
using Tango.Settings;
using Tango.SharedUI;

namespace Tango.MachineStudio.UI.ViewModels
{
    /// <summary>
    /// Represents the Machine Studio connection dialog, view model.
    /// </summary>
    /// <seealso cref="Tango.MachineStudio.Common.Notifications.DialogViewVM" />
    public class MachineConnectionViewVM : DialogViewVM
    {
        private EmulatorExternalBridge _emulator;

        private ExternalBridgeScanner _scanner;
        /// <summary>
        /// Gets or sets the machine scanner.
        /// </summary>
        public ExternalBridgeScanner Scanner
        {
            get { return _scanner; }
            set { _scanner = value; RaisePropertyChangedAuto(); }
        }

        private IExternalBridgeClient _selectedMachine;
        /// <summary>
        /// Gets or sets the selected machine.
        /// </summary>
        public IExternalBridgeClient SelectedMachine
        {
            get { return _selectedMachine; }
            set { _selectedMachine = value; RaisePropertyChangedAuto(); InvalidateRelayCommands(); }
        }

        /// <summary>
        /// Gets or sets the connect command.
        /// </summary>
        public RelayCommand ConnectCommand { get; set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="MachineConnectionViewVM"/> class.
        /// </summary>
        /// <param name="scanner">The scanner.</param>
        public MachineConnectionViewVM(ExternalBridgeScanner scanner)
        {
            Scanner = scanner;
            ConnectCommand = new RelayCommand(Connect, (x) => SelectedMachine != null);
        }

        /// <summary>
        /// Connect to the currently selected machine.
        /// </summary>
        private void Connect()
        {
            if (SelectedMachine != null)
            {
                Scanner.Stop();
                Accept();
            }
        }

        /// <summary>
        /// Invokes the <see cref="E:Tango.SharedUI.DialogViewVM.Canceled" /> event.
        /// </summary>
        protected override void Cancel()
        {
            Scanner.Stop();
            base.Cancel();
        }

        /// <summary>
        /// Called when the dialog has been shown.
        /// </summary>
        public override void OnShow()
        {
            base.OnShow();
            Scanner.AvailableMachines.Clear();

            if (SettingsManager.Default.GetOrCreate<MachineStudioSettings>().UseExternalBridgeEmulator)
            {
                if (_emulator != null)
                {
                    _emulator.Disconnect();
                }
                _emulator = new EmulatorExternalBridge();
            }

            Scanner.AvailableMachines.Add(_emulator);
            Scanner.Start();
        }
    }
}