// DatasetReplicaCatalog.h

#ifndef dset__DatasetReplicaCatalog_H
#define dset__DatasetReplicaCatalog_H

// David Adams
// November 2004
//
// A dataset replica catalog hold sth mapping between virtual and
// non-virtual (logical, physica, staged) datasets. This class provides
// a C++ interface to such a catalog.
//
// This class is build on GenericReplicaCatalog.

#include <iosfwd>
#include "dataset_id/DatasetId.h"
#include "dataset_id/DatasetIdList.h"
#include "dataset_catalog/GenericReplicaCatalog.h"

namespace dset {

class DatasetReplicaCatalog {

public:  // typedefs

  typedef int Status;
  typedef std::string Connection;
  typedef DatasetId Id;
  typedef DatasetIdList IdList;
  typedef IdList::size_type size_type;

private: // data

  GenericReplicaCatalog* m_pcat;
  
private:

  // No copying allowd.
  DatasetReplicaCatalog(const DatasetReplicaCatalog&);

  // No assignment allowed.
  DatasetReplicaCatalog& operator=(const DatasetReplicaCatalog&);

public:  // static methods

  // Return the default concrete instance of this class.
  // First pass, use set_default_instance or 
  // define an invalid catalog if this fails.
  static DatasetReplicaCatalog& default_instance();

  // Set the default instance of this class.
  // Returns 0 for success.
  static int set_default_instance(DatasetReplicaCatalog* pdrc);

  // Set the default instance of this class.
  // Returns 0 for success.
  static int set_default_instance(Connection conn = "");

  // Assign an empty DSC as the default by
  // 1. creating an empty SQLRESULT DRC drc.dat,
  // 2. appending a clause to resolver.dat and
  // 3. setting the latter as the connection configuration file.
  // This should only be used for testing.
  // The connection resolver is shared by all catalogs.
  // Returns 0 for success.
  static int create_default_instance();

public:  // methods

  // Default constructor.
  DatasetReplicaCatalog();

  // Constructor from a table.
  explicit DatasetReplicaCatalog(GenericReplicaCatalog* pcat);

  // Constructor from a catalog description.
  explicit DatasetReplicaCatalog(Connection conn);

  // Destructor.
  ~DatasetReplicaCatalog();

public:  // const methods

  // Is this a valid catalog?
  bool is_valid() const;

  // Number of logical datasets
  size_type logical_size() const;

  // Number of replicas.
  size_type replica_size() const;

  // Is a logical dataset present?
  bool has_logical(Id lid) const;

  // Is a replica dataset present?
  bool has_replica(Id rid) const;

  // Is a logical-replica mapping present?
  bool has(Id lid, Id rid) const;

  // Return the list of logical ID's.
  IdList logicals() const;

  // Return the list of replica ID's.
  IdList replicas() const;

  // Return the list of replica ID's associated with a logical ID.
  IdList replicas(Id lid) const;

  // Return the logical ID associated with a replica ID.
  // Returns invalid if there is not exactly one match.
  Id logical(Id rid) const;

public:  // non-const methods

  // Insert a logical ID.
  // Second argument is a list of associated replica ID's.
  // Error if the logical ID or any of the replica ID's are
  // already present or the catalog cannot be updated.
  // Returns 0 for success.
  // The default implementations for the first two make use of
  // the last.
  Status insert(Id lid, const IdList& rids);

  // Update a logical ID.
  // Second argument is a list of replica ID's to be appended to
  // those associated with the logical ID.
  // Error if the logical ID is not already present, any of the
  // replica ID's are already present or the catalog cannot
  // be updated.
  // Returns 0 for success.
  Status update(Id lid, const IdList& rids);

  // Remove a replica from the catalog.
  // The logical ID is *not* removed from the table.
  // Error if the specified mapping is not be present.
  // Returns 0 for success.
  Status remove_replica(Id lid, Id rid);

  // Remove a logical ID (i.e. all its mappings) from the catalog.
  // Error if the logical ID is not present or catalog cannot be
  // updated.
  // Returns 0 for success.
  Status remove_logical(Id lid);

};

}  // end dset namespace

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

#endif