/* GStreamer SRT plugin based on libsrt
 * Copyright (C) 2017, Collabora Ltd.
 *   Author:Justin Kim <justin.kim@collabora.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 "gstsrtserversink.h"
#include "gstsrt.h"
#include <srt/srt.h>

#define SRT_DEFAULT_POLL_TIMEOUT -1

#define GST_CAT_DEFAULT gst_debug_srt_base_sink
GST_DEBUG_CATEGORY (GST_CAT_DEFAULT);

enum
{
  PROP_URI = 1,
  PROP_LATENCY,
  PROP_PASSPHRASE,
  PROP_KEY_LENGTH,

  /*< private > */
  PROP_LAST
};

static GParamSpec *properties[PROP_LAST];

static void gst_srt_base_sink_uri_handler_init (gpointer g_iface,
    gpointer iface_data);
static gchar *gst_srt_base_sink_uri_get_uri (GstURIHandler * handler);
static gboolean gst_srt_base_sink_uri_set_uri (GstURIHandler * handler,
    const gchar * uri, GError ** error);

#define gst_srt_base_sink_parent_class parent_class
G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GstSRTBaseSink, gst_srt_base_sink,
    GST_TYPE_BASE_SINK,
    G_IMPLEMENT_INTERFACE (GST_TYPE_URI_HANDLER,
        gst_srt_base_sink_uri_handler_init)
    GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "srtbasesink", 0,
        "SRT Base Sink"));

static void
gst_srt_base_sink_get_property (GObject * object,
    guint prop_id, GValue * value, GParamSpec * pspec)
{
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (object);

  switch (prop_id) {
    case PROP_URI:
      if (self->uri != NULL) {
        gchar *uri_str = gst_srt_base_sink_uri_get_uri (GST_URI_HANDLER (self));
        g_value_take_string (value, uri_str);
      }
      break;
    case PROP_LATENCY:
      g_value_set_int (value, self->latency);
      break;
    case PROP_PASSPHRASE:
      g_value_set_string (value, self->passphrase);
      break;
    case PROP_KEY_LENGTH:
      g_value_set_int (value, self->key_length);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_srt_base_sink_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec)
{
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (object);

  switch (prop_id) {
    case PROP_URI:
      gst_srt_base_sink_uri_set_uri (GST_URI_HANDLER (self),
          g_value_get_string (value), NULL);
      break;
    case PROP_LATENCY:
      self->latency = g_value_get_int (value);
      break;
    case PROP_PASSPHRASE:
      g_free (self->passphrase);
      self->passphrase = g_value_dup_string (value);
      break;
    case PROP_KEY_LENGTH:
    {
      gint key_length = g_value_get_int (value);
      g_return_if_fail (key_length == 16 || key_length == 24
          || key_length == 32);
      self->key_length = key_length;
      break;
    }
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_srt_base_sink_finalize (GObject * object)
{
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (object);

  g_clear_pointer (&self->headers, gst_buffer_list_unref);
  g_clear_pointer (&self->uri, gst_uri_unref);
  g_clear_pointer (&self->passphrase, g_free);

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

static gboolean
gst_srt_base_sink_set_caps (GstBaseSink * sink, GstCaps * caps)
{
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (sink);
  GstStructure *s;
  const GValue *streamheader;

  GST_DEBUG_OBJECT (self, "setcaps %" GST_PTR_FORMAT, caps);

  g_clear_pointer (&self->headers, gst_buffer_list_unref);

  s = gst_caps_get_structure (caps, 0);
  streamheader = gst_structure_get_value (s, "streamheader");

  if (!streamheader) {
    GST_DEBUG_OBJECT (self, "'streamheader' field not present");
  } else if (GST_VALUE_HOLDS_BUFFER (streamheader)) {
    GST_DEBUG_OBJECT (self, "'streamheader' field holds buffer");
    self->headers = gst_buffer_list_new_sized (1);
    gst_buffer_list_add (self->headers, g_value_dup_boxed (streamheader));
  } else if (GST_VALUE_HOLDS_ARRAY (streamheader)) {
    guint i, size;

    GST_DEBUG_OBJECT (self, "'streamheader' field holds array");

    size = gst_value_array_get_size (streamheader);
    self->headers = gst_buffer_list_new_sized (size);

    for (i = 0; i < size; i++) {
      const GValue *v = gst_value_array_get_value (streamheader, i);
      if (!GST_VALUE_HOLDS_BUFFER (v)) {
        GST_ERROR_OBJECT (self, "'streamheader' item of unexpected type '%s'",
            G_VALUE_TYPE_NAME (v));
        return FALSE;
      }

      gst_buffer_list_add (self->headers, g_value_dup_boxed (v));
    }
  } else {
    GST_ERROR_OBJECT (self, "'streamheader' field has unexpected type '%s'",
        G_VALUE_TYPE_NAME (streamheader));
    return FALSE;
  }

  GST_DEBUG_OBJECT (self, "Collected streamheaders: %u buffers",
      self->headers ? gst_buffer_list_length (self->headers) : 0);

  return TRUE;
}

static gboolean
gst_srt_base_sink_stop (GstBaseSink * sink)
{
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (sink);

  g_clear_pointer (&self->headers, gst_buffer_list_unref);

  return TRUE;
}

static GstFlowReturn
gst_srt_base_sink_render (GstBaseSink * sink, GstBuffer * buffer)
{
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (sink);
  GstMapInfo info;
  GstSRTBaseSinkClass *bclass = GST_SRT_BASE_SINK_GET_CLASS (sink);
  GstFlowReturn ret = GST_FLOW_OK;

  if (self->headers && GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_HEADER)) {
    GST_DEBUG_OBJECT (self, "Have streamheaders,"
        " ignoring header %" GST_PTR_FORMAT, buffer);
    return GST_FLOW_OK;
  }

  GST_TRACE_OBJECT (self, "sending buffer %p, offset %"
      G_GINT64_FORMAT ", offset_end %" G_GINT64_FORMAT
      ", timestamp %" GST_TIME_FORMAT ", duration %" GST_TIME_FORMAT
      ", size %" G_GSIZE_FORMAT,
      buffer, GST_BUFFER_OFFSET (buffer),
      GST_BUFFER_OFFSET_END (buffer),
      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)),
      GST_TIME_ARGS (GST_BUFFER_DURATION (buffer)),
      gst_buffer_get_size (buffer));

  if (!gst_buffer_map (buffer, &info, GST_MAP_READ)) {
    GST_ELEMENT_ERROR (self, RESOURCE, READ,
        ("Could not map the input stream"), (NULL));
    return GST_FLOW_ERROR;
  }

  if (!bclass->send_buffer (self, &info))
    ret = GST_FLOW_ERROR;

  gst_buffer_unmap (buffer, &info);

  return ret;
}

static void
gst_srt_base_sink_class_init (GstSRTBaseSinkClass * klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  GstBaseSinkClass *gstbasesink_class = GST_BASE_SINK_CLASS (klass);

  gobject_class->set_property = gst_srt_base_sink_set_property;
  gobject_class->get_property = gst_srt_base_sink_get_property;
  gobject_class->finalize = gst_srt_base_sink_finalize;

  /**
   * GstSRTBaseSink:uri:
   *
   * The URI used by SRT Connection.
   */
  properties[PROP_URI] = g_param_spec_string ("uri", "URI",
      "URI in the form of srt://address:port", SRT_DEFAULT_URI,
      G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

  properties[PROP_LATENCY] =
      g_param_spec_int ("latency", "latency",
      "Minimum latency (milliseconds)", 0,
      G_MAXINT32, SRT_DEFAULT_LATENCY,
      G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

  properties[PROP_PASSPHRASE] = g_param_spec_string ("passphrase", "Passphrase",
      "The password for the encrypted transmission", NULL,
      G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

  properties[PROP_KEY_LENGTH] =
      g_param_spec_int ("key-length", "key length",
      "Crypto key length in bytes{16,24,32}", 16,
      32, SRT_DEFAULT_KEY_LENGTH, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);

  g_object_class_install_properties (gobject_class, PROP_LAST, properties);

  gstbasesink_class->set_caps = GST_DEBUG_FUNCPTR (gst_srt_base_sink_set_caps);
  gstbasesink_class->stop = GST_DEBUG_FUNCPTR (gst_srt_base_sink_stop);
  gstbasesink_class->render = GST_DEBUG_FUNCPTR (gst_srt_base_sink_render);
}

static void
gst_srt_base_sink_init (GstSRTBaseSink * self)
{
  self->uri = gst_uri_from_string (SRT_DEFAULT_URI);
  self->latency = SRT_DEFAULT_LATENCY;
  self->passphrase = NULL;
  self->key_length = SRT_DEFAULT_KEY_LENGTH;
}

static GstURIType
gst_srt_base_sink_uri_get_type (GType type)
{
  return GST_URI_SINK;
}

static const gchar *const *
gst_srt_base_sink_uri_get_protocols (GType type)
{
  static const gchar *protocols[] = { SRT_URI_SCHEME, NULL };

  return protocols;
}

static gchar *
gst_srt_base_sink_uri_get_uri (GstURIHandler * handler)
{
  gchar *uri_str;
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (handler);

  GST_OBJECT_LOCK (self);
  uri_str = gst_uri_to_string (self->uri);
  GST_OBJECT_UNLOCK (self);

  return uri_str;
}

static gboolean
gst_srt_base_sink_uri_set_uri (GstURIHandler * handler,
    const gchar * uri, GError ** error)
{
  GstSRTBaseSink *self = GST_SRT_BASE_SINK (handler);
  gboolean ret = TRUE;
  GstUri *parsed_uri = gst_uri_from_string (uri);

  GST_TRACE_OBJECT (self, "Requested URI=%s", uri);

  if (g_strcmp0 (gst_uri_get_scheme (parsed_uri), SRT_URI_SCHEME) != 0) {
    g_set_error (error, GST_URI_ERROR, GST_URI_ERROR_BAD_URI,
        "Invalid SRT URI scheme");
    ret = FALSE;
    goto out;
  }

  GST_OBJECT_LOCK (self);

  g_clear_pointer (&self->uri, gst_uri_unref);
  self->uri = gst_uri_ref (parsed_uri);

  GST_OBJECT_UNLOCK (self);

out:
  g_clear_pointer (&parsed_uri, gst_uri_unref);
  return ret;
}

static void
gst_srt_base_sink_uri_handler_init (gpointer g_iface, gpointer iface_data)
{
  GstURIHandlerInterface *iface = (GstURIHandlerInterface *) g_iface;

  iface->get_type = gst_srt_base_sink_uri_get_type;
  iface->get_protocols = gst_srt_base_sink_uri_get_protocols;
  iface->get_uri = gst_srt_base_sink_uri_get_uri;
  iface->set_uri = gst_srt_base_sink_uri_set_uri;
}

gboolean
gst_srt_base_sink_send_headers (GstSRTBaseSink * self,
    GstSRTBaseSinkSendCallback send_cb, gpointer user_data)
{
  guint size, i;

  g_return_val_if_fail (GST_IS_SRT_BASE_SINK (self), FALSE);
  g_return_val_if_fail (send_cb, FALSE);

  if (!self->headers)
    return TRUE;

  size = gst_buffer_list_length (self->headers);

  GST_DEBUG_OBJECT (self, "Sending %u stream headers", size);

  for (i = 0; i < size; i++) {
    GstBuffer *buffer = gst_buffer_list_get (self->headers, i);
    GstMapInfo info;
    gboolean ret;

    GST_TRACE_OBJECT (self, "sending header %u %" GST_PTR_FORMAT, i, buffer);

    if (!gst_buffer_map (buffer, &info, GST_MAP_READ)) {
      GST_ELEMENT_ERROR (self, RESOURCE, READ,
          ("Could not map the input stream"), (NULL));
      return FALSE;
    }

    ret = send_cb (self, &info, user_data);

    gst_buffer_unmap (buffer, &info);

    if (!ret)
      return FALSE;
  }

  return TRUE;
}

GstStructure *
gst_srt_base_sink_get_stats (GSocketAddress * sockaddr, SRTSOCKET sock)
{
  SRT_TRACEBSTATS stats;
  int ret;
  GValue v = G_VALUE_INIT;
  GstStructure *s;

  if (sock == SRT_INVALID_SOCK || sockaddr == NULL)
    return gst_structure_new_empty ("application/x-srt-statistics");

  s = gst_structure_new ("application/x-srt-statistics",
      "sockaddr", G_TYPE_SOCKET_ADDRESS, sockaddr, NULL);

  ret = srt_bstats (sock, &stats, 0);
  if (ret >= 0) {
    gst_structure_set (s,
        /* number of sent data packets, including retransmissions */
        "packets-sent", G_TYPE_INT64, stats.pktSent,
        /* number of lost packets (sender side) */
        "packets-sent-lost", G_TYPE_INT, stats.pktSndLoss,
        /* number of retransmitted packets */
        "packets-retransmitted", G_TYPE_INT, stats.pktRetrans,
        /* number of received ACK packets */
        "packet-ack-received", G_TYPE_INT, stats.pktRecvACK,
        /* number of received NAK packets */
        "packet-nack-received", G_TYPE_INT, stats.pktRecvNAK,
        /* time duration when UDT is sending data (idle time exclusive) */
        "send-duration-us", G_TYPE_INT64, stats.usSndDuration,
        /* number of sent data bytes, including retransmissions */
        "bytes-sent", G_TYPE_UINT64, stats.byteSent,
        /* number of retransmitted bytes */
        "bytes-retransmitted", G_TYPE_UINT64, stats.byteRetrans,
        /* number of too-late-to-send dropped bytes */
        "bytes-sent-dropped", G_TYPE_UINT64, stats.byteSndDrop,
        /* number of too-late-to-send dropped packets */
        "packets-sent-dropped", G_TYPE_INT, stats.pktSndDrop,
        /* sending rate in Mb/s */
        "send-rate-mbps", G_TYPE_DOUBLE, stats.msRTT,
        /* estimated bandwidth, in Mb/s */
        "bandwidth-mbps", G_TYPE_DOUBLE, stats.mbpsBandwidth,
        /* busy sending time (i.e., idle time exclusive) */
        "send-duration-us", G_TYPE_UINT64, stats.usSndDuration,
        "rtt-ms", G_TYPE_DOUBLE, stats.msRTT,
        "negotiated-latency-ms", G_TYPE_INT, stats.msSndTsbPdDelay, NULL);
  }

  g_value_init (&v, G_TYPE_STRING);
  g_value_take_string (&v,
      g_socket_connectable_to_string (G_SOCKET_CONNECTABLE (sockaddr)));
  gst_structure_take_value (s, "sockaddr-str", &v);

  return s;
}