#include "player.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 void on_pad_added(GstElement *element, GstPad *pad, gpointer data)
{
	GstPad *sinkpad;
	GstElement *decoder = (GstElement *) data;

	sinkpad = gst_element_get_static_pad(decoder, "sink");

	gst_pad_link(pad, sinkpad);
	gst_object_unref(sinkpad);
}

GstElement * make_element(Player * p, const char * elem_name, const char * name){
	GstElement * elem = gst_element_factory_make(elem_name, name);
	if(elem == NULL){
		g_printerr ("%s could not be created. Exiting.\n", elem_name);
		exit(EXIT_FAILURE);
	}
	gst_bin_add(GST_BIN(p->pipeline), elem);
	return elem;
}

node_t v_gst_element_link_many(GstElement * elem, va_list args){
	GstElement * next = va_arg(args, GstElement*);
	if(elem == NULL || next == NULL)
		return NULL;
	gst_element_link(elem, next);
	GstElement * last = next;
	while((next = va_arg(args, GstElement*)) != NULL){
		gst_element_link(last, next);
		last = next;
	}
	return last;
}

node_t file_node(Player * p, const char * filename, ...){
	GstElement * file_elem = make_element(p, "filesrc", filename);
	g_object_set(G_OBJECT(file_elem), "location", filename, NULL);

	node_t node;
	va_list args;
	va_start(args, filename);
		node = v_gst_element_link_many(file_elem, args);
	va_end(args);
	return node;
}

node_t demux_node(node_t demuxer, GstElement * elem, ...){
	g_signal_connect(demuxer, "pad-added", G_CALLBACK (on_pad_added), elem);

	node_t node;
	va_list args;
	va_start(args, elem);
		node = v_gst_element_link_many(elem, args);
	va_end(args);
	if(node == NULL)
		return elem;
	else
		return node;
}

node_t mux_node(node_t node1, node_t node2, GstElement * elem, ...){
	gst_element_link(node1, elem);
	gst_element_link(node2, elem);

	node_t node;
	va_list args;
	va_start(args, elem);
		node = v_gst_element_link_many(elem, args);
	va_end(args);
	return node;
}

void link_element(Player * p, const char * src, const char * dst){
	gst_element_link(gst_bin_get_by_name(p->pipeline, src),
	                 gst_bin_get_by_name(p->pipeline, dst));
}

void unlink_element(Player * p, const char * src, const char * dst){
	gst_element_unlink(gst_bin_get_by_name(p->pipeline, src),
	                   gst_bin_get_by_name(p->pipeline, dst));
}

char * get_sub_name(char * video_filename){
	char * sub_filename = malloc(strlen(video_filename)*sizeof(char));
	int dot_pos = 0;
	if(sub_filename == NULL){
		fprintf(stderr, "Malloc failed\n");
		exit(EXIT_FAILURE);
	}
	for(int i = 0; video_filename[i] != 0; i++){
		sub_filename[i] = video_filename[i];
		if(video_filename[i] == '.')
			dot_pos = i;
	}
	strcpy(sub_filename + dot_pos + 1, "srt");
	return sub_filename;
}

Player * player_init(){
	Player * p = malloc(sizeof(Player));
	if(p == NULL)
		return NULL;

	gst_init(NULL, NULL);

	p->loop = g_main_loop_new(NULL, FALSE);

	p->pipeline = gst_pipeline_new("pipeline");
	if(!p->pipeline){
		g_printerr("Pipeline could not be created.\n");
		free(p);
		return NULL;
	}

	GstBus * bus = gst_pipeline_get_bus(GST_PIPELINE(p->pipeline));
	gst_bus_add_watch(bus, bus_call, p->loop);
	gst_object_unref(bus);
	return p;
}

void player_clean(Player * p){
	gst_object_unref(GST_OBJECT (p->pipeline));
	free(p);
}