/**********************************************************************
 *
 * infodbclass.h -- 
 * Copyright (C) 1999  The New Zealand Digital Library Project
 *
 * A component of the Greenstone digital library software
 * from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id: infodbclass.h 928 2000-02-15 22:53:52Z kjm18 $
 *
 *********************************************************************/


#ifndef INFODBCLASS_H
#define INFODBCLASS_H


#include "gsdlconf.h"
#include "text_t.h"

#ifdef __WIN32__

#ifdef __cplusplus
extern "C" {
#endif
#include "autoconf.h"
#include "systems.h"
#include "gdbmconst.h"
#include "gdbm.h"
#ifdef __cplusplus
}
#endif

#else
#include <gdbm.h>
#endif


typedef map<text_t, text_tarray, lttext_t> text_tarraymap;


// infodbclass is used to store information about a object
class infodbclass {
protected:
  text_tarraymap info;

public:
  // type support for text_tarraymap
  typedef text_tarraymap::iterator iterator;
  typedef text_tarraymap::const_iterator const_iterator;
  typedef text_tarraymap::reference reference;
  typedef text_tarraymap::const_reference const_reference;
  typedef text_tarraymap::size_type size_type;
  typedef text_tarraymap::difference_type difference_type;
  typedef text_tarraymap::const_reverse_iterator const_reverse_iterator;
  typedef text_tarraymap::reverse_iterator reverse_iterator;
  
  // constructors
  infodbclass ();

  // basic container support
  iterator begin () {return info.begin();}
  const_iterator begin () const {return info.begin();}
  iterator end () {return info.end();}
  const_iterator end () const {return info.end();}

  void erase(iterator pos) {info.erase(pos);}
  void erase(iterator first, iterator last) {info.erase(first, last);}
  infodbclass &operator=(const infodbclass &x) {info=x.info;return *this;}

  bool empty () const {return info.empty();}
  size_type size() const {return info.size();}


  // added functionality
  void clear () {info.erase(info.begin(),info.end());}

  // the following functions deal with keys that can only
  // have one value for compatibility
  
  // getinfo returns NULL if there isn't an entry with
  // 'key' already defined, getintinfo returns 0 if there wasn't an
  // entry with 'key' defined and operator[] returns "" if
  // 'key' wasn't already defined (and sets 'key'="").
  void setinfo (const text_t &key, const text_t &value);
  void setintinfo (const text_t &key, int value);
  void setcinfo (const text_t &key, unsigned short c);
  text_t *getinfo (const text_t &key);
  int getintinfo (const text_t &key);
  text_t &operator[] (const text_t &key);


  // the next set of functions allow you to set and access keys
  // that can have more than one value

  // getmultinfo returns NULL if there isn't an entry with
  // 'key' already defined
  void addinfo (const text_t &key, const text_t &value);
  void addintinfo (const text_t &key, int value);
  void addcinfo (const text_t &key, unsigned short c);
  text_tarray *getmultinfo (const text_t &key);
};


class gdbmclass {
public:
  gdbmclass() {gdbmfile = NULL; logout = &cerr;};
  ~gdbmclass() {};
  
  // returns true if opened
  bool opendatabase (const text_t &filename, int mode, int num_retrys, 
		     bool need_filelock);
  void closedatabase ();

  // replaces the .c, .p, .n, .l syntax (child, parent, next, previous) 
  // it expects child, parent, etc. to exist if syntax has been used
  // so you should test before using
  text_t translate_OID (const text_t &OID, infodbclass &info);

  // returns true on success
  bool getinfo (text_t key, infodbclass &info);
  void setlogout (ostream *thelogout) {logout = thelogout;}

  // returns true if exists
  bool exists (text_t key);

  // returns true on success
  bool setinfo (const text_t &key, const infodbclass &info);
  // returns true on success
  bool setinfo (const text_t &key, const text_t &data);

  void deletekey (const text_t &key);

  // getfirstkey and getnextkey are used for traversing the database
  // no insertions or deletions should be carried out while traversing
  // the database. when there are no keys left to visit in the database
  // an empty string is returned.
  text_t getfirstkey ();
  text_t getnextkey (const text_t &key);

    // returns true on success
  bool getkeydata (text_t key, text_t &data);

protected:
  text_t openfile;
  GDBM_FILE gdbmfile;
  ostream *logout;

  void get_first_child (text_t &OID, infodbclass &info);
  void get_last_child (text_t &OID, infodbclass &info);
  void get_next_sibling (text_t &OID, infodbclass &info);
  void get_previous_sibling (text_t &OID, infodbclass &info);


  // returns true on success
  bool getinfoline (text_t::iterator &here, text_t::iterator end, 
		   text_t &key, text_t &value);
};


#endif