/* Hdf_attr.hpp */

#ifndef HDF_ATTR_HPP
#define HDF_ATTR_HPP

#include <cstdlib>
#include <iostream>
#include <vector>
#include <string>
#include "mfhdf.h"
#include "Hdf_exceptions.hpp"

class Hdf_attr {
public:
  /**
   * @enum attr_own the type of the owner of an attribute
   * An attribute can refer either to a file, an sds, a VData, a VData field or a VGroup, and the way to read them in a file depends of it
   */ 
  typedef enum {
      UNDEFINED,
      SDS,
      VDATA,
      // other owner to add
  } attr_own;
  // TODO update constructor to write attributes in a file : this one only fits to reading
  Hdf_attr(const int32 object_id, const int32 iattr, const char *attr_name, const int32 attr_type, const int32 attr_nvalues, const attr_own owner=SDS, const int32 vd_field_idx=_HDF_VDATA);
  Hdf_attr();
  Hdf_attr(const Hdf_attr &hdf_attr);
  ~Hdf_attr();
  int32 get_type() const { return type; };
  int32 get_nvalues() const { return nvalues; }
  void get_value(void *value, int32 ival = 0) const; // ival is the index of value to retrieve from values
  void get_values(void *values) const; // values must be allocated by the caller : values = new attr_type[attr.get_nvalues()]
  std::string get_name() const { return name; }
  std::string to_string() const;
  std::string list_of_values() const;

  Hdf_attr &operator= (const Hdf_attr &hdf_attr);
  friend std::ostream &operator<< (std::ostream &stream, const Hdf_attr &hdf_attr);

  // change these to control the output of list_of_values()
  // these limits are intended to avoid a too large output (only the first and the last values will be displayed, separated by ...)
  // set them to 0 to display ALL the attribute values (even if there are hundreds or thousands of them)
  static int32 chars_to_display;
  static int32 numbers_to_display;

private:
  int32 obj_id;
  int32 index;
  std::string name;
  int32 type;
  int32 nvalues;
  void* values;

  void allocate_values();
  void deallocate_values();
  void copy_values(const Hdf_attr &hdf_attr);
  
};

#endif