/* GStreamer
 * Copyright (C) 2010 Marc-Andre Lureau <marcandre.lureau@gmail.com>
 * Copyright (C) 2010 Andoni Morales Alastruey <ylatuya@gmail.com>
 * Copyright (C) 2011, Hewlett-Packard Development Company, L.P.
 *  Author: Youness Alaoui <youness.alaoui@collabora.co.uk>, Collabora Ltd.
 *  Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>, Collabora Ltd.
 *
 * Gsthlsdemux.c:
 *
 * 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.
 */
/**
 * SECTION:element-hlsdemux
 *
 * HTTP Live Streaming demuxer element.
 *
 * <refsect2>
 * <title>Example launch line</title>
 * |[
 * gst-launch souphttpsrc location=http://devimages.apple.com/iphone/samples/bipbop/gear4/prog_index.m3u8 ! hlsdemux ! decodebin2 ! videoconvert ! videoscale ! autovideosink
 * ]|
 * </refsect2>
 *
 * Last reviewed on 2010-10-07
 */

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

/* FIXME 0.11: suppress warnings for deprecated API such as GStaticRecMutex
 * with newer GLib versions (>= 2.31.0) */
#define GLIB_DISABLE_DEPRECATION_WARNINGS

#include <string.h>
#include <gst/glib-compat-private.h>
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
#include "gsthlsdemux.h"

static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src_%u",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS_ANY);

static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("application/x-hls"));

GST_DEBUG_CATEGORY_STATIC (gst_hls_demux_debug);
#define GST_CAT_DEFAULT gst_hls_demux_debug

enum
{
  PROP_0,

  PROP_FRAGMENTS_CACHE,
  PROP_BITRATE_LIMIT,
  PROP_CONNECTION_SPEED,
  PROP_LAST
};

static const float update_interval_factor[] = { 1, 0.5, 1.5, 3 };

#define DEFAULT_FRAGMENTS_CACHE 3
#define DEFAULT_FAILED_COUNT 3
#define DEFAULT_BITRATE_LIMIT 0.8
#define DEFAULT_CONNECTION_SPEED    0

/* GObject */
static void gst_hls_demux_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_hls_demux_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static void gst_hls_demux_dispose (GObject * obj);

/* GstElement */
static GstStateChangeReturn
gst_hls_demux_change_state (GstElement * element, GstStateChange transition);

/* GstHLSDemux */
static GstFlowReturn gst_hls_demux_chain (GstPad * pad, GstObject * parent,
    GstBuffer * buf);
static gboolean gst_hls_demux_sink_event (GstPad * pad, GstObject * parent,
    GstEvent * event);
static gboolean gst_hls_demux_src_event (GstPad * pad, GstObject * parent,
    GstEvent * event);
static gboolean gst_hls_demux_src_query (GstPad * pad, GstObject * parent,
    GstQuery * query);
static void gst_hls_demux_stream_loop (GstHLSDemux * demux);
static void gst_hls_demux_updates_loop (GstHLSDemux * demux);
static void gst_hls_demux_stop (GstHLSDemux * demux);
static void gst_hls_demux_pause_tasks (GstHLSDemux * demux, gboolean caching);
static gboolean gst_hls_demux_cache_fragments (GstHLSDemux * demux);
static gboolean gst_hls_demux_schedule (GstHLSDemux * demux);
static gboolean gst_hls_demux_switch_playlist (GstHLSDemux * demux);
static gboolean gst_hls_demux_get_next_fragment (GstHLSDemux * demux,
    gboolean caching);
static gboolean gst_hls_demux_update_playlist (GstHLSDemux * demux,
    gboolean update);
static void gst_hls_demux_reset (GstHLSDemux * demux, gboolean dispose);
static gboolean gst_hls_demux_set_location (GstHLSDemux * demux,
    const gchar * uri);
static gchar *gst_hls_src_buf_to_utf8_playlist (GstBuffer * buf);

#define gst_hls_demux_parent_class parent_class
G_DEFINE_TYPE (GstHLSDemux, gst_hls_demux, GST_TYPE_ELEMENT);

static void
gst_hls_demux_dispose (GObject * obj)
{
  GstHLSDemux *demux = GST_HLS_DEMUX (obj);

  if (demux->stream_task) {
    if (GST_TASK_STATE (demux->stream_task) != GST_TASK_STOPPED) {
      GST_DEBUG_OBJECT (demux, "Leaving streaming task");
      gst_task_stop (demux->stream_task);
      g_rec_mutex_lock (&demux->stream_lock);
      g_rec_mutex_unlock (&demux->stream_lock);
      gst_task_join (demux->stream_task);
    }
    gst_object_unref (demux->stream_task);
    g_rec_mutex_clear (&demux->stream_lock);
    demux->stream_task = NULL;
  }

  if (demux->updates_task) {
    if (GST_TASK_STATE (demux->updates_task) != GST_TASK_STOPPED) {
      GST_DEBUG_OBJECT (demux, "Leaving updates task");
      demux->cancelled = TRUE;
      gst_uri_downloader_cancel (demux->downloader);
      gst_task_stop (demux->updates_task);
      g_mutex_lock (&demux->updates_timed_lock);
      GST_TASK_SIGNAL (demux->updates_task);
      g_rec_mutex_lock (&demux->updates_lock);
      g_rec_mutex_unlock (&demux->updates_lock);
      g_mutex_unlock (&demux->updates_timed_lock);
      gst_task_join (demux->updates_task);
    }
    gst_object_unref (demux->updates_task);
    g_mutex_clear (&demux->updates_timed_lock);
    g_rec_mutex_clear (&demux->updates_lock);
    demux->updates_task = NULL;
  }

  if (demux->downloader != NULL) {
    g_object_unref (demux->downloader);
    demux->downloader = NULL;
  }

  gst_hls_demux_reset (demux, TRUE);

  g_queue_free (demux->queue);

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

static void
gst_hls_demux_class_init (GstHLSDemuxClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *element_class;

  gobject_class = (GObjectClass *) klass;
  element_class = (GstElementClass *) klass;

  gobject_class->set_property = gst_hls_demux_set_property;
  gobject_class->get_property = gst_hls_demux_get_property;
  gobject_class->dispose = gst_hls_demux_dispose;

  g_object_class_install_property (gobject_class, PROP_FRAGMENTS_CACHE,
      g_param_spec_uint ("fragments-cache", "Fragments cache",
          "Number of fragments needed to be cached to start playing",
          2, G_MAXUINT, DEFAULT_FRAGMENTS_CACHE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class, PROP_BITRATE_LIMIT,
      g_param_spec_float ("bitrate-limit",
          "Bitrate limit in %",
          "Limit of the available bitrate to use when switching to alternates.",
          0, 1, DEFAULT_BITRATE_LIMIT,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class, PROP_CONNECTION_SPEED,
      g_param_spec_uint ("connection-speed", "Connection Speed",
          "Network connection speed in kbps (0 = unknown)",
          0, G_MAXUINT / 1000, DEFAULT_CONNECTION_SPEED,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  element_class->change_state = GST_DEBUG_FUNCPTR (gst_hls_demux_change_state);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&srctemplate));

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&sinktemplate));

  gst_element_class_set_static_metadata (element_class,
      "HLS Demuxer",
      "Demuxer/URIList",
      "HTTP Live Streaming demuxer",
      "Marc-Andre Lureau <marcandre.lureau@gmail.com>\n"
      "Andoni Morales Alastruey <ylatuya@gmail.com>");

  GST_DEBUG_CATEGORY_INIT (gst_hls_demux_debug, "hlsdemux", 0,
      "hlsdemux element");
}

static void
gst_hls_demux_init (GstHLSDemux * demux)
{
  /* sink pad */
  demux->sinkpad = gst_pad_new_from_static_template (&sinktemplate, "sink");
  gst_pad_set_chain_function (demux->sinkpad,
      GST_DEBUG_FUNCPTR (gst_hls_demux_chain));
  gst_pad_set_event_function (demux->sinkpad,
      GST_DEBUG_FUNCPTR (gst_hls_demux_sink_event));
  gst_element_add_pad (GST_ELEMENT (demux), demux->sinkpad);

  /* Downloader */
  demux->downloader = gst_uri_downloader_new ();

  demux->do_typefind = TRUE;

  /* Properties */
  demux->fragments_cache = DEFAULT_FRAGMENTS_CACHE;
  demux->bitrate_limit = DEFAULT_BITRATE_LIMIT;
  demux->connection_speed = DEFAULT_CONNECTION_SPEED;

  demux->queue = g_queue_new ();

  /* Updates task */
  g_rec_mutex_init (&demux->updates_lock);
  demux->updates_task =
      gst_task_new ((GstTaskFunction) gst_hls_demux_updates_loop, demux, NULL);
  gst_task_set_lock (demux->updates_task, &demux->updates_lock);
  g_mutex_init (&demux->updates_timed_lock);

  /* Streaming task */
  g_rec_mutex_init (&demux->stream_lock);
  demux->stream_task =
      gst_task_new ((GstTaskFunction) gst_hls_demux_stream_loop, demux, NULL);
  gst_task_set_lock (demux->stream_task, &demux->stream_lock);

  demux->have_group_id = FALSE;
  demux->group_id = G_MAXUINT;
}

static void
gst_hls_demux_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstHLSDemux *demux = GST_HLS_DEMUX (object);

  switch (prop_id) {
    case PROP_FRAGMENTS_CACHE:
      demux->fragments_cache = g_value_get_uint (value);
      break;
    case PROP_BITRATE_LIMIT:
      demux->bitrate_limit = g_value_get_float (value);
      break;
    case PROP_CONNECTION_SPEED:
      demux->connection_speed = g_value_get_uint (value) * 1000;
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_hls_demux_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstHLSDemux *demux = GST_HLS_DEMUX (object);

  switch (prop_id) {
    case PROP_FRAGMENTS_CACHE:
      g_value_set_uint (value, demux->fragments_cache);
      break;
    case PROP_BITRATE_LIMIT:
      g_value_set_float (value, demux->bitrate_limit);
      break;
    case PROP_CONNECTION_SPEED:
      g_value_set_uint (value, demux->connection_speed / 1000);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static GstStateChangeReturn
gst_hls_demux_change_state (GstElement * element, GstStateChange transition)
{
  GstStateChangeReturn ret;
  GstHLSDemux *demux = GST_HLS_DEMUX (element);

  switch (transition) {
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      gst_hls_demux_reset (demux, FALSE);
      break;
    default:
      break;
  }

  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);

  switch (transition) {
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      demux->cancelled = TRUE;
      gst_hls_demux_stop (demux);
      gst_task_join (demux->stream_task);
      gst_hls_demux_reset (demux, FALSE);
      break;
    default:
      break;
  }
  return ret;
}

static gboolean
gst_hls_demux_src_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
  GstHLSDemux *demux;

  demux = GST_HLS_DEMUX (parent);

  switch (event->type) {
    case GST_EVENT_SEEK:
    {
      gdouble rate;
      GstFormat format;
      GstSeekFlags flags;
      GstSeekType start_type, stop_type;
      gint64 start, stop;
      GList *walk;
      GstClockTime position, current_pos, target_pos;
      gint current_sequence;
      GstM3U8MediaFile *file;

      GST_INFO_OBJECT (demux, "Received GST_EVENT_SEEK");

      if (gst_m3u8_client_is_live (demux->client)) {
        GST_WARNING_OBJECT (demux, "Received seek event for live stream");
        return FALSE;
      }

      gst_event_parse_seek (event, &rate, &format, &flags, &start_type, &start,
          &stop_type, &stop);

      if (format != GST_FORMAT_TIME)
        return FALSE;

      GST_DEBUG_OBJECT (demux, "seek event, rate: %f start: %" GST_TIME_FORMAT
          " stop: %" GST_TIME_FORMAT, rate, GST_TIME_ARGS (start),
          GST_TIME_ARGS (stop));

      GST_M3U8_CLIENT_LOCK (demux->client);
      file = GST_M3U8_MEDIA_FILE (demux->client->current->files->data);
      current_sequence = file->sequence;
      current_pos = 0;
      target_pos = (GstClockTime) start;
      for (walk = demux->client->current->files; walk; walk = walk->next) {
        file = walk->data;

        current_sequence = file->sequence;
        if (current_pos <= target_pos
            && target_pos < current_pos + file->duration) {
          break;
        }
        current_pos += file->duration;
      }
      GST_M3U8_CLIENT_UNLOCK (demux->client);

      if (walk == NULL) {
        GST_WARNING_OBJECT (demux, "Could not find seeked fragment");
        return FALSE;
      }

      if (flags & GST_SEEK_FLAG_FLUSH) {
        GST_DEBUG_OBJECT (demux, "sending flush start");
        gst_pad_push_event (demux->srcpad, gst_event_new_flush_start ());
      }

      demux->cancelled = TRUE;
      gst_task_pause (demux->stream_task);
      gst_uri_downloader_cancel (demux->downloader);
      gst_task_stop (demux->updates_task);
      g_mutex_lock (&demux->updates_timed_lock);
      GST_TASK_SIGNAL (demux->updates_task);
      g_mutex_unlock (&demux->updates_timed_lock);
      g_rec_mutex_lock (&demux->updates_lock);
      g_rec_mutex_unlock (&demux->updates_lock);
      gst_task_pause (demux->stream_task);

      /* wait for streaming to finish */
      g_rec_mutex_lock (&demux->stream_lock);

      demux->need_cache = TRUE;
      while (!g_queue_is_empty (demux->queue)) {
        GstFragment *fragment = g_queue_pop_head (demux->queue);
        g_object_unref (fragment);
      }
      g_queue_clear (demux->queue);

      GST_M3U8_CLIENT_LOCK (demux->client);
      GST_DEBUG_OBJECT (demux, "seeking to sequence %d", current_sequence);
      demux->client->sequence = current_sequence;
      gst_m3u8_client_get_current_position (demux->client, &position);
      demux->position_shift = start - position;
      demux->need_segment = TRUE;
      GST_M3U8_CLIENT_UNLOCK (demux->client);


      if (flags & GST_SEEK_FLAG_FLUSH) {
        GST_DEBUG_OBJECT (demux, "sending flush stop");
        gst_pad_push_event (demux->srcpad, gst_event_new_flush_stop (TRUE));
      }

      demux->cancelled = FALSE;
      gst_task_start (demux->stream_task);
      g_rec_mutex_unlock (&demux->stream_lock);

      return TRUE;
    }
    default:
      break;
  }

  return gst_pad_event_default (pad, parent, event);
}

static gboolean
gst_hls_demux_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
  GstHLSDemux *demux;
  GstQuery *query;
  gboolean ret;
  gchar *uri;

  demux = GST_HLS_DEMUX (parent);

  switch (event->type) {
    case GST_EVENT_EOS:{
      gchar *playlist = NULL;

      if (demux->playlist == NULL) {
        GST_WARNING_OBJECT (demux, "Received EOS without a playlist.");
        break;
      }

      GST_DEBUG_OBJECT (demux,
          "Got EOS on the sink pad: main playlist fetched");

      query = gst_query_new_uri ();
      ret = gst_pad_peer_query (demux->sinkpad, query);
      if (ret) {
        gst_query_parse_uri (query, &uri);
        gst_hls_demux_set_location (demux, uri);
        g_free (uri);
      }
      gst_query_unref (query);

      playlist = gst_hls_src_buf_to_utf8_playlist (demux->playlist);
      demux->playlist = NULL;
      if (playlist == NULL) {
        GST_WARNING_OBJECT (demux, "Error validating first playlist.");
      } else if (!gst_m3u8_client_update (demux->client, playlist)) {
        /* In most cases, this will happen if we set a wrong url in the
         * source element and we have received the 404 HTML response instead of
         * the playlist */
        GST_ELEMENT_ERROR (demux, STREAM, DECODE, ("Invalid playlist."),
            (NULL));
        return FALSE;
      }

      if (!ret && gst_m3u8_client_is_live (demux->client)) {
        GST_ELEMENT_ERROR (demux, RESOURCE, NOT_FOUND,
            ("Failed querying the playlist uri, "
                "required for live sources."), (NULL));
        return FALSE;
      }

      gst_task_start (demux->stream_task);
      gst_event_unref (event);
      return TRUE;
    }
    case GST_EVENT_SEGMENT:
      /* Swallow newsegments, we'll push our own */
      gst_event_unref (event);
      return TRUE;
    default:
      break;
  }

  return gst_pad_event_default (pad, parent, event);
}

static gboolean
gst_hls_demux_src_query (GstPad * pad, GstObject * parent, GstQuery * query)
{
  GstHLSDemux *hlsdemux;
  gboolean ret = FALSE;

  if (query == NULL)
    return FALSE;

  hlsdemux = GST_HLS_DEMUX (parent);

  switch (query->type) {
    case GST_QUERY_DURATION:{
      GstClockTime duration = -1;
      GstFormat fmt;

      gst_query_parse_duration (query, &fmt, NULL);
      if (fmt == GST_FORMAT_TIME) {
        duration = gst_m3u8_client_get_duration (hlsdemux->client);
        if (GST_CLOCK_TIME_IS_VALID (duration) && duration > 0) {
          gst_query_set_duration (query, GST_FORMAT_TIME, duration);
          ret = TRUE;
        }
      }
      GST_INFO_OBJECT (hlsdemux, "GST_QUERY_DURATION returns %s with duration %"
          GST_TIME_FORMAT, ret ? "TRUE" : "FALSE", GST_TIME_ARGS (duration));
      break;
    }
    case GST_QUERY_URI:
      if (hlsdemux->client) {
        /* FIXME: Do we answer with the variant playlist, with the current
         * playlist or the the uri of the least downlowaded fragment? */
        gst_query_set_uri (query, gst_m3u8_client_get_uri (hlsdemux->client));
        ret = TRUE;
      }
      break;
    case GST_QUERY_SEEKING:{
      GstFormat fmt;
      gint64 stop = -1;

      gst_query_parse_seeking (query, &fmt, NULL, NULL, NULL);
      GST_INFO_OBJECT (hlsdemux, "Received GST_QUERY_SEEKING with format %d",
          fmt);
      if (fmt == GST_FORMAT_TIME) {
        GstClockTime duration;

        duration = gst_m3u8_client_get_duration (hlsdemux->client);
        if (GST_CLOCK_TIME_IS_VALID (duration) && duration > 0)
          stop = duration;

        gst_query_set_seeking (query, fmt,
            !gst_m3u8_client_is_live (hlsdemux->client), 0, stop);
        ret = TRUE;
        GST_INFO_OBJECT (hlsdemux, "GST_QUERY_SEEKING returning with stop : %"
            GST_TIME_FORMAT, GST_TIME_ARGS (stop));
      }
      break;
    }
    default:
      /* Don't fordward queries upstream because of the special nature of this
       * "demuxer", which relies on the upstream element only to be fed with the
       * first playlist */
      break;
  }

  return ret;
}

static GstFlowReturn
gst_hls_demux_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
  GstHLSDemux *demux = GST_HLS_DEMUX (parent);

  if (demux->playlist == NULL)
    demux->playlist = buf;
  else
    demux->playlist = gst_buffer_append (demux->playlist, buf);

  return GST_FLOW_OK;
}

static void
gst_hls_demux_pause_tasks (GstHLSDemux * demux, gboolean caching)
{
  if (GST_TASK_STATE (demux->updates_task) != GST_TASK_STOPPED) {
    demux->cancelled = TRUE;
    gst_uri_downloader_cancel (demux->downloader);
    gst_task_pause (demux->updates_task);
    if (!caching)
      g_mutex_lock (&demux->updates_timed_lock);
    GST_TASK_SIGNAL (demux->updates_task);
    if (!caching)
      g_mutex_unlock (&demux->updates_timed_lock);
  }

  if (GST_TASK_STATE (demux->stream_task) != GST_TASK_STOPPED) {
    demux->stop_stream_task = TRUE;
    gst_task_pause (demux->stream_task);
  }
}

static void
gst_hls_demux_stop (GstHLSDemux * demux)
{
  gst_uri_downloader_cancel (demux->downloader);

  if (GST_TASK_STATE (demux->updates_task) != GST_TASK_STOPPED) {
    demux->cancelled = TRUE;
    gst_uri_downloader_cancel (demux->downloader);
    gst_task_stop (demux->updates_task);
    g_mutex_lock (&demux->updates_timed_lock);
    GST_TASK_SIGNAL (demux->updates_task);
    g_mutex_unlock (&demux->updates_timed_lock);
    g_rec_mutex_lock (&demux->updates_lock);
    g_rec_mutex_unlock (&demux->updates_lock);
  }

  if (GST_TASK_STATE (demux->stream_task) != GST_TASK_STOPPED) {
    demux->stop_stream_task = TRUE;
    gst_task_stop (demux->stream_task);
    g_rec_mutex_lock (&demux->stream_lock);
    g_rec_mutex_unlock (&demux->stream_lock);
  }
}

static void
switch_pads (GstHLSDemux * demux, GstCaps * newcaps)
{
  GstPad *oldpad = demux->srcpad;
  GstEvent *event;
  gchar *stream_id;

  GST_DEBUG ("Switching pads (oldpad:%p) with caps: %" GST_PTR_FORMAT, oldpad,
      newcaps);

  /* First create and activate new pad */
  demux->srcpad = gst_pad_new_from_static_template (&srctemplate, NULL);
  gst_pad_set_event_function (demux->srcpad,
      GST_DEBUG_FUNCPTR (gst_hls_demux_src_event));
  gst_pad_set_query_function (demux->srcpad,
      GST_DEBUG_FUNCPTR (gst_hls_demux_src_query));
  gst_pad_set_element_private (demux->srcpad, demux);
  gst_pad_set_active (demux->srcpad, TRUE);

  stream_id =
      gst_pad_create_stream_id (demux->srcpad, GST_ELEMENT_CAST (demux), NULL);

  event = gst_pad_get_sticky_event (demux->sinkpad, GST_EVENT_STREAM_START, 0);
  if (event) {
    if (gst_event_parse_group_id (event, &demux->group_id))
      demux->have_group_id = TRUE;
    else
      demux->have_group_id = FALSE;
    gst_event_unref (event);
  } else if (!demux->have_group_id) {
    demux->have_group_id = TRUE;
    demux->group_id = gst_util_group_id_next ();
  }
  event = gst_event_new_stream_start (stream_id);
  if (demux->have_group_id)
    gst_event_set_group_id (event, demux->group_id);

  gst_pad_push_event (demux->srcpad, event);
  g_free (stream_id);

  gst_pad_set_caps (demux->srcpad, newcaps);

  gst_element_add_pad (GST_ELEMENT (demux), demux->srcpad);

  gst_element_no_more_pads (GST_ELEMENT (demux));

  if (oldpad) {
    /* Push out EOS */
    gst_pad_push_event (oldpad, gst_event_new_eos ());
    gst_pad_set_active (oldpad, FALSE);
    gst_element_remove_pad (GST_ELEMENT (demux), oldpad);
  }
}

static void
gst_hls_demux_stream_loop (GstHLSDemux * demux)
{
  GstFragment *fragment;
  GstBuffer *buf;
  GstFlowReturn ret;
  GstCaps *bufcaps, *srccaps = NULL;

  /* Loop for the source pad task. The task is started when we have
   * received the main playlist from the source element. It tries first to
   * cache the first fragments and then it waits until it has more data in the
   * queue. This task is woken up when we push a new fragment to the queue or
   * when we reached the end of the playlist  */
  GST_DEBUG_OBJECT (demux, "Enter task");

  if (G_UNLIKELY (demux->need_cache)) {
    if (!gst_hls_demux_cache_fragments (demux))
      goto cache_error;

    /* we can start now the updates thread (only if on playing) */
    gst_task_start (demux->updates_task);
    GST_INFO_OBJECT (demux, "First fragments cached successfully");
  }

  if (g_queue_is_empty (demux->queue)) {
    if (demux->end_of_playlist)
      goto end_of_playlist;

    goto pause_task;
  }

  fragment = g_queue_pop_head (demux->queue);
  buf = gst_fragment_get_buffer (fragment);

  /* Figure out if we need to create/switch pads */
  if (G_LIKELY (demux->srcpad))
    srccaps = gst_pad_get_current_caps (demux->srcpad);
  bufcaps = gst_fragment_get_caps (fragment);
  if (G_UNLIKELY (!srccaps || !gst_caps_is_equal_fixed (bufcaps, srccaps)
          || demux->need_segment)) {
    switch_pads (demux, bufcaps);
    demux->need_segment = TRUE;
  }
  gst_caps_unref (bufcaps);
  if (G_LIKELY (srccaps))
    gst_caps_unref (srccaps);
  g_object_unref (fragment);

  if (demux->need_segment) {
    GstSegment segment;
    GstClockTime start = GST_BUFFER_PTS (buf);

    start += demux->position_shift;
    /* And send a newsegment */
    GST_DEBUG_OBJECT (demux, "Sending new-segment. segment start:%"
        GST_TIME_FORMAT, GST_TIME_ARGS (start));
    gst_segment_init (&segment, GST_FORMAT_TIME);
    segment.start = start;
    segment.time = start;
    gst_pad_push_event (demux->srcpad, gst_event_new_segment (&segment));
    demux->need_segment = FALSE;
    demux->position_shift = 0;
  }

  GST_DEBUG_OBJECT (demux, "Pushing buffer %p", buf);

  ret = gst_pad_push (demux->srcpad, buf);
  if (ret != GST_FLOW_OK)
    goto error_pushing;

  GST_DEBUG_OBJECT (demux, "Pushed buffer");

  return;

end_of_playlist:
  {
    GST_DEBUG_OBJECT (demux, "Reached end of playlist, sending EOS");
    gst_pad_push_event (demux->srcpad, gst_event_new_eos ());
    gst_hls_demux_pause_tasks (demux, FALSE);
    return;
  }

cache_error:
  {
    gst_task_pause (demux->stream_task);
    if (!demux->cancelled) {
      GST_ELEMENT_ERROR (demux, RESOURCE, NOT_FOUND,
          ("Could not cache the first fragments"), (NULL));
      gst_hls_demux_pause_tasks (demux, FALSE);
    }
    return;
  }

error_pushing:
  {
    if (ret == GST_FLOW_NOT_LINKED || ret < GST_FLOW_EOS) {
      GST_ELEMENT_ERROR (demux, STREAM, FAILED, (NULL),
          ("stream stopped, reason %s", gst_flow_get_name (ret)));
      gst_pad_push_event (demux->srcpad, gst_event_new_eos ());
    } else {
      GST_DEBUG_OBJECT (demux, "stream stopped, reason %s",
          gst_flow_get_name (ret));
    }
    gst_hls_demux_pause_tasks (demux, FALSE);
    return;
  }

pause_task:
  {
    GST_DEBUG_OBJECT (demux, "Pause task");
    gst_task_pause (demux->stream_task);
    return;
  }
}

static void
gst_hls_demux_reset (GstHLSDemux * demux, gboolean dispose)
{
  demux->need_cache = TRUE;
  demux->end_of_playlist = FALSE;
  demux->cancelled = FALSE;
  demux->do_typefind = TRUE;

  if (demux->input_caps) {
    gst_caps_unref (demux->input_caps);
    demux->input_caps = NULL;
  }

  if (demux->playlist) {
    gst_buffer_unref (demux->playlist);
    demux->playlist = NULL;
  }

  if (demux->client) {
    gst_m3u8_client_free (demux->client);
    demux->client = NULL;
  }

  if (!dispose) {
    demux->client = gst_m3u8_client_new ("");
  }

  while (!g_queue_is_empty (demux->queue)) {
    GstFragment *fragment = g_queue_pop_head (demux->queue);
    g_object_unref (fragment);
  }
  g_queue_clear (demux->queue);

  demux->position_shift = 0;
  demux->need_segment = TRUE;

  demux->have_group_id = FALSE;
  demux->group_id = G_MAXUINT;
}

static gboolean
gst_hls_demux_set_location (GstHLSDemux * demux, const gchar * uri)
{
  if (demux->client)
    gst_m3u8_client_free (demux->client);
  demux->client = gst_m3u8_client_new (uri);
  GST_INFO_OBJECT (demux, "Changed location: %s", uri);
  return TRUE;
}

void
gst_hls_demux_updates_loop (GstHLSDemux * demux)
{
  /* Loop for the updates. It's started when the first fragments are cached and
   * schedules the next update of the playlist (for lives sources) and the next
   * update of fragments. When a new fragment is downloaded, it compares the
   * download time with the next scheduled update to check if we can or should
   * switch to a different bitrate */

  /* block until the next scheduled update or the signal to quit this thread */
  g_mutex_lock (&demux->updates_timed_lock);
  GST_DEBUG_OBJECT (demux, "Started updates task");
  while (TRUE) {
    if (demux->cancelled)
      goto quit;

    /* schedule the next update */
    gst_hls_demux_schedule (demux);

    /*  block until the next scheduled update or the signal to quit this thread */
    GST_DEBUG_OBJECT (demux, "Waiting");
    if (g_cond_timed_wait (GST_TASK_GET_COND (demux->updates_task),
            &demux->updates_timed_lock, &demux->next_update)) {
      GST_DEBUG_OBJECT (demux, "Unlocked");
      goto quit;
    }
    GST_DEBUG_OBJECT (demux, "Continue");

    if (demux->cancelled)
      goto quit;

    /* update the playlist for live sources */
    if (gst_m3u8_client_is_live (demux->client)) {
      if (!gst_hls_demux_update_playlist (demux, TRUE)) {
        if (demux->cancelled)
          goto quit;
        demux->client->update_failed_count++;
        if (demux->client->update_failed_count < DEFAULT_FAILED_COUNT) {
          GST_WARNING_OBJECT (demux, "Could not update the playlist");
          continue;
        } else {
          GST_ELEMENT_ERROR (demux, RESOURCE, NOT_FOUND,
              ("Could not update the playlist"), (NULL));
          goto error;
        }
      }
    }

    /* if it's a live source and the playlist couldn't be updated, there aren't
     * more fragments in the playlist, so we just wait for the next schedulled
     * update */
    if (gst_m3u8_client_is_live (demux->client) &&
        demux->client->update_failed_count > 0) {
      GST_WARNING_OBJECT (demux,
          "The playlist hasn't been updated, failed count is %d",
          demux->client->update_failed_count);
      continue;
    }

    if (demux->cancelled)
      goto quit;

    /* fetch the next fragment */
    if (g_queue_is_empty (demux->queue)) {
      GST_DEBUG_OBJECT (demux, "queue empty, get next fragment");
      if (!gst_hls_demux_get_next_fragment (demux, FALSE)) {
        if (demux->cancelled) {
          goto quit;
        } else if (!demux->end_of_playlist && !demux->cancelled) {
          demux->client->update_failed_count++;
          if (demux->client->update_failed_count < DEFAULT_FAILED_COUNT) {
            GST_WARNING_OBJECT (demux, "Could not fetch the next fragment");
            continue;
          } else {
            GST_ELEMENT_ERROR (demux, RESOURCE, NOT_FOUND,
                ("Could not fetch the next fragment"), (NULL));
            goto error;
          }
        }
      } else {
        demux->client->update_failed_count = 0;

        if (demux->cancelled)
          goto quit;

        /* try to switch to another bitrate if needed */
        gst_hls_demux_switch_playlist (demux);
      }
    }
  }

quit:
  {
    GST_DEBUG_OBJECT (demux, "Stopped updates task");
    g_mutex_unlock (&demux->updates_timed_lock);
    return;
  }

error:
  {
    GST_DEBUG_OBJECT (demux, "Stopped updates task because of error");
    gst_hls_demux_pause_tasks (demux, TRUE);
    g_mutex_unlock (&demux->updates_timed_lock);
  }
}

static gboolean
gst_hls_demux_cache_fragments (GstHLSDemux * demux)
{
  gint i;

  /* If this playlist is a variant playlist, select the first one
   * and update it */
  if (gst_m3u8_client_has_variant_playlist (demux->client)) {
    GstM3U8 *child = NULL;

    if (demux->connection_speed == 0) {

      GST_M3U8_CLIENT_LOCK (demux->client);
      child = demux->client->main->current_variant->data;
      GST_M3U8_CLIENT_UNLOCK (demux->client);
    } else {
      GList *tmp = gst_m3u8_client_get_playlist_for_bitrate (demux->client,
          demux->connection_speed);

      child = GST_M3U8 (tmp->data);
    }

    gst_m3u8_client_set_current (demux->client, child);
    if (!gst_hls_demux_update_playlist (demux, FALSE)) {
      GST_ERROR_OBJECT (demux, "Could not fetch the child playlist %s",
          child->uri);
      return FALSE;
    }
  }

  if (!gst_m3u8_client_is_live (demux->client)) {
    GstClockTime duration = gst_m3u8_client_get_duration (demux->client);

    GST_DEBUG_OBJECT (demux, "Sending duration message : %" GST_TIME_FORMAT,
        GST_TIME_ARGS (duration));
    if (duration != GST_CLOCK_TIME_NONE)
      gst_element_post_message (GST_ELEMENT (demux),
          gst_message_new_duration_changed (GST_OBJECT (demux)));
  }

  /* Cache the first fragments */
  for (i = 0; i < demux->fragments_cache; i++) {
    gst_element_post_message (GST_ELEMENT (demux),
        gst_message_new_buffering (GST_OBJECT (demux),
            100 * i / demux->fragments_cache));
    g_get_current_time (&demux->next_update);
    if (!gst_hls_demux_get_next_fragment (demux, TRUE)) {
      if (demux->end_of_playlist)
        break;
      if (!demux->cancelled)
        GST_ERROR_OBJECT (demux, "Error caching the first fragments");
      return FALSE;
    }
    /* make sure we stop caching fragments if something cancelled it */
    if (demux->cancelled)
      return FALSE;
    gst_hls_demux_switch_playlist (demux);
  }
  gst_element_post_message (GST_ELEMENT (demux),
      gst_message_new_buffering (GST_OBJECT (demux), 100));

  g_get_current_time (&demux->next_update);

  demux->need_cache = FALSE;
  return TRUE;

}

static gchar *
gst_hls_src_buf_to_utf8_playlist (GstBuffer * buf)
{
  GstMapInfo info;
  gchar *playlist;

  if (!gst_buffer_map (buf, &info, GST_MAP_READ))
    return NULL;

  if (!g_utf8_validate ((gchar *) info.data, info.size, NULL))
    goto validate_error;

  /* alloc size + 1 to end with a null character */
  playlist = g_malloc0 (info.size + 1);
  memcpy (playlist, info.data, info.size);

  gst_buffer_unmap (buf, &info);
  gst_buffer_unref (buf);
  return playlist;

validate_error:
  gst_buffer_unmap (buf, &info);
  gst_buffer_unref (buf);
  return NULL;
}

static gboolean
gst_hls_demux_update_playlist (GstHLSDemux * demux, gboolean update)
{
  GstFragment *download;
  GstBuffer *buf;
  gchar *playlist;
  gboolean updated = FALSE;

  const gchar *uri = gst_m3u8_client_get_current_uri (demux->client);

  download = gst_uri_downloader_fetch_uri (demux->downloader, uri);

  if (download == NULL)
    return FALSE;

  buf = gst_fragment_get_buffer (download);
  playlist = gst_hls_src_buf_to_utf8_playlist (buf);
  g_object_unref (download);

  if (playlist == NULL) {
    GST_WARNING_OBJECT (demux, "Couldn't not validate playlist encoding");
    return FALSE;
  }

  updated = gst_m3u8_client_update (demux->client, playlist);

  /*  If it's a live source, do not let the sequence number go beyond
   * three fragments before the end of the list */
  if (updated && update == FALSE && demux->client->current &&
      gst_m3u8_client_is_live (demux->client)) {
    guint last_sequence;

    GST_M3U8_CLIENT_LOCK (demux->client);
    last_sequence =
        GST_M3U8_MEDIA_FILE (g_list_last (demux->client->current->
            files)->data)->sequence;

    if (demux->client->sequence >= last_sequence - 3) {
      GST_DEBUG_OBJECT (demux, "Sequence is beyond playlist. Moving back to %d",
          last_sequence - 3);
      demux->need_segment = TRUE;
      demux->client->sequence = last_sequence - 3;
    }
    GST_M3U8_CLIENT_UNLOCK (demux->client);
  }

  return updated;
}

static gboolean
gst_hls_demux_change_playlist (GstHLSDemux * demux, guint max_bitrate)
{
  GList *previous_variant, *current_variant;
  gint old_bandwidth, new_bandwidth;

  /* If user specifies a connection speed never use a playlist with a bandwidth
   * superior than it */
  if (demux->connection_speed != 0 && max_bitrate > demux->connection_speed)
    max_bitrate = demux->connection_speed;

  previous_variant = demux->client->main->current_variant;
  current_variant = gst_m3u8_client_get_playlist_for_bitrate (demux->client,
      max_bitrate);

retry_failover_protection:
  old_bandwidth = GST_M3U8 (previous_variant->data)->bandwidth;
  new_bandwidth = GST_M3U8 (current_variant->data)->bandwidth;

  /* Don't do anything else if the playlist is the same */
  if (new_bandwidth == old_bandwidth) {
    return TRUE;
  }

  demux->client->main->current_variant = current_variant;
  GST_M3U8_CLIENT_UNLOCK (demux->client);

  gst_m3u8_client_set_current (demux->client, current_variant->data);

  GST_INFO_OBJECT (demux, "Client was on %dbps, max allowed is %dbps, switching"
      " to bitrate %dbps", old_bandwidth, max_bitrate, new_bandwidth);

  if (gst_hls_demux_update_playlist (demux, FALSE)) {
    GstStructure *s;

    s = gst_structure_new ("playlist",
        "uri", G_TYPE_STRING, gst_m3u8_client_get_current_uri (demux->client),
        "bitrate", G_TYPE_INT, new_bandwidth, NULL);
    gst_element_post_message (GST_ELEMENT_CAST (demux),
        gst_message_new_element (GST_OBJECT_CAST (demux), s));
  } else {
    GList *failover = NULL;

    GST_INFO_OBJECT (demux, "Unable to update playlist. Switching back");
    GST_M3U8_CLIENT_LOCK (demux->client);

    failover = g_list_previous (current_variant);
    if (failover && new_bandwidth == GST_M3U8 (failover->data)->bandwidth) {
      current_variant = failover;
      goto retry_failover_protection;
    }

    demux->client->main->current_variant = previous_variant;
    GST_M3U8_CLIENT_UNLOCK (demux->client);
    gst_m3u8_client_set_current (demux->client, previous_variant->data);
    /*  Try a lower bitrate (or stop if we just tried the lowest) */
    if (new_bandwidth ==
        GST_M3U8 (g_list_first (demux->client->main->lists)->data)->bandwidth)
      return FALSE;
    else
      return gst_hls_demux_change_playlist (demux, new_bandwidth - 1);
  }

  /* Force typefinding since we might have changed media type */
  demux->do_typefind = TRUE;

  return TRUE;
}

static gboolean
gst_hls_demux_schedule (GstHLSDemux * demux)
{
  gfloat update_factor;
  gint count;

  /* As defined in §6.3.4. Reloading the Playlist file:
   * "If the client reloads a Playlist file and finds that it has not
   * changed then it MUST wait for a period of time before retrying.  The
   * minimum delay is a multiple of the target duration.  This multiple is
   * 0.5 for the first attempt, 1.5 for the second, and 3.0 thereafter."
   */
  count = demux->client->update_failed_count;
  if (count < 3)
    update_factor = update_interval_factor[count];
  else
    update_factor = update_interval_factor[3];

  /* schedule the next update using the target duration field of the
   * playlist */
  g_time_val_add (&demux->next_update,
      gst_m3u8_client_get_target_duration (demux->client)
      / GST_SECOND * G_USEC_PER_SEC * update_factor);
  GST_DEBUG_OBJECT (demux, "Next update scheduled at %s",
      g_time_val_to_iso8601 (&demux->next_update));

  return TRUE;
}

static gboolean
gst_hls_demux_switch_playlist (GstHLSDemux * demux)
{
  GTimeVal now;
  GstClockTime diff;
  gsize size;
  gint bitrate;
  GstFragment *fragment = g_queue_peek_tail (demux->queue);
  GstBuffer *buffer;

  GST_M3U8_CLIENT_LOCK (demux->client);
  if (!demux->client->main->lists) {
    GST_M3U8_CLIENT_UNLOCK (demux->client);
    return TRUE;
  }
  GST_M3U8_CLIENT_UNLOCK (demux->client);

  /* compare the time when the fragment was downloaded with the time when it was
   * scheduled */
  g_get_current_time (&now);
  diff = (GST_TIMEVAL_TO_TIME (now) - GST_TIMEVAL_TO_TIME (demux->next_update));
  buffer = gst_fragment_get_buffer (fragment);
  size = gst_buffer_get_size (buffer);
  bitrate = (size * 8) / ((double) diff / GST_SECOND);

  GST_DEBUG ("Downloaded %d bytes in %" GST_TIME_FORMAT ". Bitrate is : %d",
      (guint) size, GST_TIME_ARGS (diff), bitrate);

  gst_buffer_unref (buffer);
  return gst_hls_demux_change_playlist (demux, bitrate * demux->bitrate_limit);
}

static GstFragment *
gst_hls_demux_decrypt_fragment (GstHLSDemux * demux,
    GstFragment * encrypted_fragment, const gchar * key, const guint8 * iv)
{
  GstFragment *key_fragment, *ret;
  GstBuffer *key_buffer, *encrypted_buffer, *decrypted_buffer;
  GstMapInfo key_info, encrypted_info, decrypted_info;
  gnutls_cipher_hd_t aes_ctx;
  gnutls_datum_t key_d, iv_d;
  gsize unpadded_size;

  GST_INFO_OBJECT (demux, "Fetching key %s", key);
  key_fragment = gst_uri_downloader_fetch_uri (demux->downloader, key);
  if (key_fragment == NULL)
    return NULL;

  key_buffer = gst_fragment_get_buffer (key_fragment);
  encrypted_buffer = gst_fragment_get_buffer (encrypted_fragment);
  decrypted_buffer =
      gst_buffer_new_allocate (NULL, gst_buffer_get_size (encrypted_buffer),
      NULL);

  gst_buffer_map (key_buffer, &key_info, GST_MAP_READ);
  gst_buffer_map (encrypted_buffer, &encrypted_info, GST_MAP_READ);
  gst_buffer_map (decrypted_buffer, &decrypted_info, GST_MAP_WRITE);

  key_d.data = key_info.data;
  key_d.size = 16;
  iv_d.data = (unsigned char *) iv;
  iv_d.size = 16;
  gnutls_cipher_init (&aes_ctx, gnutls_cipher_get_id ("AES-128-CBC"), &key_d,
      &iv_d);
  gnutls_cipher_decrypt2 (aes_ctx, encrypted_info.data, encrypted_info.size,
      decrypted_info.data, decrypted_info.size);
  gnutls_cipher_deinit (aes_ctx);

  /* Handle pkcs7 unpadding here */
  unpadded_size =
      decrypted_info.size - decrypted_info.data[decrypted_info.size - 1];

  gst_buffer_unmap (decrypted_buffer, &decrypted_info);
  gst_buffer_unmap (encrypted_buffer, &encrypted_info);
  gst_buffer_unmap (key_buffer, &key_info);

  gst_buffer_resize (decrypted_buffer, 0, unpadded_size);

  gst_buffer_unref (key_buffer);
  gst_buffer_unref (encrypted_buffer);
  g_object_unref (key_fragment);
  g_object_unref (encrypted_fragment);

  ret = gst_fragment_new ();
  gst_fragment_add_buffer (ret, decrypted_buffer);
  ret->completed = TRUE;

  return ret;
}

static gboolean
gst_hls_demux_get_next_fragment (GstHLSDemux * demux, gboolean caching)
{
  GstFragment *download;
  const gchar *next_fragment_uri;
  GstClockTime duration;
  GstClockTime timestamp;
  GstBuffer *buf;
  gboolean discont;
  const gchar *key = NULL;
  const guint8 *iv = NULL;

  if (!gst_m3u8_client_get_next_fragment (demux->client, &discont,
          &next_fragment_uri, &duration, &timestamp, &key, &iv)) {
    GST_INFO_OBJECT (demux, "This playlist doesn't contain more fragments");
    demux->end_of_playlist = TRUE;
    gst_task_start (demux->stream_task);
    return FALSE;
  }

  GST_INFO_OBJECT (demux, "Fetching next fragment %s", next_fragment_uri);

  download = gst_uri_downloader_fetch_uri (demux->downloader,
      next_fragment_uri);

  if (download && key)
    download = gst_hls_demux_decrypt_fragment (demux, download, key, iv);

  if (download == NULL)
    goto error;

  buf = gst_fragment_get_buffer (download);

  GST_BUFFER_DURATION (buf) = duration;
  GST_BUFFER_PTS (buf) = timestamp;

  /* We actually need to do this every time we switch bitrate */
  if (G_UNLIKELY (demux->do_typefind)) {
    GstCaps *caps = gst_fragment_get_caps (download);

    if (!demux->input_caps || !gst_caps_is_equal (caps, demux->input_caps)) {
      gst_caps_replace (&demux->input_caps, caps);
      /* gst_pad_set_caps (demux->srcpad, demux->input_caps); */
      GST_INFO_OBJECT (demux, "Input source caps: %" GST_PTR_FORMAT,
          demux->input_caps);
      demux->do_typefind = FALSE;
    }
    gst_caps_unref (caps);
  } else {
    gst_fragment_set_caps (download, demux->input_caps);
  }

  if (discont) {
    GST_DEBUG_OBJECT (demux, "Marking fragment as discontinuous");
    GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DISCONT);
  }

  GST_DEBUG_OBJECT (demux, "Pushing fragment in queue");
  g_queue_push_tail (demux->queue, download);
  if (!caching) {
    GST_TASK_SIGNAL (demux->updates_task);
    gst_task_start (demux->stream_task);
  }
  return TRUE;

error:
  {
    gst_hls_demux_stop (demux);
    return FALSE;
  }
}
