// ApplicationSelectionCatalog.h 

#ifndef dset__ApplicationSelectionCatalog_H
#define dset__ApplicationSelectionCatalog_H

// David Adams
// November 2004
//
// An application selection catalog associates named attributes with
// application names. Each entry in the catalog has a unique name.
// The attributes include those required to record an application ID.
//
// This class is built on a generic selection catalog.

#include <string>
#include <iosfwd>
#include <set>
#include "dataset_sql/SqlQuery.h"
#include "dataset_id/UniqueId.h"
#include "dataset_catalog/GenericSelectionCatalog.h"
#include "dial_app/ApplicationId.h"

namespace dial {

class ApplicationSelectionCatalog {

public: // typedefs

  typedef std::string Connection;
  typedef dset::GenericSelectionCatalog::Name Name;
  typedef dset::GenericSelectionCatalog::NameList NameList;
  typedef dset::GenericSelectionCatalog::size_type size_type;
  typedef dset::GenericSelectionCatalog::Attributes Attributes;
  typedef std::set<ApplicationId> IdList;

private: // Data
  
  dset::GenericSelectionCatalog *m_pcat;

private:

  // No copying allowed.
  ApplicationSelectionCatalog(const ApplicationSelectionCatalog&);

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

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 ApplicationSelectionCatalog& default_instance();

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

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

  // Assign an empty ASC as the default by
  // 1. creating an empty SQLRESULT DSC dsc.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:  // constructors and destructor

  // Default constructor.
  ApplicationSelectionCatalog();

  // Constructor from a generic selectioncatalog.
  ApplicationSelectionCatalog(dset::GenericSelectionCatalog* pcat);

  // Constructor from a connection string.
  ApplicationSelectionCatalog(Connection conn);

  // Destructor.
  ~ApplicationSelectionCatalog();

public:  // const methods

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

  // Catalog type.
  Name catalog_type() const { return "ApplicationSelectionCatalog"; }

  // Return the ID encoding.
  Name id_encoding() const;

  // Return the attribute names.
  NameList schema() const;

  // Does an application name appear in the catalog?
  bool has_name(Name dsname) const;

  // Retrieve the attributes associated with a name.
  Attributes attributes(Name name) const;

  // Return the virtual ID associated with an application name.
  ApplicationId id(Name name) const;

  // Return the number of entries in the catalog.
  size_type size() const;

  // Return the namess of the first maxent applications that match
  // a query.
  NameList query(dset::SqlQuery qry, size_type maxent =20) const;

  // Retrieve the number of entries that match a select query.
  size_type query_count(dset::SqlQuery qry) const;

  // Return a web page.
  // See GenericSelectionCatalog.
  Text web_page(std::string baseurl, std::string entry,
                std::string uidurl) const;

public:  // const methods
  
  // Insert a new entry in the catalog.
  // Error if name is already present or catalog cannot be updated.
  // Value for name in attribute list is overwritten.
  // Returns 0 for success.
  int insert(Name name, const Attributes& att);

  // Update the attributes for an existing entry.
  // Error if name is not present or catalog cannot be updated.
  // Attributes may be used to rename the application.
  // Error if this attributes name is already present.
  // Returns 0 for success.
  int update(Name name, const Attributes& att);

  // Remove an entry
  // Error if name is not present or entry cannot be removed.
  // Returns 0 for success.
  int remove(Name name);

};

}  // end dset namespace

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

#endif