/*
 * uplink.C: Uplink management.
 * Rights to this code are documented in doc/pod/license.pod.
 *
 * Copyright © 2005-2007 Atheme Project (http://www.atheme.org)
 */

static char const rcsid[] = "$Id";

#include "atheme.h"
#include "datastream.h"
#include "uplink.h"

list_t uplinks;
uplink_t *curr_uplink;

static BlockHeap *uplink_heap;

static void uplink_close (connection_t *cptr);

void
init_uplinks (void)
{
  uplink_heap = BlockHeapCreate (sizeof (uplink_t), 4);
  if (!uplink_heap)
    {
      slog (LG_INFO, "init_uplinks(): block allocator failed.");
      exit (EXIT_FAILURE);
    }
}

uplink_t *
uplink_add (char *name, char *host, char *password, char *vhost, int port)
{
  uplink_t *u;
  node_t *n;

  slog (LG_DEBUG, "uplink_add(): %s -> %s:%d", me.name, name, port);

  if ((u = uplink_find (name)))
    {
      if (u->flags & UPF_ILLEGAL)
	{
	  u->flags &= ~UPF_ILLEGAL;
	  free (u->name);
	  free (u->host);
	  free (u->pass);
	  free (u->vhost);
	}
      else
	{
	  slog (LG_INFO, "Duplicate uplink %s.", name);
	  return NULL;
	}
    }
  else
    {
      u = static_cast<uplink_t *> (BlockHeapAlloc (uplink_heap));
      n = node_create ();
      u->node = n;
      node_add (u, n, &uplinks);
      cnt.uplink++;
    }

  u->name = sstrdup (name);
  u->host = sstrdup (host);
  u->pass = sstrdup (password);
  if (vhost)
    u->vhost = sstrdup (vhost);
  else
    u->vhost = sstrdup ("0.0.0.0");
  u->port = port;

  return u;
}

void
uplink_delete (uplink_t *u)
{
  node_t *n = node_find (u, &uplinks);

  free (u->name);
  free (u->host);
  free (u->pass);
  free (u->vhost);

  node_del (n, &uplinks);
  node_free (n);

  BlockHeapFree (uplink_heap, u);
  cnt.uplink--;
}

uplink_t *
uplink_find (char *name)
{
  node_t *n;

  LIST_FOREACH (n, uplinks.head)
  {
    uplink_t *u = static_cast<uplink_t *> (n->data);

    if (!strcasecmp (u->name, name))
      return u;
  }

  return NULL;
}

void
uplink_connect (void)
{
  uplink_t *u;

  if (curr_uplink == NULL)
    {
      if (uplinks.head == NULL)
	{
	  slog (LG_ERROR, "uplink_connect(): no uplinks configured, exiting. Make sure to have at least one uplink{} block in your configuration file.");
	  exit (EXIT_FAILURE);
	}
      curr_uplink = static_cast<uplink_t *> (uplinks.head->data);
      slog (LG_INFO, "uplink_connect(): connecting to first entry %s[%s]:%d.", curr_uplink->name, curr_uplink->host, curr_uplink->port);
    }
  else if (curr_uplink->node->next)
    {
      u = static_cast<uplink_t *> (curr_uplink->node->next->data);

      curr_uplink = u;
      slog (LG_INFO, "uplink_connect(): trying alternate uplink %s[%s]:%d", curr_uplink->name, curr_uplink->host, curr_uplink->port);
    }
  else
    {
      curr_uplink = static_cast<uplink_t *> (uplinks.head->data);
      slog (LG_INFO, "uplink_connect(): trying again first entry %s[%s]:%d", curr_uplink->name, curr_uplink->host, curr_uplink->port);
    }

  u = curr_uplink;

  curr_uplink->conn = connection_open_tcp (u->host, u->vhost, u->port, recvq_put, sendq_flush);
  if (curr_uplink->conn != NULL)
    curr_uplink->conn->close_handler = uplink_close;
  else
    event_add_once ("reconn", reconn, NULL, me.recontime);
}

/*
 * uplink_close()
 * 
 * inputs:
 *       connection pointer of current uplink
 *       triggered by callback close_handler
 *
 * outputs:
 *       none
 *
 * side effects:
 *       reconnection is scheduled
 *       uplink marked dead
 *       uplink deleted if it had been removed from configuration
 */
static void
uplink_close (connection_t *cptr)
{
  channel_t *c;
  dictionary_iteration_state_t state;

  event_add_once ("reconn", reconn, NULL, me.recontime);

  me.connected = false;

  if (curr_uplink->flags & UPF_ILLEGAL)
    {
      slog (LG_INFO, "uplink_close(): %s was removed from configuration, deleting", curr_uplink->name);
      uplink_delete (curr_uplink);
      if (uplinks.head == NULL)
	{
	  slog (LG_ERROR, "uplink_close(): last uplink deleted, exiting.");
	  exit (EXIT_FAILURE);
	}
      curr_uplink = static_cast<uplink_t *> (uplinks.head->data);
    }
  curr_uplink->conn = NULL;

  slog (LG_DEBUG, "uplink_close(): ----------------------- clearing -----------------------");

  /* we have to kill everything.
   * we do not clear users here because when you delete a server,
   * it deletes its users
   */
  if (me.actual != NULL)
    server_delete (me.actual);
  me.actual = NULL;
  /* remove all the channels left */
  DICTIONARY_FOREACH (c, channel_t, &state, chanlist)
  {
    channel_delete (c);
  }
  /* this leaves me.me and all users on it (i.e. services) */

  slog (LG_DEBUG, "uplink_close(): ------------------------- done -------------------------");
}