#include "videoplayer.h"

#include <QtWidgets>

#include <glib.h>
#include <gst/gst.h>
#include <gst/rtsp/gstrtsptransport.h>
#include <gst/video/videooverlay.h>


static void
pad_added_cb (GstElement *src, GstPad *srcpad, GstElement *peer)
{
    g_print ("Received new pad '%s' from '%s':\n", GST_PAD_NAME (srcpad), GST_ELEMENT_NAME (src));

    (void)src;        // remove unused variable warning
    GstPad *sinkpad = gst_element_get_static_pad (peer, "sink");
    gst_pad_link (srcpad, sinkpad);
    gst_object_unref (sinkpad);
}


void VideoPlayer::print_status_of_all()
{
  auto it = gst_bin_iterate_elements(GST_BIN(pipeline));
  GValue value = G_VALUE_INIT;
  for (GstIteratorResult r = gst_iterator_next(it, &value);
       r != GST_ITERATOR_DONE;
       r = gst_iterator_next(it, &value))
  {
    if (r == GST_ITERATOR_OK)
    {
      GstElement *e = static_cast<GstElement*>(g_value_peek_pointer(&value));
      GstState  current, pending;
      gst_element_get_state(e, &current, &pending, 100000);
      g_print("%s(%s), status = %s, pending = %s\n", G_VALUE_TYPE_NAME(&value), gst_element_get_name(e), gst_element_state_get_name(current), gst_element_state_get_name(pending));
    }
  }
}

VideoPlayer::VideoPlayer(QWidget *parent)
    : QWidget(parent)
{
    QAbstractButton *debugButton = new QPushButton(tr("?"));
    connect(debugButton, SIGNAL(clicked()), this, SLOT(debugSlot()));

    m_stopButton = new QPushButton(this);
    m_stopButton->setIcon(style()->standardIcon(QStyle::SP_MediaStop));
    m_stopButton->setEnabled(false);
    connect(m_stopButton, SIGNAL(clicked()), this, SLOT(stop()));

    m_playButton = new QPushButton(this);
    m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
    connect(m_playButton, &QAbstractButton::clicked, this, &VideoPlayer::playPause);


    // -----------------------------------------------------------------
    // Options
    QCheckBox *tcpCheckBox = new QCheckBox("Use TCP protocol", this);
    tcpCheckBox->setChecked(use_tcp);
    connect(tcpCheckBox, SIGNAL(toggled(bool)), this, SLOT(useTcp(bool)));

    QLineEdit *rtspUrlEdit = new QLineEdit(this);
    connect (rtspUrlEdit, SIGNAL(textEdited(QString)), this, SLOT(setRtspUrl(QString)));
    //rtspUrlEdit->setText("rtsp://127.0.0.1:8554/test");
    rtspUrlEdit->setText(rtspUrl);

    QFormLayout *optionsLayout = new QFormLayout();
    optionsLayout->addWidget(tcpCheckBox);
    optionsLayout->addRow("Rtsp URL", rtspUrlEdit);

    // -----------------------------------------------------------------
    // Player controls
    QBoxLayout *controlLayout = new QHBoxLayout;
    controlLayout->setMargin(0);
    controlLayout->addWidget(debugButton);
    controlLayout->addWidget(m_stopButton);
    controlLayout->addWidget(m_playButton);
    controlLayout->addStretch();

    playerWidget = new QWidget(this);

    QBoxLayout *layout = new QVBoxLayout(this);
    layout->addLayout(optionsLayout);
    layout->addWidget(playerWidget);
    layout->addLayout(controlLayout);

}

//void cb_message (GstBus *bus, GstMessage *msg, CustomData *data)
void cb_message (GstBus *bus, GstMessage *msg, GstElement *pipeline)
{
  (void)bus;          // remove unused variable warning
  int buffering_level = 0;

  switch (GST_MESSAGE_TYPE (msg)) {
  case GST_MESSAGE_BUFFERING:
    gst_message_parse_buffering (msg, &buffering_level);
    qDebug() << "Buffering level: " << buffering_level;
    /* Wait until buffering is complete before start/resume playing */
    if (buffering_level < 100) {
      gst_element_set_state (pipeline, GST_STATE_PAUSED);
    } else {
      gst_element_set_state (pipeline, GST_STATE_PLAYING);
    }
    break;
  default:
    /* Unhandled message */
    break;
  }
  return;
}

VideoPlayer::~VideoPlayer()
{
  gst_element_set_state (pipeline, GST_STATE_NULL);
  gst_object_unref (pipeline);
}

void VideoPlayer::initGst () {
  // prepare the pipeline
  gst_init (NULL, NULL);
  pipeline = gst_pipeline_new ("plop");

  GstBus *bus = gst_element_get_bus (pipeline);
  gst_bus_add_signal_watch (bus);
  g_signal_connect (bus, "message", G_CALLBACK (cb_message), pipeline);
}

void VideoPlayer::setGstTestVideo () {
  setGstTestVideo (0);
}

void VideoPlayer::setGstTestVideo (int pattern)
{
  initGst();

  gst_element_set_state (pipeline, GST_STATE_PAUSED);

  GstElement *src = gst_element_factory_make ("videotestsrc", NULL);
  GstElement *time = gst_element_factory_make ("timeoverlay", NULL);
  GstElement *sink = gst_element_factory_make ("glimagesink", NULL);
  gst_bin_add_many (GST_BIN (pipeline), src, time, sink, NULL);
  gst_element_link_many (src, time, sink, NULL);
  g_object_set (src, "pattern", pattern, NULL);
  g_object_set (time, "font-desc", "Sans, 24", NULL);

  WId xwinid = playerWidget->winId();
  gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (sink), xwinid);

  // Need to set newly added elements in the same state as the pipeline
  gst_element_set_state (src, GST_STATE_PAUSED);
  gst_element_set_state (time, GST_STATE_PAUSED);
  gst_element_set_state (sink, GST_STATE_PAUSED);

  return;
}


void VideoPlayer::setGstFileVideo ()
{
  qDebug() << "[setGstFileVideo] Entering function";
  initGst();

  GstElement *src = gst_element_factory_make ("filesrc", NULL);
  GstElement *demux = gst_element_factory_make ("qtdemux", NULL);
  GstElement *vdec = gst_element_factory_make ("avdec_h264", NULL);
  GstElement *vqueue = gst_element_factory_make ("queue2", NULL);
  GstElement *vconv = gst_element_factory_make ("videoconvert", NULL);
  GstElement *time = gst_element_factory_make ("timeoverlay", NULL);
  GstElement *sink = gst_element_factory_make ("glimagesink", NULL);
  video_sink = sink;

  // qDebug () << "[setGstFileVideo] rtspUrl = " << rtspUrl;
  g_object_set (src, "location", "sintel-trailer.mp4", NULL);
  g_object_set (time, "font-desc", "Sans, 24", NULL);
  //g_object_set (vqueue, "ring-buffer-max-size", (guint64)40000000, NULL);
  g_object_set (vqueue,
                "max-size-bytes", (guint64)128 * 1024 * 1024, // 128 MB buffer
                //"ring-buffer-max-size", (guint64)128 * 1024, // 128 KB buffer
                "use-buffering", true,
                NULL);

  // if (!rate_control) {
  //   g_object_set (src, "onvif-rate-control", FALSE, NULL);
  // }

  // if (use_tcp) {
  //   g_object_set (src, "protocols", GST_RTSP_LOWER_TRANS_TCP, NULL);
  // }

  gst_bin_add_many (GST_BIN (pipeline), src, demux, vdec, vqueue, vconv, time, sink, NULL);

  gst_element_link_many (src, demux, NULL);
  // link demux to vdec in a cb, when pad is created
  g_signal_connect (demux, "pad-added", G_CALLBACK (pad_added_cb), vdec);
  // link rest of the pipeline
  gst_element_link_many (vdec, vqueue, vconv, time, sink, NULL);

  WId xwinid = playerWidget->winId();
  gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (sink), xwinid);

  gst_element_set_state (pipeline, GST_STATE_PAUSED);
  qDebug() << "[setGstFileVideo] All done, pipeline is in PAUSED state";

  return;
}



void VideoPlayer::setGstRtspVideo ()
{
  initGst();

  GstElement *src = gst_element_factory_make ("rtspsrc", NULL);
  GstElement *vdepay = gst_element_factory_make ("rtph264depay", NULL);
  GstElement *vdec = gst_element_factory_make ("avdec_h264", NULL);
  GstElement *vqueue = gst_element_factory_make ("queue2", NULL);
  GstElement *vconv = gst_element_factory_make ("videoconvert", NULL);
  GstElement *time = gst_element_factory_make ("timeoverlay", NULL);
  GstElement *sink = gst_element_factory_make ("glimagesink", NULL);

  //g_object_set (src, "location", "rtsp://184.72.239.149/vod/mp4:BigBuckBunny_115k.mov", NULL);
  qDebug () << "[setGstRtspVideo] rtspUrl = " << rtspUrl;
  g_object_set (src, "location", rtspUrl.toStdString().c_str(), NULL);
  g_object_set (time, "font-desc", "Sans, 24", NULL);
  g_object_set (vqueue, "max-size-bytes", (guint64)40000000, NULL);

  if (use_tcp) {
    g_object_set (src, "protocols", GST_RTSP_LOWER_TRANS_TCP, NULL);
  }

  gst_bin_add_many (GST_BIN (pipeline), src, vdepay, vdec, vqueue, vconv, time, sink, NULL);
  // link src to vdepay in a cb, when pad is created
  g_signal_connect (src, "pad-added", G_CALLBACK (pad_added_cb), vdepay);
  // link rest of the pipeline
  gst_element_link_many (vdepay, vdec, vqueue, vconv, time, sink, NULL);

  WId xwinid = playerWidget->winId();
  gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (sink), xwinid);

  gst_element_set_state (pipeline, GST_STATE_PAUSED);

  return;
}


void VideoPlayer::play()
{
  if (!pipeline) {
    setGstRtspVideo();
    //setGstFileVideo();
    //setGstTestVideo();
  }

  // run the pipeline
  GstStateChangeReturn sret = gst_element_set_state (pipeline, GST_STATE_PLAYING);
  if (sret == GST_STATE_CHANGE_FAILURE) {
    gst_element_set_state (pipeline, GST_STATE_NULL);
    gst_object_unref (pipeline);
    // Exit application
    QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit()));
  }
  m_stopButton->setEnabled(true);
  playing = true;
  return;
}

void VideoPlayer::pause()
{
  qDebug() << "PAUSE called";
  //GST_DEBUG_BIN_TO_DOT_FILE((GstBin *)pipeline, GST_DEBUG_GRAPH_SHOW_ALL, "pipeline");
  GstStateChangeReturn sret = gst_element_set_state (pipeline, GST_STATE_PAUSED);
  if (sret == GST_STATE_CHANGE_FAILURE) {
    gst_element_set_state (pipeline, GST_STATE_NULL);
    gst_object_unref (pipeline);
    // Exit application
    QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit()));
  }
  playing = false;
  return;
}

void VideoPlayer::playPause()
{
  if (playing) {
    qDebug() << "toggle: play --> pause";
    m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
    VideoPlayer::pause();
  } else {
    qDebug() << "toggle: pause --> play";
    m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
    //m_playButton->setEnabled(false);
    VideoPlayer::play();
  }
  // playing boolean is set in play and pause methods
  return;
}

void VideoPlayer::stop()
{
  qDebug() << "[STOP function] called";

  if (pipeline) {
    qDebug() << "[STOP function] detected a running pipeline";
    gst_element_set_state (pipeline, GST_STATE_NULL);
    gst_object_unref (pipeline);
    pipeline = nullptr;
    qDebug() << "[STOP function] stopped and dropped pipeline";
  } else {
    qDebug() << "[STOP function] no running pipeline";
  }

  // Reinit interface
  playing = false;
  m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
  playerWidget->repaint();
  m_stopButton->setEnabled(false);

  return;
}



void VideoPlayer::debugSlot()
{
  qDebug() << "DEBUG";
  print_status_of_all();
  qDebug() << "Use TCP? " << use_tcp;
}

void VideoPlayer::useTcp(bool value)
{
  use_tcp = value;
}

void VideoPlayer::setRtspUrl(QString url)
{
  qDebug() << "setRtspUrl: " << url;
  rtspUrl = url;
}

void VideoPlayer::benSlot()
{
    qDebug() << " ben slot...";
}