/**
 * Orthanc - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012-2016 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 Affero General Public License
 * as published by the Free Software Foundation, either version 3 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
 * Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 **/


#include "QidoRs.h"

#include "Plugin.h"
#include "StowRs.h"  // For IsXmlExpected()
#include "Dicom.h"
#include "DicomResults.h"
#include "Configuration.h"
#include "../Orthanc/Core/Toolbox.h"
#include "../Orthanc/Core/OrthancException.h"

#include <gdcmTag.h>
#include <list>
#include <stdexcept>
#include <boost/lexical_cast.hpp>
#include <gdcmDict.h>
#include <gdcmDicts.h>
#include <gdcmGlobal.h>
#include <gdcmDictEntry.h>
#include <boost/regex.hpp>
#include <boost/algorithm/string/replace.hpp>


namespace
{

  enum QueryLevel
  {
    QueryLevel_Study,
    QueryLevel_Series,
    QueryLevel_Instance
  };


  class ModuleMatcher
  {
  private:
    typedef std::map<gdcm::Tag, std::string>  Filters;

    const gdcm::Dict&     dictionary_;
    bool                  fuzzy_;
    unsigned int          offset_;
    unsigned int          limit_;
    std::list<gdcm::Tag>  includeFields_;
    bool                  includeAllFields_;
    Filters               filters_;



    static inline uint16_t GetCharValue(char c)
    {
      if (c >= '0' && c <= '9')
        return c - '0';
      else if (c >= 'a' && c <= 'f')
        return c - 'a' + 10;
      else if (c >= 'A' && c <= 'F')
        return c - 'A' + 10;
      else
        return 0;
    }

    static inline uint16_t GetTagValue(const char* c)
    {
      return ((GetCharValue(c[0]) << 12) + 
              (GetCharValue(c[1]) << 8) + 
              (GetCharValue(c[2]) << 4) + 
              GetCharValue(c[3]));
    }


    static std::string Format(const gdcm::Tag& tag)
    {
      char b[16];
      sprintf(b, "%04x,%04x", tag.GetGroup(), tag.GetElement());
      return std::string(b);
    }


    gdcm::Tag  ParseTag(const std::string& key) const
    {
      if (key.find('.') != std::string::npos)
      {
        std::string s = "This DICOMweb plugin does not support hierarchical queries: " + key;
        OrthancPluginLogError(context_, s.c_str());
        throw Orthanc::OrthancException(Orthanc::ErrorCode_NotImplemented);
      }

      if (key.size() == 8 &&
          isxdigit(key[0]) &&
          isxdigit(key[1]) &&
          isxdigit(key[2]) &&
          isxdigit(key[3]) &&
          isxdigit(key[4]) &&
          isxdigit(key[5]) &&
          isxdigit(key[6]) &&
          isxdigit(key[7]))        
      {
        return gdcm::Tag(GetTagValue(key.c_str()),
                         GetTagValue(key.c_str() + 4));
      }
      else
      {
        gdcm::Tag tag;
        dictionary_.GetDictEntryByKeyword(key.c_str(), tag);

        if (tag.IsIllegal() || tag.IsPrivate())
        {
          if (key.find('.') != std::string::npos)
          {
            std::string s = "This QIDO-RS implementation does not support search over sequences: " + key;
            OrthancPluginLogError(context_, s.c_str());
            throw Orthanc::OrthancException(Orthanc::ErrorCode_NotImplemented);
          }
          else
          {
            std::string s = "Illegal tag name in QIDO-RS: " + key;
            OrthancPluginLogError(context_, s.c_str());
            throw Orthanc::OrthancException(Orthanc::ErrorCode_UnknownDicomTag);
          }
        }

        return tag;
      }
    }


    static void AddResultAttributesForLevel(std::list<gdcm::Tag>& result,
                                            QueryLevel level)
    {
      switch (level)
      {
        case QueryLevel_Study:
          // http://medical.nema.org/medical/dicom/current/output/html/part18.html#table_6.7.1-2
          result.push_back(gdcm::Tag(0x0008, 0x0005));  // Specific Character Set
          result.push_back(gdcm::Tag(0x0008, 0x0020));  // Study Date
          result.push_back(gdcm::Tag(0x0008, 0x0030));  // Study Time
          result.push_back(gdcm::Tag(0x0008, 0x0050));  // Accession Number
          result.push_back(gdcm::Tag(0x0008, 0x0056));  // Instance Availability
          result.push_back(gdcm::Tag(0x0008, 0x0061));  // Modalities in Study
          result.push_back(gdcm::Tag(0x0008, 0x0090));  // Referring Physician's Name
          result.push_back(gdcm::Tag(0x0008, 0x0201));  // Timezone Offset From UTC
          //result.push_back(gdcm::Tag(0x0008, 0x1190));  // Retrieve URL  => SPECIAL CASE
          result.push_back(gdcm::Tag(0x0010, 0x0010));  // Patient's Name
          result.push_back(gdcm::Tag(0x0010, 0x0020));  // Patient ID
          result.push_back(gdcm::Tag(0x0010, 0x0030));  // Patient's Birth Date
          result.push_back(gdcm::Tag(0x0010, 0x0040));  // Patient's Sex
          result.push_back(gdcm::Tag(0x0020, 0x000D));  // Study Instance UID
          result.push_back(gdcm::Tag(0x0020, 0x0010));  // Study ID
          result.push_back(gdcm::Tag(0x0020, 0x1206));  // Number of Study Related Series
          result.push_back(gdcm::Tag(0x0020, 0x1208));  // Number of Study Related Instances
          break;

        case QueryLevel_Series:
          // http://medical.nema.org/medical/dicom/current/output/html/part18.html#table_6.7.1-2a
          result.push_back(gdcm::Tag(0x0008, 0x0005));  // Specific Character Set
          result.push_back(gdcm::Tag(0x0008, 0x0056));  // Modality
          result.push_back(gdcm::Tag(0x0008, 0x0201));  // Timezone Offset From UTC
          result.push_back(gdcm::Tag(0x0008, 0x103E));  // Series Description
          //result.push_back(gdcm::Tag(0x0008, 0x1190));  // Retrieve URL  => SPECIAL CASE
          result.push_back(gdcm::Tag(0x0020, 0x000E));  // Series Instance UID
          result.push_back(gdcm::Tag(0x0020, 0x0011));  // Series Number
          result.push_back(gdcm::Tag(0x0020, 0x1209));  // Number of Series Related Instances
          result.push_back(gdcm::Tag(0x0040, 0x0244));  // Performed Procedure Step Start Date
          result.push_back(gdcm::Tag(0x0040, 0x0245));  // Performed Procedure Step Start Time
          result.push_back(gdcm::Tag(0x0040, 0x0275));  // Request Attribute Sequence
          break;

        case QueryLevel_Instance:
          // http://medical.nema.org/medical/dicom/current/output/html/part18.html#table_6.7.1-2b
          result.push_back(gdcm::Tag(0x0008, 0x0005));  // Specific Character Set
          result.push_back(gdcm::Tag(0x0008, 0x0016));  // SOP Class UID
          result.push_back(gdcm::Tag(0x0008, 0x0018));  // SOP Instance UID
          result.push_back(gdcm::Tag(0x0008, 0x0056));  // Instance Availability
          result.push_back(gdcm::Tag(0x0008, 0x0201));  // Timezone Offset From UTC
          result.push_back(gdcm::Tag(0x0008, 0x1190));  // Retrieve URL
          result.push_back(gdcm::Tag(0x0020, 0x0013));  // Instance Number
          result.push_back(gdcm::Tag(0x0028, 0x0010));  // Rows
          result.push_back(gdcm::Tag(0x0028, 0x0011));  // Columns
          result.push_back(gdcm::Tag(0x0028, 0x0100));  // Bits Allocated
          result.push_back(gdcm::Tag(0x0028, 0x0008));  // Number of Frames
          break;

        default:
          throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
      }
    }



  public:
    ModuleMatcher(const OrthancPluginHttpRequest* request) :
    dictionary_(gdcm::Global::GetInstance().GetDicts().GetPublicDict()),
    fuzzy_(false),
    offset_(0),
    limit_(0),
    includeAllFields_(false)
    {
      for (uint32_t i = 0; i < request->getCount; i++)
      {
        std::string key(request->getKeys[i]);
        std::string value(request->getValues[i]);

        if (key == "limit")
        {
          limit_ = boost::lexical_cast<unsigned int>(value);
        }
        else if (key == "offset")
        {
          offset_ = boost::lexical_cast<unsigned int>(value);
        }
        else if (key == "fuzzymatching")
        {
          if (value == "true")
          {
            fuzzy_ = true;
          }
          else if (value == "false")
          {
            fuzzy_ = false;
          }
          else
          {
            std::string s = "Not a proper value for fuzzy matching (true or false): " + value;
            OrthancPluginLogError(context_, s.c_str());
            throw Orthanc::OrthancException(Orthanc::ErrorCode_BadRequest);
          }
        }
        else if (key == "includefield")
        {
          if (key == "all")
          {
            includeAllFields_ = true;
          }
          else
          {
            // Split a comma-separated list of tags
            std::vector<std::string> tags;
            Orthanc::Toolbox::TokenizeString(tags, value, ',');
            for (size_t i = 0; i < tags.size(); i++)
            {
              includeFields_.push_back(ParseTag(tags[i]));
            }
          }
        }
        else
        {
          filters_[ParseTag(key)] = value;
        }
      }
    }

    unsigned int GetLimit() const
    {
      return limit_;
    }

    unsigned int GetOffset() const
    {
      return offset_;
    }

    void AddFilter(const gdcm::Tag& tag,
                   const std::string& constraint)
    {
      filters_[tag] = constraint;
    }

    void Print(std::ostream& out) const 
    {
      for (Filters::const_iterator it = filters_.begin(); 
           it != filters_.end(); ++it)
      {
        printf("Filter [%04x,%04x] = [%s]\n", it->first.GetGroup(), it->first.GetElement(), it->second.c_str());
      }
    }

    void ConvertToOrthanc(Json::Value& result,
                          QueryLevel level) const
    {
      result = Json::objectValue;

      switch (level)
      {
        case QueryLevel_Study:
          result["Level"] = "Study";
          break;

        case QueryLevel_Series:
          result["Level"] = "Series";
          break;

        case QueryLevel_Instance:
          result["Level"] = "Instance";
          break;

        default:
          throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
      }

      result["Expand"] = false;
      result["CaseSensitive"] = true;
      result["Query"] = Json::objectValue;

      for (Filters::const_iterator it = filters_.begin(); 
           it != filters_.end(); ++it)
      {
        result["Query"][Format(it->first)] = it->second;
      }
    }


    void ExtractFields(gdcm::DataSet& result,
                       const OrthancPlugins::ParsedDicomFile& dicom,
                       const std::string& wadoBase,
                       QueryLevel level) const
    {
      std::list<gdcm::Tag> fields = includeFields_;

      // The list of attributes for this query level
      AddResultAttributesForLevel(fields, level);

      // All other attributes passed as query keys
      for (Filters::const_iterator it = filters_.begin();
           it != filters_.end(); ++it)
      {
        fields.push_back(it->first);
      }

      // For instances and series, add all Study-level attributes if
      // {StudyInstanceUID} is not specified.
      if ((level == QueryLevel_Instance  || level == QueryLevel_Series) 
          && filters_.find(OrthancPlugins::DICOM_TAG_STUDY_INSTANCE_UID) == filters_.end()
        )
      {
        AddResultAttributesForLevel(fields, QueryLevel_Study);
      }

      // For instances, add all Series-level attributes if
      // {SeriesInstanceUID} is not specified.
      if (level == QueryLevel_Instance
          && filters_.find(OrthancPlugins::DICOM_TAG_SERIES_INSTANCE_UID) == filters_.end()
        )
      {
        AddResultAttributesForLevel(fields, QueryLevel_Series);
      }

      // Copy all the required fields to the target
      for (std::list<gdcm::Tag>::const_iterator
             it = fields.begin(); it != fields.end(); it++)
      {
        if (dicom.GetDataSet().FindDataElement(*it))
        {
          const gdcm::DataElement& element = dicom.GetDataSet().GetDataElement(*it);
          result.Replace(element);
        }
      }

      // Set the retrieve URL for WADO-RS
      std::string url = (wadoBase + "studies/" + 
                         dicom.GetRawTagWithDefault(OrthancPlugins::DICOM_TAG_STUDY_INSTANCE_UID, "", true));

      if (level == QueryLevel_Series || level == QueryLevel_Instance)
      {
        url += "/series/" + dicom.GetRawTagWithDefault(OrthancPlugins::DICOM_TAG_SERIES_INSTANCE_UID, "", true);
      }

      if (level == QueryLevel_Instance)
      {
        url += "/instances/" + dicom.GetRawTagWithDefault(OrthancPlugins::DICOM_TAG_SOP_INSTANCE_UID, "", true);
      }
    
      gdcm::DataElement element(OrthancPlugins::DICOM_TAG_RETRIEVE_URL);
      element.SetByteValue(url.c_str(), url.size());
      result.Replace(element);
    }
  };
}



static void ApplyMatcher(OrthancPluginRestOutput* output,
                         const OrthancPluginHttpRequest* request,
                         const ModuleMatcher& matcher,
                         QueryLevel level)
{
  Json::Value find;
  matcher.ConvertToOrthanc(find, level);

  Json::FastWriter writer;
  std::string body = writer.write(find);
  
  Json::Value resources;
  if (!OrthancPlugins::RestApiPostJson(resources, context_, "/tools/find", body) ||
      resources.type() != Json::arrayValue)
  {
    throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError);
  }

  std::list<std::string> instances;
  std::string root = (level == QueryLevel_Study ? "/studies/" : "/series/");
    
  for (Json::Value::ArrayIndex i = 0; i < resources.size(); i++)
  {
    if (level == QueryLevel_Study ||
        level == QueryLevel_Series)
    {
      // Find one child instance of this resource
      Json::Value tmp;
      if (OrthancPlugins::RestApiGetJson(tmp, context_, root + resources[i].asString() + "/instances") &&
          tmp.type() == Json::arrayValue &&
          tmp.size() > 0)
      {
        instances.push_back(tmp[0]["ID"].asString());
      }
    }
    else
    {
      instances.push_back(resources[i].asString());
    }
  }
  
  std::string wadoBase = OrthancPlugins::Configuration::GetBaseUrl(configuration_, request);

  OrthancPlugins::DicomResults results(context_, output, wadoBase, *dictionary_, IsXmlExpected(request), true);

  for (std::list<std::string>::const_iterator
         it = instances.begin(); it != instances.end(); it++)
  {
    std::string file;
    if (OrthancPlugins::RestApiGetString(file, context_, "/instances/" + *it + "/file"))
    {
      OrthancPlugins::ParsedDicomFile dicom(file);

      std::auto_ptr<gdcm::DataSet> result(new gdcm::DataSet);
      matcher.ExtractFields(*result, dicom, wadoBase, level);
      results.Add(dicom.GetFile(), *result);
    }
  }

  results.Answer();
}



void SearchForStudies(OrthancPluginRestOutput* output,
                      const char* url,
                      const OrthancPluginHttpRequest* request)
{
  if (request->method != OrthancPluginHttpMethod_Get)
  {
    OrthancPluginSendMethodNotAllowed(context_, output, "GET");
  }
  else
  {
    ModuleMatcher matcher(request);
    ApplyMatcher(output, request, matcher, QueryLevel_Study);
  }
}


void SearchForSeries(OrthancPluginRestOutput* output,
                     const char* url,
                     const OrthancPluginHttpRequest* request)
{
  if (request->method != OrthancPluginHttpMethod_Get)
  {
    OrthancPluginSendMethodNotAllowed(context_, output, "GET");
  }
  else
  {
    ModuleMatcher matcher(request);

    if (request->groupsCount == 1)
    {
      // The "StudyInstanceUID" is provided by the regular expression
      matcher.AddFilter(OrthancPlugins::DICOM_TAG_STUDY_INSTANCE_UID, request->groups[0]);
    }

    ApplyMatcher(output, request, matcher, QueryLevel_Series);
  }
}


void SearchForInstances(OrthancPluginRestOutput* output,
                        const char* url,
                        const OrthancPluginHttpRequest* request)
{
  if (request->method != OrthancPluginHttpMethod_Get)
  {
    OrthancPluginSendMethodNotAllowed(context_, output, "GET");
  }
  else
  {
    ModuleMatcher matcher(request);

    if (request->groupsCount == 1 || request->groupsCount == 2)
    {
      // The "StudyInstanceUID" is provided by the regular expression
      matcher.AddFilter(OrthancPlugins::DICOM_TAG_STUDY_INSTANCE_UID, request->groups[0]);
    }

    if (request->groupsCount == 2)
    {
      // The "SeriesInstanceUID" is provided by the regular expression
      matcher.AddFilter(OrthancPlugins::DICOM_TAG_SERIES_INSTANCE_UID, request->groups[1]);
    }

    ApplyMatcher(output, request, matcher, QueryLevel_Instance);
  }
}