// anchorman - A program to stream webcams.
//
// Copyright (C) 2011 Trever Fischer <tdfischer@fedoraproject.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//

#define G_UDEV_API_IS_SUBJECT_TO_CHANGE

#include <gst/gst.h>
#include <gudev/gudev.h>
#include <string.h>

// Original gst-launch command:
// gst-launch v4l2src device=/dev/video0 ! ffmpegcolorspace ! videorate ! videoscale ! video/x-raw-yuv,width=320,height=240 ! theoraenc bitrate=64 ! queue leaky=1 ! oggmux name=mux alsasrc device=hw:1 ! audioconvert ! vorbisenc ! queue leaky=1 ! mux. mux. ! queue ! shout2send ip=acm.cs.uakron.edu mount=lab.ogg

GMainLoop *loop;

static gchar *videoDevice = 0;
static gchar *audioDevice = 0;
static gchar *icecastServer = 0;
static gchar *icecastMount = 0;

static GOptionEntry entries[] =
{
	{ "video-device", 'v', 0, G_OPTION_ARG_STRING, &videoDevice, "Video device to use", "device" },
	{ "audio-device", 'a', 0, G_OPTION_ARG_STRING, &audioDevice, "Audio device to use", "device" },
	{ "server", 's', 0, G_OPTION_ARG_STRING, &icecastServer, "Icecast server to stream to", "server" },
	{ "mount", 'm', 0, G_OPTION_ARG_STRING, &icecastMount, "Icecast mount to stream to on the server", "mount" },
	{ NULL }
};

static const gchar *subsystems[] =
{
	"video4linux",
	NULL
};

gboolean startPipeline(GstElement *pipe) {
	GstStateChangeReturn stateChange;
	stateChange = gst_element_set_state(pipe, GST_STATE_PLAYING);
	switch(stateChange) {
		case GST_STATE_CHANGE_SUCCESS:
		case GST_STATE_CHANGE_ASYNC:
			return TRUE;
		default:
			return FALSE;
	}
}

gboolean stopPipeline(GstElement *pipe) {
	GstStateChangeReturn stateChange;
	stateChange = gst_element_set_state(pipe, GST_STATE_NULL);
	switch(stateChange) {
		case GST_STATE_CHANGE_SUCCESS:
		case GST_STATE_CHANGE_ASYNC:
			return TRUE;
		default:
			return FALSE;
	}
}

void newDevice_cb(GUdevClient *client, gchar *action, GUdevDevice *device, gpointer data)
{
	g_debug("Got %s event for %s", action, g_udev_device_get_name(device));
	if (strcmp(g_udev_device_get_device_file(device), videoDevice) == 0) {
		if (strcmp(action, "add") == 0) {
			g_print("Device added.\n");
			while(!startPipeline((GstElement*)data));
		} else if (strcmp(action, "remove") == 0) {
			g_print("Device removed.\n");
			while(!stopPipeline((GstElement*)data));
		}
	}
}

static gboolean message_cb(GstBus *bus, GstMessage *msg, gpointer data)
{
	g_debug("Got message %s", GST_MESSAGE_TYPE_NAME(msg));
}

static gboolean state_cb(GstBus *bus, GstMessage *msg, gpointer data)
{
	GstState oldState;
	GstState newState;
	GstState pendingState;
	gchar *name;

	gst_message_parse_state_changed(msg, &oldState, &newState, &pendingState);
	name = gst_element_get_name(msg->src);
	g_debug("Element %s changed state from %s to %s", name, gst_element_state_get_name(oldState), gst_element_state_get_name(newState));
	g_free(name);
}

static gboolean error_cb(GstBus *bus, GstMessage *msg, gpointer data)
{
	GError *err;
	gchar *debug;
	gst_message_parse_error(msg, &err, &debug);
	g_free(debug);
	if (err->domain == GST_RESOURCE_ERROR) {
		if (err->code == GST_RESOURCE_ERROR_OPEN_READ) {
			g_debug("Could not open a device: %s", err->message);
			goto out;
		}
	} else {
		g_error("%d: %s", err->code, err->message);
	}
	g_main_loop_quit(loop);
out:
	g_error_free(err);
}

static gboolean warning_cb(GstBus *bus, GstMessage *msg, gpointer data)
{
	GError *err;
	gchar *debug;
	gst_message_parse_warning(msg, &err, &debug);
	g_free(debug);
	g_warning("%d %d: %s", err->domain, err->code, err->message);
	if (err->domain == 992 && err->code == 13)
		while(!stopPipeline((GstElement*)data));
	g_error_free(err);
}

GstElement *buildPipeline(const gchar *videoDev, const gchar *audioDev, const gchar *server, const gchar *mount)
{
	GstElement *pipe = gst_pipeline_new(NULL);

	// Video pipeline
	GstElement *v4lsrc = gst_element_factory_make("v4l2src", NULL);
	GstElement *convert = gst_element_factory_make("ffmpegcolorspace", NULL);
	GstElement *rate = gst_element_factory_make("videorate", NULL);
	GstElement *scale = gst_element_factory_make("videoscale", NULL);
	GstElement *encode = gst_element_factory_make("theoraenc", NULL);
	GstElement *videoQueue = gst_element_factory_make("queue", NULL);
	
	gst_bin_add_many(GST_BIN(pipe), v4lsrc, convert, rate, scale, encode, videoQueue, NULL);
	gst_element_link(encode, videoQueue);
	gst_element_link_many(v4lsrc, convert, rate, scale);
	GstCaps *caps = gst_caps_new_simple("video/x-raw-yuv", "width", G_TYPE_INT, 480, "height", G_TYPE_INT, 360, NULL);
	gst_element_link_filtered(scale, encode, caps);

	// Audio pipeline
	GstElement *alsasrc = gst_element_factory_make("alsasrc", NULL);
	GstElement *audioConvert = gst_element_factory_make("audioconvert", NULL);
	GstElement *vorbisenc = gst_element_factory_make("vorbisenc", NULL);
	GstElement *audioQueue = gst_element_factory_make("queue", NULL);

	gst_bin_add_many(GST_BIN(pipe), alsasrc, audioConvert, vorbisenc, audioQueue, NULL);
	gst_element_link_many(alsasrc, audioConvert, vorbisenc, audioQueue, NULL);


	// Combine
	GstElement *oggMux = gst_element_factory_make("oggmux", NULL);
	gst_bin_add(GST_BIN(pipe), oggMux);
	gst_element_link(videoQueue, oggMux);
	gst_element_link(audioQueue, oggMux);
	
	// Broadcast!
	GstElement *shout = gst_element_factory_make("shout2send", NULL);

	gst_bin_add(GST_BIN(pipe), shout);
	gst_element_link(oggMux, shout);

	GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(pipe));
	gst_bus_add_signal_watch(bus);
	g_signal_connect(bus, "message::error", G_CALLBACK(error_cb), pipe);
	g_signal_connect(bus, "message::warning", G_CALLBACK(warning_cb), pipe);
	g_signal_connect(bus, "message::state-changed", G_CALLBACK(state_cb), pipe);
	g_signal_connect(bus, "message", G_CALLBACK(message_cb), pipe);

	if (audioDevice)
		g_object_set(G_OBJECT(alsasrc), "device", audioDev, NULL);
	if (videoDevice)
		g_object_set(G_OBJECT(v4lsrc), "device", videoDev, NULL);
	if (icecastServer)
		g_object_set(G_OBJECT(shout), "ip", server, NULL);
	if (icecastMount)
		g_object_set(G_OBJECT(shout), "mount", mount, NULL);

	g_object_set(G_OBJECT(encode), "bitrate", 64, NULL);
	g_object_set(G_OBJECT(videoQueue), "leaky", 1, NULL);
	g_object_set(G_OBJECT(audioQueue), "leaky", 1, NULL);

	return pipe;
}

int main(int argc, char* argv[])
{
	GError *error;
	GOptionContext *context;
	GstStateChangeReturn stateChange;
	GUdevDevice *dev;
	GUdevClient *udevClient;
	GstElement *pipe;

	g_thread_init(NULL);

	context = g_option_context_new(" - Stream a webcam to an icecast server");
	g_option_context_add_main_entries(context, entries, NULL);
	g_option_context_add_group(context, gst_init_get_option_group());

	if (!g_option_context_parse(context, &argc, &argv, &error)) {
		g_print("Bad arguments: %s\n", error->message);
		exit(1);
	}

	if (!gst_init_check(&argc, &argv, &error)) {
		g_print("Could not initialize GStreamer: %s\n", error->message);
		exit(1);
	}

	if (!videoDevice) {
		videoDevice = strdup("/dev/video0");
	}

	pipe = buildPipeline(videoDevice, audioDevice, icecastServer, icecastMount);
	udevClient = g_udev_client_new(subsystems);
	g_signal_connect(udevClient, "uevent", G_CALLBACK(newDevice_cb), pipe);

	startPipeline(pipe);

	loop = g_main_loop_new(NULL, FALSE);
	g_main_loop_run(loop);
}