/**
  * @RDE_HEADER@
  * Implementation of CheckStateProxyModel
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by hjl/Christian Froebel, NLE, 2019-05-10
  */

#include "check_state_proxy_model.h"

namespace LtsDataView
{
Qt::ItemFlags CheckStateProxyModel::flags(const QModelIndex &index) const
{
  if (!index.isValid())
    return sourceModel()->flags(index);  // delegate to source model for further processing if necessary

  // Sets only the checkbox nodes on user checkable,
  // checkbox leaves must be handled in source model.
  QModelIndex   sourceIndex = mapToSource(index);
  Qt::ItemFlags   fl = sourceModel()->flags(sourceIndex);
  if (index.column() == 0)
    return fl | Qt::ItemIsUserCheckable;
  return fl;
}


QVariant CheckStateProxyModel::data(const QModelIndex &index, int role) const
{
  if (!index.isValid())
    return QVariant();

  QModelIndex   sourceIndex = mapToSource(index);

  // delegate everything except CheckStateRole to source model
  if (role != Qt::CheckStateRole)
    return sourceModel()->data(sourceIndex, role);

  // delegate a leaf too with CheckStateRole to source model
  if (isLeaf(index))
    return sourceModel()->data(sourceIndex, role);

  // delegate to source model for further processing of further columns if necessary
  if (index.column() != 0)
    return sourceModel()->data(sourceIndex, role);

  // sets the node checkboxes and decoration depending on the entries in the tree structure
  int checkedCount = 0;
  int childCount = rowCount(index);
  for (int childRow = 0; childRow < childCount; ++childRow)
  {
    QModelIndex      childIndex = this->index(childRow, 0, index);
    Qt::CheckState   checkState = data(childIndex, Qt::CheckStateRole).value<Qt::CheckState>();
    if (checkState == Qt::PartiallyChecked)
      return Qt::PartiallyChecked;
    if (checkState == Qt::Checked)
      ++checkedCount;
  }
  if (checkedCount == childCount)
    return Qt::Checked;
  else if (checkedCount == 0)
    return Qt::Unchecked;
  else
    return Qt::PartiallyChecked;
}


bool CheckStateProxyModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
  if (!index.isValid())
    return false;

  QModelIndex  sourceIndex = mapToSource(index);

  // delegate to source model for further processing of further columns if necessary
  if (index.column() != 0)
    return sourceModel()->setData(sourceIndex, value, role);

  // delegate everything except CheckStateRole to source mode
  if (role != Qt::CheckStateRole)
    return sourceModel()->setData(sourceIndex, value, role);

  if (isLeaf(index))
  {
    // delegate a leaf to source model
    sourceModel()->setData(sourceIndex, value, role);

    // update parents recursively here
    QModelIndex idx = index.parent();
    do
    {
      emit dataChanged(idx, idx, {Qt::CheckStateRole});
      idx = idx.parent();
    }
    while (idx.isValid());
    return true;
  }

  // update underlying children recursively (Additional nodes with leaves may also exist)
  int childCount = rowCount(index);
  for (int childRow = 0; childRow < childCount; ++childRow)
  {
    QModelIndex  childIndex = this->index(childRow, 0, index);
    setData(childIndex, value, Qt::CheckStateRole);
  }
  return true;
}


bool CheckStateProxyModel::isLeaf(const QModelIndex &index) const
{
  QModelIndex sourceIndex = mapToSource(index);
  return sourceModel()->flags(sourceIndex).testFlag(Qt::ItemIsUserCheckable);
}


}   // namespace InfrastructureManagement