/* GStreamer

 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

 *                    2005 Wim Taymans <wim@fluendo.com>

 *                    2005 Andy Wingo <wingo@pobox.com>

 *

 * gstnetclientclock.h: clock that synchronizes itself to a time provider over

 * the network

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library 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

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library 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.

 */

/**

 * SECTION:gstnetclientclock

 * @short_description: Special clock that synchronizes to a remote time

 *                     provider.

 * @see_also: #GstClock, #GstNetTimeProvider, #GstPipeline

 *

 * This object implements a custom #GstClock that synchronizes its time

 * to a remote time provider such as #GstNetTimeProvider.

 *

 * A new clock is created with gst_net_client_clock_new() which takes the

 * address and port of the remote time provider along with a name and

 * an initial time.

 *

 * This clock will poll the time provider and will update its calibration

 * parameters based on the local and remote observations.

 *

 * Various parameters of the clock can be configured with the parent #GstClock

 * "timeout", "window-size" and "window-threshold" object properties.

 *

 * A #GstNetClientClock is typically set on a #GstPipeline with 

 * gst_pipeline_use_clock().

 *

 * Last reviewed on 2005-11-23 (0.9.5)

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "gstnettimepacket.h"

#include "gstnetclientclock.h"

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#ifdef __SYMBIAN32__

#include <sys/select.h>

#include <glib_global.h>

#endif

#if defined (_MSC_VER) && _MSC_VER >= 1400

#include <io.h>

#endif

GST_DEBUG_CATEGORY_STATIC (ncc_debug);

#define GST_CAT_DEFAULT (ncc_debug)

#define DEFAULT_ADDRESS         "127.0.0.1"

#define DEFAULT_PORT            5637

#define DEFAULT_TIMEOUT         GST_SECOND

#ifdef G_OS_WIN32

#define getsockname(sock,addr,len) getsockname(sock,addr,(int *)len)

#endif

enum

{

  PROP_0,

  PROP_ADDRESS,

  PROP_PORT,

};

#define GST_NET_CLIENT_CLOCK_GET_PRIVATE(obj)  \

  (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_NET_CLIENT_CLOCK, GstNetClientClockPrivate))

struct _GstNetClientClockPrivate

{

  GstPollFD sock;

  GstPoll *fdset;

};

#define _do_init(type) \

  GST_DEBUG_CATEGORY_INIT (ncc_debug, "netclock", 0, "Network client clock");

GST_BOILERPLATE_FULL (GstNetClientClock, gst_net_client_clock,

    GstSystemClock, GST_TYPE_SYSTEM_CLOCK, _do_init);

static void gst_net_client_clock_finalize (GObject * object);

static void gst_net_client_clock_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec);

static void gst_net_client_clock_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec);

static void gst_net_client_clock_stop (GstNetClientClock * self);

#ifdef G_OS_WIN32

static int

inet_aton (const char *c, struct in_addr *paddr)

{

  /* note that inet_addr is deprecated on unix because

   * inet_addr returns -1 (INADDR_NONE) for the valid 255.255.255.255

   * address. */

  paddr->s_addr = inet_addr (c);

  if (paddr->s_addr == INADDR_NONE)

    return 0;

  return 1;

}

#endif

static void

gst_net_client_clock_base_init (gpointer g_class)

{

  /* nop */

}

static void

gst_net_client_clock_class_init (GstNetClientClockClass * klass)

{

  GObjectClass *gobject_class;

  gobject_class = G_OBJECT_CLASS (klass);

  g_type_class_add_private (klass, sizeof (GstNetClientClockPrivate));

  gobject_class->finalize = gst_net_client_clock_finalize;

  gobject_class->get_property = gst_net_client_clock_get_property;

  gobject_class->set_property = gst_net_client_clock_set_property;

  g_object_class_install_property (gobject_class, PROP_ADDRESS,

      g_param_spec_string ("address", "address",

          "The address of the machine providing a time server, "

  g_object_class_install_property (gobject_class, PROP_PORT,

      g_param_spec_int ("port", "port",

          "The port on which the remote server is listening", 0, G_MAXUINT16,

}

static void

gst_net_client_clock_init (GstNetClientClock * self,

    GstNetClientClockClass * g_class)

{

  GstClock *clock = GST_CLOCK_CAST (self);

#ifdef G_OS_WIN32

  WSADATA w;

  int error = WSAStartup (0x0202, &w);

  if (error) {

    GST_DEBUG_OBJECT (self, "Error on WSAStartup");

  }

  if (w.wVersion != 0x0202) {

    WSACleanup ();

  }

#endif

  self->priv = GST_NET_CLIENT_CLOCK_GET_PRIVATE (self);

  self->port = DEFAULT_PORT;

  self->address = g_strdup (DEFAULT_ADDRESS);

  clock->timeout = DEFAULT_TIMEOUT;

  self->priv->sock.fd = -1;

  self->thread = NULL;

  self->servaddr = NULL;

}

static void

gst_net_client_clock_finalize (GObject * object)

{

  GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);

  if (self->thread) {

    gst_net_client_clock_stop (self);

    g_assert (self->thread == NULL);

  }

  if (self->priv->fdset) {

    gst_poll_free (self->priv->fdset);

    self->priv->fdset = NULL;

  }

  g_free (self->address);

  self->address = NULL;

  g_free (self->servaddr);

  self->servaddr = NULL;

#ifdef G_OS_WIN32

  WSACleanup ();

#endif

  G_OBJECT_CLASS (parent_class)->finalize (object);

}

static void

gst_net_client_clock_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec)

{

  GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);

  switch (prop_id) {

    case PROP_ADDRESS:

      g_free (self->address);

      if (g_value_get_string (value) == NULL)

        self->address = g_strdup (DEFAULT_ADDRESS);

      else

        self->address = g_strdup (g_value_get_string (value));

      break;

    case PROP_PORT:

      self->port = g_value_get_int (value);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}

static void

gst_net_client_clock_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec)

{

  GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);

  switch (prop_id) {

    case PROP_ADDRESS:

      g_value_set_string (value, self->address);

      break;

    case PROP_PORT:

      g_value_set_int (value, self->port);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}

static void

gst_net_client_clock_observe_times (GstNetClientClock * self,

    GstClockTime local_1, GstClockTime remote, GstClockTime local_2)

{

  GstClockTime local_avg;

  gdouble r_squared;

  GstClock *clock;

  if (local_2 < local_1)

    goto bogus_observation;

  local_avg = (local_2 + local_1) / 2;

  clock = GST_CLOCK_CAST (self);

  gst_clock_add_observation (GST_CLOCK (self), local_avg, remote, &r_squared);

  GST_CLOCK_SLAVE_LOCK (self);

  if (clock->filling) {

    self->current_timeout = 0;

  } else {

    /* geto formula */

    self->current_timeout =

        (1e-3 / (1 - MIN (r_squared, 0.99999))) * GST_SECOND;

    self->current_timeout = MIN (self->current_timeout, clock->timeout);

  }

  GST_CLOCK_SLAVE_UNLOCK (clock);

  return;

bogus_observation:

  {

    GST_WARNING_OBJECT (self, "time packet receive time < send time (%"

        GST_TIME_FORMAT " < %" GST_TIME_FORMAT ")", GST_TIME_ARGS (local_1),

        GST_TIME_ARGS (local_2));

    return;

  }

}

static gint

gst_net_client_clock_do_select (GstNetClientClock * self)

{

  while (TRUE) {

    GstClockTime diff;

    gint ret;

    GST_LOG_OBJECT (self, "doing select");

    diff = gst_clock_get_internal_time (GST_CLOCK (self));

    ret = gst_poll_wait (self->priv->fdset, self->current_timeout);

    diff = gst_clock_get_internal_time (GST_CLOCK (self)) - diff;

    if (diff > self->current_timeout)

      self->current_timeout = 0;

    else

      self->current_timeout -= diff;

    GST_LOG_OBJECT (self, "select returned %d", ret);

    if (ret < 0 && errno != EBUSY) {

      if (errno != EAGAIN && errno != EINTR)

        goto select_error;

      else

        continue;

    } else {

      return ret;

    }

    g_assert_not_reached ();

    /* log errors and keep going */

  select_error:

    {

      GST_WARNING_OBJECT (self, "select error %d: %s (%d)", ret,

          g_strerror (errno), errno);

      continue;

    }

  }

  g_assert_not_reached ();

  return -1;

}

static gpointer

gst_net_client_clock_thread (gpointer data)

{

  GstNetClientClock *self = data;

  struct sockaddr_in tmpaddr;

  socklen_t len;

  GstNetTimePacket *packet;

  gint ret;

  GstClock *clock = data;

  while (TRUE) {

    ret = gst_net_client_clock_do_select (self);

    if (ret < 0 && errno == EBUSY) {

      GST_LOG_OBJECT (self, "stop");

      goto stopped;

    } else if (ret == 0) {

      /* timed out, let's send another packet */

      GST_DEBUG_OBJECT (self, "timed out");

      packet = gst_net_time_packet_new (NULL);

      packet->local_time = gst_clock_get_internal_time (GST_CLOCK (self));

      GST_DEBUG_OBJECT (self, "sending packet, local time = %" GST_TIME_FORMAT,

          GST_TIME_ARGS (packet->local_time));

      gst_net_time_packet_send (packet, self->priv->sock.fd,

          (struct sockaddr *) self->servaddr, sizeof (struct sockaddr_in));

      g_free (packet);

      /* reset timeout */

      self->current_timeout = clock->timeout;

      continue;

    } else if (gst_poll_fd_can_read (self->priv->fdset, &self->priv->sock)) {

      /* got data in */

      GstClockTime new_local = gst_clock_get_internal_time (GST_CLOCK (self));

      len = sizeof (struct sockaddr);

      packet = gst_net_time_packet_receive (self->priv->sock.fd,

          (struct sockaddr *) &tmpaddr, &len);

      if (!packet)

        goto receive_error;

      GST_LOG_OBJECT (self, "got packet back");

      GST_LOG_OBJECT (self, "local_1 = %" GST_TIME_FORMAT,

          GST_TIME_ARGS (packet->local_time));

      GST_LOG_OBJECT (self, "remote = %" GST_TIME_FORMAT,

          GST_TIME_ARGS (packet->remote_time));

      GST_LOG_OBJECT (self, "local_2 = %" GST_TIME_FORMAT,

          GST_TIME_ARGS (new_local));

      /* observe_times will reset the timeout */

      gst_net_client_clock_observe_times (self, packet->local_time,

          packet->remote_time, new_local);

      g_free (packet);

      continue;

    } else {

      GST_WARNING_OBJECT (self, "unhandled select return state?");

      continue;

    }

    g_assert_not_reached ();

  stopped:

    {

      GST_DEBUG_OBJECT (self, "shutting down");

      /* socket gets closed in _stop() */

      return NULL;

    }

  receive_error:

    {

      GST_WARNING_OBJECT (self, "receive error");

      continue;

    }

    g_assert_not_reached ();

  }

  g_assert_not_reached ();

  return NULL;

}

static gboolean

gst_net_client_clock_start (GstNetClientClock * self)

{

  struct sockaddr_in servaddr, myaddr;

  socklen_t len;

  gint ret;

  GError *error;

  g_return_val_if_fail (self->address != NULL, FALSE);

  g_return_val_if_fail (self->servaddr == NULL, FALSE);

  if ((ret = socket (AF_INET, SOCK_DGRAM, 0)) < 0)

    goto no_socket;

  self->priv->sock.fd = ret;

  len = sizeof (myaddr);

#ifndef __SYMBIAN32__

  ret = getsockname (self->priv->sock.fd, (struct sockaddr *) &myaddr, &len);

  if (ret < 0)

    goto getsockname_error;

#endif

  memset (&servaddr, 0, sizeof (servaddr));

  servaddr.sin_family = AF_INET;        /* host byte order */

  servaddr.sin_port = htons (self->port);       /* short, network byte order */

  GST_DEBUG_OBJECT (self, "socket opened on UDP port %hd",

      ntohs (servaddr.sin_port));

   #ifndef __SYMBIAN32__

   if (!inet_aton (self->address, &servaddr.sin_addr))

      goto bad_address;

   #else

   if ((servaddr.sin_addr.s_addr=inet_addr(self->address))==-1)

   goto bad_address; 

  #endif//__SYMBIAN32__

  self->servaddr = g_malloc (sizeof (struct sockaddr_in));

  memcpy (self->servaddr, &servaddr, sizeof (servaddr));

  GST_DEBUG_OBJECT (self, "will communicate with %s:%d", self->address,

      self->port);

  gst_poll_add_fd (self->priv->fdset, &self->priv->sock);

  gst_poll_fd_ctl_read (self->priv->fdset, &self->priv->sock, TRUE);

  self->thread = g_thread_create (gst_net_client_clock_thread, self, TRUE,

      &error);

  if (!self->thread)

    goto no_thread;

  return TRUE;

  /* ERRORS */

no_socket:

  {

    GST_ERROR_OBJECT (self, "socket failed %d: %s (%d)", ret,

        g_strerror (errno), errno);

    return FALSE;

  }

getsockname_error:

  {

    GST_ERROR_OBJECT (self, "getsockname failed %d: %s (%d)", ret,

        g_strerror (errno), errno);

    close (self->priv->sock.fd);

    self->priv->sock.fd = -1;

    return FALSE;

  }

bad_address:

  {

    GST_ERROR_OBJECT (self, "inet_aton failed %d: %s (%d)", ret,

        g_strerror (errno), errno);

    close (self->priv->sock.fd);

    self->priv->sock.fd = -1;

    return FALSE;

  }

no_thread:

  {

    GST_ERROR_OBJECT (self, "could not create thread: %s", error->message);

    gst_poll_remove_fd (self->priv->fdset, &self->priv->sock);

    close (self->priv->sock.fd);

    self->priv->sock.fd = -1;

    g_free (self->servaddr);

    self->servaddr = NULL;

    g_error_free (error);

    return FALSE;

  }

}

static void

gst_net_client_clock_stop (GstNetClientClock * self)

{

  gst_poll_set_flushing (self->priv->fdset, TRUE);

  g_thread_join (self->thread);

  self->thread = NULL;

  if (self->priv->sock.fd != -1) {

    gst_poll_remove_fd (self->priv->fdset, &self->priv->sock);

    close (self->priv->sock.fd);

    self->priv->sock.fd = -1;

  }

}

/**

 * gst_net_client_clock_new:

 * @name: a name for the clock