/*
 * Global variables, needed for all threads but only initialized before any
 * FUSE threads are created
 */
const char *appfs_cachedir;
time_t appfs_boottime;
int appfs_fuse_started = 0;
int appfs_threaded_tcl;

/*
 * Global variables for AppFS caching
 */
pthread_mutex_t appfs_path_info_cache_mutex = PTHREAD_MUTEX_INITIALIZER;
int appfs_path_info_cache_size = 8209;
struct appfs_pathinfo *appfs_path_info_cache = NULL;

#ifndef TCL_THREADS
/*
 * Handle unthreaded Tcl
 */
pthread_mutex_t appfs_tcl_big_global_lock = PTHREAD_MUTEX_INITIALIZER;
#define appfs_call_libtcl_enter pthread_mutex_lock(&appfs_tcl_big_global_lock);
#define appfs_call_libtcl_exit pthread_mutex_unlock(&appfs_tcl_big_global_lock);
#else
#warning Using a Threaded Tcl interpreter may cause memory leaks
#define appfs_call_libtcl_enter /**/
#define appfs_call_libtcl_exit /**/
#endif
#define appfs_call_libtcl(x...) appfs_call_libtcl_enter x appfs_call_libtcl_exit

/*
 * Global variables for AppFS Tcl Interpreter restarting

		Tcl_DictObjGet(interp, attrs_dict, attr_key_time, &attr_value);
		if (attr_value != NULL) {
			tcl_ret = Tcl_GetWideIntFromObj(NULL, attr_value, &attr_value_wide);
			if (tcl_ret == TCL_OK) {
				pathinfo->time = attr_value_wide;
			}
		} else {
			pathinfo->time = 0;
			pathinfo->time = appfs_boottime;
		}

		Tcl_Release(interp);
	)

	if (retval == 0) {
		appfs_get_path_info_cache_add(path, fsuid, pathinfo);

 * Hot-restart support
 */
/* Initiate a hot-restart */
static void appfs_hot_restart(void) {
	APPFS_DEBUG("Asked to initiate hot restart");

	appfs_tcl_ResetInterps();

	appfs_get_path_info_cache_flush(-1, -1);

	return;
}

/*
 * Signal handler

	APPFS_DEBUG("Terminating interpreter due to thread termination");

	appfs_call_libtcl(
		Tcl_DeleteInterp(interp);
	)

	appfs_call_libtcl(
	Tcl_FinalizeThread();

		Tcl_FinalizeThread();
	)

	return;
}

/*
 * Command-line parsing tools
 */
static void appfs_print_help(FILE *channel) {
	fprintf(channel, "Usage: {appfsd|mount.appfs} [-o <option>] [-dfsh] <cachedir> <mountpoint>\n");
	fprintf(channel, "\n");
	fprintf(channel, "Options:\n");
	fprintf(channel, "  -d              Enable FUSE debug mode.\n");
	fprintf(channel, "  -f              Run in foreground.\n");
	fprintf(channel, "  -s              Enable single threaded mode.\n");
	fprintf(channel, "  -h              Give this help.\n");
	fprintf(channel, "  -o nothreads    Enable single threaded mode.\n");
	fprintf(channel, "  -o allow_other  Allow other users to access this mountpoint (default\n");
	fprintf(channel, "                  if root).\n");

	return;
}

static int appfs_opt_parse(int argc, char **argv,  struct fuse_args *args) {
	int ch;
	char *optstr, *optstr_next, *optstr_s;
	char fake_arg[3] = {'-', 0, 0};

	/*
	 * Default values
	 */
#ifdef TCL_THREADS
	appfs_threaded_tcl = 1;
#else
	appfs_threaded_tcl = 0;
#endif

	/**
	 ** Add FUSE arguments which we always supply
	 **/
	fuse_opt_add_arg(args, "-odefault_permissions,fsname=appfs,subtype=appfsd,use_ino,kernel_cache,entry_timeout=0,attr_timeout=0,big_writes,intr,hard_remove");

	if (getuid() == 0) {
		fuse_opt_parse(args, NULL, NULL, NULL);
		fuse_opt_add_arg(args, "-oallow_other");
	}

	while ((ch = getopt(argc, argv, "dfsho:")) != -1) {
		switch (ch) {
			case 'o':
				optstr_next = optstr = optstr_s = strdup(optarg);

				while (1) {
					optstr = optstr_next;

					if (!optstr) {
						break;
					}

					optstr_next = strchr(optstr, ',');
					if (optstr_next) {
						*optstr_next = '\0';
						optstr_next++;
					}

					if (strcmp(optstr, "nothreads") == 0) {
						fuse_opt_parse(args, NULL, NULL, NULL);
						fuse_opt_add_arg(args, "-s");

						appfs_threaded_tcl = 0;
					} else if (strcmp(optstr, "allow_other") == 0) {
						fuse_opt_parse(args, NULL, NULL, NULL);
						fuse_opt_add_arg(args, "-oallow_other");
					} else {
						fprintf(stderr, "appfsd: invalid option: \"-o %s\"\n", optstr);

						free(optstr_s);

						return(1);
					}
				}

				free(optstr_s);

				break;
			case 'd':
			case 'f':
			case 's':
				if (ch == 's') {
					appfs_threaded_tcl = 0;
				}

				fake_arg[1] = ch;

				APPFS_DEBUG("Passing option to FUSE: %s", fake_arg);

				fuse_opt_parse(args, NULL, NULL, NULL);
				fuse_opt_add_arg(args, fake_arg);
				break;
			case 'h':
				appfs_print_help(stdout);

				return(0);
			case ':':
			case '?':
			default:
				appfs_print_help(stderr);

				return(1);
		}
	}

	if ((optind + 2) != argc) {
		if ((optind + 2) < argc) {
			fprintf(stderr, "Too many arguments\n");
		} else {
			fprintf(stderr, "Missing cachedir or mountpoint\n");
		}

		appfs_print_help(stderr);

		return(1);
	}

	/*
	 * Set cache dir as first argument (the "device", essentially)
	 */
	appfs_cachedir = argv[optind];

	/*
	 * Pass the remaining argument to FUSE as the directory
	 */
	fuse_opt_parse(args, NULL, NULL, NULL);
	fuse_opt_add_arg(args, argv[optind + 1]);

	return(0);
}


/*
 * FUSE operations structure
 */
static struct fuse_operations appfs_operations = {
	.getattr   = appfs_fuse_getattr,
	.readdir   = appfs_fuse_readdir,

	.unlink    = appfs_fuse_unlink_rmdir,
	.rmdir     = appfs_fuse_unlink_rmdir,
	.mkdir     = appfs_fuse_mkdir,
	.chmod     = appfs_fuse_chmod,
	.symlink   = appfs_fuse_symlink,
};

/*
 * FUSE option parsing callback
 */
static int appfs_fuse_opt_cb(void *data, const char *arg, int key, struct fuse_args *outargs) {
	static int seen_cachedir = 0;

	if (key == FUSE_OPT_KEY_NONOPT && seen_cachedir == 0) {
		seen_cachedir = 1;

		appfs_cachedir = strdup(arg);

		return(0);
	}

	return(1);
}

/*
 * Entry point into this program.
 */
int main(int argc, char **argv) {
	Tcl_Interp *test_interp;
	char *test_interp_error;
	struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
	int pthread_ret;
	struct fuse_args args = FUSE_ARGS_INIT(0, NULL);
	int pthread_ret, aop_ret;
	void *signal_ret;
	char *argv0;

	/*
	 * Skip passed program name
	 */
	if (argc == 0 || argv == NULL) {
		return(1);
	}

	argv0 = argv[0];

	argc--;
	argv++;

	/*
	 * Set global variables, these should be configuration options.
	 */
	appfs_cachedir = APPFS_CACHEDIR;

	/*
	 * Tcl mode, for running raw Tcl in the same environment AppFSd would
	 * run code.
	 */
	if (argc == 2 && strcmp(argv[0], "--tcl") == 0) {
		return(appfs_tcl(argv[1]));
	}

	/*
	 * Register a signal handler for hot-restart requests
	 */
	signal_ret = signal(SIGHUP, appfs_signal_handler);
	if (signal_ret == SIG_ERR) {
		fprintf(stderr, "Unable to install signal handler for hot-restart\n");
		fprintf(stderr, "Hot-restart will not be available.\n");
	}

	/*
	 * Parse command line arguments
	 */
	/**
	 ** Restore argc/argv to original values, replacing argv[0] in case
	 ** it was moified by --cachedir option.
	 **/
	argc++;
	argv--;
	argv[0] = argv0;

	/**
	 ** Perform the argument parsing
	 **/
	aop_ret = appfs_opt_parse(argc, argv, &args);
	if (aop_ret != 0) {
		return(aop_ret);
	}

	/*
	 * Create a Tcl interpreter just to verify that things are in working 
	 * order before we become a daemon.
	 */
	test_interp = appfs_create_TclInterp(&test_interp_error);
	if (test_interp == NULL) {
		if (test_interp_error == NULL) {
			test_interp_error = "Unknown error";
		}

		fprintf(stderr, "Unable to initialize Tcl interpreter for AppFSd:\n");
		fprintf(stderr, "%s\n", test_interp_error);

		return(1);
	}

	Tcl_DeleteInterp(test_interp);

	if (appfs_threaded_tcl) {
	Tcl_FinalizeNotifier(NULL);
		Tcl_FinalizeNotifier(NULL);

	/*
	 * Register a signal handler for hot-restart requests
	 */
	signal_ret = signal(SIGHUP, appfs_signal_handler);
	if (signal_ret == SIG_ERR) {
		fprintf(stderr, "Unable to install signal handler for hot-restart\n");
		fprintf(stderr, "Hot-restart will not be available.\n");
	}

	/*
	 * Add FUSE arguments which we always supply
	 */
	fuse_opt_parse(&args, NULL, NULL, appfs_fuse_opt_cb);
	fuse_opt_add_arg(&args, "-odefault_permissions,fsname=appfs,subtype=appfsd,use_ino,kernel_cache,entry_timeout=0,attr_timeout=0,big_writes,intr,hard_remove");

	if (getuid() == 0) {
		fuse_opt_parse(&args, NULL, NULL, NULL);
		fuse_opt_add_arg(&args, "-oallow_other");
	}

	/*
	 * Enter the FUSE main loop -- this will process any arguments
	 * and start servicing requests.
	 */
	appfs_fuse_started = 1;
	return(fuse_main(args.argc, args.argv, &appfs_operations, NULL));
}