using Godot;
using Rokojori;
 
namespace Rokojori
{ 
  public class UILayouting
  {  
    public static void UpdateChild( Control control )
    {
      if ( control is UIRegion )
      {
        var childUIRegion = (UIRegion) control;
        childUIRegion.Layout();
      }
      else if ( control is UIImage )
      {
        var uiImage = (UIImage) control;

        if ( uiImage.Texture == null )
        {
          uiImage.Size = new Vector2( 0, 0 );
          return;
        }

        var tw = uiImage.Texture.GetWidth();
        var th = uiImage.Texture.GetHeight();

        var w = UINumber.Compute( control, uiImage.width, tw, tw / 100f );
        var h = UINumber.Compute( control, uiImage.height, th, th / 100f );

        uiImage.Size = new Vector2( w, h );
      } 
      else
      {
        control.UpdateMinimumSize();
        control.Size = control.GetMinimumSize();
      }

      UILayouting.UpdatePivot( control );
    }

    public static void SetPositionInParentAnchor( UIStylePropertyContainer region )
    {
      var control = (Control) region;
      var p = NodesWalker.Get().Parent( control ) as Control;
      
      var pWidth  = p == null ? UI.GetWindowWidth( control ) : UILayouting.GetWidth( p );
      var pHeight = p == null ? UI.GetWindowHeight( control ) : UILayouting.GetHeight( p );   
      
      var x = p.Position.X;
      var y = p.Position.Y;


      if ( ! UINumber.IsNullOrNone( UIStyle.Left( region ) ))
      {
        var left  = UINumber.Compute( control, UIStyle.Left( region ), 0 );
        x = left;
      }
      else if ( ! UINumber.IsNullOrNone( UIStyle.Right( region ) ) )
      {
        var right  = UINumber.Compute( control, UIStyle.Right( region ), 0 );
        x = ( pWidth - UILayouting.GetWidth( control ) ) - right;
      }

      if ( ! UINumber.IsNullOrNone( UIStyle.Top( region ) ))
      {
        var top  = UINumber.Compute( control, UIStyle.Top( region ), 0 );
        y = top;
      }
      else if ( ! UINumber.IsNullOrNone( UIStyle.Bottom( region ) ) )
      {
        var bottom  = UINumber.Compute( control, UIStyle.Bottom( region ), 0 );
        y = ( pHeight - UILayouting.GetHeight( control ) ) - bottom;
      }

      UILayouting.SetPosition( control, new Vector2( x, y ) );

      
    }

    public static void UpdatePivot( Control c )
    {
      if ( ! ( c is UIImage || c is UIRegion || c is UIText ) )
      {
        return;
      }

      var container = c as UIStylePropertyContainer;

      var pivotX  = UINumber.Compute( c, UIStyle.PivotX( container ), 0.5f * c.Size.X, c.Size.X );
      var pivotY  = UINumber.Compute( c, UIStyle.PivotY( container ), 0.5f * c.Size.Y, c.Size.Y );

      c.PivotOffset = new Vector2( pivotX, pivotY );

      c.Rotation = UINumber.Compute( c, UIStyle.Rotation( container ), 0 ); 

      var scale = UINumber.Compute( c, UIStyle.Scale( container ), 1, 1 );

      c.Scale = new Vector2( 
        UINumber.Compute( c, UIStyle.ScaleX( container ), 1, 1 ) ,
        UINumber.Compute( c, UIStyle.ScaleY( container ), 1, 1 )
      ) * scale;

    }

    public static void SetPosition( Control c, Vector2 position )
    {
      if ( UIStyling.HasInnerMargins( c ) )
      {
        var container = c as UIStylePropertyContainer;

        var margin       = UINumber.Compute( c, UIStyle.Margin( container ), 0 );
        var marginLeft   = margin + UINumber.Compute( c, UIStyle.MarginLeft( container ), 0 );
        var marginTop    = margin + UINumber.Compute( c, UIStyle.MarginTop( container ), 0 );

        position.X += marginLeft;
        position.Y += marginTop;
 
      }

      c.Position = position;
    }

    public static float GetWidth( Control c )
    {
      if ( UIStyling.HasInnerMargins( c ) )
      {
        var container = c as UIStylePropertyContainer;

        var margin       = UINumber.Compute( c, UIStyle.Margin( container ), 0 );
        var marginLeft   = margin + UINumber.Compute( c, UIStyle.MarginLeft( container ), 0 );
        var marginRight  = margin + UINumber.Compute( c, UIStyle.MarginRight( container ), 0 );

        return c.Size.X + marginLeft + marginRight;
 
      }

      return c.Size.X;
    } 
    
    public static float GetHeight( Control c )
    {
      if ( UIStyling.HasInnerMargins( c ) )
      {
        var container = c as UIStylePropertyContainer;

        var margin        = UINumber.Compute( c, UIStyle.Margin( container ), 0 );
        var marginTop     = margin + UINumber.Compute( c, UIStyle.MarginTop( container ), 0 );
        var marginBottom  = margin + UINumber.Compute( c, UIStyle.MarginBottom( container ), 0 );

        return c.Size.Y + marginTop + marginBottom;
 
      }

      return c.Size.Y;
    }

  }
}