/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkVector.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

// .NAME vtkChartSelectionHelper - helper functions for making selections in
// charts.
//
// .SECTION Description
// This contains several inline methods intended for use inside chart
// implementations to make chart selections easier. This is intended for
// internal use and the API should not be considered stable.

#ifndef __vtkChartSelectionHelper_h
#define __vtkChartSelectionHelper_h

#include "vtkNew.h"
#include "vtkAnnotationLink.h"
#include "vtkSelection.h"
#include "vtkSelectionNode.h"
#include "vtkIdTypeArray.h"
#include "vtkContextScene.h"
#include "vtkContextMouseEvent.h"

#include <vector>
#include <algorithm>

namespace vtkChartSelectionHelper
{

// Description:
// Populate the annotation link with the supplied selectionIds array, and set
// the appropriate node properties for a standard row based chart selection.
void MakeSelection(vtkAnnotationLink *link, vtkIdTypeArray *selectionIds)
{
  assert(link != NULL && selectionIds != NULL);

  vtkNew<vtkSelection> selection;
  vtkNew<vtkSelectionNode> node;
  selection->AddNode(node.GetPointer());
  node->SetContentType(vtkSelectionNode::INDICES);
  node->SetFieldType(vtkSelectionNode::POINT);
  node->SetSelectionList(selectionIds);
  link->SetCurrentSelection(selection.GetPointer());
}

// Description:
// Subtract the supplied selection from the oldSelection.
void MinusSelection(vtkIdTypeArray *selection, vtkIdTypeArray *oldSelection)
{
  // We rely on the selection id arrays being sorted.
  std::vector<vtkIdType> output;
  vtkIdType *ptrSelection =
      static_cast<vtkIdType *>(selection->GetVoidPointer(0));
  vtkIdType *ptrOldSelection =
      static_cast<vtkIdType *>(oldSelection->GetVoidPointer(0));
  vtkIdType oldSize = oldSelection->GetNumberOfTuples();
  vtkIdType size = selection->GetNumberOfTuples();
  vtkIdType i = 0;
  vtkIdType iOld = 0;

  while (i < size && iOld < oldSize)
    {
    if (ptrSelection[i] > ptrOldSelection[iOld]) // Skip the value.
      {
      output.push_back(ptrOldSelection[iOld++]);
      }
    else if (ptrSelection[i] == ptrOldSelection[iOld]) // Match - remove.
      {
      ++i;
      ++iOld;
      }
    else if (ptrSelection[i] < ptrOldSelection[iOld]) // Add the new value.
      {
      ++i;
      }
    }
  while (iOld < oldSize)
    {
    output.push_back(ptrOldSelection[iOld++]);
    }
  selection->SetNumberOfTuples(output.size());
  ptrSelection = static_cast<vtkIdType *>(selection->GetVoidPointer(0));
  for (std::vector<vtkIdType>::iterator it = output.begin();
       it != output.end(); ++it, ++ptrSelection)
    {
    *ptrSelection = *it;
    }
}

// Description:
// Add the supplied selection from the oldSelection.
void AddSelection(vtkIdTypeArray *selection, vtkIdTypeArray *oldSelection)
{
  // Add all unique array indices to create a new combined array.
  vtkIdType *ptrSelection =
      static_cast<vtkIdType *>(selection->GetVoidPointer(0));
  vtkIdType *ptrOldSelection =
      static_cast<vtkIdType *>(oldSelection->GetVoidPointer(0));
  std::vector<vtkIdType> output(selection->GetNumberOfTuples()
                                + oldSelection->GetNumberOfTuples());
  std::vector<vtkIdType>::iterator it;
  it = std::set_union(ptrSelection,
                      ptrSelection + selection->GetNumberOfTuples(),
                      ptrOldSelection,
                      ptrOldSelection + oldSelection->GetNumberOfTuples(),
                      output.begin());
  int newSize = int(it - output.begin());
  selection->SetNumberOfTuples(newSize);
  ptrSelection = static_cast<vtkIdType *>(selection->GetVoidPointer(0));
  for (std::vector<vtkIdType>::iterator i = output.begin(); i != it;
       ++i, ++ptrSelection)
    {
    *ptrSelection = *i;
    }
}

// Description:
// Toggle the supplied selection from the oldSelection.
void ToggleSelection(vtkIdTypeArray *selection, vtkIdTypeArray *oldSelection)
{
  // We rely on the selection id arrays being sorted.
  std::vector<vtkIdType> output;
  vtkIdType *ptrSelection =
      static_cast<vtkIdType *>(selection->GetVoidPointer(0));
  vtkIdType *ptrOldSelection =
      static_cast<vtkIdType *>(oldSelection->GetVoidPointer(0));
  vtkIdType oldSize = oldSelection->GetNumberOfTuples();
  vtkIdType size = selection->GetNumberOfTuples();
  vtkIdType i = 0;
  vtkIdType iOld = 0;
  while (i < size && iOld < oldSize)
    {
    if (ptrSelection[i] > ptrOldSelection[iOld]) // Retain the value.
      {
      output.push_back(ptrOldSelection[iOld++]);
      }
    else if (ptrSelection[i] == ptrOldSelection[iOld]) // Match - toggle.
      {
      ++i;
      ++iOld;
      }
    else if (ptrSelection[i] < ptrOldSelection[iOld]) // Add the new value.
      {
      output.push_back(ptrSelection[i++]);
      }
    }
  while (i < size)
    {
    output.push_back(ptrSelection[i++]);
    }
  while (iOld < oldSize)
    {
    output.push_back(ptrOldSelection[iOld++]);
    }
  selection->SetNumberOfTuples(output.size());
  ptrSelection = static_cast<vtkIdType *>(selection->GetVoidPointer(0));
  for (std::vector<vtkIdType>::iterator it = output.begin();
       it != output.end(); ++it, ++ptrSelection)
    {
    *ptrSelection = *it;
    }
}

// Description:
// Build a selection based on the supplied selectionMode using the new
// plotSelection and combining it with the oldSelection. If link is not void
// then the resulting selection will be set on the link.
void BuildSelection(vtkAnnotationLink *link, int selectionMode,
                    vtkIdTypeArray *plotSelection, vtkIdTypeArray *oldSelection)
{
  if (!plotSelection || !oldSelection)
    {
    return;
    }

  // Build a selection and set it on the annotation link if not null.
  switch(selectionMode)
    {
    case vtkContextScene::SELECTION_ADDITION:
      AddSelection(plotSelection, oldSelection);
      break;
    case vtkContextScene::SELECTION_SUBTRACTION:
      MinusSelection(plotSelection, oldSelection);
      break;
    case vtkContextScene::SELECTION_TOGGLE:
      ToggleSelection(plotSelection, oldSelection);
      break;
    case vtkContextScene::SELECTION_DEFAULT:
    default:
      // Nothing necessary - overwrite the old selection.
      break;
    }

  if (link)
    {
    MakeSelection(link, plotSelection);
    }
}

// Description:
// Combine the SelectionMode with any mouse modifiers to get an effective
// selection mode for this click event.
int GetMouseSelectionMode(const vtkContextMouseEvent &mouse, int selectionMode)
{
  // Mouse modifiers override the current selection mode.
  if (mouse.GetModifiers() & vtkContextMouseEvent::SHIFT_MODIFIER &&
      mouse.GetModifiers() & vtkContextMouseEvent::CONTROL_MODIFIER)
    {
    return vtkContextScene::SELECTION_TOGGLE;
    }
  else if (mouse.GetModifiers() & vtkContextMouseEvent::SHIFT_MODIFIER)
    {
    return vtkContextScene::SELECTION_ADDITION;
    }
  else if (mouse.GetModifiers() & vtkContextMouseEvent::CONTROL_MODIFIER)
    {
    return vtkContextScene::SELECTION_SUBTRACTION;
    }
  return selectionMode;
}

} // End vtkChartSelectionHelper namespace

#endif // __vtkChartSelectionHelper_h
// VTK-HeaderTest-Exclude: vtkChartSelectionHelper.h
