/* gtkmm example Copyright (C) 2002 gtkmm development team
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <https://www.gnu.org/licenses/>.
 */

#include <iostream>
#include "exampletreemodel.h"

ExampleTreeModel::GlueItem::GlueItem(int row_number)
: m_row_number(row_number)
{
}

int ExampleTreeModel::GlueItem::get_row_number() const
{
  return m_row_number;
}

ExampleTreeModel::GlueList::GlueList()
{
}

ExampleTreeModel::GlueList::~GlueList()
{
  //Delete each GlueItem in the list:
  for(const auto& pItem : m_list)
  {
    delete pItem;
  }
}


ExampleTreeModel::ExampleTreeModel(unsigned int columns_count)
: Glib::ObjectBase( typeid(ExampleTreeModel) ), //register a custom GType.
  Glib::Object(), //The custom GType is actually registered here.
  m_stamp(1), //When the model's stamp != the iterator's stamp then that iterator is invalid and should be ignored. Also, 0=invalid
  m_pGlueList(nullptr)
{
  //Initialize our underlying data:
  const typeListOfRows::size_type rows_count = 100;
  m_rows.resize(rows_count); //100 rows.
  for(unsigned int row_number = 0; row_number < rows_count; ++row_number)
  {
    //Create the row:
    m_rows[row_number].resize(columns_count); // 10 cells (columns) for each row.

    for(unsigned int column_number = 0; column_number < columns_count; ++column_number)
    {
      // Set the data in the row cells:
      // It is more likely that you would be reusing existing data from some other data structure,
      // instead of generating the data here.

      char buffer[20]; //You could use a std::stringstream instead.
      g_snprintf(buffer, sizeof(buffer), "%d, %d", row_number, column_number);

      (m_rows[row_number])[column_number] = buffer; //Note that all 10 columns here are of the same type.
    }
  }

  //The Column information that can be used with TreeView::append(), TreeModel::iterator[], etc.
  m_listModelColumns.resize(columns_count);
  for(unsigned int column_number = 0; column_number < columns_count; ++column_number)
  {
    m_column_record.add( m_listModelColumns[column_number] );
  }
}

ExampleTreeModel::~ExampleTreeModel()
{
  if(m_pGlueList)
  {
    delete m_pGlueList;
  }
}

//static:
Glib::RefPtr<ExampleTreeModel> ExampleTreeModel::create()
{
  return Glib::RefPtr<ExampleTreeModel>( new ExampleTreeModel );
}

Gtk::TreeModelFlags ExampleTreeModel::get_flags_vfunc() const
{
   return Gtk::TreeModelFlags(0);
}

int ExampleTreeModel::get_n_columns_vfunc() const
{
   return m_rows[0].size(); //The number of columns in the first (same as every one) row.
}

GType ExampleTreeModel::get_column_type_vfunc(int index) const
{
  if(index <= (int)m_listModelColumns.size())
    return m_listModelColumns[index].type();
  else
    return 0;
}

void ExampleTreeModel::get_value_vfunc(const TreeModel::iterator& iter, int column, Glib::ValueBase& value) const
{
  if(check_treeiter_validity(iter))
  {
    if(column <= (int)m_listModelColumns.size())
    {
      //Get the correct ValueType from the Gtk::TreeModel::Column's type, so we don't have to repeat it here:
      typeModelColumn::ValueType value_specific;
      value_specific.init( typeModelColumn::ValueType::value_type() );  //TODO: Is there any way to avoid this step?

      //Or, instead of asking the compiler for the TreeModelColumn's ValueType:
      //Glib::Value< Glib::ustring > value_specific;
      //value_specific.init( Glib::Value< Glib::ustring >::value_type() ); //TODO: Is there any way to avoid this step?

      typeListOfRows::const_iterator dataRowIter = get_data_row_iter_from_tree_row_iter(iter);
      if(dataRowIter != m_rows.end())
      {
        const typeRow& dataRow = *dataRowIter;

        Glib::ustring result = dataRow[column];

        value_specific.set(result); //The compiler would complain if the type was wrong.
        value.init( Glib::Value< Glib::ustring >::value_type() ); //TODO: Is there any way to avoid this step? Can't it copy the type as well as the value?
        value = value_specific;
      }
    }
  }
}

bool ExampleTreeModel::iter_next_vfunc(const iterator& iter, iterator& iter_next) const
{
  if( check_treeiter_validity(iter) )
  {
    //initialize the iterator:
    iter_next = iterator();
    iter_next.set_stamp(m_stamp);

    //Get the current row:
    const auto pItem = (const GlueItem*)iter.gobj()->user_data;
    typeListOfRows::size_type row_index = pItem->get_row_number();

    //Make the iter_next GtkTreeIter represent the next row:
    row_index++;
    if( row_index < m_rows.size() )
    {
      //Put the index of the next row in a GlueItem in iter_next:
      auto pItemNew = new GlueItem(row_index);
      iter_next.gobj()->user_data = (void*)pItemNew;

      remember_glue_item(pItemNew);

      return true; //success
    }
  }
  else
    iter_next = iterator(); //Set is as invalid, as the TreeModel documentation says that it should be.

  return false; //There is no next row.
}

bool ExampleTreeModel::iter_children_vfunc(const iterator& parent, iterator& iter) const
{
  return iter_nth_child_vfunc(parent, 0, iter);
}

bool ExampleTreeModel::iter_has_child_vfunc(const iterator& iter) const
{
  return (iter_n_children_vfunc(iter) > 0);
}

int ExampleTreeModel::iter_n_children_vfunc(const iterator& iter) const
{
  if(!check_treeiter_validity(iter))
    return 0;

  return 0; //There are no children
}

int ExampleTreeModel::iter_n_root_children_vfunc() const
{
  return m_rows.size();
}

bool ExampleTreeModel::iter_nth_child_vfunc(const iterator& parent, int /* n */, iterator& iter) const
{
  if(!check_treeiter_validity(parent))
  {
    iter = iterator(); //Set is as invalid, as the TreeModel documentation says that it should be.
    return false;
  }

  iter = iterator(); //Set is as invalid, as the TreeModel documentation says that it should be.
  return false; //There are no children.
}

bool ExampleTreeModel::iter_nth_root_child_vfunc(int n, iterator& iter) const
{
  if(n < (int)m_rows.size())
  {
    iter = iterator(); //clear the input parameter.
    iter.set_stamp(m_stamp);

    //Store the row_index in the GtkTreeIter:
    //See also iter_next_vfunc()

    unsigned row_index = n;

    //This will be deleted in the GlueList destructor, when old iterators are marked as invalid.
    auto pItem = new GlueItem(row_index);
    iter.gobj()->user_data = pItem;

    remember_glue_item(pItem);

    return true;
  }

  return false; //There are no children.
}


bool ExampleTreeModel::iter_parent_vfunc(const iterator& child, iterator& iter) const
{
  if(!check_treeiter_validity(child))
  {
    iter = iterator(); //Set is as invalid, as the TreeModel documentation says that it should be.
    return false;
  }

  iter = iterator(); //Set is as invalid, as the TreeModel documentation says that it should be.
  return false; //There are no children, so no parents.
}

Gtk::TreeModel::Path ExampleTreeModel::get_path_vfunc(const iterator& /* iter */) const
{
   //TODO:
   return Path();
}

bool ExampleTreeModel::get_iter_vfunc(const Path& path, iterator& iter) const
{
   unsigned sz = path.size();
   if(!sz)
   {
     iter = iterator(); //Set is as invalid, as the TreeModel documentation says that it should be.
     return false;
   }

   if(sz > 1) //There are no children.
   {
     iter = iterator(); //Set is as invalid, as the TreeModel documentation says that it should be.
     return false;
   }

   //This is a new GtkTreeIter, so it needs the current stamp value.
   //See the comment in the constructor.
   iter = iterator(); //clear the input parameter.
   iter.set_stamp(m_stamp);

   //Store the row_index in the GtkTreeIter:
   //See also iter_next_vfunc()
   //TODO: Store a pointer to some more complex data type such as a typeListOfRows::iterator.

   unsigned row_index = path[0];
   auto pItem = new GlueItem(row_index);

   //Store the GlueItem in the GtkTreeIter.
   //This will be deleted in the GlueList destructor,
   //which will be called when the old GtkTreeIters are marked as invalid,
   //when the stamp value changes.
   iter.gobj()->user_data = (void*)pItem;

   remember_glue_item(pItem);

   return true;
}

Gtk::TreeModelColumn< Glib::ustring >& ExampleTreeModel::get_model_column(int column)
{
  return m_listModelColumns[column];
}

ExampleTreeModel::typeListOfRows::iterator ExampleTreeModel::get_data_row_iter_from_tree_row_iter(const iterator& iter)
{
  //Don't call this on an invalid iter.
  const auto pItem = (const GlueItem*)iter.gobj()->user_data;

  typeListOfRows::size_type row_index = pItem->get_row_number();
  if( row_index > m_rows.size() )
    return m_rows.end();
  else
    return m_rows.begin() + row_index; //TODO: Performance.
}

ExampleTreeModel::typeListOfRows::const_iterator ExampleTreeModel::get_data_row_iter_from_tree_row_iter(const iterator& iter) const
{
  //Don't call this on an invalid iter.
  const auto pItem = (const GlueItem*)iter.gobj()->user_data;

  typeListOfRows::size_type row_index = pItem->get_row_number();
  if( row_index > m_rows.size() )
    return m_rows.end();
  else
    return m_rows.begin() + row_index; //TODO: Performance.
}

bool ExampleTreeModel::check_treeiter_validity(const iterator& iter) const
{
  // Anything that modifies the model's structure should change the model's stamp,
  // so that old iters are ignored.
  return m_stamp == iter.get_stamp();
}

void ExampleTreeModel::remember_glue_item(GlueItem* item) const
{
  //Add the GlueItem to the model's GlueList, so that
  //it can be deleted when the old GtkTreeIters are marked as invalid:
  if(!m_pGlueList)
  {
    m_pGlueList = new GlueList();
  }

  m_pGlueList->m_list.push_back(item);
}


