ReusableDicomUserConnection::Locker::Locker(ReusableDicomUserConnection& that,
                                             const RemoteModalityParameters& remote) :
   ::Orthanc::Locker(that)
 {
   that.Open(remote.GetApplicationEntityTitle(), remote.GetHost(), 
             remote.GetPort(), remote.GetManufacturer());
   connection_ = that.connection_;    
 }
  void ReusableDicomUserConnection::Open(const std::string& localAet,
                                         const RemoteModalityParameters& remote)
  {
    if (connection_ != NULL &&
        connection_->GetLocalApplicationEntityTitle() == localAet &&
        connection_->GetRemoteApplicationEntityTitle() == remote.GetApplicationEntityTitle() &&
        connection_->GetRemoteHost() == remote.GetHost() &&
        connection_->GetRemotePort() == remote.GetPort() &&
        connection_->GetRemoteManufacturer() == remote.GetManufacturer())
    {
      // The current connection can be reused
      LOG(INFO) << "Reusing the previous SCU connection";
      return;
    }

    Close();

    connection_ = new DicomUserConnection();
    connection_->SetLocalApplicationEntityTitle(localAet);
    connection_->SetRemoteModality(remote);
    connection_->Open();
  }
  void OrthancFindRequestHandler::Handle(DicomFindAnswers& answers,
                                         const DicomMap& input,
                                         const std::list<DicomTag>& sequencesToReturn,
                                         const std::string& remoteIp,
                                         const std::string& remoteAet,
                                         const std::string& calledAet)
  {
    /**
     * Ensure that the remote modality is known to Orthanc.
     **/

    RemoteModalityParameters modality;

    if (!Configuration::LookupDicomModalityUsingAETitle(modality, remoteAet))
    {
      throw OrthancException(ErrorCode_UnknownModality);
    }

    bool caseSensitivePN = Configuration::GetGlobalBoolParameter("CaseSensitivePN", false);


    /**
     * Possibly apply the user-supplied Lua filter.
     **/

    DicomMap lua;
    const DicomMap* filteredInput = &input;

    if (ApplyLuaFilter(lua, input, remoteIp, remoteAet, calledAet))
    {
      filteredInput = &lua;
    }


    /**
     * Retrieve the query level.
     **/

    assert(filteredInput != NULL);
    const DicomValue* levelTmp = filteredInput->TestAndGetValue(DICOM_TAG_QUERY_RETRIEVE_LEVEL);
    if (levelTmp == NULL ||
        levelTmp->IsNull() ||
        levelTmp->IsBinary())
    {
      LOG(ERROR) << "C-FIND request without the tag 0008,0052 (QueryRetrieveLevel)";
      throw OrthancException(ErrorCode_BadRequest);
    }

    ResourceType level = StringToResourceType(levelTmp->GetContent().c_str());

    if (level != ResourceType_Patient &&
        level != ResourceType_Study &&
        level != ResourceType_Series &&
        level != ResourceType_Instance)
    {
      throw OrthancException(ErrorCode_NotImplemented);
    }


    DicomArray query(*filteredInput);
    LOG(INFO) << "DICOM C-Find request at level: " << EnumerationToString(level);

    for (size_t i = 0; i < query.GetSize(); i++)
    {
      if (!query.GetElement(i).GetValue().IsNull())
      {
        LOG(INFO) << "  " << query.GetElement(i).GetTag()
                  << "  " << FromDcmtkBridge::GetName(query.GetElement(i).GetTag())
                  << " = " << query.GetElement(i).GetValue().GetContent();
      }
    }

    for (std::list<DicomTag>::const_iterator it = sequencesToReturn.begin();
         it != sequencesToReturn.end(); ++it)
    {
      LOG(INFO) << "  (" << it->Format()
                << ")  " << FromDcmtkBridge::GetName(*it)
                << " : sequence tag whose content will be copied";
    }


    /**
     * Build up the query object.
     **/

    LookupResource finder(level);

    for (size_t i = 0; i < query.GetSize(); i++)
    {
      const DicomTag tag = query.GetElement(i).GetTag();

      if (query.GetElement(i).GetValue().IsNull() ||
          tag == DICOM_TAG_QUERY_RETRIEVE_LEVEL ||
          tag == DICOM_TAG_SPECIFIC_CHARACTER_SET)
      {
        continue;
      }

      std::string value = query.GetElement(i).GetValue().GetContent();
      if (value.size() == 0)
      {
        // An empty string corresponds to a "*" wildcard constraint, so we ignore it
        continue;
      }

      if (FilterQueryTag(value, level, tag, modality.GetManufacturer()))
      {
        ValueRepresentation vr = FromDcmtkBridge::LookupValueRepresentation(tag);

        // DICOM specifies that searches must be case sensitive, except
        // for tags with a PN value representation
        bool sensitive = true;
        if (vr == ValueRepresentation_PersonName)
        {
          sensitive = caseSensitivePN;
        }

        finder.AddDicomConstraint(tag, value, sensitive);
      }
      else
      {
        LOG(INFO) << "Because of a patch for the manufacturer of the remote modality, " 
                  << "ignoring constraint on tag (" << tag.Format() << ") " << FromDcmtkBridge::GetName(tag);
      }
    }


    /**
     * Run the query.
     **/

    size_t maxResults = (level == ResourceType_Instance) ? maxInstances_ : maxResults_;

    std::vector<std::string> resources, instances;
    context_.GetIndex().FindCandidates(resources, instances, finder);

    assert(resources.size() == instances.size());
    bool complete = true;

    for (size_t i = 0; i < instances.size(); i++)
    {
      Json::Value dicom;
      context_.ReadJson(dicom, instances[i]);
      
      if (finder.IsMatch(dicom))
      {
        if (maxResults != 0 &&
            answers.GetSize() >= maxResults)
        {
          complete = false;
          break;
        }
        else
        {
          std::auto_ptr<DicomMap> counters(ComputeCounters(context_, instances[i], level, input));
          AddAnswer(answers, dicom, query, sequencesToReturn, counters.get());
        }
      }
    }

    LOG(INFO) << "Number of matching resources: " << answers.GetSize();

    answers.SetComplete(complete);
  }