#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdbool.h>
#include <getopt.h>
#include <sys/signalfd.h>
#include <sys/eventfd.h>
#include <signal.h>
#include <systemd/sd-daemon.h>

#include "main.h"
#include "uring.h"
#include "config.h"
#include "server.h"
#include "cfgdir.h"
#include "announce.h"
#include "systemd.h"
#include "igmp.h"

#define DEFAULT_HOMEDIR_PATH "/home/david/intest"
#define DEFAULT_MAIN_CONFIG_FILE_PATH "./mcproxy.conf"

unsigned debug_mask = DBG_ERROR | DBG_INFO;

bool exiting = false;

struct cfg *cfghack = NULL;

void
__debug(enum debug_category category, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vfprintf(stdout, fmt, ap);
	va_end(ap);
}

__attribute__((noreturn)) void
__die(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	va_end(ap);
	exit(EXIT_FAILURE);
};

static void
cfg_free(struct uring_task *task)
{
	struct cfg *cfg = container_of(task, struct cfg, task);

	debug(DBG_SIG, "called\n");
	systemd_delete(cfg);
	xfree(cfg->igmp_iface);
	cfg->igmp_iface = NULL;
	xfree(cfg->cfg_path);
	cfg->cfg_path = NULL;
	exiting = true;
	/* The cfg struct is free:d in main() */
}

enum mcfg_keys {
	MCFG_KEY_INVALID = 0,
	MCFG_KEY_IGMP,
	MCFG_KEY_IGMP_IFACE
};

struct cfg_key_value_map mcfg_key_map[] = {
	{
		.key_name = "igmp",
		.key_value = MCFG_KEY_IGMP,
		.value_type = CFG_VAL_TYPE_BOOL,
	}, {
		.key_name = "igmp_iface",
		.key_value = MCFG_KEY_IGMP_IFACE,
		.value_type = CFG_VAL_TYPE_STRING,
	}, {
		.key_name = NULL,
		.key_value = MCFG_KEY_INVALID,
		.value_type = CFG_VAL_TYPE_INVALID,
	}
};

static void
cfg_read(struct cfg *cfg)
{
	FILE *cfgfile;
	const char *path;
	char buf[4096];
	char *pos = buf;
	size_t rd = 0;
	size_t r;

	if (cfg->cfg_path)
		path = cfg->cfg_path;
	else
		path = DEFAULT_MAIN_CONFIG_FILE_PATH;

	cfgfile = fopen(path, "re");
	if (!cfgfile) {
		/* ENOENT is only an error with an explicitly set path */
		if (errno == ENOENT && !cfg->cfg_path)
			return;
		else if (errno == ENOENT)
			die("main config file (%s) missing\n", path);
		else
			perrordie("fopen");
	}

	debug(DBG_CFG, "opened main config file (%s)\n", path);

	while (rd < sizeof(buf)) {
		r = fread(pos, 1, sizeof(buf) - rd - 1, cfgfile);
		if (r == 0)
			break;
		rd += r;
		pos += r;
	}

	if (rd == 0)
		die("main config file (%s) invalid\n", path);

	if (rd >= sizeof(buf))
		die("main config file (%s) too large\n", path);

	fclose(cfgfile);
	*pos = '\0';
	pos = buf;

	if (!config_parse_header(cfg, path, "mcproxy", &pos))
		die("main config file (%s) invalid\n", path);

	while (true) {
		int key;
		const char *keyname;
		union cfg_value value;

		if (!config_parse_line(cfg, path, &pos, mcfg_key_map,
				       &key, &keyname, &value))
			break;

		if (key == MCFG_KEY_INVALID)
			die("main config file (%s) invalid\n", path);

		debug(DBG_CFG, "main cfg: key %s\n", keyname);

		switch (key) {

		case MCFG_KEY_IGMP:
			cfg->do_igmp = value.boolean;
			break;

		case MCFG_KEY_IGMP_IFACE:
			cfg->igmp_iface = xstrdup(value.str);
			if (!cfg->igmp_iface)
				perrordie("xstrdup");
			break;

		case MCFG_KEY_INVALID:
		default:
			die("main config file (%s) invalid\n", path);
		}
	}
}

const struct {
	const char *name;
	unsigned val;
} debug_category_str[] = {
	{
		.name = "config",
		.val = DBG_CFG
	},{
		.name = "refcount",
		.val = DBG_REF
	},{
		.name = "malloc",
		.val = DBG_MALLOC
	},{
		.name = "announce",
		.val = DBG_ANN
	},{
		.name = "signals",
		.val = DBG_SIG
	},{
		.name = "uring",
		.val = DBG_UR
	},{
		.name = "server",
		.val = DBG_SRV
	},{
		.name = "proxy",
		.val = DBG_PROXY
	},{
		.name = "rcon",
		.val = DBG_RCON
	},{
		.name = "idle",
		.val = DBG_IDLE
	},{
		.name = "igmp",
		.val = DBG_IGMP
	},{
		.name = NULL,
		.val = 0
	}
};

static struct cfg *
cfg_init(int argc, char **argv)
{
	struct cfg *cfg;
	int c;
	unsigned i;

	cfg = zmalloc(sizeof(*cfg));
	if (!cfg)
		perrordie("malloc");

	uring_task_init(&cfg->task, "cfg", NULL, cfg_free);
	list_init(&cfg->servers);

	while (true) {
		int option_index = 0;
		static struct option long_options[] = {
			{ "homedir",	required_argument,	0, 'h' },
			{ "debug",	required_argument,	0, 'd' },
			{ "verbose",	no_argument,		0, 'v' },
			{ 0,		0,			0,  0  }
		};

		c = getopt_long(argc, argv, ":h:d:v",
				long_options, &option_index);
		if (c == -1)
			break;

		switch (c) {
		case 'h':
			cfg->homedir = optarg;
			break;
		case 'v':
			debug_mask |= DBG_VERBOSE;
			break;
		case 'd':
			if (!strcasecmp(optarg, "all")) {
				debug_mask = ~0;
				break;
			} else if (!strcasecmp(optarg, "list")) {
				error("Debug categories:\n");
				error(" * all\n");
				for (i = 0; debug_category_str[i].name; i++)
					error(" * %s\n", debug_category_str[i].name);
				exit(EXIT_FAILURE);
			}

			for (i = 0; debug_category_str[i].name; i++) {
				if (!strcasecmp(optarg, debug_category_str[i].name))
					break;
			}

			if (!debug_category_str[i].name)
				die("invalid debug category");

			debug_mask |= debug_category_str[i].val;
			break;
		default:
			die("invalid arguments");
		}

	}

	if (optind < argc)
		die("invalid arguments");

	if (!cfg->homedir)
		cfg->homedir = DEFAULT_HOMEDIR_PATH;

	verbose("Homedir is %s\n", cfg->homedir);
	if (chdir(cfg->homedir))
		perrordie("chdir");

	return cfg;
}

struct signalfd_ev {
	struct uring_task task;
	//struct signalfd_siginfo buf;
	struct cfg *cfg;
	uint64_t buf;
};

static void
signalfd_free(struct uring_task *task)
{
	struct signalfd_ev *sev = container_of(task, struct signalfd_ev, task);

	debug(DBG_SIG, "called\n");
	sev->cfg->sev = NULL;
	xfree(sev);
}

static void
dump_tree(struct cfg *cfg)
{
	struct server *server;

	if (!debug_enabled(DBG_REF))
		return;

	debug(DBG_REF, "\n\n\n\n");
	debug(DBG_REF, "Dumping Tree\n");
	debug(DBG_REF, "============\n");
	uring_task_refdump(&cfg->task);
	uring_refdump(cfg->uev);
	if (cfg->sev)
		uring_task_refdump(&cfg->sev->task);
	igmp_refdump(cfg->igmp);
	announce_refdump(cfg->aev);
	if (cfg->iev)
		cfgdir_refdump(cfg->iev);
	list_for_each_entry(server, &cfg->servers, list)
		server_refdump(server);
	debug(DBG_REF, "============\n");
	debug(DBG_REF, "\n\n\n\n");
}

static void
signalfd_read(struct cfg *cfg, struct uring_task *task, int res)
{
	struct signalfd_ev *sev = container_of(task, struct signalfd_ev, task);
	struct server *server, *stmp;
	static int count = 0;

	if (task->dead) {
		debug(DBG_SIG, "task dead\n");
		return;
	}

	count++;
	if (count > 5) {
		error("Max signal count exceeded, force quitting\n");
		exit(EXIT_FAILURE);
	}

	if (res != sizeof(sev->buf))
		die("error in signalfd (%i)", res);

	if (sev->buf < 1000) {
		verbose("got a signal to quit\n");
		sd_notifyf(0, "STOPPING=1\nSTATUS=Received signal, exiting");
		exit(EXIT_SUCCESS);
	} else {
		verbose("got a signal to dump tree\n");
		sd_notifyf(0, "STOPPING=1\nSTATUS=Received signal, exiting");
		dump_tree(cfg);
		uring_task_put(cfg, &sev->task);
		igmp_delete(cfg);
		announce_delete(cfg);
		cfgdir_delete(cfg);
		list_for_each_entry_safe(server, stmp, &cfg->servers, list)
			server_delete(cfg, server);
		uring_delete(cfg);
		return;
	}

	uring_read(cfg, &sev->task, &sev->buf, sizeof(sev->buf), signalfd_read);
}

static int hack_efd = -1;

static void
hack_handler(int signum)
{
	uint64_t val;
	static int count = 0;

	switch (signum) {
	case SIGINT:
		debug(DBG_SIG, "Got a SIGINT\n");
		val = 1000;
		if (count > 3)
			dump_tree(cfghack);
		break;
	case SIGHUP:
		debug(DBG_SIG, "Got a SIGHUP\n");
		val = 1000;
		break;
	case SIGTERM:
		debug(DBG_SIG, "Got a SIGTERM\n");
		val = 1;
		break;
	default:
		error("Got an unknown sig (%i)\n", signum);
		val = 1;
		break;
	}

	if (count > 5) {
		error("Max signal count exceeded, force quitting\n");
		exit(EXIT_FAILURE);
	}

	write(hack_efd, &val, sizeof(val));
	count++;
}

static void
signalfd_init(struct cfg *cfg)
{
	int sfd;
	//sigset_t mask;
	struct signalfd_ev *sev;

	sev = zmalloc(sizeof(*sev));
	if (!sev)
		perrordie("malloc");

	/*
	sigfillset(&mask);
	if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0)
		perrordie("sigprocmask");

	sfd = signalfd(-1, &mask, SFD_CLOEXEC);
	if (sfd < 0)
		perrordie("signalfd");
	*/

	struct sigaction action;
	sigfillset(&action.sa_mask);
	action.sa_handler = hack_handler;
	action.sa_flags = 0;

	sigaction(SIGINT, &action, NULL);
	sigaction(SIGHUP, &action, NULL);
	sigaction(SIGTERM, &action, NULL);

	action.sa_handler = SIG_IGN;
	sigaction(SIGPIPE, &action, NULL);

	sfd = eventfd(0, EFD_CLOEXEC);
	if (sfd < 0)
		perrordie("eventfd");

	debug(DBG_SIG, "using fd %i\n", sfd);
	uring_task_init(&sev->task, "sev", uring_parent(cfg), signalfd_free);
	uring_task_set_fd(&sev->task, sfd);
	cfg->sev = sev;
	sev->cfg = cfg;
	hack_efd = sfd;
	uring_read(cfg, &sev->task, &sev->buf, sizeof(sev->buf), signalfd_read);
}

int
main(int argc, char **argv)
{
	struct cfg *cfg;
	struct server *server;
	unsigned server_count;

	cfg = cfg_init(argc, argv);

	cfghack = cfg;

	cfg_read(cfg);

	uring_init(cfg);

	signalfd_init(cfg);

	cfgdir_init(cfg);

	announce_init(cfg);

	announce_start(cfg->aev);

	igmp_init(cfg);

	uring_task_put(cfg, &cfg->task);

	server_count = 0;
	list_for_each_entry(server, &cfg->servers, list)
		server_count++;

	sd_notifyf(0, "READY=1\n"
		   "STATUS=Running, %u server configurations loaded\n"
		   "MAINPID=%lu",
		   server_count,
		   (unsigned long)getpid());

	info("mcproxy started, %u server configurations loaded\n",
	     server_count);

	uring_event_loop(cfg);

	verbose("Exiting\n");

	xfree(cfg);

	if (debug_enabled(DBG_MALLOC))
		debug_resource_usage();

	fflush(stdout);
	fflush(stderr);
	exit(EXIT_SUCCESS);
}