// ---------------------------------------------------------------------
//
// Copyright (C) 1999 - 2018 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------

#include <deal.II/numerics/data_out_stack.h>
#include <deal.II/base/quadrature_lib.h>
#include <deal.II/base/memory_consumption.h>
#include <deal.II/lac/vector.h>
#include <deal.II/lac/block_vector.h>
#include <deal.II/dofs/dof_handler.h>
#include <deal.II/dofs/dof_accessor.h>
#include <deal.II/grid/tria_iterator.h>
#include <deal.II/fe/fe.h>
#include <deal.II/fe/fe_values.h>
#include <deal.II/hp/fe_values.h>
#include <deal.II/fe/mapping_q1.h>

#include <sstream>

DEAL_II_NAMESPACE_OPEN


template <int dim, int spacedim, typename DoFHandlerType>
std::size_t
DataOutStack<dim,spacedim,DoFHandlerType>::DataVector::memory_consumption () const
{
  return (MemoryConsumption::memory_consumption (data) +
          MemoryConsumption::memory_consumption (names));
}



template <int dim, int spacedim, typename DoFHandlerType>
void DataOutStack<dim,spacedim,DoFHandlerType>::new_parameter_value (const double p,
    const double dp)
{
  parameter      = p;
  parameter_step = dp;

  // check whether the user called finish_parameter_value() at the end of the previous
  // parameter step
  //
  // this is to prevent serious waste of memory
  for (typename std::vector<DataVector>::const_iterator i=dof_data.begin();
       i!=dof_data.end(); ++i)
    Assert (i->data.size() == 0,
            ExcDataNotCleared ());
  for (typename std::vector<DataVector>::const_iterator i=cell_data.begin();
       i!=cell_data.end(); ++i)
    Assert (i->data.size() == 0,
            ExcDataNotCleared ());

}


template <int dim, int spacedim, typename DoFHandlerType>
void DataOutStack<dim,spacedim,DoFHandlerType>::attach_dof_handler (const DoFHandlerType &dof)
{
  // Check consistency of redundant
  // template parameter
  Assert (dim==DoFHandlerType::dimension, ExcDimensionMismatch(dim, DoFHandlerType::dimension));

  dof_handler = &dof;
}


template <int dim, int spacedim, typename DoFHandlerType>
void DataOutStack<dim,spacedim,DoFHandlerType>::declare_data_vector (const std::string &name,
    const VectorType   vector_type)
{
  std::vector<std::string> names;
  names.push_back (name);
  declare_data_vector (names, vector_type);
}


template <int dim, int spacedim, typename DoFHandlerType>
void DataOutStack<dim,spacedim,DoFHandlerType>::declare_data_vector (const std::vector<std::string> &names,
    const VectorType    vector_type)
{
  // make sure this function is
  // not called after some parameter
  // values have already been
  // processed
  Assert (patches.size() == 0, ExcDataAlreadyAdded());

  // also make sure that no name is
  // used twice
  for (std::vector<std::string>::const_iterator name=names.begin(); name!=names.end(); ++name)
    {
      for (typename std::vector<DataVector>::const_iterator data_set=dof_data.begin();
           data_set!=dof_data.end(); ++data_set)
        for (unsigned int i=0; i<data_set->names.size(); ++i)
          Assert (*name != data_set->names[i], ExcNameAlreadyUsed(*name));

      for (typename std::vector<DataVector>::const_iterator data_set=cell_data.begin();
           data_set!=cell_data.end(); ++data_set)
        for (unsigned int i=0; i<data_set->names.size(); ++i)
          Assert (*name != data_set->names[i], ExcNameAlreadyUsed(*name));
    };

  switch (vector_type)
    {
    case dof_vector:
      dof_data.emplace_back ();
      dof_data.back().names = names;
      break;

    case cell_vector:
      cell_data.emplace_back ();
      cell_data.back().names = names;
      break;
    };
}


template <int dim, int spacedim, typename DoFHandlerType>
template <typename number>
void DataOutStack<dim,spacedim,DoFHandlerType>::add_data_vector (const Vector<number> &vec,
    const std::string    &name)
{
  const unsigned int n_components = dof_handler->get_fe(0).n_components ();

  std::vector<std::string> names;
  // if only one component or vector
  // is cell vector: we only need one
  // name
  if ((n_components == 1) ||
      (vec.size() == dof_handler->get_triangulation().n_active_cells()))
    {
      names.resize (1, name);
    }
  else
    // otherwise append _i to the
    // given name
    {
      names.resize (n_components);
      for (unsigned int i=0; i<n_components; ++i)
        {
          std::ostringstream namebuf;
          namebuf << '_' << i;
          names[i] = name + namebuf.str();
        }
    }

  add_data_vector (vec, names);
}


template <int dim, int spacedim, typename DoFHandlerType>
template <typename number>
void DataOutStack<dim,spacedim,DoFHandlerType>::add_data_vector (const Vector<number> &vec,
    const std::vector<std::string> &names)
{
  Assert (dof_handler != nullptr,
          Exceptions::DataOutImplementation::ExcNoDoFHandlerSelected ());
  // either cell data and one name,
  // or dof data and n_components names
  Assert (((vec.size() == dof_handler->get_triangulation().n_active_cells()) &&
           (names.size() == 1))
          ||
          ((vec.size() == dof_handler->n_dofs()) &&
           (names.size() == dof_handler->get_fe(0).n_components())),
          Exceptions::DataOutImplementation::ExcInvalidNumberOfNames (names.size(),
              dof_handler->get_fe(0).n_components()));
  for (unsigned int i=0; i<names.size(); ++i)
    Assert (names[i].find_first_not_of("abcdefghijklmnopqrstuvwxyz"
                                       "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                                       "0123456789_<>()") == std::string::npos,
            Exceptions::DataOutImplementation::ExcInvalidCharacter (names[i],
                names[i].find_first_not_of("abcdefghijklmnopqrstuvwxyz"
                                           "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                                           "0123456789_<>()")));

  if (vec.size() == dof_handler->n_dofs())
    {
      typename std::vector<DataVector>::iterator data_vector=dof_data.begin();
      for (; data_vector!=dof_data.end(); ++data_vector)
        if (data_vector->names == names)
          {
            data_vector->data.reinit (vec.size());
            std::copy (vec.begin(), vec.end(),
                       data_vector->data.begin());
            return;
          };

      // ok. not found. there is a
      // slight chance that
      // n_dofs==n_cells, so only
      // bomb out if the next if
      // statement will not be run
      if (dof_handler->n_dofs() != dof_handler->get_triangulation().n_active_cells())
        Assert (false, ExcVectorNotDeclared (names[0]));
    }

  // search cell data
  if ((vec.size() != dof_handler->n_dofs()) ||
      (dof_handler->n_dofs() == dof_handler->get_triangulation().n_active_cells()))
    {
      typename std::vector<DataVector>::iterator data_vector=cell_data.begin();
      for (; data_vector!=cell_data.end(); ++data_vector)
        if (data_vector->names == names)
          {
            data_vector->data.reinit (vec.size());
            std::copy (vec.begin(), vec.end(),
                       data_vector->data.begin());
            return;
          };
      Assert (false, ExcVectorNotDeclared (names[0]));
    };

  // we have either return or Assert
  // statements above, so shouldn't
  // get here!
  Assert (false, ExcInternalError());
}


template <int dim, int spacedim, typename DoFHandlerType>
void DataOutStack<dim,spacedim,DoFHandlerType>::build_patches (const unsigned int nnnn_subdivisions)
{
  // this is mostly copied from the
  // DataOut class
  unsigned int n_subdivisions = (nnnn_subdivisions != 0)
                                ? nnnn_subdivisions
                                : this->default_subdivisions;

  Assert (n_subdivisions >= 1,
          Exceptions::DataOutImplementation::ExcInvalidNumberOfSubdivisions(n_subdivisions));
  Assert (dof_handler != nullptr,
          Exceptions::DataOutImplementation::ExcNoDoFHandlerSelected());

  this->validate_dataset_names();

  const unsigned int n_components   = dof_handler->get_fe(0).n_components();
  const unsigned int n_datasets     = dof_data.size() * n_components +
                                      cell_data.size();

  // first count the cells we want to
  // create patches of and make sure
  // there is enough memory for that
  unsigned int n_patches = 0;
  for (typename DoFHandlerType::active_cell_iterator
       cell=dof_handler->begin_active();
       cell != dof_handler->end(); ++cell)
    ++n_patches;


  // before we start the loop:
  // create a quadrature rule that
  // actually has the points on this
  // patch, and an object that
  // extracts the data on each
  // cell to these points
  QTrapez<1>     q_trapez;
  QIterated<dim> patch_points (q_trapez, n_subdivisions);

  // create collection objects from
  // single quadratures,
  // and finite elements. if we have
  // an hp DoFHandler,
  // dof_handler.get_fe() returns a
  // collection of which we do a
  // shallow copy instead
  const hp::QCollection<dim>       q_collection (patch_points);
  const hp::FECollection<dim>     &fe_collection = dof_handler->get_fe_collection();

  hp::FEValues<dim> x_fe_patch_values (fe_collection, q_collection,
                                       update_values);

  const unsigned int n_q_points = patch_points.size();
  std::vector<double>          patch_values (n_q_points);
  std::vector<Vector<double> > patch_values_system (n_q_points,
                                                    Vector<double>(n_components));

  // add the required number of
  // patches. first initialize a template
  // patch with n_q_points (in the plane
  // of the cells) times n_subdivisions+1 (in
  // the time direction) points
  dealii::DataOutBase::Patch<dim+1,dim+1>  default_patch;
  default_patch.n_subdivisions = n_subdivisions;
  default_patch.data.reinit (n_datasets, n_q_points*(n_subdivisions+1));
  patches.insert (patches.end(), n_patches, default_patch);

  // now loop over all cells and
  // actually create the patches
  typename std::vector< dealii::DataOutBase::Patch<dim+1,dim+1> >::iterator
  patch = patches.begin() + (patches.size()-n_patches);
  unsigned int cell_number = 0;
  for (typename DoFHandlerType::active_cell_iterator cell=dof_handler->begin_active();
       cell != dof_handler->end(); ++cell, ++patch, ++cell_number)
    {
      Assert (cell->is_locally_owned(),
              ExcNotImplemented());

      Assert (patch != patches.end(), ExcInternalError());

      // first fill in the vertices of the patch

      // Patches are organized such
      // that the parameter direction
      // is the last
      // coordinate. Thus, vertices
      // are two copies of the space
      // patch, one at parameter-step
      // and one at parameter.
      switch (dim)
        {
        case 1:
          patch->vertices[0] = Point<dim+1>(cell->vertex(0)(0),
                                            parameter-parameter_step);
          patch->vertices[1] = Point<dim+1>(cell->vertex(1)(0),
                                            parameter-parameter_step);
          patch->vertices[2] = Point<dim+1>(cell->vertex(0)(0),
                                            parameter);
          patch->vertices[3] = Point<dim+1>(cell->vertex(1)(0),
                                            parameter);
          break;

        case 2:
          patch->vertices[0] = Point<dim+1>(cell->vertex(0)(0),
                                            cell->vertex(0)(1),
                                            parameter-parameter_step);
          patch->vertices[1] = Point<dim+1>(cell->vertex(1)(0),
                                            cell->vertex(1)(1),
                                            parameter-parameter_step);
          patch->vertices[2] = Point<dim+1>(cell->vertex(2)(0),
                                            cell->vertex(2)(1),
                                            parameter-parameter_step);
          patch->vertices[3] = Point<dim+1>(cell->vertex(3)(0),
                                            cell->vertex(3)(1),
                                            parameter-parameter_step);
          patch->vertices[4] = Point<dim+1>(cell->vertex(0)(0),
                                            cell->vertex(0)(1),
                                            parameter);
          patch->vertices[5] = Point<dim+1>(cell->vertex(1)(0),
                                            cell->vertex(1)(1),
                                            parameter);
          patch->vertices[6] = Point<dim+1>(cell->vertex(2)(0),
                                            cell->vertex(2)(1),
                                            parameter);
          patch->vertices[7] = Point<dim+1>(cell->vertex(3)(0),
                                            cell->vertex(3)(1),
                                            parameter);
          break;

        default:
          Assert (false, ExcNotImplemented());
        };


      // now fill in the data values.
      // note that the required order is
      // with highest coordinate running
      // fastest, we need to enter each
      // value (n_subdivisions+1) times
      // in succession
      if (n_datasets > 0)
        {
          x_fe_patch_values.reinit (cell);
          const FEValues<dim> &fe_patch_values
            = x_fe_patch_values.get_present_fe_values ();

          // first fill dof_data
          for (unsigned int dataset=0; dataset<dof_data.size(); ++dataset)
            {
              if (n_components == 1)
                {
                  fe_patch_values.get_function_values (dof_data[dataset].data,
                                                       patch_values);
                  for (unsigned int i=0; i<n_subdivisions+1; ++i)
                    for (unsigned int q=0; q<n_q_points; ++q)
                      patch->data(dataset,q+n_q_points*i) = patch_values[q];
                }
              else
                // system of components
                {
                  fe_patch_values.get_function_values (dof_data[dataset].data,
                                                       patch_values_system);
                  for (unsigned int component=0; component<n_components; ++component)
                    for (unsigned int i=0; i<n_subdivisions+1; ++i)
                      for (unsigned int q=0; q<n_q_points; ++q)
                        patch->data(dataset*n_components+component,
                                    q+n_q_points*i)
                          = patch_values_system[q](component);
                }
            }

          // then do the cell data
          for (unsigned int dataset=0; dataset<cell_data.size(); ++dataset)
            {
              const double value = cell_data[dataset].data(cell_number);
              for (unsigned int q=0; q<n_q_points; ++q)
                for (unsigned int i=0; i<n_subdivisions+1; ++i)
                  patch->data(dataset+dof_data.size()*n_components,
                              q*(n_subdivisions+1)+i) = value;
            }
        }
    }
}


template <int dim, int spacedim, typename DoFHandlerType>
void DataOutStack<dim,spacedim,DoFHandlerType>::finish_parameter_value ()
{
  // release lock on dof handler
  dof_handler = nullptr;
  for (typename std::vector<DataVector>::iterator i=dof_data.begin();
       i!=dof_data.end(); ++i)
    i->data.reinit (0);

  for (typename std::vector<DataVector>::iterator i=cell_data.begin();
       i!=cell_data.end(); ++i)
    i->data.reinit (0);
}



template <int dim, int spacedim, typename DoFHandlerType>
std::size_t
DataOutStack<dim,spacedim,DoFHandlerType>::memory_consumption () const
{
  return (DataOutInterface<dim+1>::memory_consumption () +
          MemoryConsumption::memory_consumption (parameter) +
          MemoryConsumption::memory_consumption (parameter_step) +
          MemoryConsumption::memory_consumption (dof_handler) +
          MemoryConsumption::memory_consumption (patches) +
          MemoryConsumption::memory_consumption (dof_data) +
          MemoryConsumption::memory_consumption (cell_data));
}



template <int dim, int spacedim, typename DoFHandlerType>
const std::vector< dealii::DataOutBase::Patch<dim+1,dim+1> > &
DataOutStack<dim,spacedim,DoFHandlerType>::get_patches () const
{
  return patches;
}



template <int dim, int spacedim, typename DoFHandlerType>
std::vector<std::string> DataOutStack<dim,spacedim,DoFHandlerType>::get_dataset_names () const
{
  std::vector<std::string> names;
  for (typename std::vector<DataVector>::const_iterator dataset=dof_data.begin();
       dataset!=dof_data.end(); ++dataset)
    names.insert (names.end(), dataset->names.begin(), dataset->names.end());
  for (typename std::vector<DataVector>::const_iterator dataset=cell_data.begin();
       dataset!=cell_data.end(); ++dataset)
    names.insert (names.end(), dataset->names.begin(), dataset->names.end());

  return names;
}



// explicit instantiations
#include "data_out_stack.inst"


DEAL_II_NAMESPACE_CLOSE