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

 Program:   Visualization Toolkit
 Module:    vtkAMRBaseReader.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.

 =========================================================================*/
/**
 * @class   vtkAMRBaseReader
 *
 *
 * An abstract class that encapsulates common functionality for all AMR readers.
*/

#ifndef vtkAMRBaseReader_h
#define vtkAMRBaseReader_h

#include "vtkIOAMRModule.h" // For export macro
#include "vtkOverlappingAMRAlgorithm.h"
#include <vector>    // STL vector header
#include <map>       // STL map header
#include <utility>   // for STL pair

// Forward Declarations
class vtkOverlappingAMR;
class vtkMultiProcessController;
class vtkDataArraySelection;
class vtkCallbackCommand;
class vtkIndent;
class vtkAMRDataSetCache;
class vtkUniformGrid;
class vtkDataArray;

class VTKIOAMR_EXPORT vtkAMRBaseReader :
  public vtkOverlappingAMRAlgorithm
{
public:
  vtkTypeMacro( vtkAMRBaseReader, vtkOverlappingAMRAlgorithm );
  void PrintSelf(ostream &os, vtkIndent indent) override;

  /**
   * Initializes the AMR reader.
   * All concrete instances must call this method in their constructor.
   */
  void Initialize();

  //@{
  /**
   * Set/Get Reader caching property
   */
  vtkSetMacro( EnableCaching, int );
  vtkGetMacro( EnableCaching, int );
  vtkBooleanMacro( EnableCaching, int );
  bool IsCachingEnabled() const
  {
     return( (this->EnableCaching)?true:false);
  };
  //@}

  //@{
  /**
   * Set/Get a multiprocess-controller for reading in parallel.
   * By default this parameter is set to nullptr by the constructor.
   */
  vtkSetMacro( Controller, vtkMultiProcessController* );
  vtkGetMacro( Controller, vtkMultiProcessController* );
  //@}

  //@{
  /**
   * Set the level, up to which the blocks are loaded.
   */
  vtkSetMacro( MaxLevel,int);
  //@}

  //@{
  /**
   * Get the data array selection tables used to configure which data
   * arrays are loaded by the reader.
   */
  vtkGetObjectMacro(CellDataArraySelection, vtkDataArraySelection);
  vtkGetObjectMacro(PointDataArraySelection, vtkDataArraySelection);
  //@}

  //@{
  /**
   * Get the number of point or cell arrays available in the input.
   */
  int GetNumberOfPointArrays();
  int GetNumberOfCellArrays();
  //@}

  //@{
  /**
   * Get the name of the point or cell array with the given index in
   * the input.
   */
  const char* GetPointArrayName(int index);
  const char* GetCellArrayName(int index);
  //@}

  //@{
  /**
   * Get/Set whether the point or cell array with the given name is to
   * be read.
   */
  int GetPointArrayStatus(const char* name);
  int GetCellArrayStatus(const char* name);
  void SetPointArrayStatus(const char* name, int status);
  void SetCellArrayStatus(const char* name, int status);
  //@}

  //@{
  /**
   * Set/Get the filename. Concrete instances of this class must implement
   * the SetFileName method accordingly.
   */
  vtkGetStringMacro( FileName );
  virtual void SetFileName( const char *fileName ) = 0;
  //@}

  /**
   * Returns the total number of blocks. Implemented by concrete instances.
   */
  virtual int GetNumberOfBlocks() = 0;

  /**
   * Returns the total number of levels. Implemented by concrete instances.
   */
  virtual int GetNumberOfLevels() = 0;

protected:
  vtkAMRBaseReader();
  ~vtkAMRBaseReader() override;

  // Desscription:
  // Checks if this reader instance is attached to a communicator
  // with more than one MPI processes.
  bool IsParallel();

  /**
   * Determines if the block is owned by this process based on the
   * the block index and total number of processes.
   */
  bool IsBlockMine( const int blockIdx );

  /**
   * Loads the AMR block corresponding to the given index. The block
   * is either loaded from the file, or, from the cache if caching is
   * enabled.
   */
  vtkUniformGrid* GetAMRBlock( const int blockIdx );

  /**
   * This method assigns blocks to processes using block-cyclic distribution.
   * It is the method that is used to load distributed AMR data by default.
   */
  void AssignAndLoadBlocks( vtkOverlappingAMR *amrds );

  /**
   * This method loads all the blocks in the BlockMap for the given process.
   * It assumes that the downstream module is doing an upstream request with
   * the flag LOAD_REQUESTED_BLOCKS which indicates that the downstream filter
   * has already assigned which blocks are needed for each process.
   */
  void LoadRequestedBlocks( vtkOverlappingAMR *amrds );

  /**
   * Loads the AMR data corresponding to the given field name.
   * NOTE: Currently, only cell-data are supported.
   */
  void GetAMRData(
    const int blockIdx, vtkUniformGrid *block, const char *fieldName );


  /**
   * Loads the AMR point data corresponding to the given field name.
   */
  void GetAMRPointData(
    const int blockIdx, vtkUniformGrid *block, const char *fieldName );

  /**
   * A wrapper that loops over point arrays and load the point
   * arrays that are enabled, i.e., selected for the given block.
   * NOTE: This method is currently not implemented.
   */
  void LoadPointData( const int blockIdx, vtkUniformGrid *block );

  /**
   * A wrapper that loops over all cell arrays and loads the cell
   * arrays that are enabled, i.e., selected for the given block.
   * The data are either loaded from the file, or, from the cache if
   * caching is enabled.
   */
  void LoadCellData( const int blockIdx, vtkUniformGrid *block );

  /**
   * Returns the block process ID for the block corresponding to the
   * given block index. If this reader instance is serial, i.e., there
   * is no controller associated, the method returns 0. Otherwise, static
   * block-cyclic-distribution is assumed and each block is assigned to
   * a process according to blockIdx%N, where N is the total number of
   * processes.
   */
  int GetBlockProcessId( const int blockIdx );

  /**
   * Initializes the request of blocks to be loaded. This method checks
   * if an upstream request has been issued from a downstream module which
   * specifies which blocks are to be loaded, otherwise, it uses the max
   * level associated with this reader instance to determine which blocks
   * are to be loaded.
   */
  void SetupBlockRequest( vtkInformation *outputInfo );

  /**
   * Reads all the metadata from the file. Implemented by concrete classes.
   */
  virtual void ReadMetaData() = 0;

  /**
   * Returns the block level for the given block
   */
  virtual int GetBlockLevel( const int blockIdx ) = 0;

  /**
   * Loads all the AMR metadata & constructs the LevelIdxPair12InternalIdx
   * datastructure which maps (level,id) pairs to an internal linear index
   * used to identify the corresponding block.
   */
  virtual int FillMetaData( ) = 0;

  /**
   * Loads the block according to the index w.r.t. the generated BlockMap.
   */
  virtual vtkUniformGrid* GetAMRGrid( const int blockIdx ) = 0;

  /**
   * Loads the block data
   */
  virtual void GetAMRGridData(
      const int blockIdx, vtkUniformGrid *block, const char *field ) = 0;

  /**
   * Loads the block Point data
   */
  virtual void GetAMRGridPointData(
      const int blockIdx, vtkUniformGrid *block, const char *field ) = 0;

  //@{
  /**
   * Standard Pipeline methods, subclasses may override this method if needed.
   */
 int RequestData(
      vtkInformation* vtkNotUsed(request),
      vtkInformationVector** vtkNotUsed(inputVector),
      vtkInformationVector* outputVector ) override;
  int RequestInformation(
      vtkInformation* rqst,
      vtkInformationVector** inputVector,
      vtkInformationVector* outputVector ) override;
  int FillOutputPortInformation(int port,vtkInformation *info) override;
  //@}

  // Array selection member variables and methods
  vtkDataArraySelection *PointDataArraySelection;
  vtkDataArraySelection *CellDataArraySelection;
  vtkCallbackCommand    *SelectionObserver;

  /**
   * Initializes the array selections. If this is an initial request,
   * i.e., the first load from the file, all the arrays are deselected,
   * and the InitialRequest ivar is set to false.
   */
  void InitializeArraySelections();

  /**
   * Initializes the PointDataArraySelection & CellDataArraySelection
   */
  virtual void SetUpDataArraySelections() = 0;

  /**
   * Call-back registered with the SelectionObserver.
   */
  static void SelectionModifiedCallback(
    vtkObject *caller,unsigned long eid,void *clientdata,void *calldata );

  bool InitialRequest;
  int MaxLevel;
  char *FileName;
  vtkMultiProcessController *Controller;

  int EnableCaching;
  vtkAMRDataSetCache *Cache;
  int NumBlocksFromFile;
  int NumBlocksFromCache;

  vtkOverlappingAMR *Metadata;
  bool LoadedMetaData;

    std::vector<int> BlockMap;

private:
  vtkAMRBaseReader( const vtkAMRBaseReader& ) = delete;
  void operator=( const vtkAMRBaseReader& ) = delete;
};

#endif /* vtkAMRBaseReader_h */