/* Routines for handling XML generic OS data provided by target.

   Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "target.h"
#include "vec.h"
#include "xml-support.h"
#include "osdata.h"
#include "gdb_string.h"
#include "ui-out.h"
#include "gdbcmd.h"

#if !defined(HAVE_LIBEXPAT)

struct osdata *
osdata_parse (const char *xml)
{
  static int have_warned;

  if (!have_warned)
    {
      have_warned = 1;
      warning (_("Can not parse XML OS data; XML support was disabled "
                "at compile time"));
    }

  return NULL;
}

#else /* HAVE_LIBEXPAT */

#include "xml-support.h"

/* Internal parsing data passed to all XML callbacks.  */
struct osdata_parsing_data
  {
    struct osdata *osdata;
    char *property_name;
  };

/* Handle the start of a <osdata> element.  */

static void
osdata_start_osdata (struct gdb_xml_parser *parser,
                        const struct gdb_xml_element *element,
                        void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct osdata_parsing_data *data = user_data;
  char *type;
  struct osdata *osdata;

  if (data->osdata)
    gdb_xml_error (parser, _("Seen more than on osdata element"));

  type = VEC_index (gdb_xml_value_s, attributes, 0)->value;
  osdata = XZALLOC (struct osdata);
  osdata->type = xstrdup (type);
  data->osdata = osdata;
}

/* Handle the start of a <item> element.  */

static void
osdata_start_item (struct gdb_xml_parser *parser,
                  const struct gdb_xml_element *element,
                  void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct osdata_parsing_data *data = user_data;
  struct osdata_item item = { NULL };

  VEC_safe_push (osdata_item_s, data->osdata->items, &item);
}

/* Handle the start of a <column> element.  */

static void
osdata_start_column (struct gdb_xml_parser *parser,
                    const struct gdb_xml_element *element,
                    void *user_data, VEC(gdb_xml_value_s) *attributes)
{
  struct osdata_parsing_data *data = user_data;
  const char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;

  data->property_name = xstrdup (name);
}

/* Handle the end of a <column> element.  */

static void
osdata_end_column (struct gdb_xml_parser *parser,
                  const struct gdb_xml_element *element,
                  void *user_data, const char *body_text)
{
  struct osdata_parsing_data *data = user_data;
  struct osdata *osdata = data->osdata;
  struct osdata_item *item = VEC_last (osdata_item_s, osdata->items);
  struct osdata_column *col = VEC_safe_push (osdata_column_s,
                                            item->columns, NULL);

  /* Transfer memory ownership.  NAME was already strdup'ed.  */
  col->name = data->property_name;
  col->value = xstrdup (body_text);
  data->property_name = NULL;
}

/* Discard the constructed osdata (if an error occurs).  */

static void
clear_parsing_data (void *p)
{
  struct osdata_parsing_data *data = p;

  osdata_free (data->osdata);
  data->osdata = NULL;
  xfree (data->property_name);
  data->property_name = NULL;
}

/* The allowed elements and attributes for OS data object.
   The root element is a <osdata>.  */

const struct gdb_xml_attribute column_attributes[] = {
  { "name", GDB_XML_AF_NONE, NULL, NULL },
  { NULL, GDB_XML_AF_NONE, NULL, NULL }
};

const struct gdb_xml_element item_children[] = {
  { "column", column_attributes, NULL,
    GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
    osdata_start_column, osdata_end_column },
  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};

const struct gdb_xml_attribute osdata_attributes[] = {
  { "type", GDB_XML_AF_NONE, NULL, NULL },
  { NULL, GDB_XML_AF_NONE, NULL, NULL }
};

const struct gdb_xml_element osdata_children[] = {
  { "item", NULL, item_children,
    GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
    osdata_start_item, NULL },
  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};

const struct gdb_xml_element osdata_elements[] = {
  { "osdata", osdata_attributes, osdata_children,
    GDB_XML_EF_NONE, osdata_start_osdata, NULL },
  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};

struct osdata *
osdata_parse (const char *xml)
{
  struct gdb_xml_parser *parser;
  struct cleanup *before_deleting_result, *back_to;
  struct osdata_parsing_data data = { NULL };

  back_to = make_cleanup (null_cleanup, NULL);
  parser = gdb_xml_create_parser_and_cleanup (_("osdata"),
                                             osdata_elements, &data);
  gdb_xml_use_dtd (parser, "osdata.dtd");

  before_deleting_result = make_cleanup (clear_parsing_data, &data);

  if (gdb_xml_parse (parser, xml) == 0)
    /* Parsed successfully, don't need to delete the result.  */
    discard_cleanups (before_deleting_result);

  do_cleanups (back_to);
  return data.osdata;
}
#endif

static void
osdata_item_clear (struct osdata_item *item)
{
  if (item->columns != NULL)
    {
      struct osdata_column *col;
      int ix;

      for (ix = 0;
	   VEC_iterate (osdata_column_s, item->columns,
			ix, col);
	   ix++)
       {
	 xfree (col->name);
	 xfree (col->value);
       }
      VEC_free (osdata_column_s, item->columns);
      item->columns = NULL;
    }
}

void
osdata_free (struct osdata *osdata)
{
  if (osdata == NULL)
    return;

  if (osdata->items != NULL)
    {
      struct osdata_item *item;
      int ix;

      for (ix = 0;
          VEC_iterate (osdata_item_s, osdata->items,
                       ix, item);
          ix++)
       osdata_item_clear (item);
      VEC_free (osdata_item_s, osdata->items);
    }

  xfree (osdata);
}

static void
osdata_free_cleanup (void *arg)
{
  struct osdata *osdata = arg;

  osdata_free (osdata);
}

struct cleanup *
make_cleanup_osdata_free (struct osdata *data)
{
  return make_cleanup (osdata_free_cleanup, data);
}

struct osdata *
get_osdata (const char *type)
{
  struct osdata *osdata = NULL;
  char *xml = target_get_osdata (type);

  if (xml)
    {
      struct cleanup *old_chain = make_cleanup (xfree, xml);

      if (xml[0] == '\0')
	{
	  if (type)
	    warning (_("Empty data returned by target.  Wrong osdata type?"));
	  else
	    warning (_("Empty type list returned by target.  No type data?"));
	}
      else
	osdata = osdata_parse (xml);

      do_cleanups (old_chain);
    }

  if (!osdata)
    error (_("Can not fetch data now.\n"));

  return osdata;
}

const char *
get_osdata_column (struct osdata_item *item, const char *name)
{
  struct osdata_column *col;
  int ix_cols; 
  
  for (ix_cols = 0;
       VEC_iterate (osdata_column_s, item->columns,
		    ix_cols, col);
       ix_cols++)
    if (strcmp (col->name, name) == 0)
      return col->value;

  return NULL;
}

static void
info_osdata_command (char *type, int from_tty)
{
  struct osdata *osdata = NULL;
  struct osdata_item *last;
  struct cleanup *old_chain;
  int ncols;
  int nprocs;

  osdata = get_osdata (type);
  old_chain = make_cleanup_osdata_free (osdata);

  nprocs = VEC_length (osdata_item_s, osdata->items);

  if (!type && nprocs == 0)
    error (_("Available types of OS data not reported."));

  last = VEC_last (osdata_item_s, osdata->items);
  if (last && last->columns)
    ncols = VEC_length (osdata_column_s, last->columns);
  else
    ncols = 0;

  make_cleanup_ui_out_table_begin_end (uiout, ncols, nprocs,
				       "OSDataTable");

  if (last && last->columns)
    {
      struct osdata_column *col;
      int ix;

      for (ix = 0;
          VEC_iterate (osdata_column_s, last->columns,
                       ix, col);
          ix++)
       ui_out_table_header (uiout, 10, ui_left,
                            col->name, col->name);
    }

  ui_out_table_body (uiout);

  if (nprocs != 0)
    {
      struct osdata_item *item;
      int ix_items;

      for (ix_items = 0;
          VEC_iterate (osdata_item_s, osdata->items,
                       ix_items, item);
          ix_items++)
       {
         struct cleanup *old_chain;
         struct ui_stream *stb;
         int ix_cols;
         struct osdata_column *col;

         stb = ui_out_stream_new (uiout);
         old_chain = make_cleanup_ui_out_stream_delete (stb);
         make_cleanup_ui_out_tuple_begin_end (uiout, "item");

         for (ix_cols = 0;
              VEC_iterate (osdata_column_s, item->columns,
                           ix_cols, col);
              ix_cols++)
           ui_out_field_string (uiout, col->name, col->value);

         do_cleanups (old_chain);

         ui_out_text (uiout, "\n");
       }
    }

  do_cleanups (old_chain);
}

extern initialize_file_ftype _initialize_osdata; /* -Wmissing-prototypes */

void
_initialize_osdata (void)
{
  add_info ("os", info_osdata_command,
           _("Show OS data ARG."));
}