/* GStreamer
 * Copyright (C) <2005> Philippe Khalaf <burger@speedy.org> 
 *
 * 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.
 */

#include "gstbasertpdepayload.h"

GST_DEBUG_CATEGORY (basertpdepayload_debug);
#define GST_CAT_DEFAULT (basertpdepayload_debug)

/* Filter signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  ARG_0,
  ARG_QUEUE_DELAY,
};

static GstElementClass *parent_class = NULL;

static void gst_base_rtp_depayload_base_init (GstBaseRTPDepayloadClass * klass);
static void gst_base_rtp_depayload_class_init (GstBaseRTPDepayloadClass *
    klass);
static void gst_base_rtp_depayload_init (GstBaseRTPDepayload * filter,
    gpointer g_class);

static void gst_base_rtp_depayload_push (GstBaseRTPDepayload * filter,
    GstBuffer * rtp_buf);

GType
gst_base_rtp_depayload_get_type (void)
{
  static GType plugin_type = 0;

  if (!plugin_type) {
    static const GTypeInfo plugin_info = {
      sizeof (GstBaseRTPDepayloadClass),
      (GBaseInitFunc) gst_base_rtp_depayload_base_init,
      NULL,
      (GClassInitFunc) gst_base_rtp_depayload_class_init,
      NULL,
      NULL,
      sizeof (GstBaseRTPDepayload),
      0,
      (GInstanceInitFunc) gst_base_rtp_depayload_init,
    };
    plugin_type = g_type_register_static (GST_TYPE_ELEMENT,
        "GstBaseRTPDepayload", &plugin_info, 0);
  }
  return plugin_type;
}

static void gst_base_rtp_depayload_finalize (GObject * object);
static void gst_base_rtp_depayload_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_base_rtp_depayload_get_property (GObject * object,
    guint prop_id, GValue * value, GParamSpec * pspec);

static gboolean gst_base_rtp_depayload_setcaps (GstPad * pad, GstCaps * caps);

static GstFlowReturn gst_base_rtp_depayload_chain (GstPad * pad,
    GstBuffer * in);
static gboolean
gst_base_rtp_depayload_handle_sink_event (GstPad * pad, GstEvent * event);

static GstStateChangeReturn gst_base_rtp_depayload_change_state (GstElement *
    element, GstStateChange transition);
static GstFlowReturn gst_base_rtp_depayload_add_to_queue (GstBaseRTPDepayload *
    filter, GstBuffer * in);

static void gst_base_rtp_depayload_set_gst_timestamp
    (GstBaseRTPDepayload * filter, guint32 timestamp, GstBuffer * buf);

static void
gst_base_rtp_depayload_wait (GstBaseRTPDepayload * filter, GstClockTime time);

static void
gst_base_rtp_depayload_base_init (GstBaseRTPDepayloadClass * klass)
{
  /*GstElementClass *element_class = GST_ELEMENT_CLASS (klass); */
}

static void
gst_base_rtp_depayload_class_init (GstBaseRTPDepayloadClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = G_OBJECT_CLASS (klass);
  gstelement_class = (GstElementClass *) klass;
  parent_class = g_type_class_peek_parent (klass);

  gobject_class->set_property = gst_base_rtp_depayload_set_property;
  gobject_class->get_property = gst_base_rtp_depayload_get_property;

  g_object_class_install_property (gobject_class, ARG_QUEUE_DELAY,
      g_param_spec_uint ("queue_delay", "Queue Delay",
          "Amount of ms to queue/buffer", 0, G_MAXUINT, 0, G_PARAM_READWRITE));

  gobject_class->finalize = gst_base_rtp_depayload_finalize;

  gstelement_class->change_state = gst_base_rtp_depayload_change_state;

  klass->add_to_queue = gst_base_rtp_depayload_add_to_queue;
  klass->set_gst_timestamp = gst_base_rtp_depayload_set_gst_timestamp;

  GST_DEBUG_CATEGORY_INIT (basertpdepayload_debug, "basertpdepayload", 0,
      "Base class for RTP Depayloaders");
}

static void
gst_base_rtp_depayload_init (GstBaseRTPDepayload * filter, gpointer g_class)
{
  GstPadTemplate *pad_template;

  GST_DEBUG_OBJECT (filter, "init");

  pad_template =
      gst_element_class_get_pad_template (GST_ELEMENT_CLASS (g_class), "sink");
  g_return_if_fail (pad_template != NULL);
  filter->sinkpad = gst_pad_new_from_template (pad_template, "sink");
  gst_pad_set_setcaps_function (filter->sinkpad,
      gst_base_rtp_depayload_setcaps);
  gst_pad_set_chain_function (filter->sinkpad, gst_base_rtp_depayload_chain);
  gst_pad_set_event_function (filter->sinkpad,
      gst_base_rtp_depayload_handle_sink_event);
  gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);

  pad_template =
      gst_element_class_get_pad_template (GST_ELEMENT_CLASS (g_class), "src");
  g_return_if_fail (pad_template != NULL);
  filter->srcpad = gst_pad_new_from_template (pad_template, "src");
  gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);

  filter->queue = g_queue_new ();

  filter->queue_delay = RTP_QUEUE_DELAY;
  filter->need_newsegment = TRUE;

  /* this one needs to be overwritten by child */
  filter->clock_rate = 0;
}

static void
gst_base_rtp_depayload_finalize (GObject * object)
{
  g_queue_free (GST_BASE_RTP_DEPAYLOAD (object)->queue);

  if (G_OBJECT_CLASS (parent_class)->finalize)
    G_OBJECT_CLASS (parent_class)->finalize (object);
}

static gboolean
gst_base_rtp_depayload_setcaps (GstPad * pad, GstCaps * caps)
{
  GstBaseRTPDepayload *filter;

  filter = GST_BASE_RTP_DEPAYLOAD (gst_pad_get_parent (pad));
  g_return_val_if_fail (filter != NULL, FALSE);
  g_return_val_if_fail (GST_IS_BASE_RTP_DEPAYLOAD (filter), FALSE);

  GstBaseRTPDepayloadClass *bclass = GST_BASE_RTP_DEPAYLOAD_GET_CLASS (filter);

  if (bclass->set_caps)
    return bclass->set_caps (filter, caps);
  else
    return TRUE;
}

static GstFlowReturn
gst_base_rtp_depayload_chain (GstPad * pad, GstBuffer * in)
{
  GstBaseRTPDepayload *filter;
  GstBaseRTPDepayloadClass *bclass;
  GstFlowReturn ret = GST_FLOW_OK;

  filter = GST_BASE_RTP_DEPAYLOAD (GST_OBJECT_PARENT (pad));

  g_return_val_if_fail (filter->clock_rate > 0, GST_FLOW_ERROR);

  bclass = GST_BASE_RTP_DEPAYLOAD_GET_CLASS (filter);

  if (filter->queue_delay == 0) {
    GST_DEBUG_OBJECT (filter, "Pushing directly!");
    gst_base_rtp_depayload_push (filter, in);
  } else {
    if (bclass->add_to_queue)
      ret = bclass->add_to_queue (filter, in);
  }
  return ret;
}

static gboolean
gst_base_rtp_depayload_handle_sink_event (GstPad * pad, GstEvent * event)
{
  GstBaseRTPDepayload *filter =
      GST_BASE_RTP_DEPAYLOAD (GST_OBJECT_PARENT (pad));
  gboolean res = TRUE;

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_NEWSEGMENT:
    {
      GST_DEBUG_OBJECT (filter,
          "Upstream sent a NEWSEGMENT, handle in worker thread.");
      /* the worker thread will assign a new RTP-TS<->GST-TS mapping
       * based on the next processed RTP packet */
      filter->need_newsegment = TRUE;
      gst_event_unref (event);
      break;
    }
    default:
      /* pass other events forward */
      res = gst_pad_push_event (filter->srcpad, event);
      break;
  }

  return res;
}

static GstFlowReturn
gst_base_rtp_depayload_add_to_queue (GstBaseRTPDepayload * filter,
    GstBuffer * in)
{
  GQueue *queue = filter->queue;

  /* our first packet, just push it */
  QUEUE_LOCK (filter);
  if (g_queue_is_empty (queue)) {
    g_queue_push_tail (queue, in);
    QUEUE_UNLOCK (filter);
  } else {
    guint16 seqnum, queueseq;
    guint32 timestamp;

    seqnum = gst_rtp_buffer_get_seq (in);
    queueseq = gst_rtp_buffer_get_seq (GST_BUFFER (g_queue_peek_head (queue)));

    /* look for right place to insert it */
    int i = 0;

    while (seqnum > queueseq) {
      gpointer data;

      i++;
      data = g_queue_peek_nth (queue, i);
      if (!data)
        break;

      queueseq = gst_rtp_buffer_get_seq (GST_BUFFER (data));
    }

    /* now insert it at that place */
    g_queue_push_nth (queue, in, i);
    QUEUE_UNLOCK (filter);

    timestamp = gst_rtp_buffer_get_timestamp (in);

    GST_DEBUG_OBJECT (filter,
        "Packet added to queue %d at pos %d timestamp %u sn %d",
        g_queue_get_length (queue), i, timestamp, seqnum);
  }
  return GST_FLOW_OK;
}

static void
gst_base_rtp_depayload_push (GstBaseRTPDepayload * filter, GstBuffer * rtp_buf)
{
  GstBaseRTPDepayloadClass *bclass = GST_BASE_RTP_DEPAYLOAD_GET_CLASS (filter);
  GstBuffer *out_buf;
  GstCaps *srccaps;

  /* let's send it out to processing */
  out_buf = bclass->process (filter, rtp_buf);
  if (out_buf) {
    /* set the caps */
    srccaps = GST_PAD_CAPS (filter->srcpad);

    if (srccaps)
      gst_buffer_set_caps (GST_BUFFER (out_buf), srccaps);

    /* set the timestamp
     * I am assuming here that the timestamp of the last RTP buffer
     * is the same as the timestamp wanted on the collector
     * maybe i should add a way to override this timestamp from the
     * depayloader child class
     */
    bclass->set_gst_timestamp (filter, gst_rtp_buffer_get_timestamp (rtp_buf),
        out_buf);
    /* push it */
    GST_DEBUG_OBJECT (filter, "Pushing buffer size %d, timestamp %u",
        GST_BUFFER_SIZE (out_buf), GST_BUFFER_TIMESTAMP (out_buf));
    gst_pad_push (filter->srcpad, GST_BUFFER (out_buf));
    gst_buffer_unref (rtp_buf);
    GST_DEBUG_OBJECT (filter, "Pushed buffer");
  }
}

static void
gst_base_rtp_depayload_set_gst_timestamp (GstBaseRTPDepayload * filter,
    guint32 timestamp, GstBuffer * buf)
{
  guint64 ts = ((timestamp * GST_SECOND) / filter->clock_rate);

  /* rtp timestamps are based on the clock_rate
   * gst timesamps are in nanoseconds
   */
  GST_DEBUG_OBJECT (filter, "calculating ts : timestamp : %u, clockrate : %u",
      timestamp, filter->clock_rate);

  /* add delay to timestamp */
  GST_BUFFER_TIMESTAMP (buf) = ts + (filter->queue_delay * GST_MSECOND);

  GST_DEBUG_OBJECT (filter, "calculated ts %"
      GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)));

  /* if this is the first buf send a discont */
  if (filter->need_newsegment) {
    /* send discont */
    GstEvent *event = gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_TIME,
        GST_BUFFER_TIMESTAMP (buf), GST_CLOCK_TIME_NONE, 0);

    gst_pad_push_event (filter->srcpad, event);
    filter->need_newsegment = FALSE;
    GST_DEBUG_OBJECT (filter, "Pushed newsegment event on this first buffer");
  }
}

static void
gst_base_rtp_depayload_queue_release (GstBaseRTPDepayload * filter)
{
  GQueue *queue = filter->queue;
  guint32 headts, tailts;
  GstBaseRTPDepayloadClass *bclass;

  if (g_queue_is_empty (queue))
    return;

  /* if our queue is getting to big (more than RTP_QUEUEDELAY ms of data)
   * release heading buffers
   */
  GST_DEBUG_OBJECT (filter, "clockrate %d, queue_delay %d", filter->clock_rate,
      filter->queue_delay);
  gfloat q_size_secs = (gfloat) filter->queue_delay / 1000;
  guint maxtsunits = (gfloat) filter->clock_rate * q_size_secs;

  QUEUE_LOCK (filter);
  headts =
      gst_rtp_buffer_get_timestamp (GST_BUFFER (g_queue_peek_head (queue)));
  tailts =
      gst_rtp_buffer_get_timestamp (GST_BUFFER (g_queue_peek_tail (queue)));

  bclass = GST_BASE_RTP_DEPAYLOAD_GET_CLASS (filter);

  /*GST_DEBUG("maxtsunit is %u %u %u %u", maxtsunits, headts, tailts, headts - tailts); */
  while (headts - tailts > maxtsunits) {
    GST_DEBUG_OBJECT (filter, "Poping packet from queue");
    if (bclass->process) {
      GstBuffer *in = g_queue_pop_head (queue);

      gst_base_rtp_depayload_push (filter, in);
    }
    headts =
        gst_rtp_buffer_get_timestamp (GST_BUFFER (g_queue_peek_head (queue)));
  }
  QUEUE_UNLOCK (filter);
}


static gpointer
gst_base_rtp_depayload_thread (GstBaseRTPDepayload * filter)
{
  while (filter->thread_running) {
    gst_base_rtp_depayload_queue_release (filter);
    /* sleep for 5msec (XXX: 5msec is a value that works for audio and video,
     * should be adjusted based on frequency of incoming packet, 
     * or by data comsumption rate of the sink (depends on how
     * clock-drift compensation is implemented) */
    gst_base_rtp_depayload_wait (filter, GST_MSECOND * 5);
  }
  return NULL;
}

static gboolean
gst_base_rtp_depayload_start_thread (GstBaseRTPDepayload * filter)
{
  GST_DEBUG_OBJECT (filter, "Starting queue release thread");
  filter->thread_running = TRUE;
  filter->thread = g_thread_create ((GThreadFunc) gst_base_rtp_depayload_thread,
      filter, TRUE, NULL);
  GST_DEBUG_OBJECT (filter, "Started queue release thread");
  return TRUE;
}

static gboolean
gst_base_rtp_depayload_stop_thread (GstBaseRTPDepayload * filter)
{
  filter->thread_running = FALSE;

  if (filter->thread) {
    g_thread_join (filter->thread);
    filter->thread = NULL;
  }
  QUEUE_LOCK_FREE (filter);
  return TRUE;
}

static void
gst_base_rtp_depayload_wait (GstBaseRTPDepayload * filter, GstClockTime time)
{
  GstClockID id;

  g_return_if_fail (GST_CLOCK_TIME_IS_VALID (time));
  if (GST_ELEMENT_CLOCK (filter) == NULL) {
    GST_DEBUG_OBJECT (filter, "No clock given yet");
    return;
  }

  id = gst_clock_new_single_shot_id (GST_ELEMENT_CLOCK (filter), time);

  gst_clock_id_wait (id, NULL);
  gst_clock_id_unref (id);
}

static GstStateChangeReturn
gst_base_rtp_depayload_change_state (GstElement * element,
    GstStateChange transition)
{
  GstBaseRTPDepayload *filter;

  g_return_val_if_fail (GST_IS_BASE_RTP_DEPAYLOAD (element),
      GST_STATE_CHANGE_FAILURE);
  filter = GST_BASE_RTP_DEPAYLOAD (element);

  /* we disallow changing the state from the thread */
  if (g_thread_self () == filter->thread)
    return GST_STATE_CHANGE_FAILURE;


  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
      if (!gst_base_rtp_depayload_start_thread (filter))
        goto start_failed;
      break;
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      break;
    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
      break;
    default:
      break;
  }

  switch (transition) {
    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
      break;
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      break;
    case GST_STATE_CHANGE_READY_TO_NULL:
      gst_base_rtp_depayload_stop_thread (filter);
      break;
    default:
      break;
  }
  return GST_STATE_CHANGE_SUCCESS;

  /* ERRORS */
start_failed:
  {
    return GST_STATE_CHANGE_FAILURE;
  }
}

static void
gst_base_rtp_depayload_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstBaseRTPDepayload *filter;

  g_return_if_fail (GST_IS_BASE_RTP_DEPAYLOAD (object));
  filter = GST_BASE_RTP_DEPAYLOAD (object);

  switch (prop_id) {
    case ARG_QUEUE_DELAY:
      filter->queue_delay = g_value_get_uint (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_base_rtp_depayload_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstBaseRTPDepayload *filter;

  g_return_if_fail (GST_IS_BASE_RTP_DEPAYLOAD (object));
  filter = GST_BASE_RTP_DEPAYLOAD (object);

  switch (prop_id) {
    case ARG_QUEUE_DELAY:
      g_value_set_uint (value, filter->queue_delay);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}