/** Main routine.
 *
 * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
 * @copyright 2014-2015, Institute for Automation of Complex Power Systems, EONERC
 *   This file is part of S2SS. All Rights Reserved. Proprietary and confidential.
 *   Unauthorized copying of this file, via any medium is strictly prohibited.
 *********************************************************************************/

#include <stdlib.h>
#include <string.h>

#include <signal.h>
#include <unistd.h>

#include <sched.h>

#include "config.h"
#include "utils.h"
#include "cfg.h"
#include "path.h"
#include "node.h"
#include "stats.h"
#include "checks.h"

#ifdef ENABLE_OPAL_ASYNC
  #include "opal.h"
#endif

/** Linked list of nodes */
struct list nodes;
/** Linked list of paths */
struct list paths;
/** The global configuration */
struct settings settings;
/** libconfig handle */
static config_t config;

static void quit()
{
	info("Stopping paths");
	FOREACH(&paths, it)
		path_stop(it->path);

	info("Stopping nodes");
	FOREACH(&nodes, it)
		node_stop(it->node);

	info("De-initializing node types");
	node_deinit();

	/* Freeing dynamically allocated memory */
	list_destroy(&paths);
	list_destroy(&nodes);
	config_destroy(&config);

	info("Goodbye!");

	_exit(EXIT_SUCCESS);
}

static void realtime_init()
{ INDENT
	/* Use FIFO scheduler with real time priority */
	if (settings.priority) {
		struct sched_param param = {
			.sched_priority = settings.priority
		};

		if (sched_setscheduler(0, SCHED_FIFO, &param))
			serror("Failed to set real time priority");
		else
			debug(3, "Set task priority to %u", settings.priority);
	}

	/* Pin threads to CPUs by setting the affinity */
	if (settings.affinity) {
		cpu_set_t cset = to_cpu_set(settings.affinity);
		if (sched_setaffinity(0, sizeof(cset), &cset))
			serror("Failed to set CPU affinity to '%#x'", settings.affinity);
		else
			debug(3, "Set affinity to %#x", settings.affinity);
	}
}

/* Setup exit handler */
static void signals_init()
{
	struct sigaction sa_quit = {
		.sa_flags = SA_SIGINFO,
		.sa_sigaction = quit
	};

	sigemptyset(&sa_quit.sa_mask);
	sigaction(SIGINT, &sa_quit, NULL);
	sigaction(SIGTERM, &sa_quit, NULL);
}

static void usage(const char *name)
{
	printf("Usage: %s CONFIG\n", name);
	printf("  CONFIG is a required path to a configuration file\n\n");
#ifdef ENABLE_OPAL_ASYNC
	printf("Usage: %s OPAL_ASYNC_SHMEM_NAME OPAL_ASYNC_SHMEM_SIZE OPAL_PRINT_SHMEM_NAME\n", name);
	printf("  This type of invocation is used by OPAL-RT Asynchronous processes.\n");
	printf("  See in the RT-LAB User Guide for more information.\n\n");
#endif
	printf("Supported features:\n");
#ifdef ENABLE_PCI
	printf(" - libpci: GTFPGA PCIe card\n");
#endif
#ifdef ENABLE_SOCKET
	printf(" - libnl3: Network Emulation\n");
#endif
#ifdef ENABLE_OPAL_ASYNC
	printf(" - libOpalAsyncApi: run as OPAL Asynchronous Process\n");
#endif
	printf("\n");
	printf("Simulator2Simulator Server %s (built on %s %s)\n",
		BLU(VERSION), MAG(__DATE__), MAG(__TIME__));
	printf(" copyright 2014-2015, Institute for Automation of Complex Power Systems, EONERC\n");
	printf(" Steffen Vogel <StVogel@eonerc.rwth-aachen.de>\n");

	exit(EXIT_FAILURE);
}

int main(int argc, char *argv[])
{
	_mtid = pthread_self();

	/* Check arguments */
#ifdef ENABLE_OPAL_ASYNC
	if (argc != 2 && argc != 4)
#else
	if (argc != 2)
#endif
		usage(argv[0]);

	char *configfile = (argc == 2) ? argv[1] : "opal-shmem.conf";

	log_reset();
	info("This is Simulator2Simulator Server (S2SS)");
	info ("  Version: %s (built on %s, %s)", BLD(YEL(VERSION)),
		BLD(MAG(__DATE__)), BLD(MAG(__TIME__)));

	/* Checks system requirements*/
	if (check_root())
		error("The server requires superuser privileges!");
#ifdef LICENSE
	if (check_license_trace())
		error("This software should not be traced!");
	if (check_license_time())
		error("Your license expired");
	if (check_license_ids())
		error("This version is compiled for a different machine!");
#endif
	if (check_kernel_version())
		error("Your kernel version is to old: required >= %u.%u", KERNEL_VERSION_MAJ, KERNEL_VERSION_MIN);
	if (check_kernel_cmdline())
		warn("You should reserve some cores for the server (see 'isolcpus')");
	if (check_kernel_rtpreempt())
		warn("We recommend to use an RT_PREEMPT patched kernel!");

	/* Initialize lists */
	list_init(&nodes, (dtor_cb_t) node_destroy);
	list_init(&paths, (dtor_cb_t) path_destroy);

	info("Initialize real-time system");
	realtime_init();

	info("Initialize signals");
	signals_init();

	info("Parsing configuration");
	config_init(&config);
	config_parse(configfile, &config, &settings, &nodes, &paths);

	info("Initialize node types");
	node_init(argc, argv, &settings);

	info("Starting nodes");
	FOREACH(&nodes, it)
		node_start(it->node);

	info("Starting paths");
	FOREACH(&paths, it)
		path_start(it->path);

	/* Run! */
	if (settings.stats > 0) {
		stats_header();

		for (;;) FOREACH(&paths, it) {
			usleep(settings.stats * 1e6);
			path_run_hook(it->path, HOOK_PERIODIC);
		}
	}
	else
		pause();

	return 0;
}