// FileId.h

#ifndef hes_FileId_H
#define hes_FileId_H

// David Adams
// February 2002
//
// Holds the ID for a HES file.
//
// The ID has three pieces:
//   FileType
//   24-bit hi index
//   32-bit lo index
//
// The 8-bit index representation of the file type and the high index are
// merged to form the 32-bit type_hi index.
//
// A file ID can be recorded as and reconstituted from the type_hi and lo
// indices.

#include <iosfwd>
#include "Index.h"

namespace hes {

class FileType;

class FileId {

public:  // static methods

  // Return version number.
  // This will change if the bit allocations change.
  static int version();

private:  // data

  // Index.
  Index m_hi;
  Index m_lo;

public:  // methods

  // Default constructor.
  FileId();

  // Constructor from type and indices.
  FileId(FileType type, Index hi, Index lo);
 
  // Constructor from the type_hi and lo indices.
  FileId(Index type_hi, Index lo);

  // Return if this is a valid index.
  bool is_valid() const;

  // Return the file type.
  FileType file_type() const;

  // Return the indices.
  Index hi_index() const;
  Index lo_index() const;
  Index type_hi_index() const;

};

}  // end namespace hes

// Ordering.
bool operator<(const hes::FileId& lhs, const hes::FileId& rhs);

// Equality.
bool operator==(const hes::FileId& lhs, const hes::FileId& rhs);

// Inequality.
bool operator!=(const hes::FileId& lhs, const hes::FileId& rhs);

// Output stream.
std::ostream& operator<<(std::ostream& lhs, const hes::FileId& rhs);

#endif