/**
 * graphtastical.C: Create a .dot file from Ermyth's database.
 *
 * Copyright © 2007 Pippijn van Steenhoven / The Ermyth Team
 * Rights to this code are as documented in COPYING.
 *
 * Creates a .dot file for use with neato which displays
 * user->channel relationships.
 *
 * == How to generate the graphs and How It Works ==
 * Graphtastical creates a .dot file for graphviz's neato
 * filter to use. The DOT language describes a graph's
 * structure to graphviz in an opaque way.
 *
 * Because Graphviz nodes use unique identifiers for
 * interconnection, the channels.dot file contains also
 * information about social networks.
 *
 * Eventually Graphtastical will dump other graph datafiles
 * too.
 *
 * To make a file from the data dumped by Graphtastical,
 * the following commands will do:
 *
 * $ cat channels.dot | neato -Tgif -o map-channels.gif
 * $ cat channels.dot | neato -Tsvg -o map-channels.svg
 *
 * Some maps (for larger networks) are going to be large,
 * so you may want to provide links to both the GIF and
 * SVG files as some people may only be able to make use of
 * one or the other. Why that is, I'm not sure, and I'm not
 * covering it here.
 *
 * == Privacy concerns ==
 * If you are running Graphtastical on a network that has
 * privacy concerns; you probably shouldn't.
 *
 *
 * Portions of this file were derived from sources bearing the following license:
 * Copyright © 2007 William Pitcock
 * Rights to this code are as documented in doc/pod/license.pod.
 *
 * $Id: graphtastical.C,v 1.7 2007/09/22 14:27:27 pippijn Exp $
 */

#include <boost/foreach.hpp>

#include "atheme.h"
#include <ermyth/module.h>
#include <account/chanacs.h>
#include <account/mychan.h>
#include <account/myuser.h>
#include <account/kline.h>
#include <account/svsignore.h>

static char const rcsid[] = "$Id: graphtastical.C,v 1.7 2007/09/22 14:27:27 pippijn Exp $";

REGISTER_MODULE ("contrib/graphtastical", true, "The Ermyth Team <http://ermyth.xinutec.org>");

/* write channels.dot */
static void
write_channels_dot_file (void *arg)
{
//  myuser_t *mu;
  mychan_t *mc;
  chanacs_t *ca;
//  kline_t *k;
//  svsignore_t *svsignore;
//  soper_t *soper;
  node_t *n;//, *tn, *tn2;
  FILE *f;
  int errno1, was_errored = 0;
  int root = 1;
  mychan_t *pmc;

  errno = 0;

  /* write to a temporary file first */
  if (!(f = fopen (DATADIR "/channels.dot.new", "w")))
    {
      errno1 = errno;
      slog (LG_ERROR, "graphtastical: cannot create channels.dot.new: %s", strerror (errno1));
      return;
    }

  fprintf (f, "graph channels {\n");
  fprintf (f, "edge [color=blue len=7.5 fontsize=10]\n");
  fprintf (f, "node [fontsize=10]\n");

  slog (LG_DEBUG, "graphtastical: dumping mychans");

  foreach (mychan_t::pair_type &mp, mychan_t::map)
    {
      mc = mp.second;
      fprintf (f, "\"%s\"", mc->name);
      
      if (!root)
        fprintf (f, "-- \"%s\"", pmc->name);

      pmc = mc;
      
      fprintf (f, "[fontsize=10]\n");
      
      LIST_FOREACH (n, mc->chanacs.head)
      {
        ca = (chanacs_t *) n->data;
        
        if (ca->level & CA_AKICK)
          continue;
        
        fprintf (f, "\"%s\" -- \"%s\" [fontsize=10]\n", ca->myuser ? ca->myuser->name : ca->host, mc->name);
      }
    }
  
  fprintf (f, "}\n");
  
  was_errored = ferror (f);
  was_errored |= fclose (f);
  if (was_errored)
    {
      errno1 = errno;
      slog (LG_ERROR, "graphtastical: cannot write to channels.dot.new: %s", strerror (errno1));
      return;
    }
  
  /* now, replace the old database with the new one, using an atomic rename */
  unlink (DATADIR "/channels.dot");

  if ((rename (DATADIR "/channels.dot.new", DATADIR "/channels.dot")) < 0)
    {
      errno1 = errno;
      slog (LG_ERROR, "graphtastical: cannot rename channels.dot.new to channels.dot: %s", strerror (errno1));
      return;
    }
}

bool
_modinit (module *m)
{
  write_channels_dot_file (NULL);

  event_add ("write_channels_dot_file", write_channels_dot_file, NULL, 60);

  return true;
}

void
_moddeinit (void)
{
  event_delete (write_channels_dot_file, NULL);
}

/* vim:cinoptions=>s,e0,n0,f0,{0,}0,^0,=s,ps,t0,c3,+s,(2s,us,)20,*30,gs,hs
 * vim:ts=8
 * vim:sw=8
 * vim:noexpandtab
 */