#include "rodisc.h"

#include <gio/gio.h>

static GVolumeMonitor *monitor;

static bool guess_volume_type(GVolume *volume, const char **type)
{
	GIcon *icon = g_volume_get_icon(volume);
	g_return_val_if_fail(G_IS_THEMED_ICON(icon), false);
	GThemedIcon *ticon = G_THEMED_ICON(icon);
	
	const gchar * const * names = g_themed_icon_get_names(ticon);
	for (const gchar * const * name = names; *name; ++name) {
		if (g_str_has_prefix(*name, "media-optical")) {
			if (g_str_has_prefix(*name, "media-optical-dvd")) {
				*type = RODISC_TYPE_DVD;
			} else if (g_str_has_prefix(*name, "media-optical-cd")) {
				*type = RODISC_TYPE_CD;
			} else {
				*type = RODISC_TYPE_GENERIC;
			}
			return true;
		}
	}

	return false;
}

static bool set_disc_attrs(RODisc *disc, GVolume *volume)
{
	g_free(disc->label);

	disc->label = g_volume_get_identifier(volume, G_VOLUME_IDENTIFIER_KIND_LABEL);
	if (!disc->label || disc->label[0] == '\0') {
		g_free(disc->label);
		disc->label = g_volume_get_name(volume);
	}
	if (!disc->label || disc->label[0] == '\0') {
		g_free(disc->label);
		disc->label = g_strdup("Disc");
	}

	// Open file and seek to end to verify read permission and file size

	GError *error = NULL;
	GFileInputStream * stream = g_file_read(disc->file, NULL, &error);

	if (!stream) {
		g_warning("Could not open file '%s' for reading: %s",
		          disc->file_path, error->message);
		g_error_free(error);
		return false;
	}

	if (!g_seekable_seek(G_SEEKABLE(stream), 0, G_SEEK_END, NULL, &error)) {
		g_warning("Could not seek in file '%s' for obtaining file size: %s",
		          disc->file_path, error->message);
		g_error_free(error);
		return false;
	}

	disc->size = g_seekable_tell(G_SEEKABLE(stream));

	g_input_stream_close(G_INPUT_STREAM(stream), NULL, NULL);
	g_object_unref(stream);

	return true;
}

static void try_add_volume(GVolume *volume)
{
	const char * type;
	if (!guess_volume_type(volume, &type)) {
		// Ignore non-optical device
		return;
	}

	char *device_file_path = g_volume_get_identifier(volume, G_VOLUME_IDENTIFIER_KIND_UNIX_DEVICE);
	if (!device_file_path) {
		return;
	}

	RODisc *disc = rodisc_new();

	char *basename = g_path_get_basename(device_file_path);

	disc->id = device_file_path;
	disc->uri = g_strconcat("/", basename, NULL);
	disc->file = g_file_new_for_path(device_file_path);
	disc->file_path = g_file_get_path(disc->file);
	disc->type = type;

	g_free(basename);

	if (set_disc_attrs(disc, volume)) {
		rodisc_export(disc);
	} else {
		rodisc_destroy(disc);
	}
}

static void try_update_volume(GVolume *volume, RODisc *disc)
{
	const char * type;
	if (!guess_volume_type(volume, &type)) {
		g_debug("no longer a optical media");
		rodisc_remove(disc);
		return;
	}

	disc->type = type;

	if (set_disc_attrs(disc, volume)) {
		rodisc_refresh(disc);
	} else {
		rodisc_remove(disc);
	}
}

static void monitor_volume_added_cb(GVolumeMonitor *volume_monitor, GVolume *volume,
                                    gpointer user_data)
{
	char *device_file_path = g_volume_get_identifier(volume, G_VOLUME_IDENTIFIER_KIND_UNIX_DEVICE);
	if (!device_file_path) {
		return;
	}

	g_debug("Volume added: %s", device_file_path);

	RODisc *disc = rodisc_lookup(device_file_path);
	if (disc) {
		g_warning("Device already added: %s", device_file_path);
	} else {
		try_add_volume(volume);
	}

	g_free(device_file_path);
}

static void monitor_volume_changed_cb(GVolumeMonitor *volume_monitor, GVolume *volume,
                                      gpointer user_data)
{
	char *device_file_path = g_volume_get_identifier(volume, G_VOLUME_IDENTIFIER_KIND_UNIX_DEVICE);
	if (!device_file_path) {
		return;
	}

	g_debug("Volume changed: %s", device_file_path);

	RODisc *disc = rodisc_lookup(device_file_path);
	if (disc) {
		try_update_volume(volume, disc);
	} else {
		try_add_volume(volume);
	}

	g_free(device_file_path);
}

static void monitor_volume_removed_cb(GVolumeMonitor *volume_monitor, GVolume *volume,
                                      gpointer user_data)
{
	char *device_file_path = g_volume_get_identifier(volume, G_VOLUME_IDENTIFIER_KIND_UNIX_DEVICE);
	if (!device_file_path) {
		return;
	}

	g_debug("Volume removed: %s", device_file_path);

	RODisc *disc = rodisc_lookup(device_file_path);
	if (disc) {
		rodisc_remove(disc);
	}

	g_free(device_file_path);
}

static void enumerate_volumes()
{
	GList *volumes = g_volume_monitor_get_volumes(monitor);
	for (GList *l = volumes; l != NULL; l = l->next) {
		GVolume *volume = G_VOLUME(l->data);
		try_add_volume(volume);
	}
	g_list_free_full(volumes, g_object_unref);
}

bool monitor_start()
{
	monitor = g_volume_monitor_get();
	if (!monitor) {
		g_warning("Could not get volume monitor");
		return false;
	}

	g_signal_connect(monitor, "volume-added",
	                 G_CALLBACK(monitor_volume_added_cb), NULL);
	g_signal_connect(monitor, "volume-changed",
	                 G_CALLBACK(monitor_volume_changed_cb), NULL);
	g_signal_connect(monitor, "volume-removed",
	                 G_CALLBACK(monitor_volume_removed_cb), NULL);

	enumerate_volumes();

	return true;
}

void monitor_stop()
{
	g_object_unref(monitor);
}