/**
 * Orthanc - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012-2015 Sebastien Jodogne, Medical Physics
 * Department, University Hospital of Liege, Belgium
 *
 * 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 3 of the
 * License, or (at your option) any later version.
 *
 * In addition, as a special exception, the copyright holders of this
 * program give permission to link the code of its release with the
 * OpenSSL project's "OpenSSL" library (or with modified versions of it
 * that use the same license as the "OpenSSL" library), and distribute
 * the linked executables. You must obey the GNU General Public License
 * in all respects for all of the code used other than "OpenSSL". If you
 * modify file(s) with this exception, you may extend this exception to
 * your version of the file(s), but you are not obligated to do so. If
 * you do not wish to do so, delete this exception statement from your
 * version. If you delete this exception statement from all source files
 * in the program, then also delete it here.
 * 
 * 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, see <http://www.gnu.org/licenses/>.
 **/


#include "PrecompiledHeadersServer.h"
#include "ResourceFinder.h"

#include "FromDcmtkBridge.h"

#include <glog/logging.h>
#include <boost/algorithm/string/predicate.hpp>

namespace Orthanc
{
  static bool Compare(const std::string& a,
                      const std::string& b,
                      bool caseSensitive)
  {
    if (caseSensitive)
    {
      return a == b;
    }
    else
    {
      return boost::iequals(a, b);
    }
  }


  namespace
  {
    class CandidateResources
    {
    private:
      ServerIndex&  index_;
      ResourceType  level_;
      bool  isFilterApplied_;
      std::set<std::string>  filtered_;

     
      static void ListToSet(std::set<std::string>& target,
                            const std::list<std::string>& source)
      {
        for (std::list<std::string>::const_iterator
               it = source.begin(); it != source.end(); ++it)
        {
          target.insert(*it);
        }
      }


    public:
      CandidateResources(ServerIndex& index) : 
        index_(index), 
        level_(ResourceType_Patient), 
        isFilterApplied_(false)
      {
      }

      ResourceType GetLevel() const
      {
        return level_;
      }

      void GoDown()
      {
        assert(level_ != ResourceType_Instance);

        if (isFilterApplied_)
        {
          std::set<std::string> tmp = filtered_;

          filtered_.clear();

          for (std::set<std::string>::const_iterator 
                 it = tmp.begin(); it != tmp.end(); ++it)
          {
            std::list<std::string> children;
            index_.GetChildren(children, *it);
            ListToSet(filtered_, children);
          }
        }

        switch (level_)
        {
          case ResourceType_Patient:
            level_ = ResourceType_Study;
            break;

          case ResourceType_Study:
            level_ = ResourceType_Series;
            break;

          case ResourceType_Series:
            level_ = ResourceType_Instance;
            break;

          default:
            throw OrthancException(ErrorCode_InternalError);
        }
      }


      void Flatten(std::list<std::string>& resources) const
      {
        resources.clear();

        if (isFilterApplied_)
        {
          for (std::set<std::string>::const_iterator 
                 it = filtered_.begin(); it != filtered_.end(); ++it)
          {
            resources.push_back(*it);
          }
        }
        else
        {
          Json::Value tmp;
          index_.GetAllUuids(tmp, level_);
          for (Json::Value::ArrayIndex i = 0; i < tmp.size(); i++)
          {
            resources.push_back(tmp[i].asString());
          }
        }
      }


      void RestrictIdentifier(const DicomTag& tag, 
                              const std::string& value)
      {
        assert((level_ == ResourceType_Patient && tag == DICOM_TAG_PATIENT_ID) ||
               (level_ == ResourceType_Study && tag == DICOM_TAG_STUDY_INSTANCE_UID) ||
               (level_ == ResourceType_Study && tag == DICOM_TAG_ACCESSION_NUMBER) ||
               (level_ == ResourceType_Series && tag == DICOM_TAG_SERIES_INSTANCE_UID) ||
               (level_ == ResourceType_Instance && tag == DICOM_TAG_SOP_INSTANCE_UID));

        LOG(INFO) << "Lookup for identifier tag "
                  << FromDcmtkBridge::GetName(tag) << " (value: " << value << ")";

        std::list<std::string> resources;
        index_.LookupIdentifier(resources, tag, value, level_);

        if (isFilterApplied_)
        {
          std::set<std::string>  s;
          ListToSet(s, resources);

          std::set<std::string> tmp = filtered_;
          filtered_.clear();

          for (std::set<std::string>::const_iterator 
                 it = tmp.begin(); it != tmp.end(); ++it)
          {
            if (s.find(*it) != s.end())
            {
              filtered_.insert(*it);
            }
          }
        }
        else
        {
          assert(filtered_.empty());
          isFilterApplied_ = true;
          ListToSet(filtered_, resources);
        }
      }


      void RestrictMainDicomTags(const ResourceFinder::Query& query,
                                 bool caseSensitive)
      {
        std::list<std::string> resources;
        Flatten(resources);

        isFilterApplied_ = true;
        filtered_.clear();

        for (std::list<std::string>::const_iterator
               it = resources.begin(); it != resources.end(); it++)
        {
          DicomMap mainTags;
          if (index_.GetMainDicomTags(mainTags, *it, level_))
          {
            for (ResourceFinder::Query::const_iterator 
                   tag = query.begin(); tag != query.end(); ++tag)
            {
              assert(DicomMap::IsMainDicomTag(tag->first, level_));
              LOG(INFO) << "Lookup for main DICOM tag "
                        << FromDcmtkBridge::GetName(tag->first) << " (value: " << tag->second << ")";

              const DicomValue* value = mainTags.TestAndGetValue(tag->first);
              if (value != NULL &&
                  Compare(value->AsString(), tag->second, caseSensitive))
              {
                filtered_.insert(*it);
              }
            }            
          }
        }
      }
    };
  }


  ResourceFinder::ResourceFinder(ServerContext& context) : 
    context_(context),
    level_(ResourceType_Patient),
    caseSensitive_(true)
  {
  }


  void ResourceFinder::AddTag(const std::string& tag,
                              const std::string& value)
  {
    AddTag(FromDcmtkBridge::ParseTag(tag.c_str()), value);
  }


  void ResourceFinder::Apply(std::list<std::string>& result)
  {
    result.clear();
  }
}