/*=========================================================================
                                                                                
  Program:   gdcm
  Module:    $RCSfile: gdcmDict.cxx,v $
  Language:  C++
  Date:      $Date: 2005/01/07 09:03:52 $
  Version:   $Revision: 1.55 $
                                                                                
  Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
  l'Image). All rights reserved. See Doc/License.txt or
  http://www.creatis.insa-lyon.fr/Public/Gdcm/License.html for details.
                                                                                
     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.
                                                                                
=========================================================================*/

#include "gdcmDict.h"
#include "gdcmUtil.h"
#include "gdcmDebug.h"

#include <fstream>
#include <iostream>
#include <iomanip>

namespace gdcm 
{
void FillDefaultDataDict(Dict *d);
//-----------------------------------------------------------------------------
// Constructor / Destructor
/**
 * \brief   Constructor
 * @param   filename from which to build the dictionary.
 */
Dict::Dict(std::string const &filename)
{
   uint16_t group;
   uint16_t element;
   TagName vr;
   TagName fourth;
   TagName name;

   std::ifstream from( filename.c_str() );
   if( !from )
   {
      dbg.Verbose(2,"Dict::Dict: can't open dictionary", filename.c_str());
      // Using default embeded one:
      FillDefaultDataDict( this );
   }
   else
   {
      while (!from.eof())
      {
         from >> std::hex;
         from >> group;
         from >> element;
         from >> vr;
         from >> fourth;
         from >> std::ws;  //remove white space
         std::getline(from, name);
   
         const DictEntry newEntry(group, element, vr, fourth, name);
         AddNewEntry(newEntry);
      }

      Filename = filename;
   }
   from.close();
}

/**
 * \brief  Destructor 
 */
Dict::~Dict()
{
   // we assume all the pointed DictEntries are already cleaned-up
   // when we clean KeyHt.
   KeyHt.clear();
}

//-----------------------------------------------------------------------------
// Print
/**
 * \brief   Print all the dictionary entries contained in this dictionary.
 *          Entries will be sorted by tag i.e. the couple (group, element).
 * @param   os The output stream to be written to.
 */
void Dict::Print(std::ostream &os)
{
   os << "Dict file name : " << Filename << std::endl;
   PrintByKey(os);
}

/**
 * \brief   Print all the dictionary entries contained in this dictionary.
 *          Entries will be sorted by tag i.e. the couple (group, element).
 * @param   os The output stream to be written to.
 */
void Dict::PrintByKey(std::ostream &os)
{
   std::ostringstream s;

   for (TagKeyHT::iterator tag = KeyHt.begin(); tag != KeyHt.end(); ++tag)
   {
      s << "Entry : ";
      s << "(" << std::hex << std::setw(4) << tag->second.GetGroup() << ',';
      s << std::hex << std::setw(4) << tag->second.GetElement() << ") = "
        << std::dec;
      s << tag->second.GetVR() << ", ";
      s << tag->second.GetFourth() << ", ";
      s << tag->second.GetName() << "."  << std::endl;
   }
   os << s.str();
}

//-----------------------------------------------------------------------------
// Public
/**
 * \ingroup Dict
 * \brief  adds a new Dicom Dictionary Entry 
 * @param   newEntry entry to add 
 * @return  false if Dicom Element already exists
 */
bool Dict::AddNewEntry(DictEntry const &newEntry) 
{
   const TagKey &key = newEntry.GetKey();

   if(KeyHt.count(key) == 1)
   {
      dbg.Verbose(1, "Dict::AddNewEntry already present", key.c_str());
      return false;
   } 
   else 
   {
      KeyHt.insert( TagKeyHT::value_type(newEntry.GetKey(), newEntry));
      return true;
   }
}

/**
 * \ingroup Dict
 * \brief  replaces an already existing Dicom Element by a new one
 * @param   newEntry new entry (overwrites any previous one with same tag)
 * @return  false if Dicom Element doesn't exist
 */
bool Dict::ReplaceEntry(DictEntry const &newEntry)
{
   if ( RemoveEntry(newEntry.GetKey()) )
   {
       KeyHt.insert( TagKeyHT::value_type(newEntry.GetKey(), newEntry));
       return true;
   } 
   return false;
}

/**
 * \ingroup Dict
 * \brief  removes an already existing Dicom Dictionary Entry,
 *         identified by its Tag
 * @param   key (group|element)
 * @return  false if Dicom Dictionary Entry doesn't exist
 */
bool Dict::RemoveEntry (TagKey const &key) 
{
   TagKeyHT::const_iterator it = KeyHt.find(key);
   if(it != KeyHt.end()) 
   {
      const DictEntry& entryToDelete = it->second;
      KeyHt.erase(key);

      return true;
   } 
   else 
   {
      dbg.Verbose(1, "Dict::RemoveEntry unfound entry", key.c_str());
      return false;
  }
}

/**
 * \brief  removes an already existing Dicom Dictionary Entry, 
 *          identified by its group,element number
 * @param   group   Dicom group number of the Dicom Element
 * @param   elem Dicom element number of the Dicom Element
 * @return  false if Dicom Dictionary Entry doesn't exist
 */
bool Dict::RemoveEntry (uint16_t group, uint16_t elem)
{
   return RemoveEntry(DictEntry::TranslateToKey(group, elem));
}

/**
 * \brief   Get the dictionnary entry identified by a given tag (group,element)
 * @param   group   group of the entry to be found
 * @param   element element of the entry to be found
 * @return  the corresponding dictionnary entry when existing, NULL otherwise
 */
DictEntry *Dict::GetDictEntryByNumber(uint16_t group, uint16_t element)
{
   TagKey key = DictEntry::TranslateToKey(group, element);
   TagKeyHT::iterator it = KeyHt.find(key);
   if ( it == KeyHt.end() )
   {
      return 0;
   }
   return &(it->second);
}

/** 
 * \brief   Consider all the entries of the public dicom dictionnary. 
 *          Build all list of all the tag names of all those entries.
 * \sa      DictSet::GetPubDictTagNamesByCategory
 * @return  A list of all entries of the public dicom dictionnary.
 */
EntryNamesList *Dict::GetDictEntryNames() 
{
   EntryNamesList *result = new EntryNamesList;
   for (TagKeyHT::iterator tag = KeyHt.begin(); tag != KeyHt.end(); ++tag)
   {
      result->push_back( tag->second.GetName() );
   }
   return result;
}

/** 
 * \ingroup Dict
 * \brief   Consider all the entries of the public dicom dictionnary.
 *          Build an hashtable whose keys are the names of the groups
 *          (fourth field in each line of dictionary) and whose corresponding
 *          values are lists of all the dictionnary entries among that
 *          group. Note that apparently the Dicom standard doesn't explicitely
 *          define a name (as a string) for each group.
 *          A typical usage of this method would be to enable a dynamic
 *          configuration of a Dicom file browser: the admin/user can
 *          select in the interface which Dicom tags should be displayed.
 * \warning Dicom *doesn't* define any name for any 'categorie'
 *          (the dictionnary fourth field was formerly NIH defined
 *           - and no longer he is-
 *           and will be removed when Dicom provides us a text file
 *           with the 'official' Dictionnary, that would be more friendly
 *           than asking us to perform a line by line check of the dictionnary
 *           at the beginning of each year to -try to- guess the changes)
 *           Therefore : please NEVER use that fourth field :-(
 *
 * @return  An hashtable: whose keys are the names of the groups and whose
 *          corresponding values are lists of all the dictionnary entries
 *          among that group.
 */
EntryNamesByCatMap *Dict::GetDictEntryNamesByCategory() 
{
   EntryNamesByCatMap *result = new EntryNamesByCatMap;

   for (TagKeyHT::iterator tag = KeyHt.begin(); tag != KeyHt.end(); ++tag)
   {
      (*result)[tag->second.GetFourth()].push_back(tag->second.GetName());
   }

   return result;
}

//-----------------------------------------------------------------------------
// Protected

//-----------------------------------------------------------------------------
// Private

//-----------------------------------------------------------------------------

} // end namespace gdcm