// DataHeaderList.h

#ifndef dial__DataHeaderList_H
#define dial__DataHeaderList_H

// Provides access to the data headers in an ATLAS-POOL
// collection.
//
// Usage:
//   DataHeaderList dhl("mycoll");
//   DataHeaderList::Iterator idh = dhl.iterator();
//   while ( idh.isValid() ) {
//     const DataHeader& dh = *idh;
//     cout << dh << endl;
//   }

#ifndef __CINT__
#include "SGTools/DataHeader.h"
#include "Collection/Collection.h"
#endif

namespace pool {
class IFileCatalog;
class IDataSvc;
}

namespace dset {

class DataHeaderList {

public:  // typedefs

#ifndef __CINT__
  typedef pool::Collection<DataHeader> DHCollection;
  typedef DHCollection::Iterator Iterator;
#endif

private:  // data

  // Validity.
  int m_error;

  // POOL stuff.
#ifndef __CINT__
  pool::IFileCatalog* m_pfc;
  pool::IDataSvc* m_pds;
  DHCollection* m_pcol;
#else
  int* m_pfc;
  int* m_pds;
  int* m_pcol;
#endif

  // Names of the DB (file), collection and file catalog.
  // We assume an implicit collection.
  std::string m_dbname;
  std::string m_collname;
  std::string m_catname;

  // Directory for temporary files.
  // This is deleted in in destructor if not blank.
  std::string m_tmpdir;

public:  // methods

  // Constructor.
  //   dbname = name of the DB (file) holding the implicit collection
  //   catname = name of the XML catalog holding this file
  //             If blank, "POOLContainer_DataHeader"
  //   collname = name of the collection in the file
  //              If blank, a temporary catalog is created and then
  //              deleted by the destructor
  DataHeaderList(std::string dbname, std::string catname ="",
                 std::string catname ="");

  // Destructor.
  ~DataHeaderList();

  // Validity.
  bool is_valid() const;

  // Error code.
  int error() const;

  // Return the DB (file) name.
  std::string database_name() const;

  // Return the collection name.
  std::string collection_name() const;

  // Return the file catalog name.
  std::string file_catalog_name() const;

#ifndef __CINT__
  // Return the POOL data service.
  pool::IDataSvc* data_service() const;

  // Return an iterator.
  Iterator iterator() const;
#endif

};

}  // end namespace dial

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

#endif