/**
 * \mainpage
 *
 * This C/C++ SDK allows external developers to create plugins that
 * can be loaded into Orthanc to extend its functionality. Each
 * Orthanc plugin must expose 4 public functions with the following
 * signatures:
 * 
 * -# <tt>int32_t OrthancPluginInitialize(const OrthancPluginContext* context)</tt>:
 *    This function is invoked by Orthanc when it loads the plugin on startup.
 *    The plugin must:
 *    - Check its compatibility with the Orthanc version using
 *      ::OrthancPluginCheckVersion().
 *    - Store the context pointer so that it can use the plugin 
 *      services of Orthanc.
 *    - Register all its REST callbacks using ::OrthancPluginRegisterRestCallback().
 *    - Register all its callbacks for received instances using ::OrthancPluginRegisterOnStoredInstanceCallback().
 *    - Possibly register a custom storage area using ::OrthancPluginRegisterStorageArea().
 * -# <tt>void OrthancPluginFinalize()</tt>:
 *    This function is invoked by Orthanc during its shutdown. The plugin
 *    must free all its memory.
 * -# <tt>const char* OrthancPluginGetName()</tt>:
 *    The plugin must return a short string to identify itself.
 * -# <tt>const char* OrthancPluginGetVersion()</tt>:
 *    The plugin must return a string containing its version number.
 *
 * The name and the version of a plugin is only used to prevent it
 * from being loaded twice.
 * 
 * The various callbacks are guaranteed to be executed in mutual
 * exclusion since Orthanc 0.8.5.
 **/



/**
 * @defgroup CInterface C Interface 
 * @brief The C interface to create Orthanc plugins.
 * 
 * These functions must be used to create C plugins for Orthanc.
 **/



/**
 * Orthanc - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012-2014 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/>.
 **/



#pragma once


#include <stdio.h>
#include <string.h>

#ifdef WIN32
#define ORTHANC_PLUGINS_API __declspec(dllexport)
#else
#define ORTHANC_PLUGINS_API
#endif

#define ORTHANC_PLUGINS_MINIMAL_MAJOR_NUMBER     0
#define ORTHANC_PLUGINS_MINIMAL_MINOR_NUMBER     8
#define ORTHANC_PLUGINS_MINIMAL_REVISION_NUMBER  5



/********************************************************************
 ** Check that function inlining is properly supported. The use of
 ** inlining is required, to avoid the duplication of object code
 ** between two compilation modules that would use the Orthanc Plugin
 ** API.
 ********************************************************************/

/* If the auto-detection of the "inline" keyword below does not work
   automatically and that your compiler is known to properly support
   inlining, uncomment the following #define and adapt the definition
   of "static inline". */

/* #define ORTHANC_PLUGIN_INLINE static inline */

#ifndef ORTHANC_PLUGIN_INLINE
#  if __STDC_VERSION__ >= 199901L
/*   This is C99 or above: http://predef.sourceforge.net/prestd.html */
#    define ORTHANC_PLUGIN_INLINE static inline
#  elif defined(__cplusplus)
/*   This is C++ */
#    define ORTHANC_PLUGIN_INLINE static inline
#  elif defined(__GNUC__)
/*   This is GCC running in C89 mode */
#    define ORTHANC_PLUGIN_INLINE static __inline
#  elif defined(_MSC_VER)
/*   This is Visual Studio running in C89 mode */
#    define ORTHANC_PLUGIN_INLINE static __inline
#  else
#    error Your compiler is not known to support the "inline" keyword
#  endif
#endif



/********************************************************************
 ** Inclusion of standard libraries.
 ********************************************************************/

#ifdef _MSC_VER
#include "../../Resources/ThirdParty/VisualStudio/stdint.h"
#else
#include <stdint.h>
#endif

#include <stdlib.h>



/********************************************************************
 ** Definition of the Orthanc Plugin API.
 ********************************************************************/

/** @{ */

#ifdef __cplusplus
extern "C"
{
#endif

  /**
   * The various HTTP methods for a REST call.
   **/
  typedef enum
  {
    OrthancPluginHttpMethod_Get = 1,    /*!< GET request */
    OrthancPluginHttpMethod_Post = 2,   /*!< POST request */
    OrthancPluginHttpMethod_Put = 3,    /*!< PUT request */
    OrthancPluginHttpMethod_Delete = 4  /*!< DELETE request */
  } OrthancPluginHttpMethod;


  /**
   * @brief The parameters of a REST request.
   **/
  typedef struct
  {
    /**
     * @brief The HTTP method.
     **/
    OrthancPluginHttpMethod method;    

    /**
     * @brief The number of groups of the regular expression.
     **/
    uint32_t                groupsCount;

    /**
     * @brief The matched values for the groups of the regular expression.
     **/
    const char* const*      groups;

    /**
     * @brief For a GET request, the number of GET parameters.
     **/
    uint32_t                getCount;

    /**
     * @brief For a GET request, the keys of the GET parameters.
     **/
    const char* const*      getKeys;

    /**
     * @brief For a GET request, the values of the GET parameters.
     **/
    const char* const*      getValues;

    /**
     * @brief For a PUT or POST request, the content of the body.
     **/
    const char*             body;

    /**
     * @brief For a PUT or POST request, the number of bytes of the body.
     **/
    uint32_t                bodySize;


    /* --------------------------------------------------
       New in version 0.8.1
       -------------------------------------------------- */

    /**
     * @brief The number of HTTP headers.
     **/
    uint32_t                headersCount;

    /**
     * @brief The keys of the HTTP headers (always converted to low-case).
     **/
    const char* const*      headersKeys;

    /**
     * @brief The values of the HTTP headers.
     **/
    const char* const*      headersValues;

  } OrthancPluginHttpRequest;


  typedef enum 
  {
    /* Generic services */
    _OrthancPluginService_LogInfo = 1,
    _OrthancPluginService_LogWarning = 2,
    _OrthancPluginService_LogError = 3,
    _OrthancPluginService_GetOrthancPath = 4,
    _OrthancPluginService_GetOrthancDirectory = 5,
    _OrthancPluginService_GetConfigurationPath = 6,

    /* Registration of callbacks */
    _OrthancPluginService_RegisterRestCallback = 1000,
    _OrthancPluginService_RegisterOnStoredInstanceCallback = 1001,
    _OrthancPluginService_RegisterStorageArea = 1002,
    _OrthancPluginService_RegisterOnChangeCallback = 1003,

    /* Sending answers to REST calls */
    _OrthancPluginService_AnswerBuffer = 2000,
    _OrthancPluginService_CompressAndAnswerPngImage = 2001,
    _OrthancPluginService_Redirect = 2002,
    _OrthancPluginService_SendHttpStatusCode = 2003,
    _OrthancPluginService_SendUnauthorized = 2004,
    _OrthancPluginService_SendMethodNotAllowed = 2005,
    _OrthancPluginService_SetCookie = 2006,
    _OrthancPluginService_SetHttpHeader = 2007,

    /* Access to the Orthanc database and API */
    _OrthancPluginService_GetDicomForInstance = 3000,
    _OrthancPluginService_RestApiGet = 3001,
    _OrthancPluginService_RestApiPost = 3002,
    _OrthancPluginService_RestApiDelete = 3003,
    _OrthancPluginService_RestApiPut = 3004,
    _OrthancPluginService_LookupPatient = 3005,
    _OrthancPluginService_LookupStudy = 3006,
    _OrthancPluginService_LookupSeries = 3007,
    _OrthancPluginService_LookupInstance = 3008,
    _OrthancPluginService_LookupStudyWithAccessionNumber = 3009,

    /* Access to DICOM instances */
    _OrthancPluginService_GetInstanceRemoteAet = 4000,
    _OrthancPluginService_GetInstanceSize = 4001,
    _OrthancPluginService_GetInstanceData = 4002,
    _OrthancPluginService_GetInstanceJson = 4003,
    _OrthancPluginService_GetInstanceSimplifiedJson = 4004,
    _OrthancPluginService_HasInstanceMetadata = 4005,
    _OrthancPluginService_GetInstanceMetadata = 4006
  } _OrthancPluginService;



  /**
   * The memory layout of the pixels of an image.
   **/
  typedef enum
  {
    /**
     * @brief Graylevel 8bpp image.
     *
     * The image is graylevel. Each pixel is unsigned and stored in
     * one byte.
     **/
    OrthancPluginPixelFormat_Grayscale8 = 1,

    /**
     * @brief Graylevel, unsigned 16bpp image.
     *
     * The image is graylevel. Each pixel is unsigned and stored in
     * two bytes.
     **/
    OrthancPluginPixelFormat_Grayscale16 = 2,

    /**
     * @brief Graylevel, signed 16bpp image.
     *
     * The image is graylevel. Each pixel is signed and stored in two
     * bytes.
     **/
    OrthancPluginPixelFormat_SignedGrayscale16 = 3,

    /**
     * @brief Color image in RGB24 format.
     *
     * This format describes a color image. The pixels are stored in 3
     * consecutive bytes. The memory layout is RGB.
     **/
    OrthancPluginPixelFormat_RGB24 = 4,

    /**
     * @brief Color image in RGBA32 format.
     *
     * This format describes a color image. The pixels are stored in 4
     * consecutive bytes. The memory layout is RGBA.
     **/
    OrthancPluginPixelFormat_RGBA32 = 5
  } OrthancPluginPixelFormat;



  /**
   * The content types that are supported by Orthanc plugins.
   **/
  typedef enum
  {
    OrthancPluginContentType_Unknown = 0,      /*!< Unknown content type */
    OrthancPluginContentType_Dicom = 1,        /*!< DICOM */
    OrthancPluginContentType_DicomAsJson = 2   /*!< JSON summary of a DICOM file */
  } OrthancPluginContentType;



  /**
   * The supported type of DICOM resources.
   **/
  typedef enum
  {
    OrthancPluginResourceType_Patient = 0,     /*!< Patient */
    OrthancPluginResourceType_Study = 1,       /*!< Study */
    OrthancPluginResourceType_Series = 2,      /*!< Series */
    OrthancPluginResourceType_Instance = 3     /*!< Instance */
  } OrthancPluginResourceType;



  /**
   * The supported type of changes that can happen to DICOM resources.
   **/
  typedef enum
  {
    OrthancPluginChangeType_CompletedSeries = 0,    /*!< Series is now complete */
    OrthancPluginChangeType_Deleted = 1,            /*!< Deleted resource */
    OrthancPluginChangeType_NewChildInstance = 2,   /*!< A new instance was added to this resource */
    OrthancPluginChangeType_NewInstance = 3,        /*!< New instance received */
    OrthancPluginChangeType_NewPatient = 4,         /*!< New patient created */
    OrthancPluginChangeType_NewSeries = 5,          /*!< New series created */
    OrthancPluginChangeType_NewStudy = 6,           /*!< New study created */
    OrthancPluginChangeType_StablePatient = 7,      /*!< Timeout: No new instance in this patient */
    OrthancPluginChangeType_StableSeries = 8,       /*!< Timeout: No new instance in this series */
    OrthancPluginChangeType_StableStudy = 9         /*!< Timeout: No new instance in this study */
  } OrthancPluginChangeType;



  /**
   * @brief A memory buffer allocated by the core system of Orthanc.
   *
   * A memory buffer allocated by the core system of Orthanc. When the
   * content of the buffer is not useful anymore, it must be free by a
   * call to ::OrthancPluginFreeMemoryBuffer().
   **/
  typedef struct
  {
    /**
     * @brief The content of the buffer.
     **/
    void*      data;

    /**
     * @brief The number of bytes in the buffer.
     **/
    uint32_t   size;
  } OrthancPluginMemoryBuffer;




  /**
   * @brief Opaque structure that represents the HTTP connection to the client application.
   **/
  typedef struct _OrthancPluginRestOutput_t OrthancPluginRestOutput;



  /**
   * @brief Opaque structure that represents a DICOM instance received by Orthanc.
   **/
  typedef struct _OrthancPluginDicomInstance_t OrthancPluginDicomInstance;



  /**
   * @brief Signature of a callback function that answers to a REST request.
   **/
  typedef int32_t (*OrthancPluginRestCallback) (
    OrthancPluginRestOutput* output,
    const char* url,
    const OrthancPluginHttpRequest* request);



  /**
   * @brief Signature of a callback function that is triggered when Orthanc receives a DICOM instance.
   **/
  typedef int32_t (*OrthancPluginOnStoredInstanceCallback) (
    OrthancPluginDicomInstance* instance,
    const char* instanceId);



  /**
   * @brief Signature of a callback function that is triggered when a change happens to some DICOM resource.
   **/
  typedef int32_t (*OrthancPluginOnChangeCallback) (
    OrthancPluginChangeType changeType,
    OrthancPluginResourceType resourceType,
    const char* resourceId);



  /**
   * @brief Signature of a function to free dynamic memory.
   **/
  typedef void (*OrthancPluginFree) (void* buffer);



  /**
   * @brief Callback for writing to the storage area.
   *
   * Signature of a callback function that is triggered when Orthanc writes a file to the storage area.
   *
   * @param uuid The UUID of the file.
   * @param content The content of the file.
   * @param size The size of the file.
   * @param type The content type corresponding to this file. 
   * @return 0 if success, other value if error.
   **/
  typedef int32_t (*OrthancPluginStorageCreate) (
    const char* uuid,
    const void* content,
    int64_t size,
    OrthancPluginContentType type);



  /**
   * @brief Callback for reading from the storage area.
   *
   * Signature of a callback function that is triggered when Orthanc reads a file from the storage area.
   *
   * @param content The content of the file (output).
   * @param size The size of the file (output).
   * @param uuid The UUID of the file of interest.
   * @param type The content type corresponding to this file. 
   * @return 0 if success, other value if error.
   **/
  typedef int32_t (*OrthancPluginStorageRead) (
    void** content,
    int64_t* size,
    const char* uuid,
    OrthancPluginContentType type);



  /**
   * @brief Callback for removing a file from the storage area.
   *
   * Signature of a callback function that is triggered when Orthanc deletes a file from the storage area.
   *
   * @param uuid The UUID of the file to be removed.
   * @param type The content type corresponding to this file. 
   * @return 0 if success, other value if error.
   **/
  typedef int32_t (*OrthancPluginStorageRemove) (
    const char* uuid,
    OrthancPluginContentType type);



  /**
   * @brief Opaque structure that contains information about the Orthanc core.
   **/
  typedef struct _OrthancPluginContext_t
  {
    void*              pluginsManager;
    const char*        orthancVersion;
    OrthancPluginFree  Free;
    int32_t          (*InvokeService) (struct _OrthancPluginContext_t* context,
                                       _OrthancPluginService service,
                                       const void* params);
  } OrthancPluginContext;



  /**
   * @brief Free a string.
   * 
   * Free a string that was allocated by the core system of Orthanc.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param str The string to be freed.
   **/
  ORTHANC_PLUGIN_INLINE void  OrthancPluginFreeString(
    OrthancPluginContext* context, 
    char* str)
  {
    if (str != NULL)
    {
      context->Free(str);
    }
  }


  /**
   * @brief Check the compatibility of the plugin wrt. the version of its hosting Orthanc.
   * 
   * This function checks whether the version of this C header is
   * compatible with the current version of Orthanc. The result of
   * this function should always be checked in the
   * OrthancPluginInitialize() entry point of the plugin.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @return 1 if and only if the versions are compatible. If the
   * result is 0, the initialization of the plugin should fail.
   **/
  ORTHANC_PLUGIN_INLINE int  OrthancPluginCheckVersion(
    OrthancPluginContext* context)
  {
    int major, minor, revision;

    /* Assume compatibility with the mainline */
    if (!strcmp(context->orthancVersion, "mainline"))
    {
      return 1;
    }

    /* Parse the version of the Orthanc core */
    if ( 
#ifdef _MSC_VER
      sscanf_s
#else
      sscanf
#endif
      (context->orthancVersion, "%d.%d.%d", &major, &minor, &revision) != 3)
    {
      return 0;
    }

    /* Check the major number of the version */

    if (major > ORTHANC_PLUGINS_MINIMAL_MAJOR_NUMBER)
    {
      return 1;
    }

    if (major < ORTHANC_PLUGINS_MINIMAL_MAJOR_NUMBER)
    {
      return 0;
    }

    /* Check the minor number of the version */

    if (minor > ORTHANC_PLUGINS_MINIMAL_MINOR_NUMBER)
    {
      return 1;
    }

    if (minor < ORTHANC_PLUGINS_MINIMAL_MINOR_NUMBER)
    {
      return 0;
    }

    /* Check the revision number of the version */

    if (revision >= ORTHANC_PLUGINS_MINIMAL_REVISION_NUMBER)
    {
      return 1;
    }
    else
    {
      return 0;
    }
  }


  /**
   * @brief Free a memory buffer.
   * 
   * Free a memory buffer that was allocated by the core system of Orthanc.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param buffer The memory buffer to release.
   **/
  ORTHANC_PLUGIN_INLINE void  OrthancPluginFreeMemoryBuffer(
    OrthancPluginContext* context, 
    OrthancPluginMemoryBuffer* buffer)
  {
    context->Free(buffer->data);
  }


  /**
   * @brief Log an error.
   *
   * Log an error message using the Orthanc logging system.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param message The message to be logged.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginLogError(
    OrthancPluginContext* context,
    const char* message)
  {
    context->InvokeService(context, _OrthancPluginService_LogError, message);
  }


  /**
   * @brief Log a warning.
   *
   * Log a warning message using the Orthanc logging system.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param message The message to be logged.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginLogWarning(
    OrthancPluginContext* context,
    const char* message)
  {
    context->InvokeService(context, _OrthancPluginService_LogWarning, message);
  }


  /**
   * @brief Log an information.
   *
   * Log an information message using the Orthanc logging system.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param message The message to be logged.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginLogInfo(
    OrthancPluginContext* context,
    const char* message)
  {
    context->InvokeService(context, _OrthancPluginService_LogInfo, message);
  }



  typedef struct
  {
    const char* pathRegularExpression;
    OrthancPluginRestCallback callback;
  } _OrthancPluginRestCallback;

  /**
   * @brief Register a REST callback.
   *
   * This function registers a REST callback against a regular
   * expression for a URI. This function must be called during the
   * initialization of the plugin, i.e. inside the
   * OrthancPluginInitialize() public function.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param pathRegularExpression Regular expression for the URI. May contain groups.
   * @param callback The callback function to handle the REST call.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginRegisterRestCallback(
    OrthancPluginContext*     context,
    const char*               pathRegularExpression,
    OrthancPluginRestCallback callback)
  {
    _OrthancPluginRestCallback params;
    params.pathRegularExpression = pathRegularExpression;
    params.callback = callback;
    context->InvokeService(context, _OrthancPluginService_RegisterRestCallback, &params);
  }



  typedef struct
  {
    OrthancPluginOnStoredInstanceCallback callback;
  } _OrthancPluginOnStoredInstanceCallback;

  /**
   * @brief Register a callback for received instances.
   *
   * This function registers a callback function that is called
   * whenever a new DICOM instance is stored into the Orthanc core.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param callback The callback function.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginRegisterOnStoredInstanceCallback(
    OrthancPluginContext*                  context,
    OrthancPluginOnStoredInstanceCallback  callback)
  {
    _OrthancPluginOnStoredInstanceCallback params;
    params.callback = callback;

    context->InvokeService(context, _OrthancPluginService_RegisterOnStoredInstanceCallback, &params);
  }



  typedef struct
  {
    OrthancPluginRestOutput* output;
    const char*              answer;
    uint32_t                 answerSize;
    const char*              mimeType;
  } _OrthancPluginAnswerBuffer;

  /**
   * @brief Answer to a REST request.
   *
   * This function answers to a REST request with the content of a memory buffer.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param answer Pointer to the memory buffer containing the answer.
   * @param answerSize Number of bytes of the answer.
   * @param mimeType The MIME type of the answer.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginAnswerBuffer(
    OrthancPluginContext*    context,
    OrthancPluginRestOutput* output,
    const char*              answer,
    uint32_t                 answerSize,
    const char*              mimeType)
  {
    _OrthancPluginAnswerBuffer params;
    params.output = output;
    params.answer = answer;
    params.answerSize = answerSize;
    params.mimeType = mimeType;
    context->InvokeService(context, _OrthancPluginService_AnswerBuffer, &params);
  }


  typedef struct
  {
    OrthancPluginRestOutput*  output;
    OrthancPluginPixelFormat  format;
    uint32_t                  width;
    uint32_t                  height;
    uint32_t                  pitch;
    const void*               buffer;
  } _OrthancPluginCompressAndAnswerPngImage;

  /**
   * @brief Answer to a REST request with a PNG image.
   *
   * This function answers to a REST request with a PNG image. The
   * parameters of this function describe a memory buffer that
   * contains an uncompressed image. The image will be automatically compressed
   * as a PNG image by the core system of Orthanc.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param format The memory layout of the uncompressed image.
   * @param width The width of the image.
   * @param height The height of the image.
   * @param pitch The pitch of the image (i.e. the number of bytes
   * between 2 successive lines of the image in the memory buffer.
   * @param buffer The memory buffer containing the uncompressed image.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginCompressAndAnswerPngImage(
    OrthancPluginContext*     context,
    OrthancPluginRestOutput*  output,
    OrthancPluginPixelFormat  format,
    uint32_t                  width,
    uint32_t                  height,
    uint32_t                  pitch,
    const void*               buffer)
  {
    _OrthancPluginCompressAndAnswerPngImage params;
    params.output = output;
    params.format = format;
    params.width = width;
    params.height = height;
    params.pitch = pitch;
    params.buffer = buffer;
    context->InvokeService(context, _OrthancPluginService_CompressAndAnswerPngImage, &params);
  }



  typedef struct
  {
    OrthancPluginMemoryBuffer*  target;
    const char*                 instanceId;
  } _OrthancPluginGetDicomForInstance;

  /**
   * @brief Retrieve a DICOM instance using its Orthanc identifier.
   * 
   * Retrieve a DICOM instance using its Orthanc identifier. The DICOM
   * file is stored into a newly allocated memory buffer.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param target The target memory buffer.
   * @param instanceId The Orthanc identifier of the DICOM instance of interest.
   * @return 0 if success, other value if error.
   **/
  ORTHANC_PLUGIN_INLINE int  OrthancPluginGetDicomForInstance(
    OrthancPluginContext*       context,
    OrthancPluginMemoryBuffer*  target,
    const char*                 instanceId)
  {
    _OrthancPluginGetDicomForInstance params;
    params.target = target;
    params.instanceId = instanceId;
    return context->InvokeService(context, _OrthancPluginService_GetDicomForInstance, &params);
  }



  typedef struct
  {
    OrthancPluginMemoryBuffer*  target;
    const char*                 uri;
  } _OrthancPluginRestApiGet;

  /**
   * @brief Make a GET call to the built-in Orthanc REST API.
   * 
   * Make a GET call to the built-in Orthanc REST API. The result to
   * the query is stored into a newly allocated memory buffer.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param target The target memory buffer.
   * @param uri The URI in the built-in Orthanc API.
   * @return 0 if success, other value if error.
   **/
  ORTHANC_PLUGIN_INLINE int  OrthancPluginRestApiGet(
    OrthancPluginContext*       context,
    OrthancPluginMemoryBuffer*  target,
    const char*                 uri)
  {
    _OrthancPluginRestApiGet params;
    params.target = target;
    params.uri = uri;
    return context->InvokeService(context, _OrthancPluginService_RestApiGet, &params);
  }



  typedef struct
  {
    OrthancPluginMemoryBuffer*  target;
    const char*                 uri;
    const char*                 body;
    uint32_t                    bodySize;
  } _OrthancPluginRestApiPostPut;

  /**
   * @brief Make a POST call to the built-in Orthanc REST API.
   * 
   * Make a POST call to the built-in Orthanc REST API. The result to
   * the query is stored into a newly allocated memory buffer.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param target The target memory buffer.
   * @param uri The URI in the built-in Orthanc API.
   * @param body The body of the POST request.
   * @param bodySize The size of the body.
   * @return 0 if success, other value if error.
   **/
  ORTHANC_PLUGIN_INLINE int  OrthancPluginRestApiPost(
    OrthancPluginContext*       context,
    OrthancPluginMemoryBuffer*  target,
    const char*                 uri,
    const char*                 body,
    uint32_t                    bodySize)
  {
    _OrthancPluginRestApiPostPut params;
    params.target = target;
    params.uri = uri;
    params.body = body;
    params.bodySize = bodySize;
    return context->InvokeService(context, _OrthancPluginService_RestApiPost, &params);
  }



  /**
   * @brief Make a DELETE call to the built-in Orthanc REST API.
   * 
   * Make a DELETE call to the built-in Orthanc REST API.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param uri The URI to delete in the built-in Orthanc API.
   * @return 0 if success, other value if error.
   **/
  ORTHANC_PLUGIN_INLINE int  OrthancPluginRestApiDelete(
    OrthancPluginContext*       context,
    const char*                 uri)
  {
    return context->InvokeService(context, _OrthancPluginService_RestApiDelete, uri);
  }



  /**
   * @brief Make a PUT call to the built-in Orthanc REST API.
   * 
   * Make a PUT call to the built-in Orthanc REST API. The result to
   * the query is stored into a newly allocated memory buffer.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param target The target memory buffer.
   * @param uri The URI in the built-in Orthanc API.
   * @param body The body of the PUT request.
   * @param bodySize The size of the body.
   * @return 0 if success, other value if error.
   **/
  ORTHANC_PLUGIN_INLINE int  OrthancPluginRestApiPut(
    OrthancPluginContext*       context,
    OrthancPluginMemoryBuffer*  target,
    const char*                 uri,
    const char*                 body,
    uint32_t                    bodySize)
  {
    _OrthancPluginRestApiPostPut params;
    params.target = target;
    params.uri = uri;
    params.body = body;
    params.bodySize = bodySize;
    return context->InvokeService(context, _OrthancPluginService_RestApiPut, &params);
  }



  typedef struct
  {
    OrthancPluginRestOutput* output;
    const char*              argument;
  } _OrthancPluginOutputPlusArgument;

  /**
   * @brief Redirect a REST request.
   *
   * This function answers to a REST request by redirecting the user
   * to another URI using HTTP status 301.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param redirection Where to redirect.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginRedirect(
    OrthancPluginContext*    context,
    OrthancPluginRestOutput* output,
    const char*              redirection)
  {
    _OrthancPluginOutputPlusArgument params;
    params.output = output;
    params.argument = redirection;
    context->InvokeService(context, _OrthancPluginService_Redirect, &params);
  }



  typedef struct
  {
    char**       result;
    const char*  argument;
  } _OrthancPluginRetrieveDynamicString;

  /**
   * @brief Look for a patient.
   *
   * Look for a patient stored in Orthanc, using its Patient ID tag (0x0010, 0x0020).
   * This function uses the database index to run as fast as possible (it does not loop
   * over all the stored patients).
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param patientID The Patient ID of interest.
   * @return The NULL value if the patient is non-existent, or a string containing the 
   * Orthanc ID of the patient. This string must be freed by OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char* OrthancPluginLookupPatient(
    OrthancPluginContext*  context,
    const char*            patientID)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = patientID;

    if (context->InvokeService(context, _OrthancPluginService_LookupPatient, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Look for a study.
   *
   * Look for a study stored in Orthanc, using its Study Instance UID tag (0x0020, 0x000d).
   * This function uses the database index to run as fast as possible (it does not loop
   * over all the stored studies).
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param studyUID The Study Instance UID of interest.
   * @return The NULL value if the study is non-existent, or a string containing the 
   * Orthanc ID of the study. This string must be freed by OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char* OrthancPluginLookupStudy(
    OrthancPluginContext*  context,
    const char*            studyUID)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = studyUID;

    if (context->InvokeService(context, _OrthancPluginService_LookupStudy, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Look for a study, using the accession number.
   *
   * Look for a study stored in Orthanc, using its Accession Number tag (0x0008, 0x0050).
   * This function uses the database index to run as fast as possible (it does not loop
   * over all the stored studies).
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param accessionNumber The Accession Number of interest.
   * @return The NULL value if the study is non-existent, or a string containing the 
   * Orthanc ID of the study. This string must be freed by OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char* OrthancPluginLookupStudyWithAccessionNumber(
    OrthancPluginContext*  context,
    const char*            accessionNumber)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = accessionNumber;

    if (context->InvokeService(context, _OrthancPluginService_LookupStudyWithAccessionNumber, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Look for a series.
   *
   * Look for a series stored in Orthanc, using its Series Instance UID tag (0x0020, 0x000e).
   * This function uses the database index to run as fast as possible (it does not loop
   * over all the stored series).
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param seriesUID The Series Instance UID of interest.
   * @return The NULL value if the series is non-existent, or a string containing the 
   * Orthanc ID of the series. This string must be freed by OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char* OrthancPluginLookupSeries(
    OrthancPluginContext*  context,
    const char*            seriesUID)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = seriesUID;

    if (context->InvokeService(context, _OrthancPluginService_LookupSeries, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Look for an instance.
   *
   * Look for an instance stored in Orthanc, using its SOP Instance UID tag (0x0008, 0x0018).
   * This function uses the database index to run as fast as possible (it does not loop
   * over all the stored instances).
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param sopInstanceUID The SOP Instance UID of interest.
   * @return The NULL value if the instance is non-existent, or a string containing the 
   * Orthanc ID of the instance. This string must be freed by OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char* OrthancPluginLookupInstance(
    OrthancPluginContext*  context,
    const char*            sopInstanceUID)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = sopInstanceUID;

    if (context->InvokeService(context, _OrthancPluginService_LookupInstance, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }



  typedef struct
  {
    OrthancPluginRestOutput* output;
    uint16_t                 status;
  } _OrthancPluginSendHttpStatusCode;

  /**
   * @brief Send a HTTP status code.
   *
   * This function answers to a REST request by sending a HTTP status
   * code (such as "400 - Bad Request"). Note that:
   * - Successful requests (status 200) must use ::OrthancPluginAnswerBuffer().
   * - Redirections (status 301) must use ::OrthancPluginRedirect().
   * - Unauthorized access (status 401) must use ::OrthancPluginSendUnauthorized().
   * - Methods not allowed (status 405) must use ::OrthancPluginSendMethodNotAllowed().
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param status The HTTP status code to be sent.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginSendHttpStatusCode(
    OrthancPluginContext*    context,
    OrthancPluginRestOutput* output,
    uint16_t                 status)
  {
    _OrthancPluginSendHttpStatusCode params;
    params.output = output;
    params.status = status;
    context->InvokeService(context, _OrthancPluginService_SendHttpStatusCode, &params);
  }


  /**
   * @brief Signal that a REST request is not authorized.
   *
   * This function answers to a REST request by signaling that it is
   * not authorized.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param realm The realm for the authorization process.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginSendUnauthorized(
    OrthancPluginContext*    context,
    OrthancPluginRestOutput* output,
    const char*              realm)
  {
    _OrthancPluginOutputPlusArgument params;
    params.output = output;
    params.argument = realm;
    context->InvokeService(context, _OrthancPluginService_SendUnauthorized, &params);
  }


  /**
   * @brief Signal that this URI does not support this HTTP method.
   *
   * This function answers to a REST request by signaling that the
   * queried URI does not support this method.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param allowedMethods The allowed methods for this URI (e.g. "GET,POST" after a PUT or a POST request).
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginSendMethodNotAllowed(
    OrthancPluginContext*    context,
    OrthancPluginRestOutput* output,
    const char*              allowedMethods)
  {
    _OrthancPluginOutputPlusArgument params;
    params.output = output;
    params.argument = allowedMethods;
    context->InvokeService(context, _OrthancPluginService_SendMethodNotAllowed, &params);
  }


  typedef struct
  {
    OrthancPluginRestOutput* output;
    const char*              key;
    const char*              value;
  } _OrthancPluginSetHttpHeader;

  /**
   * @brief Set a cookie.
   *
   * This function sets a cookie in the HTTP client.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param cookie The cookie to be set.
   * @param value The value of the cookie.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginSetCookie(
    OrthancPluginContext*    context,
    OrthancPluginRestOutput* output,
    const char*              cookie,
    const char*              value)
  {
    _OrthancPluginSetHttpHeader params;
    params.output = output;
    params.key = cookie;
    params.value = value;
    context->InvokeService(context, _OrthancPluginService_SetCookie, &params);
  }


  /**
   * @brief Set some HTTP header.
   *
   * This function sets a HTTP header in the HTTP answer.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param output The HTTP connection to the client application.
   * @param key The HTTP header to be set.
   * @param value The value of the HTTP header.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginSetHttpHeader(
    OrthancPluginContext*    context,
    OrthancPluginRestOutput* output,
    const char*              key,
    const char*              value)
  {
    _OrthancPluginSetHttpHeader params;
    params.output = output;
    params.key = key;
    params.value = value;
    context->InvokeService(context, _OrthancPluginService_SetHttpHeader, &params);
  }


  typedef struct
  {
    char**                      resultStringToFree;
    const char**                resultString;
    int64_t*                    resultInt64;
    const char*                 key;
    OrthancPluginDicomInstance* instance;
  } _OrthancPluginAccessDicomInstance;


  /**
   * @brief Get the AET of a DICOM instance.
   *
   * This function returns the Application Entity Title (AET) of the
   * DICOM modality from which a DICOM instance originates.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param instance The instance of interest.
   * @return The AET if success, NULL if error.
   **/
  ORTHANC_PLUGIN_INLINE const char* OrthancPluginGetInstanceRemoteAet(
    OrthancPluginContext*        context,
    OrthancPluginDicomInstance*  instance)
  {
    const char* result;

    _OrthancPluginAccessDicomInstance params;
    memset(&params, 0, sizeof(params));
    params.resultString = &result;
    params.instance = instance;

    if (context->InvokeService(context, _OrthancPluginService_GetInstanceRemoteAet, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Get the size of a DICOM file.
   *
   * This function returns the number of bytes of the given DICOM instance.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param instance The instance of interest.
   * @return The size of the file, -1 in case of error.
   **/
  ORTHANC_PLUGIN_INLINE int64_t OrthancPluginGetInstanceSize(
    OrthancPluginContext*       context,
    OrthancPluginDicomInstance* instance)
  {
    int64_t size;

    _OrthancPluginAccessDicomInstance params;
    memset(&params, 0, sizeof(params));
    params.resultInt64 = &size;
    params.instance = instance;

    if (context->InvokeService(context, _OrthancPluginService_GetInstanceSize, &params))
    {
      /* Error */
      return -1;
    }
    else
    {
      return size;
    }
  }


  /**
   * @brief Get the data of a DICOM file.
   *
   * This function returns a pointer to the content of the given DICOM instance.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param instance The instance of interest.
   * @return The pointer to the DICOM data, NULL in case of error.
   **/
  ORTHANC_PLUGIN_INLINE const char* OrthancPluginGetInstanceData(
    OrthancPluginContext*        context,
    OrthancPluginDicomInstance*  instance)
  {
    const char* result;

    _OrthancPluginAccessDicomInstance params;
    memset(&params, 0, sizeof(params));
    params.resultString = &result;
    params.instance = instance;

    if (context->InvokeService(context, _OrthancPluginService_GetInstanceData, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Get the DICOM tag hierarchy as a JSON file.
   *
   * This function returns a pointer to a newly created string
   * containing a JSON file. This JSON file encodes the tag hierarchy
   * of the given DICOM instance.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param instance The instance of interest.
   * @return The NULL value in case of error, or a string containing the JSON file.
   * This string must be freed by OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char* OrthancPluginGetInstanceJson(
    OrthancPluginContext*        context,
    OrthancPluginDicomInstance*  instance)
  {
    char* result;

    _OrthancPluginAccessDicomInstance params;
    memset(&params, 0, sizeof(params));
    params.resultStringToFree = &result;
    params.instance = instance;

    if (context->InvokeService(context, _OrthancPluginService_GetInstanceJson, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Get the DICOM tag hierarchy as a JSON file (with simplification).
   *
   * This function returns a pointer to a newly created string
   * containing a JSON file. This JSON file encodes the tag hierarchy
   * of the given DICOM instance. In contrast with
   * ::OrthancPluginGetInstanceJson(), the returned JSON file is in
   * its simplified version.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param instance The instance of interest.
   * @return The NULL value in case of error, or a string containing the JSON file.
   * This string must be freed by OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char* OrthancPluginGetInstanceSimplifiedJson(
    OrthancPluginContext*        context,
    OrthancPluginDicomInstance*  instance)
  {
    char* result;

    _OrthancPluginAccessDicomInstance params;
    memset(&params, 0, sizeof(params));
    params.resultStringToFree = &result;
    params.instance = instance;

    if (context->InvokeService(context, _OrthancPluginService_GetInstanceSimplifiedJson, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Check whether a DICOM instance is associated with some metadata.
   *
   * This function checks whether the DICOM instance of interest is
   * associated with some metadata. As of Orthanc 0.8.1, in the
   * callbacks registered by
   * ::OrthancPluginRegisterOnStoredInstanceCallback(), the only
   * possibly available metadata are "ReceptionDate", "RemoteAET" and
   * "IndexInSeries".
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param instance The instance of interest.
   * @param metadata The metadata of interest.
   * @return 1 if the metadata is present, 0 if it is absent, -1 in case of error.
   **/
  ORTHANC_PLUGIN_INLINE int  OrthancPluginHasInstanceMetadata(
    OrthancPluginContext*        context,
    OrthancPluginDicomInstance*  instance,
    const char*                  metadata)
  {
    int64_t result;

    _OrthancPluginAccessDicomInstance params;
    memset(&params, 0, sizeof(params));
    params.resultInt64 = &result;
    params.instance = instance;
    params.key = metadata;

    if (context->InvokeService(context, _OrthancPluginService_HasInstanceMetadata, &params))
    {
      /* Error */
      return -1;
    }
    else
    {
      return (result != 0);
    }
  }


  /**
   * @brief Get the value of some metadata associated with a given DICOM instance.
   *
   * This functions returns the value of some metadata that is associated with the DICOM instance of interest.
   * Before calling this function, the existence of the metadata must have been checked with
   * ::OrthancPluginHasInstanceMetadata().
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param instance The instance of interest.
   * @param metadata The metadata of interest.
   * @return The metadata value if success, NULL if error.
   **/
  ORTHANC_PLUGIN_INLINE const char* OrthancPluginGetInstanceMetadata(
    OrthancPluginContext*        context,
    OrthancPluginDicomInstance*  instance,
    const char*                  metadata)
  {
    const char* result;

    _OrthancPluginAccessDicomInstance params;
    memset(&params, 0, sizeof(params));
    params.resultString = &result;
    params.instance = instance;
    params.key = metadata;

    if (context->InvokeService(context, _OrthancPluginService_GetInstanceMetadata, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }



  typedef struct
  {
    OrthancPluginStorageCreate  create_;
    OrthancPluginStorageRead    read_;
    OrthancPluginStorageRemove  remove_;
    OrthancPluginFree           free_;
  } _OrthancPluginRegisterStorageArea;

  /**
   * @brief Register a custom storage area.
   *
   * This function registers a custom storage area, to replace the
   * built-in way Orthanc stores its files on the filesystem. This
   * function must be called during the initialization of the plugin,
   * i.e. inside the OrthancPluginInitialize() public function.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param create The callback function to store a file on the custom storage area.
   * @param read The callback function to read a file from the custom storage area.
   * @param remove The callback function to remove a file from the custom storage area.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginRegisterStorageArea(
    OrthancPluginContext*       context,
    OrthancPluginStorageCreate  create,
    OrthancPluginStorageRead    read,
    OrthancPluginStorageRemove  remove)
  {
    _OrthancPluginRegisterStorageArea params;
    params.create_ = create;
    params.read_ = read;
    params.remove_ = remove;

#ifdef  __cplusplus
    params.free_ = ::free;
#else
    params.free_ = free;
#endif

    context->InvokeService(context, _OrthancPluginService_RegisterStorageArea, &params);
  }



  /**
   * @brief Return the path to the Orthanc executable.
   *
   * This function returns the path to the Orthanc executable.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @return NULL in the case of an error, or a newly allocated string
   * containing the path. This string must be freed by
   * OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char *OrthancPluginGetOrthancPath(OrthancPluginContext* context)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = NULL;

    if (context->InvokeService(context, _OrthancPluginService_GetOrthancPath, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Return the directory containing the Orthanc.
   *
   * This function returns the path to the directory containing the Orthanc executable.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @return NULL in the case of an error, or a newly allocated string
   * containing the path. This string must be freed by
   * OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char *OrthancPluginGetOrthancDirectory(OrthancPluginContext* context)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = NULL;

    if (context->InvokeService(context, _OrthancPluginService_GetOrthancDirectory, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }


  /**
   * @brief Return the path to the configuration file.
   *
   * This function returns the path to the configuration file that was
   * specified when starting Orthanc.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @return NULL in the case of an error, or a newly allocated string
   * containing the path. This string must be freed by
   * OrthancPluginFreeString().
   **/
  ORTHANC_PLUGIN_INLINE char *OrthancPluginGetConfigurationPath(OrthancPluginContext* context)
  {
    char* result;

    _OrthancPluginRetrieveDynamicString params;
    params.result = &result;
    params.argument = NULL;

    if (context->InvokeService(context, _OrthancPluginService_GetConfigurationPath, &params))
    {
      /* Error */
      return NULL;
    }
    else
    {
      return result;
    }
  }



  typedef struct
  {
    OrthancPluginOnChangeCallback callback;
  } _OrthancPluginOnChangeCallback;

  /**
   * @brief Register a callback to monitor changes.
   *
   * This function registers a callback function that is called
   * whenever a change happens to some DICOM resource.
   * 
   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
   * @param callback The callback function.
   **/
  ORTHANC_PLUGIN_INLINE void OrthancPluginRegisterOnChangeCallback(
    OrthancPluginContext*          context,
    OrthancPluginOnChangeCallback  callback)
  {
    _OrthancPluginOnChangeCallback params;
    params.callback = callback;

    context->InvokeService(context, _OrthancPluginService_RegisterOnChangeCallback, &params);
  }




#ifdef  __cplusplus
}
#endif


/** @} */