/*============================================================================
 * Management of the GUI parameters file: output parameters
 *============================================================================*/

/*
  This file is part of Code_Saturne, a general-purpose CFD tool.

  Copyright (C) 1998-2015 EDF S.A.

  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 2 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, write to the Free Software Foundation, Inc., 51 Franklin
  Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

/*----------------------------------------------------------------------------*/

#include "cs_defs.h"

/*----------------------------------------------------------------------------
 * Standard C library headers
 *----------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>

/*----------------------------------------------------------------------------
 * libxml2 library headers
 *----------------------------------------------------------------------------*/

#if defined(HAVE_LIBXML2)

#include <libxml/tree.h>
#include <libxml/parser.h>
#include <libxml/xpath.h>
#include <libxml/xpathInternals.h>

#endif

/*----------------------------------------------------------------------------
 * Local headers
 *----------------------------------------------------------------------------*/

#include "bft_mem.h"
#include "bft_error.h"
#include "bft_printf.h"

#include "fvm_selector.h"

#include "mei_evaluate.h"

#include "cs_base.h"
#include "cs_gui_util.h"
#include "cs_gui_variables.h"
#include "cs_mesh_location.h"
#include "cs_selector.h"
#include "cs_post.h"
#include "cs_field.h"
#include "cs_field_pointer.h"
#include "cs_parameters.h"
#include "cs_thermal_model.h"
#include "cs_time_moment.h"

/*----------------------------------------------------------------------------
 * Header for the current file
 *----------------------------------------------------------------------------*/

#include "cs_gui_output.h"

/*----------------------------------------------------------------------------*/

BEGIN_C_DECLS

/*! \cond DOXYGEN_SHOULD_SKIP_THIS */

/*=============================================================================
 * Local Macro Definitions
 *============================================================================*/

/* debugging switch */
#define _XML_DEBUG_ 0

/*============================================================================
 * Local Structure Definitions
 *============================================================================*/

/*============================================================================
 * External global variables
 *============================================================================*/

/*============================================================================
 * Private global variables
 *============================================================================*/

/*============================================================================
 * Static global variables
 *============================================================================*/

/*============================================================================
 * Private function definitions
 *============================================================================*/

/*----------------------------------------------------------------------------
 * Get output control value parameters.
 *
 * parameters:
 *   param               <--   name of the parameter
 *   keyword             -->   output control parameter
 *----------------------------------------------------------------------------*/

static void
_output_value(const char  *const param,
              int         *const keyword)
{
  char *path = NULL;
  int   result;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 3, "analysis_control", "output", param);

  if (cs_gui_strcmp(param, "auxiliary_restart_file_writing")) {

    cs_xpath_add_attribute(&path, "status");
    if(cs_gui_get_status(path, &result)) *keyword = result;

  }
  else {

    cs_xpath_add_function_text(&path);
    if (cs_gui_get_int(path, &result)) *keyword = result;

  }

  BFT_FREE(path);
}

/*----------------------------------------------------------------------------
 * Get output control value parameters for frequency output
 *
 * parameters:
 *   param               <--   name of the parameter
 *   keyword             -->   output control parameter
 *----------------------------------------------------------------------------*/

static void
_output_time_value(const char  *const param,
                   double      *const keyword)
{
  char *path = NULL;
  char *choice = NULL;
  double result = 0.0;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 3, "analysis_control", "output", param);

  cs_xpath_add_function_text(&path);
  if (cs_gui_get_double(path, &result)) *keyword = result;

  BFT_FREE(choice);
  BFT_FREE(path);
}

/*----------------------------------------------------------------------------
 * Return the output format and options for postprocessing.
 *
 * parameters
 *   param         -->  name of the parameter
 *   keyword       <--  output keyword string
 *   max_key_size  -->  maximum keyword size
 *----------------------------------------------------------------------------*/

static void
_output_choice(const char  *const param,
               char        *const keyword,
               size_t             max_key_size)
{
  char *path = NULL;
  char *choice = NULL;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 3, "analysis_control", "output", param);
  cs_xpath_add_attribute(&path, "choice");
  choice = cs_gui_get_attribute_value(path);
  BFT_FREE(path);

  if (choice != NULL) {
    strncpy(keyword, choice, max_key_size);
    keyword[max_key_size] = '\0';
  }
  else
    keyword[0] = '\0';

  BFT_FREE(choice);
}

/*----------------------------------------------------------------------------
 * Get postprocessing value status for surfacic variables
 *
 * parameters:
 *   name         --> name of the parameter
 *   default_val  --> default value
 *----------------------------------------------------------------------------*/

static bool
_surfacic_variable_post(const char  *name,
                        bool         default_val)
{
  int   result = 0;
  char *path = NULL;

  bool active = default_val;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "property");
  cs_xpath_add_test_attribute(&path, "name", name);

  if (cs_gui_get_nb_element(path) > 0) {

    /* If base path present but not recording status, default to true */
    active = true;

    cs_xpath_add_element(&path, "postprocessing_recording");
    cs_xpath_add_attribute(&path, "status");
    if (cs_gui_get_status(path, &result)) {
      if (result == 1)
        active = true;
      else
        active = false;
    }

  }

  BFT_FREE(path);

  return active;
}

/*----------------------------------------------------------------------------
 * Get the attribute value from the xpath query.
 *
 * parameters:
 *   path          <-> path for xpath query (NULL on return)
 *   child         <-- child markup
 *   keyword       --> value of attribute node
 *----------------------------------------------------------------------------*/

static void
_attribute_value(char               **path,
                 const char    *const child,
                 int           *const keyword)
{
  int   result;

  assert(path != NULL);
  assert(child != NULL);

  cs_xpath_add_attribute(path, "status");

  if (   cs_gui_strcmp(child, "postprocessing_recording")
      || cs_gui_strcmp(child, "listing_printing")) *keyword = -999;

  if (cs_gui_get_status(*path, &result))
    *keyword = result;

  BFT_FREE(*path);
}

/*----------------------------------------------------------------------------
 * Get the attribute value associated to a child markup from a variable.
 *
 * parameters:
 *   name          <--  name of the variable markup
 *   child         <--  child markup
 *   keyword       -->  value of attribute node contained in the child markup
 *----------------------------------------------------------------------------*/

static void
_variable_attribute(const char  *name,
                    const char  *child,
                    int         *keyword)
{
  char *path = NULL;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "variable");
  cs_xpath_add_test_attribute(&path, "name", name);
  cs_xpath_add_element(&path, child);
  _attribute_value(&path, child, keyword);
}

/*-----------------------------------------------------------------------------
 * Return number of <probe recording> tags in the <variable> tag.
 *----------------------------------------------------------------------------*/

static int
_variable_number_probes(const char  *variable)
{
  char *path = NULL;
  char *choice = NULL;
  int   nb_probes;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "variable");
  cs_xpath_add_test_attribute(&path, "name", variable);
  cs_xpath_add_element(&path, "probes");
  cs_xpath_add_attribute(&path, "choice");
  choice = cs_gui_get_attribute_value(path);

  if (choice)
    nb_probes = atoi(choice);
  else
    nb_probes = -1;

  BFT_FREE(choice);
  BFT_FREE(path);

  return nb_probes;
}

/*-----------------------------------------------------------------------------
 * Return probe number for <probe_recording> tag for variable.
 *
 * parameters:
 *   variable   <--  name of variable
 *   num_probe  <--  number of <probe_recording> tags
 *----------------------------------------------------------------------------*/

static int
_variable_probe_name(const char *variable,
                     int         num_probe)
{
  char *path = NULL;
  char *strvalue = NULL;
  int   intvalue;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "variable");
  cs_xpath_add_test_attribute(&path, "name", variable);
  cs_xpath_add_element(&path, "probes");
  cs_xpath_add_element_num(&path, "probe_recording", num_probe);
  cs_xpath_add_attribute(&path, "name");

  strvalue = cs_gui_get_attribute_value(path);

  if (strvalue == NULL)
    bft_error(__FILE__, __LINE__, 0, _("Invalid xpath: %s\n"), path);

  intvalue = atoi(strvalue);

  BFT_FREE(strvalue);
  BFT_FREE(path);

  return intvalue;
}

/*-----------------------------------------------------------------------------
 * Return variable label.
 *
 * parameters:
 *   variable   <-- name of variable
 *----------------------------------------------------------------------------*/

static char *
_variable_label(const char *variable)
{
  char *path = NULL;
  char *label = NULL;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "variable");
  cs_xpath_add_test_attribute(&path, "name", variable);
  cs_xpath_add_attribute(&path, "label");

  label = cs_gui_get_attribute_value(path);

  BFT_FREE(path);

  return label;
}

/*-----------------------------------------------------------------------------
 * Post-processing options for all variables (velocity, pressure, ...)
 *
 * parameters:
 *   f_id               <-- field id
 *   ihisvr             --> histo output
 *   nvppmx             <-- number of printed variables
 *----------------------------------------------------------------------------*/

static void
_variable_post(int         f_id,
               int        *ihisvr,
               const int  *nvppmx)
{
  int   nb_probes;
  int   iprob;
  char *label = NULL;
  int   num_probe;

  cs_field_t  *f = cs_field_by_id(f_id);
  const int var_key_id = cs_field_key_id("post_id");
  int ipp = cs_field_get_key_int(f, var_key_id);

  if (ipp == -1) return;

  int f_post = 0, f_log = 0;
  const int k_post = cs_field_key_id("post_vis");
  const int k_log  = cs_field_key_id("log");
  const int k_lbl = cs_field_key_id("label");

  _variable_attribute(f->name,
                      "postprocessing_recording",
                      &f_post);
  if (f_post != -999)
    cs_field_set_key_int(f, k_post, f_post);

  _variable_attribute(f->name,
                      "listing_printing",
                      &f_log);
  if (f_log != -999)
    cs_field_set_key_int(f, k_log, f_log);

  nb_probes = _variable_number_probes(f->name);

  ihisvr[0 + (ipp - 1)] = nb_probes;

  if (f->dim > 1)
    for (int idim = 1; idim < f->dim; idim++)
      ihisvr[0 + (ipp - 1) + idim] = nb_probes;

  if (nb_probes > 0) {
    for (iprob = 0; iprob < nb_probes; iprob++) {
      num_probe = _variable_probe_name(f->name, iprob+1);
      ihisvr[(iprob+1)*(*nvppmx) + (ipp - 1)] = num_probe;
      if (f->dim > 1)
        for (int idim = 1; idim < f->dim; idim++)
          ihisvr[(iprob+1)*(*nvppmx) + (ipp - 1) + idim] = num_probe;
    }
  }

  label = _variable_label(f->name);
  if (label != NULL)
    cs_field_set_key_str(f, k_lbl, label);

  BFT_FREE(label);
}

/*-----------------------------------------------------------------------------
 * Return status of the property for physical model
 *
 * parameters:
 *   name          <--  name of the variable markup
 *   child         <--  child markup
 *   value_type    <-- type of value (listing_printing, postprocessing ..)
 *----------------------------------------------------------------------------*/

static void
_property_output_status(const char  *name,
                        const char  *child,
                        int         *keyword)
{
  char *path = NULL;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "property");
  cs_xpath_add_test_attribute(&path, "name", name);
  cs_xpath_add_element(&path, child);
  _attribute_value(&path, child, keyword);
}

/*-----------------------------------------------------------------------------
 * Return probe number for sub tag "probe_recording" for property.
 *
 * parameters:
 *   property   <--  name of property
 *   num_probe  <-- number of <probe_recording> tags
 *----------------------------------------------------------------------------*/

static int
_property_probe_name(const char  *property,
                     int          num_probe)
{
  char *path = NULL;
  char *strvalue = NULL;
  int   value;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "property");
  cs_xpath_add_test_attribute(&path, "name", property);
  cs_xpath_add_element(&path, "probes");
  cs_xpath_add_element_num(&path, "probe_recording", num_probe);
  cs_xpath_add_attribute(&path, "name");

  strvalue = cs_gui_get_attribute_value(path);

  if (strvalue == NULL)
    bft_error(__FILE__, __LINE__, 0, _("Invalid xpath: %s\n"), path);

  value = atoi(strvalue);

  BFT_FREE(path);
  BFT_FREE(strvalue);

  return value;
}

/*-----------------------------------------------------------------------------
 * Return number of sub tags <probe_recording> for property.
 *----------------------------------------------------------------------------*/

static int
_property_number_probes(const char  *property)
{
  char *path = NULL;
  char *choice = NULL;
  int   nb_probes;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "property");
  cs_xpath_add_test_attribute(&path, "name", property);
  cs_xpath_add_element(&path, "probes");
  cs_xpath_add_attribute(&path, "choice");
  choice = cs_gui_get_attribute_value(path);

  if (choice) {
    nb_probes = atoi(choice);
    BFT_FREE(choice);
  }
  else
    nb_probes = -1;

  BFT_FREE(path);

  return nb_probes;
}

/*-----------------------------------------------------------------------------
 * Return the label model's property.
 *
 * parameters:
 *   property   <--  name of property
 *----------------------------------------------------------------------------*/

static char *
_get_property_label(const char  *property)
{
  char *path = NULL;
  char *label_name = NULL;

  path = cs_xpath_short_path();
  cs_xpath_add_element(&path, "property");
  cs_xpath_add_test_attribute(&path, "name", property);
  cs_xpath_add_attribute(&path, "label");

  label_name = cs_gui_get_attribute_value(path);

  BFT_FREE(path);

  return label_name;
}

/*-----------------------------------------------------------------------------
 * Post-processing options for properties
 *
 * parameters:
 *   f_id               <-- field id
 *   ihisvr             --> histo output
 *   nvppmx             <-- number of printed variables
 *----------------------------------------------------------------------------*/

static void
_property_post(int         f_id,
               int        *ihisvr,
               const int  *nvppmx)
{
  int nb_probes;
  int iprob;
  char *label = NULL;
  int num_probe;

  cs_field_t  *f = cs_field_by_id(f_id);
  const int var_key_id = cs_field_key_id("post_id");
  int ipp = cs_field_get_key_int(f, var_key_id);

  if (ipp == -1) return;

  int f_post = 0, f_log = 0;
  const int k_post = cs_field_key_id("post_vis");
  const int k_log  = cs_field_key_id("log");
  const int k_lbl = cs_field_key_id("label");

  /* Visualization outputs frequency */
  _property_output_status(f->name,
                          "postprocessing_recording",
                          &f_post);
  if (f_post != -999)
    cs_field_set_key_int(f, k_post, f_post);

  /* Listing output frequency */
  _property_output_status(f->name,
                          "listing_printing",
                          &f_log);
  if (f_log != -999)
    cs_field_set_key_int(f, k_log, f_log);

  /* Activated probes */
  nb_probes = _property_number_probes(f->name);

  ihisvr[0 + (ipp - 1)] = nb_probes;

  if (nb_probes > 0) {
    for (iprob=0; iprob<nb_probes; iprob++){
      num_probe = _property_probe_name(f->name, iprob+1);
      ihisvr[(iprob + 1)*(*nvppmx) + (ipp - 1)] = num_probe;
      if (f->dim > 1)
        for (int idim = 1; idim < f->dim; idim++)
          ihisvr[(iprob+1)*(*nvppmx) + (ipp - 1) + idim] = num_probe;
    }
  }

  /* Take into account labels */

  label = _get_property_label(f->name);
  if (label != NULL)
    cs_field_set_key_str(f, k_lbl, label);

  BFT_FREE(label);
}

/*-----------------------------------------------------------------------------
 * Return status of the moment for physical models
 *
 * parameters:
 *   moment_id  <-- id of moment
 *   child      <-- child markup
 *   value_type <-- type of value (listing_printing, postprocessing ..)
 *----------------------------------------------------------------------------*/

static void
_time_moment_output_status(int          moment_id,
                           const char  *child,
                           int         *keyword)
{
  char *path = NULL;

  path = cs_xpath_short_path();
  cs_xpath_add_element_num(&path, "time_average", moment_id+1);
  cs_xpath_add_element(&path, child);
  _attribute_value(&path, child, keyword);
}

/*-----------------------------------------------------------------------------
 * Return probe number for sub tag "probe_recording" for moment.
 *
 * parameters:
 *   moment_id  <-- id of moment
 *   num_probe  <-- number of <probe_recording> tags
 *----------------------------------------------------------------------------*/

static int
_time_moment_probe_name(int  moment_id,
                        int  num_probe)
{
  char *path = NULL;
  char *strvalue = NULL;
  int   value;

  path = cs_xpath_short_path();
  cs_xpath_add_element_num(&path, "time_average", moment_id+1);
  cs_xpath_add_element(&path, "probes");
  cs_xpath_add_element_num(&path, "probe_recording", num_probe);
  cs_xpath_add_attribute(&path, "name");

  strvalue = cs_gui_get_attribute_value(path);

  if (strvalue == NULL)
    bft_error(__FILE__, __LINE__, 0, _("Invalid xpath: %s\n"), path);

  value = atoi(strvalue);

  BFT_FREE(path);
  BFT_FREE(strvalue);

  return value;
}

/*-----------------------------------------------------------------------------
 * Return number of sub tags <probe_recording> for moment.
 *
 * parameters:
 *   moment_id  <-- id of moment
 *----------------------------------------------------------------------------*/

static int
_time_moment_number_probes(int moment_id)
{
  char *path = NULL;
  char *choice = NULL;
  int   nb_probes;

  path = cs_xpath_short_path();
  cs_xpath_add_element_num(&path, "time_average", moment_id+1);
  cs_xpath_add_element(&path, "probes");
  cs_xpath_add_attribute(&path, "choice");
  choice = cs_gui_get_attribute_value(path);

  if (choice) {
    nb_probes = atoi(choice);
    BFT_FREE(choice);
  }
  else
    nb_probes = -1;

  BFT_FREE(path);

  return nb_probes;
}

/*-----------------------------------------------------------------------------
 * Post-processing options for time moments
 *
 * parameters:
 *   f_id               <-- field id
 *   ihisvr             --> histo output
 *   nvppmx             <-- number of printed variables
 *----------------------------------------------------------------------------*/

static void
_time_moment_post(int         f_id,
                  int         moment_id,
                  int        *ihisvr,
                  const int  *nvppmx)
{
  int nb_probes;
  int iprob;
  char *label = NULL;
  int num_probe;

  cs_field_t  *f = cs_field_by_id(f_id);
  const int var_key_id = cs_field_key_id("post_id");
  int ipp = cs_field_get_key_int(f, var_key_id);

  if (ipp == -1) return;

  int f_post = 0, f_log = 0;
  const int k_post = cs_field_key_id("post_vis");
  const int k_log  = cs_field_key_id("log");

  /* Visualization outputs frequency */
  _time_moment_output_status(moment_id,
                             "postprocessing_recording",
                             &f_post);
  if (f_post != -999)
    cs_field_set_key_int(f, k_post, f_post);

  /* Listing output frequency */
  _time_moment_output_status(moment_id,
                             "listing_printing",
                             &f_log);
  if (f_log != -999)
    cs_field_set_key_int(f, k_log, f_log);

  /* Activated probes */
  nb_probes = _time_moment_number_probes(moment_id);

  ihisvr[0 + (ipp - 1)] = nb_probes;

  if (nb_probes > 0) {
    for (iprob=0; iprob<nb_probes; iprob++){
      num_probe = _time_moment_probe_name(moment_id, iprob+1);
      ihisvr[(iprob + 1)*(*nvppmx) + (ipp - 1)] = num_probe;
      if (f->dim > 1)
        for (int idim = 1; idim < f->dim; idim++)
          ihisvr[(iprob+1)*(*nvppmx) + (ipp - 1) + idim] = num_probe;
    }
  }

  BFT_FREE(label);
}

/*-----------------------------------------------------------------------------
 * Return a single coordinate of a monitoring probe.
 *
 * parameters
 *   num_probe            <--  number aka name of the monitoring probe
 *   probe_coord          <--  one coordinate of the monitoring probe
 *----------------------------------------------------------------------------*/

static double
_probe_coordinate(int          num_probe,
                  const char  *probe_coord)
{
  char  *path = NULL;
  double result = 0.0;

  assert(num_probe > 0);

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, "probe", num_probe);
  cs_xpath_add_element(&path, probe_coord);
  cs_xpath_add_function_text(&path);

  if (!cs_gui_get_double(path, &result))
    bft_error(__FILE__, __LINE__, 0,
              _("Coordinate %s of the monitoring probe number %i "
                "not found.\nXpath: %s\n"), probe_coord, num_probe, path);

  BFT_FREE(path);

  return result;
}

/*----------------------------------------------------------------------------
 * Return the location of a mesh.
 *
 * parameters:
 *   num                <--  number of a mesh
 *----------------------------------------------------------------------------*/

static char
*_output_mesh_location(int  num)
{
  char *path = NULL;
  char *location = NULL;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, "mesh", num);
  cs_xpath_add_element(&path, "location");
  cs_xpath_add_function_text(&path);
  location = cs_gui_get_text_value(path);

  BFT_FREE(path);
  return location;
}

/*----------------------------------------------------------------------------
 * Return the density for a particle mesh.
 *
 * parameters:
 *   num                <--  number of a mesh
 *----------------------------------------------------------------------------*/

static double
_output_particle_density(int  num)
{
  char *path = NULL;
  double result = 1.;

  double density = 1.;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, "mesh", num);
  cs_xpath_add_element(&path, "density");
  cs_xpath_add_function_text(&path);
  if (cs_gui_get_double(path, &result))
    density = result;

  BFT_FREE(path);
  return density;
}

/*----------------------------------------------------------------------------
 * Return the frequency of a writer.
 *
 * parameters:
 *   num                <--  number of the writer
 *----------------------------------------------------------------------------*/

static double
_output_writer_frequency(int  num)
{
  char *path = NULL;
  char *path_bis = NULL;
  double time_step = 0.0;
  double result = 0.0;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, "writer", num);
  BFT_MALLOC(path_bis, strlen(path) +1, char);
  strcpy(path_bis, path);
  cs_xpath_add_element(&path, "frequency");
  cs_xpath_add_function_text(&path);
  if (cs_gui_get_double(path, &result))
    time_step = result;
  else {
    cs_xpath_add_element(&path_bis, "frequency_time");
    cs_xpath_add_function_text(&path_bis);
    if (cs_gui_get_double(path_bis, &result))
      time_step = result;
  }

  BFT_FREE(path);
  BFT_FREE(path_bis);
  return time_step;
}

/*----------------------------------------------------------------------------
 * Return an option for a mesh or a writer call by a number.
 *
 * parameters:
 *   type                 <--  'writer' or 'mesh'
 *   choice               <--  type of option to get
 *   option               <--  the option needed
 *   num                  <--  number of the mesh or the writer
 *----------------------------------------------------------------------------*/

static char *
_output_type_options(const char  *type,
                     const char  *choice,
                     const char  *option,
                     int          num)
{
  char *path = NULL;
  char *description = NULL;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, type, num);
  cs_xpath_add_element(&path, option);

  if (cs_gui_strcmp(option, "frequency") && choice == NULL) {
    description = cs_gui_get_text_value(path);
  }
  else {
    cs_xpath_add_attribute(&path, choice);
    description = cs_gui_get_attribute_value(path);
  }

  BFT_FREE(path);

  if (description == NULL) {
    BFT_MALLOC(description, 1, char);
    description[0] = '\0';
  }

  return description;
}

/*----------------------------------------------------------------------------
 * Return the id of a writer associated with a mesh.
 *
 * parameters:
 *   num_mesh                <--  number of the given mesh
 *   num_writer              <--  number of the associated writer
 *----------------------------------------------------------------------------*/

static int
_output_associate_mesh_writer(int  num_mesh,
                              int  num_writer)
{
  char *path = NULL;
  char *id = NULL;
  int description;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, "mesh"  , num_mesh);
  cs_xpath_add_element_num(&path, "writer", num_writer);
  cs_xpath_add_attribute(&path, "id");

  id = cs_gui_get_attribute_value(path);
  description = atoi(id);

  BFT_FREE(path);
  BFT_FREE(id);
  return description;
}

/*----------------------------------------------------------------------------
 * Return a choice for a mesh or a writer call by a number.
 *
 * parameters:
 *   type                <--   'writer' or 'mesh'
 *   choice              <--   the option needed
 *   num                 <--   the number of the mesh or writer
 *----------------------------------------------------------------------------*/

static char *
_output_type_choice(const char  *type,
                    const char  *choice,
                    int          num)
{
  char *path = NULL;
  char *description = NULL;

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, type, num);
  cs_xpath_add_attribute(&path, choice);
  description = cs_gui_get_attribute_value(path);

  BFT_FREE(path);
  return description;
}

/*-----------------------------------------------------------------------------
 * Initialize mei tree and check for symbols existence.
 *
 * parameters:
 *   formula        <--  mei formula
 *   symbols        <--  array of symbol to check
 *   symbol_size    -->  number of symbol in symbols
 *----------------------------------------------------------------------------*/

static mei_tree_t *
_init_mei_tree(const int        num,
               const cs_int_t  *ntcabs,
               const cs_real_t *ttcabs)
{
  char *path = NULL;
  char *formula = NULL;

  /* return an empty interpreter */

  path = cs_xpath_init_path();
  cs_xpath_add_elements(&path, 2, "analysis_control", "output");
  cs_xpath_add_element_num(&path, "writer", num);
  cs_xpath_add_element(&path, "frequency");
  cs_xpath_add_function_text(&path);
  formula = cs_gui_get_text_value(path);
  mei_tree_t *tree = mei_tree_new(formula);

  /* add commun variables */
  mei_tree_insert(tree, "niter", *ntcabs );
  mei_tree_insert(tree, "t", *ttcabs);

  /* try to build the interpreter */
  if (mei_tree_builder(tree))
    bft_error(__FILE__, __LINE__, 0,
              _("Error: can not interpret expression: %s\n"), tree->string);
  /* check for symbols */
  if (mei_tree_find_symbol(tree, "iactive"))
    bft_error(__FILE__, __LINE__, 0,
              _("Error: can not find the required symbol: %s\n"), "iactive");

  return tree;
}

/*! (DOXYGEN_SHOULD_SKIP_THIS) \endcond */

/*============================================================================
 * Public Fortran function definitions
 *============================================================================*/

/*----------------------------------------------------------------------------
 * activation of a writer depending of a formula
 *
 * Fortran Interface:
 *
 * subroutine uinpst (ttcabs, ntcabs)
 * *****************
 *
 * integer         uref   -->   reference velocity
 * double          almax  -->   reference length
 *----------------------------------------------------------------------------*/

void CS_PROCF (uinpst, UINPST) (const cs_int_t  *ntcabs,
                                const cs_real_t *ttcabs)
{
  int i, id, nwriter;
  int iactive;
  char *frequency_choice;
  char *id_s;
  mei_tree_t *ev_formula  = NULL;
  nwriter = cs_gui_get_tag_count("/analysis_control/output/writer", 1);
  for (i = 1; i <= nwriter; i++) {
    id = 0;
    id_s = _output_type_choice("writer","id",i);
    if (id_s != NULL) {
      id = atoi(id_s);
      BFT_FREE(id_s);
    }
    frequency_choice = _output_type_options("writer", "period", "frequency", i);
    if (cs_gui_strcmp(frequency_choice, "formula")) {
      ev_formula = _init_mei_tree(i, ntcabs, ttcabs);
      mei_evaluate(ev_formula);
      iactive =  mei_tree_lookup(ev_formula, "iactive");
      mei_tree_destroy(ev_formula);
      if (iactive == 1)
        cs_post_activate_writer(id, true);
      else
        cs_post_activate_writer(id, false);
    }
    BFT_FREE(frequency_choice);
  }
}

/*----------------------------------------------------------------------------
 * Determine output boundary fields
 *----------------------------------------------------------------------------*/

void CS_PROCF (cspstb, CSPSTB) (cs_int_t        *ipstdv)
{
  if (!cs_gui_file_is_loaded())
    return;

  /* Surfacic variables output */

  for (int i = 0; i < 5; i++)
    ipstdv[i] = 0;

  if (_surfacic_variable_post("stress", true))
    ipstdv[0] += 1;
  if (_surfacic_variable_post("stress_tangential", false))
    ipstdv[0] += 2;
  if (_surfacic_variable_post("stress_normal", false))
    ipstdv[0] += 4;

  if (_surfacic_variable_post("yplus", true))
    ipstdv[1] = 1;
  if (_surfacic_variable_post("tplus", true))
    ipstdv[2] = 1;
  if (_surfacic_variable_post("thermal_flux", true))
    ipstdv[3] = 1;
  if (_surfacic_variable_post("boundary_temperature", true)) {
    cs_field_t *bf = cs_parameters_add_boundary_temperature();
    if (bf != NULL) {
      int k_vis = cs_field_key_id("post_vis");
      cs_field_set_key_int(bf, k_vis, 1);
    }
  }

  if (_surfacic_variable_post("boundary_layer_nusselt", true))
    ipstdv[4] = 1;
}

/*----------------------------------------------------------------------------
 * Determine output options.
 *----------------------------------------------------------------------------*/

void CS_PROCF (csenso, CSENSO) (const cs_int_t  *nvppmx,
                                cs_int_t        *ncapt,
                                cs_int_t        *nthist,
                                cs_real_t       *frhist,
                                cs_int_t        *ntlist,
                                cs_int_t        *iecaux,
                                cs_int_t        *ihisvr,
                                cs_int_t        *tplfmt,
                                cs_real_t       *xyzcap)
{
  int i;
  int ipp;
  int *ippfld;
  char fmtprb[16];

  if (!cs_gui_file_is_loaded())
    return;

  {
    int n_fields = cs_field_n_fields();
    int ipp_max = 1;
    const int k_pp = cs_field_key_id("post_id");
    for (int f_id = 0; f_id < n_fields; f_id++) {
      const cs_field_t *f = cs_field_by_id(f_id);
      int ipp1 = cs_field_get_key_int(f, k_pp);
      int ipp2 = ipp1 + f->dim - 1;
      ipp_max = CS_MAX(ipp_max, ipp2);
    }
    BFT_MALLOC(ippfld, ipp_max, int);
    for (ipp = 0; ipp < ipp_max; ipp++)
      ippfld[ipp] = -1;
    for (int f_id = 0; f_id < n_fields; f_id++) {
      const cs_field_t *f = cs_field_by_id(f_id);
      ipp = cs_field_get_key_int(f, k_pp);
      if (ipp > 1)
        ippfld[ipp - 1] = f_id;
    }
  }

  _output_value("auxiliary_restart_file_writing", iecaux);
  _output_value("listing_printing_frequency", ntlist);
  _output_value("probe_recording_frequency", nthist);
  _output_time_value("probe_recording_frequency_time", frhist);

  _output_choice("probe_format", fmtprb, sizeof(fmtprb) - 1);

  /* Time plot (probe) format */
  if (!strcmp(fmtprb, "DAT"))
    *tplfmt = 1;
  else if (!strcmp(fmtprb, "CSV"))
    *tplfmt = 2;

  *ncapt = cs_gui_get_tag_count("/analysis_control/output/probe", 1);
  for (i = 0; i < *ncapt; i++) {
    xyzcap[0 + i*3] = _probe_coordinate(i+1, "probe_x");
    xyzcap[1 + i*3] = _probe_coordinate(i+1, "probe_y");
    xyzcap[2 + i*3] = _probe_coordinate(i+1, "probe_z");
  }

  const int n_fields = cs_field_n_fields();

  /* temporary field -> moment ids */
  int *moment_id = NULL;
  const int n_moments = cs_time_moment_n_moments();
  if (n_moments > 0) {
    BFT_MALLOC(moment_id, n_fields, int);
    for (int f_id = 0; f_id < n_fields; f_id++)
      moment_id[f_id] = -1;
    for (int m_id = 0; m_id < n_moments; m_id++) {
      const cs_field_t *f = cs_time_moment_get_field(m_id);
      if (f != NULL)
        moment_id[f->id] = m_id;
    }
  }

  /* variable output */
  for (int f_id = 0; f_id < n_fields; f_id++) {
    const cs_field_t  *f = cs_field_by_id(f_id);
    if (f->type & CS_FIELD_VARIABLE)
      _variable_post(f->id, ihisvr, nvppmx);
    else if (f->type & CS_FIELD_PROPERTY)
      _property_post(f->id, ihisvr, nvppmx);
    else if (moment_id != NULL) {
      if (moment_id[f_id] > -1)
        _time_moment_post(f->id, moment_id[f_id], ihisvr, nvppmx);
    }
  }

  BFT_FREE(moment_id);

#if _XML_DEBUG_
  bft_printf("==>CSENSO\n");
  bft_printf("--iecaux = %i\n", *iecaux);
  bft_printf("--ntlist = %i\n", *ntlist);
  bft_printf("--nthist = %i\n", *nthist);
  bft_printf("--frhist = %f\n", *frhist);
  bft_printf("--ncapt  = %i\n", *ncapt);
  bft_printf("--tplfmt = %i\n", *tplfmt);
  for (i=0; i < *ncapt; i++) {
    bft_printf("--xyzcap[%i][0] = %f\n", i, xyzcap[0 +i*3]);
    bft_printf("--xyzcap[%i][1] = %f\n", i, xyzcap[1 +i*3]);
    bft_printf("--xyzcap[%i][2] = %f\n", i, xyzcap[2 +i*3]);
  }
  const int k_post = cs_field_key_id("post_id");
  for (int f_id = 0; f_id < cs_field_n_fields(); f_id++) {
    const cs_field_t *f = cs_field_by_id(f_id);
    const int ipp = cs_field_get_key_int(f, k_post);
    bft_printf("-->variable post_id[%i] = %s\n", ipp, f->name);
    bft_printf("--ihisvr[0][%i]= %i \n", ipp, ihisvr[0 + (ipp-1)]);
    if (ihisvr[0 + (ipp-1)]>0)
      for (j=0; j<ihisvr[0 + (ipp-1)]; j++)
        bft_printf("--ihisvr[%i][%i]= %i \n", j+1, ipp,
                   ihisvr[(j+1)*(*nvppmx) + (ipp-1)]);
  }
#endif

  BFT_FREE(ippfld);
}

/*============================================================================
 * Public function definitions
 *============================================================================*/

/*----------------------------------------------------------------------------
 * Define postprocessing meshes using an XML file.
 *----------------------------------------------------------------------------*/

void
cs_gui_postprocess_meshes(void)
{
  int i, j, id, id_writer;
  char *id_s = NULL;
  char *label = NULL;
  char *all_variables = NULL;
  bool auto_vars = true;
  bool add_groups = true;
  char *location = NULL;
  int n_writers, nmesh;
  char *type = NULL;
  char *path = NULL;
  int *writer_ids = NULL;

  if (!cs_gui_file_is_loaded())
    return;

  nmesh = cs_gui_get_tag_count("/analysis_control/output/mesh", 1);

  for (i = 1; i <= nmesh; i++) {
    id_s = _output_type_choice("mesh","id",i);
    id = atoi(id_s);
    label = _output_type_choice("mesh","label",i);
    all_variables = _output_type_options("mesh", "status", "all_variables", i);
    if (cs_gui_strcmp(all_variables,"on"))
      auto_vars = true;
    else if (cs_gui_strcmp(all_variables, "off"))
      auto_vars = false;
    location = _output_mesh_location(i);
    type = _output_type_choice("mesh","type",i);
    path = cs_xpath_init_path();
    cs_xpath_add_elements(&path, 2, "analysis_control", "output");
    cs_xpath_add_element_num(&path, "mesh", i);
    cs_xpath_add_element(&path, "writer");
    n_writers = cs_gui_get_nb_element(path);
    BFT_MALLOC(writer_ids, n_writers, int);
    for (j = 0; j <= n_writers-1; j++) {
      id_writer = _output_associate_mesh_writer(i,j+1);
      writer_ids[j] = id_writer;
    }
    if (cs_gui_strcmp(type, "cells")) {
      cs_post_define_volume_mesh(id, label, location, add_groups, auto_vars,
                                 n_writers, writer_ids);
    } else if(cs_gui_strcmp(type, "interior_faces")) {
      cs_post_define_surface_mesh(id, label, location, NULL,
                                  add_groups, auto_vars,
                                  n_writers, writer_ids);
    } else if(cs_gui_strcmp(type, "boundary_faces")) {
      cs_post_define_surface_mesh(id, label, NULL, location,
                                  add_groups, auto_vars,
                                  n_writers, writer_ids);
    } else if(cs_gui_strcmp(type, "boundary_faces")) {
      cs_post_define_surface_mesh(id, label, NULL, location,
                                  add_groups, auto_vars,
                                  n_writers, writer_ids);
    } else if(   cs_gui_strcmp(type, "particles")
              || cs_gui_strcmp(type, "trajectories")) {
      bool trajectory = cs_gui_strcmp(type, "trajectories") ? true : false;
      double density = _output_particle_density(i);
      cs_post_define_particles_mesh(id, label, location,
                                    density, trajectory, auto_vars,
                                    n_writers, writer_ids);
    }

    BFT_FREE(writer_ids);
    BFT_FREE(id_s);
    BFT_FREE(label);
    BFT_FREE(all_variables);
    BFT_FREE(location);
    BFT_FREE(type);
    BFT_FREE(path);
  }
}

/*----------------------------------------------------------------------------
 * Define postprocessing writers using an XML file.
 *----------------------------------------------------------------------------*/

void
cs_gui_postprocess_writers(void)
{
  int i;
  char *label = NULL;
  char *directory = NULL;
  char *format_name = NULL;
  char *format_options = NULL;
  char *time_dependency = NULL;
  char *frequency_choice = NULL;
  char *output_end_s = NULL;
  char *id_s = NULL;

  int n_writers = 0;

  if (!cs_gui_file_is_loaded())
    return;

  n_writers = cs_gui_get_tag_count("/analysis_control/output/writer", 1);

  for (i = 1; i <= n_writers; i++) {

    int id = 0;
    fvm_writer_time_dep_t  time_dep = FVM_WRITER_FIXED_MESH;
    bool output_at_end = true;
    cs_int_t time_step = -1;
    cs_real_t time_value = -1.0;

    id_s = _output_type_choice("writer", "id", i);
    id = atoi(id_s);
    label = _output_type_choice("writer", "label", i);
    directory = _output_type_options("writer", "name", "directory", i);
    frequency_choice = _output_type_options("writer", "period", "frequency", i);
    output_end_s = _output_type_options("writer", "status", "output_at_end", i);
    if (cs_gui_strcmp(frequency_choice, "none")) {
      time_step = -1;
      time_value = -1.;
    } else if (cs_gui_strcmp(frequency_choice, "time_step")) {
      time_step = (int)_output_writer_frequency(i);
      time_value = -1.;
    } else if (cs_gui_strcmp(frequency_choice, "time_value")) {
      time_step = -1;
      time_value = _output_writer_frequency(i);
    } else if (cs_gui_strcmp(frequency_choice, "formula")) {
      time_step = -1;
      time_value = -1.;
    }
    if (cs_gui_strcmp(output_end_s, "off"))
      output_at_end = false;
    format_name = _output_type_options("writer", "name", "format",i);
    format_options = _output_type_options("writer", "options", "format", i);
    time_dependency
      = _output_type_options("writer", "choice", "time_dependency", i);
    if (cs_gui_strcmp(time_dependency, "fixed_mesh"))
      time_dep = FVM_WRITER_FIXED_MESH;
    else if(cs_gui_strcmp(time_dependency, "transient_coordinates"))
      time_dep = FVM_WRITER_TRANSIENT_COORDS;
    else if(cs_gui_strcmp(time_dependency, "transient_connectivity"))
      time_dep = FVM_WRITER_TRANSIENT_CONNECT;
    cs_post_define_writer(id,
                          label,
                          directory,
                          format_name,
                          format_options,
                          time_dep,
                          output_at_end,
                          time_step,
                          time_value);
    BFT_FREE(id_s);
    BFT_FREE(label);
    BFT_FREE(format_name);
    BFT_FREE(format_options);
    BFT_FREE(time_dependency);
    BFT_FREE(output_end_s);
    BFT_FREE(frequency_choice);
    BFT_FREE(directory);
  }
}

/*-----------------------------------------------------------------------------
 * Post-processing options for fields
 *
 * These options are used for fields not mapped to variables or properties.
 *----------------------------------------------------------------------------*/

void
cs_gui_postprocess_fields(void)
{
  if (!cs_gui_file_is_loaded())
    return;
}

/*----------------------------------------------------------------------------*/

END_C_DECLS
