Align elements horizontally to max width but wrap when parent squeezed - wpf

Question

I have a Grid which contains two Buttons. I want the first button to align to left and the second one to the right (this is why I'm using Grid as the parent). When the whole window is squeezed so much that the buttons cannot be entirely visible, I want them to wrap - ie. first one stays aligned to left but the second one is moved to a new row (and preferably but not necessarily is still aligned to right). For that I'd use a WrapPanel but the WrapPanel will not fill the parent window and hence will not align the buttons to left and right.
Is there any way to get both - the horizontal alignment and wrapping?
My current code:
<Grid Grid.Row="2" Visibility="{Binding Attachments.Count, Converter={StaticResource GreaterThanGivenValueVisibilityConverter}, ConverterParameter=1}">
<Button Grid.Row="1" Grid.Column="1" HorizontalAlignment="Left" VerticalAlignment="Top" Height="30" BorderThickness="0" Focusable="False" Command="{Binding ExpandAttachmentsPanel}">
</Button>
<Button Grid.Row="1" Grid.Column="2" HorizontalAlignment="Right" VerticalAlignment="Top" Height="30" BorderThickness="0" Focusable="False" Command="{Binding DownloadAllAttachmentsCommand}">
</Button>
</Grid>

Answer 1

Is there any way to get both - the horizontal alignment and wrapping?
There is no built-in Panel that gives you this behaviour but you should be able to handle the SizeChanged event of the WrapPanel and programmatically adjust the Margin of one of the Buttons. Something like this:
<WrapPanel x:Name="wp" Background="Yellow" SizeChanged="WrapPanel_SizeChanged">
<Button x:Name="btn1" Width="100">
<TextBlock>1</TextBlock>
</Button>
<Button x:Name="btn2" Width="100">
<TextBlock>2</TextBlock>
</Button>
</WrapPanel>
private void WrapPanel_SizeChanged(object sender, SizeChangedEventArgs e)
{
btn1.Margin = new Thickness(0, 0, Math.Max(0, wp.ActualWidth - btn1.ActualWidth - btn2.ActualWidth), 0);
}