/**
 * Palantir - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012 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.
 * 
 * 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 "StoreScp.h"

#include "../FromDcmtkBridge.h"
#include "../ToDcmtkBridge.h"
#include "../../Core/PalantirException.h"

#include <dcmtk/dcmdata/dcfilefo.h>
#include <dcmtk/dcmdata/dcmetinf.h>
#include <dcmtk/dcmdata/dcostrmb.h>
#include <dcmtk/dcmdata/dcdeftag.h>
#include <dcmtk/dcmnet/diutil.h>


namespace Palantir
{
  namespace Internals
  {
    extern OFLogger Logger;
  }


  namespace
  {  
    struct StoreCallbackData
    {
      IStoreRequestHandler* handler;
      const char* distantAET;
      const char* modality;
      const char* affectedSOPInstanceUID;
      uint32_t messageID;
    };


    static int SaveToMemoryBuffer(DcmDataset* dataSet,
                                  std::vector<uint8_t>& buffer)
    {
      // Determine the transfer syntax which shall be used to write the
      // information to the file. We always switch to the Little Endian
      // syntax, with explicit length.

      // http://support.dcmtk.org/docs/dcxfer_8h-source.html
      E_TransferSyntax xfer = EXS_LittleEndianExplicit;
      E_EncodingType encodingType = /*opt_sequenceType*/ EET_ExplicitLength;

      uint32_t s = dataSet->getLength(xfer, encodingType);

      buffer.resize(s);
      DcmOutputBufferStream ob(&buffer[0], s);

      dataSet->transferInit();
      OFCondition c = dataSet->write(ob, xfer, encodingType, NULL,
                                     /*opt_groupLength*/ EGL_recalcGL,
                                     /*opt_paddingType*/ EPD_withoutPadding);
      dataSet->transferEnd();
      if (c.good())
      {
        return 0;
      }
      else
      {
        buffer.clear();
        return -1;
      }

#if 0
      OFCondition cond = cbdata->dcmff->saveFile(fileName.c_str(), xfer, 
                                                 encodingType, 
                                                 /*opt_groupLength*/ EGL_recalcGL,
                                                 /*opt_paddingType*/ EPD_withoutPadding,
                                                 OFstatic_cast(Uint32, /*opt_filepad*/ 0), 
                                                 OFstatic_cast(Uint32, /*opt_itempad*/ 0),
                                                 (opt_useMetaheader) ? EWM_fileformat : EWM_dataset);
#endif
    }


    static void
    storeScpCallback(
      void *callbackData,
      T_DIMSE_StoreProgress *progress,
      T_DIMSE_C_StoreRQ *req,
      char * /*imageFileName*/, DcmDataset **imageDataSet,
      T_DIMSE_C_StoreRSP *rsp,
      DcmDataset **statusDetail)
    /*
     * This function.is used to indicate progress when storescp receives instance data over the
     * network. On the final call to this function (identified by progress->state == DIMSE_StoreEnd)
     * this function will store the data set which was received over the network to a file.
     * Earlier calls to this function will simply cause some information to be dumped to stdout.
     *
     * Parameters:
     *   callbackData  - [in] data for this callback function
     *   progress      - [in] The state of progress. (identifies if this is the initial or final call
     *                   to this function, or a call in between these two calls.
     *   req           - [in] The original store request message.
     *   imageFileName - [in] The path to and name of the file the information shall be written to.
     *   imageDataSet  - [in] The data set which shall be stored in the image file
     *   rsp           - [inout] the C-STORE-RSP message (will be sent after the call to this function)
     *   statusDetail  - [inout] This variable can be used to capture detailed information with regard to
     *                   the status information which is captured in the status element (0000,0900). Note
     *                   that this function does specify any such information, the pointer will be set to NULL.
     */
    {
      StoreCallbackData *cbdata = OFstatic_cast(StoreCallbackData *, callbackData);

      DIC_UI sopClass;
      DIC_UI sopInstance;

      // if this is the final call of this function, save the data which was received to a file
      // (note that we could also save the image somewhere else, put it in database, etc.)
      if (progress->state == DIMSE_StoreEnd)
      {
        OFString tmpStr;

        // do not send status detail information
        *statusDetail = NULL;

        // Concerning the following line: an appropriate status code is already set in the resp structure,
        // it need not be success. For example, if the caller has already detected an out of resources problem
        // then the status will reflect this.  The callback function is still called to allow cleanup.
        //rsp->DimseStatus = STATUS_Success;

        // we want to write the received information to a file only if this information
        // is present and the options opt_bitPreserving and opt_ignore are not set.
        if ((imageDataSet != NULL) && (*imageDataSet != NULL))
        {
          DicomMap summary;
          Json::Value dicomJson;
          std::vector<uint8_t> buffer;

          try
          {
            FromDcmtkBridge::Convert(summary, **imageDataSet);
            FromDcmtkBridge::ToJson(dicomJson, **imageDataSet);       

            if (SaveToMemoryBuffer(*imageDataSet, buffer) < 0)
            {
              OFLOG_ERROR(Internals::Logger, "cannot write DICOM file to memory");
              rsp->DimseStatus = STATUS_STORE_Refused_OutOfResources;
            }
          }
          catch (...)
          {
            rsp->DimseStatus = STATUS_STORE_Refused_OutOfResources;
          }

          // check the image to make sure it is consistent, i.e. that its sopClass and sopInstance correspond
          // to those mentioned in the request. If not, set the status in the response message variable.
          if ((rsp->DimseStatus == STATUS_Success))
          {
            // which SOP class and SOP instance ?
            if (!DU_findSOPClassAndInstanceInDataSet(*imageDataSet, sopClass, sopInstance, /*opt_correctUIDPadding*/ OFFalse))
            {
              //OFLOG_ERROR(Internals::Logger, "bad DICOM file: " << fileName);
              rsp->DimseStatus = STATUS_STORE_Error_CannotUnderstand;
            }
            else if (strcmp(sopClass, req->AffectedSOPClassUID) != 0)
            {
              rsp->DimseStatus = STATUS_STORE_Error_DataSetDoesNotMatchSOPClass;
            }
            else if (strcmp(sopInstance, req->AffectedSOPInstanceUID) != 0)
            {
              rsp->DimseStatus = STATUS_STORE_Error_DataSetDoesNotMatchSOPClass;
            }
            else
            {
              try
              {
                cbdata->handler->Handle(buffer, summary, dicomJson, cbdata->distantAET);
              }
              catch (PalantirException& e)
              {
                rsp->DimseStatus = STATUS_STORE_Refused_OutOfResources;
                OFLOG_ERROR(Internals::Logger, "Exception while storing DICOM: " << e.What());
              }
            }
          }
        }
      }
    }
  }

/*
 * This function processes a DIMSE C-STORE-RQ commmand that was
 * received over the network connection.
 *
 * Parameters:
 *   assoc  - [in] The association (network connection to another DICOM application).
 *   msg    - [in] The DIMSE C-STORE-RQ message that was received.
 *   presID - [in] The ID of the presentation context which was specified in the PDV which contained
 *                 the DIMSE command.
 */
  OFCondition Internals::storeScp(T_ASC_Association * assoc, 
                                  T_DIMSE_Message * msg, 
                                  T_ASC_PresentationContextID presID,
                                  IStoreRequestHandler& handler)
  {
    OFCondition cond = EC_Normal;
    T_DIMSE_C_StoreRQ *req;

    // assign the actual information of the C-STORE-RQ command to a local variable
    req = &msg->msg.CStoreRQ;

    // intialize some variables
    StoreCallbackData callbackData;
    callbackData.handler = &handler;
    callbackData.modality = dcmSOPClassUIDToModality(req->AffectedSOPClassUID, "UNKNOWN");
    callbackData.affectedSOPInstanceUID = req->AffectedSOPInstanceUID;
    callbackData.messageID = req->MessageID;
    if (assoc && assoc->params)
    {
      callbackData.distantAET = assoc->params->DULparams.callingAPTitle;
    }
    else
    {
      callbackData.distantAET = "";
    }

    DcmFileFormat dcmff;

    // store SourceApplicationEntityTitle in metaheader
    if (assoc && assoc->params)
    {
      const char *aet = assoc->params->DULparams.callingAPTitle;
      if (aet) dcmff.getMetaInfo()->putAndInsertString(DCM_SourceApplicationEntityTitle, aet);
    }

    // define an address where the information which will be received over the network will be stored
    DcmDataset *dset = dcmff.getDataset();

    cond = DIMSE_storeProvider(assoc, presID, req, NULL, /*opt_useMetaheader*/OFFalse, &dset,
                               storeScpCallback, &callbackData, 
                               /*opt_blockMode*/ DIMSE_BLOCKING, 
                               /*opt_dimse_timeout*/ 0);

    // if some error occured, dump corresponding information and remove the outfile if necessary
    if (cond.bad())
    {
      OFString temp_str;
      OFLOG_ERROR(Logger, "Store SCP Failed: " << DimseCondition::dump(temp_str, cond));
    }

    // return return value
    return cond;
  }
}