#include <gst/gst.h>
#include <glib.h>


static gboolean
bus_call (GstBus     *bus,
          GstMessage *msg,
          gpointer    data)
{
  GMainLoop *loop = (GMainLoop *) data;

  switch (GST_MESSAGE_TYPE (msg)) {

    case GST_MESSAGE_EOS:
      g_print ("End of stream\n");
      g_main_loop_quit (loop);
      break;

    case GST_MESSAGE_ERROR: {
      gchar  *debug;
      GError *error;

      gst_message_parse_error (msg, &error, &debug);
      g_free (debug);

      g_printerr ("Error: %s\n", error->message);
      g_error_free (error);

      g_main_loop_quit (loop);
      break;
    }
    default:
      break;
  }

  return TRUE;
}

static gboolean
timeout (gpointer data)
{
  GstElement *pipeline = (GstElement*) data;

  g_print ("Flushing pipeline ...\n");
  GstEvent *flush_event = gst_event_new_flush_start();
  if (!gst_element_send_event(pipeline, flush_event)) {
    g_printerr ("Couldn't send flush-start\n");
  }

  flush_event = gst_event_new_flush_stop(TRUE);
  if (!gst_element_send_event(pipeline, flush_event)) {
    g_printerr ("Couldn't send flush-stop");
  }

  return FALSE;
}

int
main (int   argc,
      char *argv[])
{
  GMainLoop *loop;

  GstElement *pipeline, *source, *parser, *convert, *sink;
  GstBus *bus;
  guint bus_watch_id;

  /* Initialisation */
  gst_init (&argc, &argv);

  loop = g_main_loop_new (NULL, FALSE);


  /* Check input arguments */
  if (argc != 2) {
    g_printerr ("Usage: %s <WAV filename>\n", argv[0]);
    return -1;
  }


  /* Create gstreamer elements */
  pipeline = gst_pipeline_new ("test");
  source   = gst_element_factory_make ("filesrc", NULL);
  parser = gst_element_factory_make ("wavparse", NULL);
  convert = gst_element_factory_make ("audioconvert", NULL);
  sink     = gst_element_factory_make ("alsasink", NULL);

  if (!pipeline || !source || !parser || !convert || !sink) {
    g_printerr ("One element could not be created. Exiting.\n");
    return -1;
  }
 /* Set up the pipeline */

  /* we set the input filename to the source element */
  g_object_set (G_OBJECT (source), "location", argv[1], NULL);

  /* we add a message handler */
  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
  bus_watch_id = gst_bus_add_watch (bus, bus_call, loop);
  gst_object_unref (bus);

  /* we add all elements into the pipeline */
  /* filesrc | wavparse | alsasink */
  gst_bin_add_many (GST_BIN (pipeline),
                    source, parser, convert, sink, NULL);

  gst_element_link_many (source, parser, convert, sink, NULL);

  /* Set the pipeline to "playing" state*/
  g_print ("Now playing: %s\n", argv[1]);
  gst_element_set_state (pipeline, GST_STATE_PLAYING);

  GSource *s = g_timeout_source_new(2000);
  g_source_set_callback(s, timeout, pipeline, NULL);
  g_source_attach(s, NULL);
  g_source_unref(s);

  /* Iterate */
  g_print ("Running...\n");
  g_main_loop_run (loop);


  /* Out of the main loop, clean up nicely */
  g_print ("Returned, stopping playback\n");
  gst_element_set_state (pipeline, GST_STATE_NULL);

  g_print ("Deleting pipeline\n");
  gst_object_unref (GST_OBJECT (pipeline));
  g_source_remove (bus_watch_id);
  g_main_loop_unref (loop);

  return 0;
}
