using Telerik.Windows.Controls;

    /// <summary>
    /// TODO: Update summary.
    /// </summary>
    public class CellValidationBehavior : Behavior<RadGridView>
    {
        private EquipmentQuickEntryViewModel _viewModel = null;

        /// <summary>
        /// Overrides the OnAttached event so we can hook up the RowLoaded event
        /// </summary>
        protected override void OnAttached()
        {
            base.OnAttached();

            this.AssociatedObject.DataLoaded += new EventHandler<EventArgs>(DataLoaded);
            this.AssociatedObject.CellValidating += new EventHandler<GridViewCellValidatingEventArgs>(CellValidating);
            this.AssociatedObject.RowValidated += new EventHandler<GridViewRowValidatedEventArgs>(RowValidated);
        }

        /// <summary>
        /// Overrides the OnDetaching method to add handlers to some DragDrop events
        /// </summary>
        protected override void OnDetaching()
        {
            base.OnDetaching();

            this.AssociatedObject.DataLoaded -= new EventHandler<EventArgs>(DataLoaded);
            this.AssociatedObject.CellValidating -= new EventHandler<GridViewCellValidatingEventArgs>(CellValidating);
            this.AssociatedObject.RowValidated -= new EventHandler<GridViewRowValidatedEventArgs>(RowValidated);
        }

        /// <summary>
        /// Captures the DataLoaded event from the grid
        /// </summary>
        /// <param name="sender">The RadGridView we attached to</param>
        /// <param name="e">The EventArgs</param>
        private void DataLoaded(object sender, EventArgs e)
        {
            var grid = this.AssociatedObject;
            var dataSource = (ObservableCollection<EquipmentToAdd>)grid.ItemsSource;

            if (dataSource.Count>0)
            {
                if (_viewModel == null)
                {
                    _viewModel = grid.DataContext as EquipmentQuickEntryViewModel;
                }

                var selectedRow = _viewModel.SelectedRowNumber;

                grid.ScrollIntoView(grid.Items[selectedRow], grid.Columns["SerialNumber"]);

                grid.CurrentCellInfo = new GridViewCellInfo(grid.Items[selectedRow], grid.Columns["SerialNumber"]);

                var equipment = (EquipmentToAdd)grid.Items[selectedRow];

                if (equipment.IsInUse)
                {
                    return;
                }
                
                grid.BeginEdit();
            }
        }

        /// <summary>
        /// Captures the CellValidating event from the grid
        /// </summary>
        /// <param name="sender">The RadGridView we attached to</param>
        /// <param name="e">The GridViewCellValidatingEventArgs</param>
        private void CellValidating(object sender, GridViewCellValidatingEventArgs e)
            {
            if (e.Cell.Column.UniqueName != "SerialNumber")
            {
                return;
            }

            var value = e.NewValue.ToString();

            if (!string.IsNullOrEmpty(value))
            {
                if (this._viewModel == null)
                {
                    this._viewModel = ((RadGridView)sender).DataContext as EquipmentQuickEntryViewModel;
                }
                EquipmentToAdd thisEquipment = (EquipmentToAdd)e.Row.DataContext;
                var isDuplicate = this._viewModel.IsDuplicateSerialNumber(value, thisEquipment);

                if (isDuplicate)
                {
                    e.IsValid = false;
                    e.ErrorMessage = "That serial number already exists";
                    return;
                }

                _viewModel.UpdateCanSave();
            }
        }

        /// <summary>
        /// Captures the RowValidated event from the grid
        /// </summary>
        /// <param name="sender">The RadGridView we attached to</param>
        /// <param name="e">The GridViewRowValidatedEventArgs</param>
        private void RowValidated(object sender, GridViewRowValidatedEventArgs e)
        {
            if (_viewModel == null)
            {
                _viewModel = ((RadGridView)sender).DataContext as EquipmentQuickEntryViewModel;
            }

            _viewModel.UpdateCanSave();
        }
    }