/*************************************************************************************
   
   Toolkit for WPF

   Copyright (C) 2007-2018 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://wpftoolkit.codeplex.com/license 

   For more features, controls, and fast professional support,
   pick up the Plus Edition at https://xceed.com/xceed-toolkit-plus-for-wpf/

   Stay informed: follow @datagrid on Twitter or Like http://facebook.com/datagrids

  ***********************************************************************************/

using System.Linq;
using System.Windows;
using System.Windows.Media;
using Xceed.Wpf.AvalonDock.Layout;

namespace Xceed.Wpf.AvalonDock.Controls
{
  internal class DocumentPaneDropTarget : DropTarget<LayoutDocumentPaneControl>
  {
    #region Members

    private LayoutDocumentPaneControl _targetPane;
    private int _tabIndex = -1;

    #endregion

    #region Constructors

    internal DocumentPaneDropTarget( LayoutDocumentPaneControl paneControl, Rect detectionRect, DropTargetType type )
        : base( paneControl, detectionRect, type )
    {
      _targetPane = paneControl;
    }

    internal DocumentPaneDropTarget( LayoutDocumentPaneControl paneControl, Rect detectionRect, DropTargetType type, int tabIndex )
        : base( paneControl, detectionRect, type )
    {
      _targetPane = paneControl;
      _tabIndex = tabIndex;
    }

    #endregion

    #region Overrides

    protected override void Drop( LayoutDocumentFloatingWindow floatingWindow )
    {
      ILayoutDocumentPane targetModel = _targetPane.Model as ILayoutDocumentPane;

      switch( Type )
      {
        case DropTargetType.DocumentPaneDockBottom:
          #region DropTargetType.DocumentPaneDockBottom
          {
            var newLayoutDocumentPane = new LayoutDocumentPane( floatingWindow.RootDocument );
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Vertical };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( targetModel as LayoutDocumentPane );
              newParentModel.Children.Add( newLayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Vertical )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Vertical;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex + 1, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Vertical;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( targetModel );
                newChildGroup.Children.Add( newLayoutDocumentPane );
              }

            }
          }
          break;
        #endregion
        case DropTargetType.DocumentPaneDockTop:
          #region DropTargetType.DocumentPaneDockTop
          {
            var newLayoutDocumentPane = new LayoutDocumentPane( floatingWindow.RootDocument );
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Vertical };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( targetModel as LayoutDocumentPane );
              newParentModel.Children.Insert( 0, newLayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Vertical )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Vertical;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Vertical;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( newLayoutDocumentPane );
                newChildGroup.Children.Add( targetModel );
              }

            }
          }
          break;
        #endregion
        case DropTargetType.DocumentPaneDockLeft:
          #region DropTargetType.DocumentPaneDockLeft
          {
            var newLayoutDocumentPane = new LayoutDocumentPane( floatingWindow.RootDocument );
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Horizontal };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( targetModel );
              newParentModel.Children.Insert( 0, newLayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Horizontal )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Horizontal;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Horizontal;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( newLayoutDocumentPane );
                newChildGroup.Children.Add( targetModel );
              }
            }
          }
          break;
        #endregion
        case DropTargetType.DocumentPaneDockRight:
          #region DropTargetType.DocumentPaneDockRight
          {
            var newLayoutDocumentPane = new LayoutDocumentPane( floatingWindow.RootDocument );
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Horizontal };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( targetModel as LayoutDocumentPane );
              newParentModel.Children.Add( newLayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Horizontal )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Horizontal;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex + 1, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Horizontal;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( targetModel );
                newChildGroup.Children.Add( newLayoutDocumentPane );
              }

            }
          }
          break;
        #endregion

        case DropTargetType.DocumentPaneDockInside:
          #region DropTargetType.DocumentPaneDockInside
          {
            var paneModel = targetModel as LayoutDocumentPane;
            var sourceModel = floatingWindow.RootDocument;

            int i = 0;
            if( _tabIndex != -1 )
            {
              i = _tabIndex;
            }
            else
            {
              var previousIndex = 0;
              var previousContainer = ( ( ILayoutPreviousContainer )sourceModel ).PreviousContainer;
              if( object.ReferenceEquals( previousContainer, targetModel ) && ( sourceModel.PreviousContainerIndex != -1 ) )
              {
                previousIndex = sourceModel.PreviousContainerIndex;
              }

              i = previousIndex;
            }
            sourceModel.IsActive = false;
            paneModel.Children.Insert( i, sourceModel );
            sourceModel.IsActive = true;
          }
          break;
          #endregion


      }

      base.Drop( floatingWindow );
    }

    protected override void Drop( LayoutAnchorableFloatingWindow floatingWindow )
    {
      ILayoutDocumentPane targetModel = _targetPane.Model as ILayoutDocumentPane;

      switch( Type )
      {
        case DropTargetType.DocumentPaneDockBottom:
          #region DropTargetType.DocumentPaneDockBottom
          {
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;
            var newLayoutDocumentPane = new LayoutDocumentPane();

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Vertical };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( targetModel as LayoutDocumentPane );
              newParentModel.Children.Add( newLayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Vertical )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Vertical;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex + 1, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Vertical;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( targetModel );
                newChildGroup.Children.Add( newLayoutDocumentPane );
              }
            }

            foreach( var cntToTransfer in floatingWindow.RootPanel.Descendents().OfType<LayoutAnchorable>().ToArray() )
              newLayoutDocumentPane.Children.Add( cntToTransfer );

          }
          break;
        #endregion
        case DropTargetType.DocumentPaneDockTop:
          #region DropTargetType.DocumentPaneDockTop
          {
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;
            var newLayoutDocumentPane = new LayoutDocumentPane();

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Vertical };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( newLayoutDocumentPane );
              newParentModel.Children.Add( targetModel as LayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Vertical )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Vertical;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Vertical;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( newLayoutDocumentPane );
                newChildGroup.Children.Add( targetModel );
              }
            }

            foreach( var cntToTransfer in floatingWindow.RootPanel.Descendents().OfType<LayoutAnchorable>().ToArray() )
              newLayoutDocumentPane.Children.Add( cntToTransfer );

          }
          break;
        #endregion
        case DropTargetType.DocumentPaneDockLeft:
          #region DropTargetType.DocumentPaneDockLeft
          {
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;
            var newLayoutDocumentPane = new LayoutDocumentPane();

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Horizontal };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( newLayoutDocumentPane );
              newParentModel.Children.Add( targetModel as LayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Horizontal )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Horizontal;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Horizontal;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( newLayoutDocumentPane );
                newChildGroup.Children.Add( targetModel );
              }

            }

            foreach( var cntToTransfer in floatingWindow.RootPanel.Descendents().OfType<LayoutAnchorable>().ToArray() )
              newLayoutDocumentPane.Children.Add( cntToTransfer );

          }
          break;
        #endregion
        case DropTargetType.DocumentPaneDockRight:
          #region DropTargetType.DocumentPaneDockRight
          {
            var parentModel = targetModel.Parent as LayoutDocumentPaneGroup;
            var newLayoutDocumentPane = new LayoutDocumentPane();

            if( parentModel == null )
            {
              var parentContainer = targetModel.Parent as ILayoutContainer;
              var newParentModel = new LayoutDocumentPaneGroup() { Orientation = System.Windows.Controls.Orientation.Horizontal };
              parentContainer.ReplaceChild( targetModel, newParentModel );
              newParentModel.Children.Add( targetModel as LayoutDocumentPane );
              newParentModel.Children.Add( newLayoutDocumentPane );
            }
            else
            {
              var manager = parentModel.Root.Manager;
              if( !manager.AllowMixedOrientation || parentModel.Orientation == System.Windows.Controls.Orientation.Horizontal )
              {
                parentModel.Orientation = System.Windows.Controls.Orientation.Horizontal;
                int targetPaneIndex = parentModel.IndexOfChild( targetModel );
                parentModel.Children.Insert( targetPaneIndex + 1, newLayoutDocumentPane );
              }
              else
              {
                LayoutDocumentPaneGroup newChildGroup = new LayoutDocumentPaneGroup();
                newChildGroup.Orientation = System.Windows.Controls.Orientation.Horizontal;
                parentModel.ReplaceChild( targetModel, newChildGroup );
                newChildGroup.Children.Add( targetModel );
                newChildGroup.Children.Add( newLayoutDocumentPane );
              }
            }

            foreach( var cntToTransfer in floatingWindow.RootPanel.Descendents().OfType<LayoutAnchorable>().ToArray() )
              newLayoutDocumentPane.Children.Add( cntToTransfer );

          }
          break;
        #endregion
        case DropTargetType.DocumentPaneDockInside:
          #region DropTargetType.DocumentPaneDockInside
          {
            var paneModel = targetModel as LayoutDocumentPane;
            var layoutAnchorablePaneGroup = floatingWindow.RootPanel as LayoutAnchorablePaneGroup;

            bool checkPreviousContainer = true;
            int i = 0;
            if( _tabIndex != -1 )
            {
              i = _tabIndex;
              checkPreviousContainer = false;
            }
            LayoutAnchorable anchorableToActivate = null;

            foreach( var anchorableToImport in layoutAnchorablePaneGroup.Descendents().OfType<LayoutAnchorable>().ToArray() )
            {
              if( checkPreviousContainer )
              {
                var previousContainer = ( ( ILayoutPreviousContainer )anchorableToImport ).PreviousContainer;
                if( object.ReferenceEquals( previousContainer, targetModel ) && ( anchorableToImport.PreviousContainerIndex != -1 ) )
                {
                  i = anchorableToImport.PreviousContainerIndex;
                }
                checkPreviousContainer = false;
              }

              anchorableToImport.SetCanCloseInternal( true );

              paneModel.Children.Insert( i, anchorableToImport );
              i++;
              anchorableToActivate = anchorableToImport;
            }

            anchorableToActivate.IsActive = true;
          }
          break;
          #endregion
      }

      base.Drop( floatingWindow );
    }

    public override System.Windows.Media.Geometry GetPreviewPath( OverlayWindow overlayWindow, LayoutFloatingWindow floatingWindowModel )
    {
      switch( Type )
      {
        case DropTargetType.DocumentPaneDockInside:
          {
            var targetScreenRect = TargetElement.GetScreenArea();
            targetScreenRect.Offset( -overlayWindow.Left, -overlayWindow.Top );

            if( _tabIndex == -1 )
            {
              return new RectangleGeometry( targetScreenRect );
            }
            else
            {
              var translatedDetectionRect = new Rect( DetectionRects[ 0 ].TopLeft, DetectionRects[ 0 ].BottomRight );
              translatedDetectionRect.Offset( -overlayWindow.Left, -overlayWindow.Top );

              var pathFigure = new PathFigure();
              pathFigure.StartPoint = targetScreenRect.BottomRight;
              pathFigure.Segments.Add( new LineSegment() { Point = new Point( targetScreenRect.Right, translatedDetectionRect.Bottom ) } );
              pathFigure.Segments.Add( new LineSegment() { Point = translatedDetectionRect.BottomRight } );
              pathFigure.Segments.Add( new LineSegment() { Point = translatedDetectionRect.TopRight } );
              pathFigure.Segments.Add( new LineSegment() { Point = translatedDetectionRect.TopLeft } );
              pathFigure.Segments.Add( new LineSegment() { Point = translatedDetectionRect.BottomLeft } );
              pathFigure.Segments.Add( new LineSegment() { Point = new Point( targetScreenRect.Left, translatedDetectionRect.Bottom ) } );
              pathFigure.Segments.Add( new LineSegment() { Point = targetScreenRect.BottomLeft } );
              pathFigure.IsClosed = true;
              pathFigure.IsFilled = true;
              pathFigure.Freeze();
              return new PathGeometry( new PathFigure[] { pathFigure } );
            }
          }
        case DropTargetType.DocumentPaneDockBottom:
          {
            var targetScreenRect = TargetElement.GetScreenArea();
            targetScreenRect.Offset( -overlayWindow.Left, -overlayWindow.Top );
            targetScreenRect.Offset( 0.0, targetScreenRect.Height / 2.0 );
            targetScreenRect.Height /= 2.0;
            return new RectangleGeometry( targetScreenRect );
          }
        case DropTargetType.DocumentPaneDockTop:
          {
            var targetScreenRect = TargetElement.GetScreenArea();
            targetScreenRect.Offset( -overlayWindow.Left, -overlayWindow.Top );
            targetScreenRect.Height /= 2.0;
            return new RectangleGeometry( targetScreenRect );
          }
        case DropTargetType.DocumentPaneDockLeft:
          {
            var targetScreenRect = TargetElement.GetScreenArea();
            targetScreenRect.Offset( -overlayWindow.Left, -overlayWindow.Top );
            targetScreenRect.Width /= 2.0;
            return new RectangleGeometry( targetScreenRect );
          }
        case DropTargetType.DocumentPaneDockRight:
          {
            var targetScreenRect = TargetElement.GetScreenArea();
            targetScreenRect.Offset( -overlayWindow.Left, -overlayWindow.Top );
            targetScreenRect.Offset( targetScreenRect.Width / 2.0, 0.0 );
            targetScreenRect.Width /= 2.0;
            return new RectangleGeometry( targetScreenRect );
          }
      }

      return null;
    }

    #endregion
  }
}