/*
 ============================================================================
 Name        : gstreamer01_uri.c
 Author      : EC
 Version     : simple hello-world for audio-files only
 USAGE		 : <uri with ogg-file> as arg, e.g. file:///home/pi/Music/cp.ogg
 INFO		 : docs.gstreamer.com 	 	 	 :
 Copyright   : Your copyright notice
 Description : Hello World in C, Ansi-style
 : hello_world-Bsp für GStreamer
 ============================================================================
 */

#include <gst/gst.h>
#include <stdio.h>
#include <stdlib.h>

/* Structure to contain all our information, so we can pass it to callbacks */
typedef struct _CustomData {
	GstElement *pipeline;
	GstElement *source;
	GstElement *audio_converter;
	GstElement *audio_sink;
	GstElement *video_converter;
	GstElement *video_sink;
} CustomData;

/* Handler for the pad-added signal */
static void pad_added_handler(GstElement *src, GstPad *pad, CustomData *data);

int main(int argc, char *argv[]) {
	CustomData data;
	GstBus *bus;
	GstMessage *msg;
	GstStateChangeReturn ret;
	gboolean terminate = FALSE;

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

	/* Initialize GStreamer */
	gst_init(&argc, &argv);

	/* Create the elements */
	data.source = gst_element_factory_make("uridecodebin", "source");
	data.audio_converter = gst_element_factory_make("audioconvert",
			"audio_converter");
	data.audio_sink = gst_element_factory_make("autoaudiosink", "audio_sink");
	data.video_converter = gst_element_factory_make("videoconvert",
			"video_converter");
	data.video_sink = gst_element_factory_make("ximagesink", "video_sink");

	/* Create the empty pipeline */
	data.pipeline = gst_pipeline_new("test-pipeline");

	if (!data.pipeline || !data.source || !data.audio_converter
			|| !data.audio_sink || !data.video_converter || !data.video_sink) {
		g_printerr("Not all elements could be created.\n");
		return -1;
	}

	/* Build the pipeline. Note that we are NOT linking the source at this
	 * point. We will do it later. */
	gst_bin_add_many(GST_BIN(data.pipeline), data.source, data.audio_converter,
			data.audio_sink, data.video_sink, data.video_converter, NULL);
	if (!gst_element_link(data.audio_converter, data.audio_sink)) {
		g_printerr("Elements could not be linked.\n");
		gst_object_unref(data.pipeline);
		return -1;
	}

	//Same for video
	if (!gst_element_link(data.video_converter, data.video_sink)) {
		g_printerr("Elements could not be linked.\n");
		gst_object_unref(data.pipeline);
		return -1;
	}

	/* Set the URI to play */
	// g_object_set (data.source, "uri", "http://docs.gstreamer.com/media/sintel_trailer-480p.webm", NULL);
	g_object_set(data.source, "uri", argv[1], NULL);

	/* Connect to the pad-added signal */
	g_signal_connect(data.source, "pad-added", G_CALLBACK(pad_added_handler),
			&data);

	/* Start playing */
	ret = gst_element_set_state(data.pipeline, GST_STATE_PLAYING);
	if (ret == GST_STATE_CHANGE_FAILURE) {
		g_printerr("Unable to set the pipeline to the playing state.\n");
		gst_object_unref(data.pipeline);
		return -1;
	}

	/* Listen to the bus */
	bus = gst_element_get_bus(data.pipeline);
	do {
		msg = gst_bus_timed_pop_filtered(bus, GST_CLOCK_TIME_NONE,
				GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_ERROR
						| GST_MESSAGE_EOS);

		/* Parse message */
		if (msg != NULL) {
			GError *err;
			gchar *debug_info;

			switch (GST_MESSAGE_TYPE(msg)) {
			case GST_MESSAGE_ERROR:
				gst_message_parse_error(msg, &err, &debug_info);
				g_printerr("Error received from element %s: %s\n",
						GST_OBJECT_NAME(msg->src), err->message);
				g_printerr("Debugging information: %s\n",
						debug_info ? debug_info : "none");
				g_clear_error(&err);
				g_free(debug_info);
				terminate = TRUE;
				break;
			case GST_MESSAGE_EOS:
				g_print("End-Of-Stream reached.\n");
				terminate = TRUE;
				break;
			case GST_MESSAGE_STATE_CHANGED:
				/* We are only interested in state-changed messages from the pipeline */
				if (GST_MESSAGE_SRC(msg) == GST_OBJECT(data.pipeline)) {
					GstState old_state, new_state, pending_state;
					gst_message_parse_state_changed(msg, &old_state, &new_state,
							&pending_state);
					g_print("Pipeline state changed from %s to %s:\n",
							gst_element_state_get_name(old_state),
							gst_element_state_get_name(new_state));
				}
				break;
			default:
				/* We should not reach here */
				g_printerr("Unexpected message received.\n");
				break;
			}
			gst_message_unref(msg);
		}
	} while (!terminate);

	/* Free resources */
	gst_object_unref(bus);
	gst_element_set_state(data.pipeline, GST_STATE_NULL);
	gst_object_unref(data.pipeline);
	return 0;
}

/* This function will be called by the pad-added signal */
static void pad_added_handler(GstElement *src, GstPad *new_pad,
		CustomData *data) {
	GstPad *audio_sink_pad = gst_element_get_static_pad(data->audio_converter,
			"sink");
	GstPad *video_sink_pad = gst_element_get_static_pad(data->video_converter,
			"sink");
	GstPadLinkReturn ret;
	GstCaps *new_pad_caps = NULL;
	GstStructure *new_pad_struct = NULL;
	const gchar *new_pad_type = NULL;

	g_print("Received new pad '%s' from '%s':\n", GST_PAD_NAME(new_pad),
			GST_ELEMENT_NAME(src));


	/* Check the new pad's type */
	new_pad_caps = gst_pad_query_caps(new_pad, NULL);
	new_pad_struct = gst_caps_get_structure(new_pad_caps, 0);
	new_pad_type = gst_structure_get_name(new_pad_struct);

	if (g_str_has_prefix(new_pad_type, "audio/x-raw")) {
		if (gst_pad_is_linked(audio_sink_pad)) {
			g_print("Audio pad linked already\n");
			goto exit;
		}
		ret = gst_pad_link(new_pad, audio_sink_pad);
	} else if (g_str_has_prefix(new_pad_type, "video/x-raw")) {
		g_print("Linking the video pad to the video converter sink\n");
		g_print("Is pad linked: %d\n", gst_pad_is_linked(video_sink_pad));
		if (gst_pad_is_linked(video_sink_pad)) {
			g_print("Video pad linked already\n");
			goto exit;
		}
		ret = gst_pad_link(new_pad, video_sink_pad);
	}
	if (GST_PAD_LINK_FAILED(ret)) {
		g_print("  Type is '%s' but link failed.\n", new_pad_type);
	} else {
		g_print("  Link succeeded (type '%s').\n", new_pad_type);
	}

	exit:
	/* Unreference the new pad's caps, if we got them */
	if (new_pad_caps != NULL)
		gst_caps_unref(new_pad_caps);

	/* Unreference the sink pad */
	gst_object_unref(audio_sink_pad);
	gst_object_unref(video_sink_pad);
}