/**
 * Orthanc - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012-2013 Medical Physics Department, CHU 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 "OrthancRestApi.h"

#include "../ServerToolbox.h"



// DICOM tags for RT-STRUCT

/**
 * REFERENCE: http://www.dabsoft.ch/dicom/3/C.8.8.6/
 *
 * IMPORTANT: The points/vertices coordinates are reported in [mm]. 
 * 
 * TODO: Support "Contour Offset Vector"
 **/


#define REFERENCED_STUDY_SEQUENCE "0008,1110"
#define REFERENCED_SOP_INSTANCE_UID "0008,1155"
#define FRAME_OF_REFERENCE_UID "0020,0052"
#define REFERENCED_FRAME_OF_REFERENCE_SEQUENCE "3006,0010"
#define STRUCTURE_SET_ROI_SEQUENCE "3006,0020"
#define ROI_NUMBER "3006,0022"
#define ROI_NAME "3006,0026"
#define ROI_GENERATION_ALGORITHM "3006,0036"
#define ROI_CONTOUR_SEQUENCE "3006,0039"
#define REFERENCED_ROI_NUMBER "3006,0084"
#define ROI_DISPLAY_COLOR "3006,002a"
#define CONTOUR_SEQUENCE "3006,0040"
#define CONTOUR_IMAGE_SEQUENCE "3006,0016"
#define CONTOUR_GEOMETRIC_TYPE "3006,0042"
#define NUMBER_OF_CONTOUR_POINTS "3006,0046"
#define CONTOUR_DATA "3006,0050"
#define CONTOUR_SLAB_THICKNESS "3006,0044"
#define SLICE_THICKNESS "0018,0050"



#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
#include <boost/geometry/geometries/linestring.hpp>

namespace Orthanc
{
  static bool CheckSeriesModality(Json::Value& study,
                                  Json::Value& series,
                                  Json::Value& content,
                                  ServerContext& context,
                                  const std::string& seriesId,
                                  const std::string& modality)
  {
    if (!context.GetIndex().LookupResource(series, seriesId, ResourceType_Series))
    {
      return false;
    }

    // Retrieve the parent study
    std::string studyId = series["ParentStudy"].asString();
    if (!context.GetIndex().LookupResource(study, studyId, ResourceType_Study))
    {
      return false;
    }

    // Check the modality and that there is a single instance inside the series
    if (!series["MainDicomTags"].isMember("Modality") ||
        series["MainDicomTags"]["Modality"].asString() != modality ||
        series["Instances"].size() != 1)
    {
      return false;
    }

    // Retrieve the instance data
    std::string instanceId = series["Instances"][0].asString();

    context.ReadJson(content, instanceId);

    return true;
  }


  static bool ContourToPoints(Json::Value& result,
                              const Json::Value& source)
  {
    std::vector<std::string> points;
    Toolbox::TokenizeString(points, source.asString(), '\\');

    if (points.size() % 3 != 0)
    {
      return false;
    }

    result = Json::arrayValue;

    for (size_t k = 0; k < points.size(); k += 3)
    {
      Json::Value p = Json::arrayValue;

      try
      {
        p.append(boost::lexical_cast<float>(points[k]));
        p.append(boost::lexical_cast<float>(points[k + 1]));
        p.append(boost::lexical_cast<float>(points[k + 2]));
      }
      catch (boost::bad_lexical_cast)
      {
        return false;
      }

      result.append(p);
    }

    return true;
  }


  static bool GetRtStructuresInfo(Json::Value& study,
                                  Json::Value& series,
                                  Json::Value& content,
                                  std::string& frameOfReference,
                                  ServerContext& context,
                                  const std::string& seriesId)
  {
    if (!CheckSeriesModality(study, series, content, context, seriesId, "RTSTRUCT"))
    {
      return false;
    }

    // Check that the "ReferencedStudySequence" (if any) is the same as the parent study.
    if (content.isMember(REFERENCED_STUDY_SEQUENCE))
    {
      if (content[REFERENCED_STUDY_SEQUENCE]["Value"].size() != 1 ||
          !content[REFERENCED_STUDY_SEQUENCE]["Value"][0].isMember(REFERENCED_SOP_INSTANCE_UID) ||
          content[REFERENCED_STUDY_SEQUENCE]["Value"][0][REFERENCED_SOP_INSTANCE_UID]["Value"].asString() != 
          study["MainDicomTags"]["StudyInstanceUID"].asString())
      {
        return false;
      }
    }

    // Lookup for the frame of reference. Orthanc does not support
    // RTSTRUCT with multiple frames of reference.
    if (!content.isMember(REFERENCED_FRAME_OF_REFERENCE_SEQUENCE) ||
        content[REFERENCED_FRAME_OF_REFERENCE_SEQUENCE]["Value"].size() != 1 ||
        !content[REFERENCED_FRAME_OF_REFERENCE_SEQUENCE]["Value"][0].isMember(FRAME_OF_REFERENCE_UID))
    {
      return false;
    }

    frameOfReference = content[REFERENCED_FRAME_OF_REFERENCE_SEQUENCE]["Value"][0][FRAME_OF_REFERENCE_UID]["Value"].asString();

    return true;
  }


  static bool GetRtStructuresRoi(Json::Value& result,
                                 Json::Value& contourSequence,
                                 std::string& instanceId,
                                 ServerContext& context,
                                 const std::string& seriesId,
                                 const std::string& roiNumber)
  {
    Json::Value study, series, content;
    std::string frameOfReference;

    if (!GetRtStructuresInfo(study, series, content, frameOfReference, context, seriesId))
    {
      return false;
    }

    if (!content.isMember(STRUCTURE_SET_ROI_SEQUENCE) ||
        !content.isMember(ROI_CONTOUR_SEQUENCE))
    {
      return false;
    }

    instanceId = series["Instances"][0].asString();

    bool found = false;

    for (Json::Value::ArrayIndex i = 0; i < content[STRUCTURE_SET_ROI_SEQUENCE]["Value"].size(); i++)
    {
      const Json::Value& roi = content[STRUCTURE_SET_ROI_SEQUENCE]["Value"][i];

      if (roi.isMember(ROI_NUMBER) &&
          roi.isMember(ROI_NAME) &&
          roi[ROI_NUMBER]["Value"].asString() == roiNumber)
      {
        result["InternalIndex"] = i;
        result["Number"] = boost::lexical_cast<unsigned int>(roiNumber);
        result["Name"] = roi[ROI_NAME]["Value"].asString();
        result["GenerationAlgorithm"] = roi[ROI_GENERATION_ALGORITHM]["Value"].asString();
        found = true;
      }
    }

    if (!found)
    {
      return false;
    }

    for (Json::Value::ArrayIndex i = 0; i < content[ROI_CONTOUR_SEQUENCE]["Value"].size(); i++)
    {
      const Json::Value& contour = content[ROI_CONTOUR_SEQUENCE]["Value"][i];

      if (contour.isMember(REFERENCED_ROI_NUMBER) &&
          contour.isMember(ROI_DISPLAY_COLOR) &&
          contour.isMember(CONTOUR_SEQUENCE) &&
          contour[REFERENCED_ROI_NUMBER]["Value"].asString() == roiNumber)
      {
        std::vector<std::string> color;
        Toolbox::TokenizeString(color, contour[ROI_DISPLAY_COLOR]["Value"].asString(), '\\');

        result["DisplayColor"] = Json::arrayValue;
        if (color.size() != 3)
        {
          return false;
        }

        for (size_t k = 0; k < color.size(); k++)
        {
          try
          {
            result["DisplayColor"].append(boost::lexical_cast<int>(color[k]));
          }
          catch (boost::bad_lexical_cast)
          {
            return false;
          }
        }

        contourSequence = contour[CONTOUR_SEQUENCE]["Value"];

        return true;
      }
    }

    return false;
  }


  static bool GetClosedPlanarPoints(Json::Value& result,
                                    ServerContext& context,
                                    const std::string& instanceId,
                                    const Json::Value& roi,
                                    unsigned int index)
  {
    boost::mutex::scoped_lock lock(context.GetDicomFileMutex());
    ParsedDicomFile& dicom = context.GetDicomFile(instanceId);

    ParsedDicomFile::SequencePath path;
    path.push_back(std::make_pair(DicomTag(0x3006, 0x0039 /* ROIContourSequence */), roi["InternalIndex"].asInt()));
    path.push_back(std::make_pair(DicomTag(0x3006, 0x0040 /* ContourSequence */), index));
        
    std::string contourData;
    std::string numberOfPoints;

    if (dicom.GetTagValue(contourData, path, DicomTag(0x3006, 0x0050 /* ContourData */)) &&
        dicom.GetTagValue(numberOfPoints, path, DicomTag(0x3006, 0x0046 /* NumberOfContourPoints */)) &&
        ContourToPoints(result, contourData) &&
        result.size() == boost::lexical_cast<unsigned int>(numberOfPoints))
    {
      return true;
    }
    else
    {
      return false;
    }
  }



  static bool LookupReferencedInstance(Json::Value& result,
                                       ServerContext& context,
                                       const Json::Value& contour)
  {
    if (contour.isMember(CONTOUR_IMAGE_SEQUENCE) &&
        contour[CONTOUR_IMAGE_SEQUENCE]["Value"].size() == 1 &&
        contour[CONTOUR_IMAGE_SEQUENCE]["Value"][0].isMember(REFERENCED_SOP_INSTANCE_UID))
    {
      std::string uid = contour[CONTOUR_IMAGE_SEQUENCE]["Value"][0][REFERENCED_SOP_INSTANCE_UID]["Value"].asString();

      std::list<std::string> instance;
      context.GetIndex().LookupTagValue(instance, DICOM_TAG_SOP_INSTANCE_UID, uid);

      if (instance.size() == 1 &&
          context.GetIndex().LookupResource(result, instance.front(), ResourceType_Instance))
      {
        return true;
      }
    }

    return false;
  }


  static bool GetRtStructuresClosedPlanarThickness(float& result,
                                                   ServerContext& context,
                                                   const Json::Value& contour)
  {
    if (contour.isMember(CONTOUR_SLAB_THICKNESS))
    {
      result = boost::lexical_cast<float>(contour[CONTOUR_SLAB_THICKNESS]["Value"].asString());
      return true;
    }

    // No slab thickness is explicitely specified: Fallback to
    // the thickness of the referred instance

    Json::Value instance;
    if (LookupReferencedInstance(instance, context, contour))
    {
      Json::Value info;
      context.ReadJson(info, instance["ID"].asString());       

      if (info.isMember(SLICE_THICKNESS))
      {
        result = boost::lexical_cast<float>(info[SLICE_THICKNESS]["Value"].asString());
        return true;
      }
    }

    return false;
  }
                                       


  static void GetRtStructuresInfo(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value study, series, content;
    std::string frameOfReference;
    if (GetRtStructuresInfo(study, series, content, frameOfReference, context, call.GetUriComponent("id", "")))
    {
      Json::Value result;

      result["Study"] = study["ID"];


      // Lookup the series with the same frame of reference inside this study
      result["RelatedSeries"] = Json::arrayValue;

      for (Json::Value::ArrayIndex i = 0; i < study["Series"].size(); i++)
      {
        Json::Value otherSeries;
        if (context.GetIndex().LookupResource(otherSeries, study["Series"][i].asString(), ResourceType_Series) &&
            otherSeries["Instances"].size() > 0)
        {
          Json::Value info;
          context.ReadJson(info, otherSeries["Instances"][0].asString());

          if (info.isMember(FRAME_OF_REFERENCE_UID))
          {
            result["RelatedSeries"].append(study["Series"][i].asString());
          }
        }
      }


      call.GetOutput().AnswerJson(result);
    }
  }


  static void GetRtStructuresListOfROIs(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value study, series, content;
    std::string frameOfReference;
    if (GetRtStructuresInfo(study, series, content, frameOfReference, context, call.GetUriComponent("id", "")))
    {
      Json::Value result(Json::arrayValue);

      if (content.isMember(STRUCTURE_SET_ROI_SEQUENCE))
      {
        for (Json::Value::ArrayIndex i = 0; i < content[STRUCTURE_SET_ROI_SEQUENCE]["Value"].size(); i++)
        {
          if (content[STRUCTURE_SET_ROI_SEQUENCE]["Value"][i].isMember(ROI_NUMBER))
          {
            result.append(boost::lexical_cast<int>(content[STRUCTURE_SET_ROI_SEQUENCE]["Value"][i][ROI_NUMBER]["Value"].asString()));
          }
        }
      }

      call.GetOutput().AnswerJson(result);
    }
  }


  static void GetRtStructuresROI(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      roi.removeMember("InternalIndex");
      call.GetOutput().AnswerJson(roi);
    }
  }


  static void GetRtStructuresROIPoints(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      Json::Value result = Json::arrayValue;

      for (Json::Value::ArrayIndex i = 0; i < contour.size(); i++)
      {
        if (contour[i][CONTOUR_GEOMETRIC_TYPE]["Value"].asString() == "POINT")
        {
          Json::Value p;
          if (ContourToPoints(p, contour[i][CONTOUR_DATA]["Value"].asString()) &&
              p.size() == 1)
          {
            result.append(p[0]);
          }
        }
      }

      call.GetOutput().AnswerJson(result);
    }
  }


  static void GetRtStructuresListOfClosedPlanars(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      Json::Value result = Json::arrayValue;

      for (Json::Value::ArrayIndex i = 0; i < contour.size(); i++)
      {
        if (contour[i].isMember(CONTOUR_IMAGE_SEQUENCE) &&
            contour[i].isMember(CONTOUR_GEOMETRIC_TYPE) &&
            contour[i].isMember(NUMBER_OF_CONTOUR_POINTS) &&
            contour[i].isMember(CONTOUR_DATA) &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"].size() == 1 &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"][0].isMember(REFERENCED_SOP_INSTANCE_UID) &&
            contour[i][CONTOUR_GEOMETRIC_TYPE]["Value"].asString() == "CLOSED_PLANAR")
        {
          result.append(i);
        }
      }

      call.GetOutput().AnswerJson(result);
    }
  }


  static void GetRtStructuresSingleClosedPlanar(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour, result;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      unsigned int index = boost::lexical_cast<unsigned int>(call.GetUriComponent("polygon", ""));

      if (GetClosedPlanarPoints(result, context, instanceId, roi, index))
      {
        call.GetOutput().AnswerJson(result);
      }
    }
  }


  static void GetRtStructuresClosedPlanarThickness(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      unsigned int index = boost::lexical_cast<unsigned int>(call.GetUriComponent("polygon", ""));

      float thickness;
      if (GetRtStructuresClosedPlanarThickness(thickness, context, contour[index]))
      {
        call.GetOutput().AnswerBuffer(boost::lexical_cast<std::string>(thickness), "text/plain");
      }
    }
  }


  static bool ComputeClosedPlanarArea(double& area,
                                      const Json::Value& vertices)
  {
    if (vertices.size() <= 1)
    {
      area = 0;
      return true;
    }
         
    // Check that all the points share the same z coordinates
    for (Json::Value::ArrayIndex i = 1; i < vertices.size(); i++)
    {
      static float THRESHOLD = 10.0f * std::numeric_limits<float>::epsilon();

      assert(vertices[i].size() == 3);
      if (fabs(vertices[i][2].asFloat() - vertices[0][2].asFloat()) > THRESHOLD)
      {
        // This point has not the same z coordinate
        return false;
      }
    }

    // Calculate the area of a cartesian polygon
    // TODO - What happens if self-crossing polygon?
    typedef boost::geometry::model::d2::point_xy<float> point_type;

    boost::geometry::model::linestring<point_type> points;

    points.resize(vertices.size());
    for (Json::Value::ArrayIndex i = 0; i < vertices.size(); i++)
    {
      float x = vertices[i][0].asFloat();
      float y = vertices[i][1].asFloat();
      points[i] = boost::geometry::make<point_type>(x, y);
    }

    boost::geometry::model::polygon<point_type> poly;
    boost::geometry::append(poly, points);
               
    area = abs(boost::geometry::area(poly));
    return true;
  }


  static void GetRtStructuresClosedPlanarArea(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour, vertices;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      unsigned int index = boost::lexical_cast<unsigned int>(call.GetUriComponent("polygon", ""));

      double area;
      if (GetClosedPlanarPoints(vertices, context, instanceId, roi, index) &&
          ComputeClosedPlanarArea(area, vertices))
      {
        call.GetOutput().AnswerBuffer(boost::lexical_cast<std::string>(area), "text/plain");
      }
    }
  }


  static void GetRtStructuresInstanceOfClosedPlanar(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      unsigned int index = boost::lexical_cast<unsigned int>(call.GetUriComponent("polygon", ""));

      Json::Value result;
      if (LookupReferencedInstance(result, context, contour[index]))
      {
        call.GetOutput().AnswerJson(result);
      }
    }
  }


  static void GetRtStructuresListOfInstances(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      Json::Value result = Json::arrayValue;

      for (Json::Value::ArrayIndex i = 0; i < contour.size(); i++)
      {
        if (contour[i].isMember(CONTOUR_IMAGE_SEQUENCE) &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"].size() == 1 &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"][0].isMember(REFERENCED_SOP_INSTANCE_UID))
        {
          std::string uid = contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"][0][REFERENCED_SOP_INSTANCE_UID]["Value"].asString();

          std::list<std::string> instance;
          context.GetIndex().LookupTagValue(instance, DICOM_TAG_SOP_INSTANCE_UID, uid);

          if (instance.size() == 1)
          {
            result.append(instance.front());
          }
        }
      }

      call.GetOutput().AnswerJson(result);
    }
  }



  static void GetRtStructuresClosedPlanarsOfInstance(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour, instance;
    std::string instanceId;

    if (context.GetIndex().LookupResource(instance, call.GetUriComponent("instance", ""), ResourceType_Instance) &&
        GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      Json::Value result = Json::arrayValue;

      for (Json::Value::ArrayIndex i = 0; i < contour.size(); i++)
      {
        if (contour[i].isMember(CONTOUR_DATA) &&
            contour[i].isMember(CONTOUR_IMAGE_SEQUENCE) &&
            contour[i].isMember(NUMBER_OF_CONTOUR_POINTS) &&
            contour[i].isMember(CONTOUR_GEOMETRIC_TYPE) &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"].size() == 1 &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"][0].isMember(REFERENCED_SOP_INSTANCE_UID) &&
            contour[i][CONTOUR_GEOMETRIC_TYPE]["Value"].asString() == "CLOSED_PLANAR")
        {
          std::string uid = contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"][0][REFERENCED_SOP_INSTANCE_UID]["Value"].asString();

          Json::Value points;
          if (uid == instance["MainDicomTags"]["SOPInstanceUID"].asString() &&
              GetClosedPlanarPoints(points, context, instanceId, roi, i))
          {
            result.append(points);
          }             
        }
      }

      call.GetOutput().AnswerJson(result);
    }
  }



  static void GetRtStructuresPointsOfInstance(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour, instance;
    std::string instanceId;

    if (context.GetIndex().LookupResource(instance, call.GetUriComponent("instance", ""), ResourceType_Instance) &&
        GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      Json::Value result = Json::arrayValue;

      for (Json::Value::ArrayIndex i = 0; i < contour.size(); i++)
      {
        if (contour[i].isMember(CONTOUR_DATA) &&
            contour[i].isMember(CONTOUR_IMAGE_SEQUENCE) &&
            contour[i].isMember(CONTOUR_GEOMETRIC_TYPE) &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"].size() == 1 &&
            contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"][0].isMember(REFERENCED_SOP_INSTANCE_UID) &&
            contour[i][CONTOUR_GEOMETRIC_TYPE]["Value"].asString() == "POINT")
        {
          std::string uid = contour[i][CONTOUR_IMAGE_SEQUENCE]["Value"][0][REFERENCED_SOP_INSTANCE_UID]["Value"].asString();

          if (uid == instance["MainDicomTags"]["SOPInstanceUID"].asString())
          {
            Json::Value p;
            if (ContourToPoints(p, contour[i][CONTOUR_DATA]["Value"].asString()) &&
                p.size() == 1)
            {
              result.append(p[0]);
            }
          }
        }
      }

      call.GetOutput().AnswerJson(result);
    }
  }


  static void GetRtStructuresVolume(RestApi::GetCall& call)
  {
    ServerContext& context = OrthancRestApi::GetContext(call);

    Json::Value roi, contour, vertices;
    std::string instanceId;

    if (GetRtStructuresRoi(roi, contour, instanceId, context, 
                           call.GetUriComponent("id", ""),
                           call.GetUriComponent("roi", "")))
    {
      double volume = 0;

      for (Json::Value::ArrayIndex i = 0; i < contour.size(); i++)
      {
        double area;
        float thickness;

        if (contour[i].isMember(CONTOUR_GEOMETRIC_TYPE) &&
            contour[i][CONTOUR_GEOMETRIC_TYPE]["Value"].asString() == "CLOSED_PLANAR" &&
            GetClosedPlanarPoints(vertices, context, instanceId, roi, i) &&
            ComputeClosedPlanarArea(area, vertices) &&
            GetRtStructuresClosedPlanarThickness(thickness, context, contour[i]))
        {
          volume += area * static_cast<double>(thickness);
        }
      }

      call.GetOutput().AnswerBuffer(boost::lexical_cast<std::string>(volume), "text/plain");
    }
  }


  void OrthancRestApi::RegisterRadiotherapy()
  {
    Register("/series/{id}/rt-structures", GetRtStructuresInfo);
    Register("/series/{id}/rt-structures/roi", GetRtStructuresListOfROIs);
    Register("/series/{id}/rt-structures/roi/{roi}/info", GetRtStructuresROI);
    Register("/series/{id}/rt-structures/roi/{roi}/points", GetRtStructuresROIPoints);
    Register("/series/{id}/rt-structures/roi/{roi}/closed-planar", GetRtStructuresListOfClosedPlanars);
    Register("/series/{id}/rt-structures/roi/{roi}/closed-planar/{polygon}/vertices", GetRtStructuresSingleClosedPlanar);
    Register("/series/{id}/rt-structures/roi/{roi}/closed-planar/{polygon}/thickness", GetRtStructuresClosedPlanarThickness);
    Register("/series/{id}/rt-structures/roi/{roi}/closed-planar/{polygon}/instance", GetRtStructuresInstanceOfClosedPlanar);
    Register("/series/{id}/rt-structures/roi/{roi}/closed-planar/{polygon}/area", GetRtStructuresClosedPlanarArea);
    Register("/series/{id}/rt-structures/roi/{roi}/instances", GetRtStructuresListOfInstances);
    Register("/series/{id}/rt-structures/roi/{roi}/instances/{instance}/closed-planar", GetRtStructuresClosedPlanarsOfInstance);
    Register("/series/{id}/rt-structures/roi/{roi}/instances/{instance}/points", GetRtStructuresPointsOfInstance);
    Register("/series/{id}/rt-structures/roi/{roi}/volume", GetRtStructuresVolume);
  }

}


//  curl http://localhost:8042/series/0b9e2bb2-605a59aa-f27c0260-9cc4faf6-9d8bf457/rt-structures
//  curl http://localhost:8042/series/ef041e6b-c855e775-f7e0f7fe-dc3c17dc-533cb8c5/rt-structures