/* GDBus - GLib D-Bus Library
 *
 * Copyright (C) 2008-2009 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General
 * Public License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Author: David Zeuthen <davidz@redhat.com>
 */

#include "config.h"

#include <stdlib.h>
#include <string.h>

#include "gdbusutils.h"

#include "glibintl.h"

/**
 * SECTION:gdbusutils
 * @title: D-Bus Utilities
 * @short_description: Various utilities related to D-Bus.
 * @include: gio/gio.h
 *
 * Various utility routines related to D-Bus.
 */

static gboolean
is_valid_bus_name_character (gint c,
                             gboolean allow_hyphen)
{
  return
    (c >= '0' && c <= '9') ||
    (c >= 'A' && c <= 'Z') ||
    (c >= 'a' && c <= 'z') ||
    (c == '_') ||
    (allow_hyphen && c == '-');
}

static gboolean
is_valid_initial_bus_name_character (gint c,
                                     gboolean allow_initial_digit,
                                     gboolean allow_hyphen)
{
  if (allow_initial_digit)
    return is_valid_bus_name_character (c, allow_hyphen);
  else
    return
      (c >= 'A' && c <= 'Z') ||
      (c >= 'a' && c <= 'z') ||
      (c == '_') ||
      (allow_hyphen && c == '-');
}

static gboolean
is_valid_name (const gchar *start,
               guint len,
               gboolean allow_initial_digit,
               gboolean allow_hyphen)
{
  gboolean ret;
  const gchar *s;
  const gchar *end;
  gboolean has_dot;

  ret = FALSE;

  if (len == 0)
    goto out;

  s = start;
  end = s + len;
  has_dot = FALSE;
  while (s != end)
    {
      if (*s == '.')
        {
          s += 1;
          if (G_UNLIKELY (!is_valid_initial_bus_name_character (*s, allow_initial_digit, allow_hyphen)))
            goto out;
          has_dot = TRUE;
        }
      else if (G_UNLIKELY (!is_valid_bus_name_character (*s, allow_hyphen)))
        {
          goto out;
        }
      s += 1;
    }

  if (G_UNLIKELY (!has_dot))
    goto out;

  ret = TRUE;

 out:
  return ret;
}

/**
 * g_dbus_is_name:
 * @string: The string to check.
 *
 * Checks if @string is a valid D-Bus bus name (either unique or well-known).
 *
 * Returns: %TRUE if valid, %FALSE otherwise.
 *
 * Since: 2.26
 */
gboolean
g_dbus_is_name (const gchar *string)
{
  guint len;
  gboolean ret;
  const gchar *s;
  const gchar *end;

  g_return_val_if_fail (string != NULL, FALSE);

  ret = FALSE;

  len = strlen (string);
  if (G_UNLIKELY (len == 0 || len > 255))
    goto out;

  s = string;
  end = s + len;
  if (*s == ':')
    {
      /* handle unique name */
      if (!is_valid_name (s + 1, len - 1, TRUE, TRUE))
        goto out;
      ret = TRUE;
      goto out;
    }
  else if (G_UNLIKELY (*s == '.'))
    {
      /* can't start with a . */
      goto out;
    }
  else if (G_UNLIKELY (!is_valid_initial_bus_name_character (*s, FALSE, TRUE)))
    goto out;

  ret = is_valid_name (s + 1, len - 1, FALSE, TRUE);

 out:
  return ret;
}

/**
 * g_dbus_is_unique_name:
 * @string: The string to check.
 *
 * Checks if @string is a valid D-Bus unique bus name.
 *
 * Returns: %TRUE if valid, %FALSE otherwise.
 *
 * Since: 2.26
 */
gboolean
g_dbus_is_unique_name (const gchar *string)
{
  gboolean ret;
  guint len;

  g_return_val_if_fail (string != NULL, FALSE);

  ret = FALSE;

  len = strlen (string);
  if (G_UNLIKELY (len == 0 || len > 255))
    goto out;

  if (G_UNLIKELY (*string != ':'))
    goto out;

  if (G_UNLIKELY (!is_valid_name (string + 1, len - 1, TRUE, TRUE)))
    goto out;

  ret = TRUE;

 out:
  return ret;
}

/**
 * g_dbus_is_member_name:
 * @string: The string to check.
 *
 * Checks if @string is a valid D-Bus member (e.g. signal or method) name.
 *
 * Returns: %TRUE if valid, %FALSE otherwise.
 *
 * Since: 2.26
 */
gboolean
g_dbus_is_member_name (const gchar *string)
{
  gboolean ret;
  guint n;

  ret = FALSE;
  if (G_UNLIKELY (string == NULL))
    goto out;

  if (G_UNLIKELY (!is_valid_initial_bus_name_character (string[0], FALSE, FALSE)))
    goto out;

  for (n = 1; string[n] != '\0'; n++)
    {
      if (G_UNLIKELY (!is_valid_bus_name_character (string[n], FALSE)))
        {
          goto out;
        }
    }

  ret = TRUE;

 out:
  return ret;
}

/**
 * g_dbus_is_interface_name:
 * @string: The string to check.
 *
 * Checks if @string is a valid D-Bus interface name.
 *
 * Returns: %TRUE if valid, %FALSE otherwise.
 *
 * Since: 2.26
 */
gboolean
g_dbus_is_interface_name (const gchar *string)
{
  guint len;
  gboolean ret;
  const gchar *s;
  const gchar *end;

  g_return_val_if_fail (string != NULL, FALSE);

  ret = FALSE;

  len = strlen (string);
  if (G_UNLIKELY (len == 0 || len > 255))
    goto out;

  s = string;
  end = s + len;
  if (G_UNLIKELY (*s == '.'))
    {
      /* can't start with a . */
      goto out;
    }
  else if (G_UNLIKELY (!is_valid_initial_bus_name_character (*s, FALSE, FALSE)))
    goto out;

  ret = is_valid_name (s + 1, len - 1, FALSE, FALSE);

 out:
  return ret;
}

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

/* TODO: maybe move to glib? if so, it should conform to http://en.wikipedia.org/wiki/Guid and/or
 *       http://tools.ietf.org/html/rfc4122 - specifically it should have hyphens then.
 */

/**
 * g_dbus_generate_guid:
 *
 * Generate a D-Bus GUID that can be used with
 * e.g. g_dbus_connection_new().
 *
 * See the D-Bus specification regarding what strings are valid D-Bus
 * GUID (for example, D-Bus GUIDs are not RFC-4122 compliant).
 *
 * Returns: A valid D-Bus GUID. Free with g_free().
 *
 * Since: 2.26
 */
gchar *
g_dbus_generate_guid (void)
{
  GString *s;
  GTimeVal now;
  guint32 r1;
  guint32 r2;
  guint32 r3;

  s = g_string_new (NULL);

  r1 = g_random_int ();
  r2 = g_random_int ();
  r3 = g_random_int ();
  g_get_current_time (&now);

  g_string_append_printf (s, "%08x", r1);
  g_string_append_printf (s, "%08x", r2);
  g_string_append_printf (s, "%08x", r3);
  g_string_append_printf (s, "%08x", (guint32) now.tv_sec);

  return g_string_free (s, FALSE);
}

/**
 * g_dbus_is_guid:
 * @string: The string to check.
 *
 * Checks if @string is a D-Bus GUID.
 *
 * See the D-Bus specification regarding what strings are valid D-Bus
 * GUID (for example, D-Bus GUIDs are not RFC-4122 compliant).
 *
 * Returns: %TRUE if @string is a guid, %FALSE otherwise.
 *
 * Since: 2.26
 */
gboolean
g_dbus_is_guid (const gchar *string)
{
  gboolean ret;
  guint n;

  g_return_val_if_fail (string != NULL, FALSE);

  ret = FALSE;

  for (n = 0; n < 32; n++)
    {
      if (!g_ascii_isxdigit (string[n]))
        goto out;
    }
  if (string[32] != '\0')
    goto out;

  ret = TRUE;

 out:
  return ret;
}

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

/**
 * g_dbus_is_activated:
 *
 * Determine if the process has been activated by a message bus.
 *
 * Returns: %TRUE if this process has been started by a message bus, %FALSE otherwise.
 *
 * Since: 2.26
 */
gboolean
g_dbus_is_activated (void)
{
  /* TODO: technically this will make child processes forked by us
   * return TRUE too..
   */
  return g_getenv ("DBUS_STARTER_BUS_TYPE") != NULL;
}

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