/* GStreamer
 * Copyright (C) 2017 Matthew Waters <matthew@centricular.com>
 *
 * 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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "transportstream.h"
#include "transportsendbin.h"
#include "transportreceivebin.h"
#include "gstwebrtcbin.h"
#include "utils.h"
#include "gst/webrtc/webrtc-priv.h"

#define GST_CAT_DEFAULT transport_stream_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

#define transport_stream_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (TransportStream, transport_stream, GST_TYPE_OBJECT,
    GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "webrtctransportstream", 0,
        "webrtctransportstream"););

enum
{
  PROP_0,
  PROP_WEBRTC,
  PROP_SESSION_ID,
  PROP_DTLS_CLIENT,
};

GstCaps *
transport_stream_get_caps_for_pt (TransportStream * stream, guint pt)
{
  GstCaps *ret = NULL;
  GstStructure *ret_s, *item_s;
  guint i, len, si, slen;
  const gchar *field_name;

  len = stream->ptmap->len;
  for (i = 0; i < len; i++) {
    PtMapItem *item = &g_array_index (stream->ptmap, PtMapItem, i);
    if (item->pt == pt) {
      if (item->caps) {
        if (ret == NULL) {
          ret = gst_caps_copy (item->caps);
          ret_s = gst_caps_get_structure (ret, 0);
        } else {
          /* Append the "ssrc-*" fields for current PT entry to ret */
          item_s = gst_caps_get_structure (item->caps, 0);
          slen = gst_structure_n_fields (item_s);
          for (si = 0; si < slen; ++si) {
            field_name = gst_structure_nth_field_name (item_s, si);
            if (!g_str_has_prefix (field_name, "ssrc-"))
              continue;

            gst_structure_set (ret_s, field_name, G_TYPE_STRING,
                gst_structure_get_string (item_s, field_name), NULL);
          }
        }
      }
    }
  }

  return ret;
}

int
transport_stream_get_pt (TransportStream * stream, const gchar * encoding_name,
    guint media_idx)
{
  guint i;
  gint ret = -1;

  for (i = 0; i < stream->ptmap->len; i++) {
    PtMapItem *item = &g_array_index (stream->ptmap, PtMapItem, i);

    if (media_idx != -1 && media_idx != item->media_idx)
      continue;

    if (!gst_caps_is_empty (item->caps)) {
      GstStructure *s = gst_caps_get_structure (item->caps, 0);
      if (!g_strcmp0 (gst_structure_get_string (s, "encoding-name"),
              encoding_name)) {
        ret = item->pt;
        break;
      }
    }
  }

  return ret;
}

int *
transport_stream_get_all_pt (TransportStream * stream,
    const gchar * encoding_name, gsize * pt_len)
{
  guint i;
  gsize ret_i = 0;
  gsize ret_size = 8;
  int *ret = NULL;

  for (i = 0; i < stream->ptmap->len; i++) {
    PtMapItem *item = &g_array_index (stream->ptmap, PtMapItem, i);
    if (!gst_caps_is_empty (item->caps)) {
      GstStructure *s = gst_caps_get_structure (item->caps, 0);
      if (!g_strcmp0 (gst_structure_get_string (s, "encoding-name"),
              encoding_name)) {
        if (!ret)
          ret = g_new0 (int, ret_size);
        if (ret_i >= ret_size) {
          ret_size *= 2;
          ret = g_realloc_n (ret, ret_size, sizeof (int));
        }
        ret[ret_i++] = item->pt;
      }
    }
  }

  *pt_len = ret_i;
  return ret;
}

static void
transport_stream_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  TransportStream *stream = TRANSPORT_STREAM (object);

  switch (prop_id) {
    case PROP_WEBRTC:
      gst_object_set_parent (GST_OBJECT (stream), g_value_get_object (value));
      break;
  }

  GST_OBJECT_LOCK (stream);
  switch (prop_id) {
    case PROP_WEBRTC:
      break;
    case PROP_SESSION_ID:
      stream->session_id = g_value_get_uint (value);
      break;
    case PROP_DTLS_CLIENT:
      stream->dtls_client = g_value_get_boolean (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
  GST_OBJECT_UNLOCK (stream);
}

static void
transport_stream_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  TransportStream *stream = TRANSPORT_STREAM (object);

  GST_OBJECT_LOCK (stream);
  switch (prop_id) {
    case PROP_SESSION_ID:
      g_value_set_uint (value, stream->session_id);
      break;
    case PROP_DTLS_CLIENT:
      g_value_set_boolean (value, stream->dtls_client);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
  GST_OBJECT_UNLOCK (stream);
}

static void
transport_stream_dispose (GObject * object)
{
  TransportStream *stream = TRANSPORT_STREAM (object);

  gst_clear_object (&stream->send_bin);
  gst_clear_object (&stream->receive_bin);
  gst_clear_object (&stream->transport);
  gst_clear_object (&stream->rtxsend);
  gst_clear_object (&stream->rtxreceive);
  gst_clear_object (&stream->reddec);
  gst_clear_object (&stream->stream);
  g_list_free_full (stream->fecdecs, (GDestroyNotify) gst_object_unref);
  stream->fecdecs = NULL;

  GST_OBJECT_PARENT (object) = NULL;

  G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
transport_stream_finalize (GObject * object)
{
  TransportStream *stream = TRANSPORT_STREAM (object);

  g_array_free (stream->ptmap, TRUE);
  g_ptr_array_free (stream->ssrcmap, TRUE);

  gst_clear_object (&stream->rtxsend_stream_id);
  gst_clear_object (&stream->rtxsend_repaired_stream_id);
  gst_clear_object (&stream->rtxreceive_stream_id);
  gst_clear_object (&stream->rtxreceive_repaired_stream_id);

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

static void
transport_stream_constructed (GObject * object)
{
  TransportStream *stream = TRANSPORT_STREAM (object);
  GstWebRTCBin *webrtc;
  GstWebRTCICETransport *ice_trans;

  stream->transport =
      gst_object_ref_sink (gst_webrtc_dtls_transport_new (stream->session_id));

  webrtc = GST_WEBRTC_BIN (gst_object_get_parent (GST_OBJECT (object)));

  g_object_bind_property (stream->transport, "client", stream, "dtls-client",
      G_BINDING_BIDIRECTIONAL);

  /* Need to go full Java and have a transport manager?
   * Or make the caller set the ICE transport up? */

  stream->stream = _find_ice_stream_for_session (webrtc, stream->session_id);
  if (stream->stream == NULL) {
    stream->stream = gst_webrtc_ice_add_stream (webrtc->priv->ice,
        stream->session_id);
    _add_ice_stream_item (webrtc, stream->session_id, stream->stream);
  } else {
    stream->stream = gst_object_ref (stream->stream);
  }
  ice_trans = gst_webrtc_ice_find_transport (webrtc->priv->ice, stream->stream,
      GST_WEBRTC_ICE_COMPONENT_RTP);
  gst_webrtc_dtls_transport_set_transport (stream->transport, ice_trans);
  gst_object_unref (ice_trans);

  stream->send_bin = g_object_new (transport_send_bin_get_type (), "stream",
      stream, NULL);
  gst_object_ref_sink (stream->send_bin);
  stream->receive_bin = g_object_new (transport_receive_bin_get_type (),
      "stream", stream, NULL);
  gst_object_ref_sink (stream->receive_bin);

  gst_object_unref (webrtc);

  G_OBJECT_CLASS (parent_class)->constructed (object);
}

static void
transport_stream_class_init (TransportStreamClass * klass)
{
  GObjectClass *gobject_class = (GObjectClass *) klass;

  gobject_class->constructed = transport_stream_constructed;
  gobject_class->get_property = transport_stream_get_property;
  gobject_class->set_property = transport_stream_set_property;
  gobject_class->dispose = transport_stream_dispose;
  gobject_class->finalize = transport_stream_finalize;

  /* some acrobatics are required to set the parent before _constructed()
   * has been called */
  g_object_class_install_property (gobject_class,
      PROP_WEBRTC,
      g_param_spec_object ("webrtc", "Parent webrtcbin",
          "Parent webrtcbin",
          GST_TYPE_WEBRTC_BIN,
          G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class,
      PROP_SESSION_ID,
      g_param_spec_uint ("session-id", "Session ID",
          "Session ID used for this transport",
          0, G_MAXUINT, 0,
          G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class,
      PROP_DTLS_CLIENT,
      g_param_spec_boolean ("dtls-client", "DTLS client",
          "Whether we take the client role in DTLS negotiation",
          FALSE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}

static void
clear_ptmap_item (PtMapItem * item)
{
  if (item->caps)
    gst_caps_unref (item->caps);
}

static SsrcMapItem *
ssrcmap_item_new (GstWebRTCRTPTransceiverDirection direction, guint32 ssrc,
    guint media_idx)
{
  SsrcMapItem *ssrc_item = g_new0 (SsrcMapItem, 1);

  ssrc_item->direction = direction;
  ssrc_item->media_idx = media_idx;
  ssrc_item->ssrc = ssrc;
  g_weak_ref_init (&ssrc_item->rtpjitterbuffer, NULL);

  return ssrc_item;
}

static void
ssrcmap_item_free (SsrcMapItem * item)
{
  g_weak_ref_clear (&item->rtpjitterbuffer);
  g_clear_pointer (&item->mid, g_free);
  g_clear_pointer (&item->rid, g_free);
  g_free (item);
}

SsrcMapItem *
transport_stream_find_ssrc_map_item (TransportStream * stream,
    gconstpointer data, FindSsrcMapFunc func)
{
  int i;

  for (i = 0; i < stream->ssrcmap->len; i++) {
    SsrcMapItem *item = g_ptr_array_index (stream->ssrcmap, i);

    if (func (item, data))
      return item;
  }

  return NULL;
}

void
transport_stream_filter_ssrc_map_item (TransportStream * stream,
    gconstpointer data, FindSsrcMapFunc func)
{
  int i;

  for (i = 0; i < stream->ssrcmap->len;) {
    SsrcMapItem *item = g_ptr_array_index (stream->ssrcmap, i);

    if (!func (item, data)) {
      GST_TRACE_OBJECT (stream, "removing ssrc %u", item->ssrc);
      g_ptr_array_remove_index_fast (stream->ssrcmap, i);
    } else {
      i++;
    }
  }
}

SsrcMapItem *
transport_stream_add_ssrc_map_item (TransportStream * stream,
    GstWebRTCRTPTransceiverDirection direction, guint32 ssrc, guint media_idx)
{
  SsrcMapItem *ret = NULL;

  g_return_val_if_fail (direction ==
      GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_RECVONLY
      || direction == GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_SENDONLY, NULL);
  g_return_val_if_fail (ssrc != 0, NULL);

  GST_INFO_OBJECT (stream, "Adding mapping for rtp session %u media_idx %u "
      "direction %s ssrc %u", stream->session_id, media_idx,
      gst_webrtc_rtp_transceiver_direction_to_string (direction), ssrc);

  /* XXX: duplicates? */
  ret = ssrcmap_item_new (direction, ssrc, media_idx);

  g_ptr_array_add (stream->ssrcmap, ret);

  return ret;
}

static void
transport_stream_init (TransportStream * stream)
{
  stream->ptmap = g_array_new (FALSE, TRUE, sizeof (PtMapItem));
  g_array_set_clear_func (stream->ptmap, (GDestroyNotify) clear_ptmap_item);
  stream->ssrcmap = g_ptr_array_new_with_free_func (
      (GDestroyNotify) ssrcmap_item_free);

  stream->rtphdrext_id_stream_id = -1;
  stream->rtphdrext_id_repaired_stream_id = -1;
}

TransportStream *
transport_stream_new (GstWebRTCBin * webrtc, guint session_id)
{
  TransportStream *stream;

  stream = g_object_new (transport_stream_get_type (), "webrtc", webrtc,
      "session-id", session_id, NULL);

  return stream;
}
