// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
/**
 * @class   vtkXdmfReaderInternal
 *
 */

#ifndef vtkXdmfReaderInternal_h
#define vtkXdmfReaderInternal_h

// NAMING CONVENTION *********************************************************
// * all member variables of the type XdmfXml* begin with XML eg. XMLNode
// * all non-member variables of the type XdmfXml* begin with xml eg. xmlNode
// * all member variables of the type XdmfElement (and subclasses) begin with
//   XMF eg. XMFGrid
// * all non-member variables of the type XdmfElement (and subclasses) begin
//   with xmf eg. xmfGrid
// ***************************************************************************

#include "vtkMutableDirectedGraph.h"
#include "vtkSILBuilder.h"

#include "vtk_xdmf2.h"
#include VTKXDMF2_HEADER(XdmfArray.h)
#include VTKXDMF2_HEADER(XdmfAttribute.h)
#include VTKXDMF2_HEADER(XdmfDOM.h)
//?
#include VTKXDMF2_HEADER(XdmfDataDesc.h)
//?
#include VTKXDMF2_HEADER(XdmfDataItem.h)
#include VTKXDMF2_HEADER(XdmfGrid.h)
//?
#include VTKXDMF2_HEADER(XdmfTopology.h)
//?
#include VTKXDMF2_HEADER(XdmfGeometry.h)
//?
#include VTKXDMF2_HEADER(XdmfTime.h)
//?
#include VTKXDMF2_HEADER(XdmfSet.h)

#include <algorithm>
#include <cassert>
#include <functional>
#include <map>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <vtksys/SystemTools.hxx>

VTK_ABI_NAMESPACE_BEGIN
class vtkXdmfDomain;
class VTKIOXDMF2_EXPORT vtkXdmfDocument
{
public:
  //---------------------------------------------------------------------------
  ///@{
  /**
   * Parse an xmf file (or string). Both these methods use caching hence calling
   * these methods repeatedly with the same argument will NOT result in
   * re-parsing of the xmf.
   */
  bool Parse(const char* xmffilename);
  bool ParseString(const char* xmfdata, size_t length);
  ///@}

  //---------------------------------------------------------------------------
  /**
   * Returns the names for available domains.
   */
  const std::vector<std::string>& GetDomains() { return this->Domains; }

  //---------------------------------------------------------------------------
  ///@{
  /**
   * Set the active domain. This will result in processing of the domain xmf if
   * the selected domain is different from the active one.
   */
  bool SetActiveDomain(const char* domainname);
  bool SetActiveDomain(int index);
  ///@}

  //---------------------------------------------------------------------------
  /**
   * Returns the active domain.
   */
  vtkXdmfDomain* GetActiveDomain() { return this->ActiveDomain; }

  //---------------------------------------------------------------------------
  ///@{
  /**
   * Constructor/Destructor
   */
  vtkXdmfDocument();
  ~vtkXdmfDocument();
  ///@}

private:
  // Populates the list of domains.
  void UpdateDomains();

  int ActiveDomainIndex;
  xdmf2::XdmfDOM XMLDOM;
  vtkXdmfDomain* ActiveDomain;
  std::vector<std::string> Domains;

  char* LastReadContents;
  size_t LastReadContentsLength;
  std::string LastReadFilename;
};

// I don't use vtkDataArraySelection since it's very slow when it comes to large
// number of arrays.
class vtkXdmfArraySelection : public std::map<std::string, bool>
{
public:
  void Merge(const vtkXdmfArraySelection& other)
  {
    vtkXdmfArraySelection::const_iterator iter = other.begin();
    for (; iter != other.end(); ++iter)
    {
      (*this)[iter->first] = iter->second;
    }
  }

  void AddArray(const char* name, bool status = true) { (*this)[name] = status; }

  bool ArrayIsEnabled(const char* name)
  {
    vtkXdmfArraySelection::iterator iter = this->find(name);
    if (iter != this->end())
    {
      return iter->second;
    }

    // don't know anything about this array, enable it by default.
    return true;
  }

  bool HasArray(const char* name)
  {
    vtkXdmfArraySelection::iterator iter = this->find(name);
    return (iter != this->end());
  }

  int GetArraySetting(const char* name) { return this->ArrayIsEnabled(name) ? 1 : 0; }

  void SetArrayStatus(const char* name, bool status) { this->AddArray(name, status); }

  const char* GetArrayName(int index)
  {
    int cc = 0;
    for (vtkXdmfArraySelection::iterator iter = this->begin(); iter != this->end(); ++iter)
    {

      if (cc == index)
      {
        return iter->first.c_str();
      }
      cc++;
    }
    return nullptr;
  }

  int GetNumberOfArrays() { return static_cast<int>(this->size()); }
};

//***************************************************************************
class VTKIOXDMF2_EXPORT vtkXdmfDomain
{
private:
  XdmfInt64 NumberOfGrids;
  xdmf2::XdmfGrid* XMFGrids;

  XdmfXmlNode XMLDomain;
  xdmf2::XdmfDOM* XMLDOM;

  unsigned int GridsOverflowCounter;
  // these are node indices used when building the SIL.
  vtkIdType SILBlocksRoot;
  std::map<std::string, vtkIdType> GridCenteredAttrbuteRoots;
  std::map<vtkIdType, std::map<XdmfInt64, vtkIdType>> GridCenteredAttrbuteValues;

  vtkSILBuilder* SILBuilder;
  vtkMutableDirectedGraph* SIL;
  vtkXdmfArraySelection* PointArrays;
  vtkXdmfArraySelection* CellArrays;
  vtkXdmfArraySelection* Grids;
  vtkXdmfArraySelection* Sets;
  std::map<XdmfFloat64, int> TimeSteps; //< Only discrete timesteps are currently
                                        //  supported.
  std::map<int, XdmfFloat64> TimeStepsRev;

public:
  //---------------------------------------------------------------------------
  // does not take ownership of the DOM, however the xmlDom must exist as long
  // as the instance is in use.
  vtkXdmfDomain(xdmf2::XdmfDOM* xmlDom, int domain_index);

  //---------------------------------------------------------------------------
  /**
   * After instantiating, check that the domain is valid. If this returns false,
   * it means that the specified domain could not be located.
   */
  bool IsValid() { return (this->XMLDomain != nullptr); }

  //---------------------------------------------------------------------------
  vtkGraph* GetSIL() { return this->SIL; }

  //---------------------------------------------------------------------------
  /**
   * Returns the number of top-level grids present in this domain.
   */
  XdmfInt64 GetNumberOfGrids() { return this->NumberOfGrids; }

  //---------------------------------------------------------------------------
  /**
   * Provides access to a top-level grid from this domain.
   */
  xdmf2::XdmfGrid* GetGrid(XdmfInt64 cc);

  //---------------------------------------------------------------------------
  /**
   * Returns the VTK data type need for this domain. If the domain has only 1
   * grid, then a vtkDataSet-type is returned, otherwise a vtkMultiBlockDataSet
   * is required.
   * Returns -1 on error.
   */
  int GetVTKDataType();

  //---------------------------------------------------------------------------
  /**
   * Returns the timesteps.
   */
  const std::map<XdmfFloat64, int>& GetTimeSteps() { return this->TimeSteps; }
  const std::map<int, XdmfFloat64>& GetTimeStepsRev() { return this->TimeStepsRev; }

  //---------------------------------------------------------------------------
  /**
   * Given a time value, returns the index.
   */
  int GetIndexForTime(double time);

  //---------------------------------------------------------------------------
  ///@{
  /**
   * Returns the time value at the given index.
   */
  XdmfFloat64 GetTimeForIndex(int index)
  {
    std::map<int, XdmfFloat64>::iterator iter = this->TimeStepsRev.find(index);
    return (iter != this->TimeStepsRev.end()) ? iter->second : 0.0;
  }
  ///@}

  //---------------------------------------------------------------------------
  /**
   * If xmfGrid is a temporal collection, returns the child-grid matching the
   * requested time.
   */
  xdmf2::XdmfGrid* GetGrid(xdmf2::XdmfGrid* xmfGrid, double time);

  //---------------------------------------------------------------------------
  /**
   * Returns true if the grids is a structured dataset.
   */
  bool IsStructured(xdmf2::XdmfGrid*);

  //---------------------------------------------------------------------------
  /**
   * Returns the whole extents for the dataset if the grid if IsStructured()
   * returns true for the given grid. Returns true if the extents are valid.
   * NOTE: returned extents are always (0, dimx-1, 0, dimy-1, 0, dimz-1).
   */
  bool GetWholeExtent(xdmf2::XdmfGrid*, int extents[6]);

  //---------------------------------------------------------------------------
  /**
   * Returns the spacing and origin for the grid if the grid topology ==
   * XDMF_2DCORECTMESH or XDMF_3DCORECTMESH i.e. image data.  Returns true if
   * the extents are valid.
   */
  bool GetOriginAndSpacing(xdmf2::XdmfGrid*, double origin[3], double spacing[3]);

  //---------------------------------------------------------------------------
  ~vtkXdmfDomain();

  // Returns VTK data type based on grid type and topology.
  // Returns -1 on error.
  int GetVTKDataType(xdmf2::XdmfGrid* xmfGrid);

  // Returns the dimensionality (or rank) of the topology for the given grid.
  // Returns -1 is the xmfGrid is not a uniform i.e. is a collection or a tree.
  static int GetDataDimensionality(xdmf2::XdmfGrid* xmfGrid);

  vtkXdmfArraySelection* GetPointArraySelection() { return this->PointArrays; }
  vtkXdmfArraySelection* GetCellArraySelection() { return this->CellArrays; }
  vtkXdmfArraySelection* GetGridSelection() { return this->Grids; }
  vtkXdmfArraySelection* GetSetsSelection() { return this->Sets; }

private:
  /**
   * There are a few meta-information that we need to collect from the domain
   * * number of data-arrays so that the user can choose which to load.
   * * grid-structure so that the user can choose the hierarchy
   * * time information so that reader can report the number of timesteps
   * available.
   * This does another book-keeping task of ensuring that all grids have valid
   * names. If a grid is not named, then we make up a name.
   * TODO: We can use GRID centered attributes to create hierarchies in the SIL.
   */
  void CollectMetaData();

  // Used by CollectMetaData().
  void CollectMetaData(xdmf2::XdmfGrid* xmfGrid, vtkIdType silParent);

  // Used by CollectMetaData().
  void CollectNonLeafMetaData(xdmf2::XdmfGrid* xmfGrid, vtkIdType silParent);

  // Used by CollectMetaData().
  void CollectLeafMetaData(xdmf2::XdmfGrid* xmfGrid, vtkIdType silParent);

  ///@{
  /**
   * Use this to add an association with the grid attribute with the node for
   * the grid in the SIL if applicable. Returns true if the attribute was added.
   */
  bool UpdateGridAttributeInSIL(xdmf2::XdmfAttribute* xmfAttribute, vtkIdType gridSILId);
  ///@}
};

VTK_ABI_NAMESPACE_END
#endif
// VTK-HeaderTest-Exclude: vtkXdmfReaderInternal.h