#include "global.h"
#include "rtlm.h"
#include "utils.h"
#include "mqttd.h"
#include "mqttd_calls.h"


static void *startSession(sched_task_t *task);


static inline struct tagSession *
initSession(int sock, ait_val_t * __restrict v)
{
	struct tagSession *sess = NULL;
	const char *str;

	ioTRACE(5);

	if (!v)
		return NULL;

	sess = malloc(sizeof(struct tagSession));
	if (!sess) {
		ioDEBUG(3, "Error:: in malloc #%d - %s", errno, strerror(errno));
		io_freeVar(v);
		return NULL;
	} else
		memset(sess, 0, sizeof(struct tagSession));

	TAILQ_INIT(&sess->sess_sndqueue);

	str = (const char*) cfg_GetAttribute(&cfg, CFG("mqttd"), CFG("retry"));
	if (!str)
		sess->sess_retry = DEFAULT_RETRY;
	else
		sess->sess_retry = strtol(str, NULL, 0);

	sess->sess_buf = mqtt_msgAlloc(USHRT_MAX);
	if (!sess->sess_buf) {
		ioDEBUG(3, "Error:: in msgAlloc #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		free(sess);
		io_freeVar(v);
		return NULL;
	}

	sess->sess_sock = sock;
	strlcpy(sess->sess_addr, (char*) AIT_GET_STR(v), sizeof sess->sess_addr);
	io_freeVar(v);
	return sess;
}

static void
finiSession(struct tagSession *sess, int preservSock)
{
	struct tagStore *store;

	ioTRACE(5);

	if (!sess)
		return;

	if (call.FiniSessPUB)
		call.FiniSessPUB(&cfg, pub, sess->sess_cid, sess->sess_user, "%");

	while ((store = TAILQ_FIRST(&sess->sess_sndqueue))) {
		TAILQ_REMOVE(&sess->sess_sndqueue, store, st_node);

		if (store->st_subscr.sub_topic._base)
			free(store->st_subscr.sub_topic._base);
		if (store->st_subscr.sub_value._base)
			free(store->st_subscr.sub_value._base);

		free(store);
	}

	if (sess->sess_will.msg)
		free(sess->sess_will.msg);
	if (sess->sess_will.topic)
		free(sess->sess_will.topic);

	if (sess->sess_sock > STDERR_FILENO && !preservSock)
		srv_Close(sess->sess_sock);

	mqtt_msgFree(&sess->sess_buf, 42);

	free(sess);
}

static void
stopSession(struct tagSession *sess)
{
	mqtt_msg_t msg = { NULL, 0 };
	int ret;

	ioTRACE(4);

	assert(sess);

	pthread_mutex_lock(&mtx_sess);
	TAILQ_REMOVE(&Sessions, sess, sess_node);
	pthread_mutex_unlock(&mtx_sess);

	ret = mqtt_msgDISCONNECT(&msg);
	if ((ret = send(sess->sess_sock, msg.msg_base, ret, 0)) == -1)
		ioDEBUG(3, "Error:: send(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
	else {
		ioDEBUG(5, "Sended %d bytes for disconnect", ret);
		free(msg.msg_base);
		memset(&msg, 0, sizeof msg);
	}

	ioDEBUG(1, "Close socket=%d", sess->sess_sock);
	finiSession(sess, 0);

	call.LOG(logg, "Session %s stopped from %s for user %s.\n", sess->sess_cid, 
			sess->sess_addr, sess->sess_user);
}

static int
KASession(struct tagSession *sess)
{
	mqtt_msg_t msg = { NULL, 0 };
	int ret;
	struct pollfd pfd;

	ioTRACE(4);

	assert(sess);

	/* ping request */
	ret = mqtt_msgPINGREQ(&msg);
	if ((ret = send(sess->sess_sock, msg.msg_base, ret, 0)) == -1) {
		ioDEBUG(3, "Error:: send(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
		return -1;
	} else {
		ioDEBUG(5, "Sended %d bytes for ping request", ret);
		free(msg.msg_base);
		memset(&msg, 0, sizeof msg);
	}

	pfd.fd = sess->sess_sock;
	pfd.events = POLLIN | POLLPRI;
	if ((ret = poll(&pfd, 1, sess->sess_ka * 1000)) == -1 || 
			pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
		ioDEBUG(3, "Error:: poll(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
		return -1;
	} else if (!ret) {
		ioDEBUG(5, "Warning:: Session is abandoned ... must be disconnect!");
		return 1;
	}
	/* receive & decode packet */
	if (recv(sess->sess_sock, sess->sess_buf->msg_base, sess->sess_buf->msg_len, 0) == -1) {
		ioDEBUG(3, "Error:: recv(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
		return -1;
	}
	if (mqtt_readPINGRESP(sess->sess_buf)) {
		ioDEBUG(5, "Warning:: Session is broken, not hear ping response ... must be disconnect!");
		return 2;
	}

	/* Keep Alive is OK! */
	return 0;
}

static void *
thrSession(struct tagSession *sess)
{
	mqtt_msg_t msg = { NULL, 0 };
	int ret, locKill = 42;
	struct pollfd pfd;
	struct mqtthdr *hdr;
	ait_val_t *v;
	struct tagStore *store;

	pthread_cleanup_push((void(*)(void*)) stopSession, sess);
	ioTRACE(2);

	pfd.fd = sess->sess_sock;
	pfd.events = POLLIN | POLLPRI;
	while (!Kill && locKill) {
		if ((ret = poll(&pfd, 1, sess->sess_ka * 1000)) == -1 || 
				pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) {
			ioDEBUG(3, "Error:: poll(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
			break;
		} else if (!ret && (ret = KASession(sess))) {
			call.LOG(logg, "Session %s keep-alive missing from %s for user %s ...\n", 
					sess->sess_cid, sess->sess_addr, sess->sess_user);
			break;
		}
		/* receive & decode packet */
		if ((ret = recv(sess->sess_sock, sess->sess_buf->msg_base, sess->sess_buf->msg_len, 0)) == -1) {
			ioDEBUG(3, "Error:: recv(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
			break;
		} else if (!ret) {
			ioDEBUG(4, "Session %s EOF received.", sess->sess_cid);
			break;
		} else
			hdr = (struct mqtthdr*) sess->sess_buf->msg_base;

		/* dispatch message type */
		switch (hdr->mqtt_msg.type) {
			case MQTT_TYPE_CONNECT:
				ioDEBUG(5, "Exec CONNECT session");
				pthread_mutex_lock(&mtx_sess);
				TAILQ_REMOVE(&Sessions, sess, sess_node);
				pthread_mutex_unlock(&mtx_sess);

				if (call.FiniSessPUB)
					call.FiniSessPUB(&cfg, pub, sess->sess_cid, sess->sess_user, "%");

				while ((store = TAILQ_FIRST(&sess->sess_sndqueue))) {
					TAILQ_REMOVE(&sess->sess_sndqueue, store, st_node);

					if (store->st_subscr.sub_topic._base)
						free(store->st_subscr.sub_topic._base);
					if (store->st_subscr.sub_value._base)
						free(store->st_subscr.sub_value._base);

					free(store);
				}

				if (sess->sess_will.msg)
					free(sess->sess_will.msg);
				if (sess->sess_will.topic)
					free(sess->sess_will.topic);

				if ((v = io_allocVar())) {
					AIT_SET_STR(v, sess->sess_addr);
					if (!schedEvent(root, startSession, v, (u_long) sess->sess_sock, sess, ret))
						io_freeVar(v);
				} else
					ioLIBERR(mqtt);

				locKill ^= locKill;

				call.LOG(logg, "Session %s stopped from %s for user %s.\n", sess->sess_cid, 
						sess->sess_addr, sess->sess_user);
				continue;
			case MQTT_TYPE_DISCONNECT:
				ioDEBUG(5, "Exec DISCONNECT session");
				pthread_mutex_lock(&mtx_sess);
				TAILQ_REMOVE(&Sessions, sess, sess_node);
				pthread_mutex_unlock(&mtx_sess);

				finiSession(sess, 0);
				locKill ^= locKill;

				call.LOG(logg, "Session %s stopped from %s for user %s.\n", sess->sess_cid, 
						sess->sess_addr, sess->sess_user);
				continue;
			case MQTT_TYPE_PUBLISH:
				ioDEBUG(5, "Exec PUBLISH topic QoS=%d", hdr->mqtt_msg.qos);
				if (Publish(sess))
					locKill ^= locKill;
				break;
			case MQTT_TYPE_PUBREL:
				break;
			case MQTT_TYPE_SUBSCRIBE:
				break;
			case MQTT_TYPE_UNSUBSCRIBE:
				break;
			case MQTT_TYPE_PINGREQ:
				break;
			default:
				ioDEBUG(5, "Error:: Session %s, wrong command %d - DISCARDED", 
						sess->sess_cid, hdr->mqtt_msg.type);
				break;
		}
	}

	pthread_cleanup_pop(locKill);
	pthread_exit(NULL);
}

static void *
startSession(sched_task_t *task)
{
	u_char basebuf[USHRT_MAX];
	mqtt_msg_t msg = { NULL, 0 }, buf = { basebuf, sizeof basebuf };
	mqtthdr_connflgs_t flg;
	mqtthdr_connack_t cack;
	struct tagSession *s, *sess = NULL;
	int ret;
	pthread_attr_t attr;

	ioTRACE(4);

	assert(task);

	if (!TASK_DATA(task)) {
		sess = initSession(TASK_FD(task), TASK_ARG(task));
		if (!sess) {
			io_freeVar(TASK_ARG(task));
			close(TASK_FD(task));
			return NULL;
		}

		/* receive & decode packet */
		if (recv(sess->sess_sock, buf.msg_base, buf.msg_len, 0) == -1) {
			ioDEBUG(3, "Error:: recv(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
			finiSession(sess, 0);
			return NULL;
		}
	} else {
		sess = TASK_DATA(task);
		buf.msg_len = TASK_DATLEN(task) > sizeof basebuf ? sizeof basebuf : TASK_DATLEN(task);
		memcpy(buf.msg_base, sess->sess_buf->msg_base, buf.msg_len);
	}

	cack = mqtt_readCONNECT(&buf, &sess->sess_ka, sess->sess_cid, sizeof sess->sess_cid, 
			sess->sess_user, sizeof sess->sess_user, sess->sess_pass, sizeof sess->sess_pass, 
			&sess->sess_will.topic, &sess->sess_will.msg);
	ret = cack.retcode;
	flg.flags = cack.reserved;
	if (flg.reserved) {
		ioDEBUG(3, "Error:: in MQTT protocol #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		goto end;
	} else {
		sess->sess_clean = flg.clean_sess;
		sess->sess_will.qos = flg.will_qos;
		sess->sess_will.retain = flg.will_retain;
		sess->sess_will.flag = flg.will_flg;
	}

	/* check online table for user */
	if (call.LoginACC(&cfg, acc, sess->sess_user, sess->sess_pass) < 1) {
		ioDEBUG(0, "Login:: DENIED for username %s and password %s", 
				sess->sess_user, sess->sess_pass);
		ret = MQTT_RETCODE_DENIED;
		goto end;
	} else {
		ioDEBUG(1, "Login:: ALLOWED for username %s ...", sess->sess_user);
		ret = MQTT_RETCODE_ACCEPTED;
	}
	if (call.FiniSessPUB(&cfg, pub, sess->sess_cid, sess->sess_user, "%") > 0) {
		ioDEBUG(2, "Old session %s should be disconnect!", sess->sess_cid);
		TAILQ_FOREACH(s, &Sessions, sess_node)
			if (!strcmp(s->sess_cid, sess->sess_cid)) {
				/* found stale session & disconnect it! */
				stopSession(s);
				break;
			}
	}
	if (call.InitSessPUB(&cfg, pub, sess->sess_cid, sess->sess_user, sess->sess_addr, 
				sess->sess_will.flag, sess->sess_will.topic, sess->sess_will.msg, 
				sess->sess_will.qos, sess->sess_will.retain) == -1) {
		ioDEBUG(0, "Session %s DENIED for username %s", sess->sess_cid, sess->sess_user);
		ret = MQTT_RETCODE_DENIED;
		goto end;
	} else {
		ioDEBUG(0, "Session %s from %s and username %s is started", 
				sess->sess_cid, sess->sess_addr, sess->sess_user);
		ret = MQTT_RETCODE_ACCEPTED;
	}

	ret = mqtt_msgCONNACK(&msg, ret);
	if ((ret = send(sess->sess_sock, msg.msg_base, ret, 0)) == -1) {
		ioDEBUG(3, "Error:: send(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
		finiSession(sess, 0);
		return NULL;
	} else {
		ioDEBUG(5, "Sended %d bytes", ret);
		free(msg.msg_base);
		memset(&msg, 0, sizeof msg);
	}

	/* Start session thread OK ... */
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

	pthread_mutex_lock(&mtx_sess);
	TAILQ_INSERT_TAIL(&Sessions, sess, sess_node);
	pthread_create(&sess->sess_tid, &attr, (void*(*)(void*)) thrSession, sess);
	pthread_mutex_unlock(&mtx_sess);

	call.LOG(logg, "Session %s started from %s for user %s (timeout=%d) OK!\n", sess->sess_cid, 
			sess->sess_addr, sess->sess_user, sess->sess_ka);

	pthread_attr_destroy(&attr);
	return NULL;
end:	/* close client connection */
	ret = mqtt_msgCONNACK(&msg, ret);
	if ((ret = send(sess->sess_sock, msg.msg_base, ret, 0)) == -1) {
		ioDEBUG(3, "Error:: send(%d) #%d - %s", sess->sess_sock, errno, strerror(errno));
	} else {
		ioDEBUG(5, "Sended %d bytes", ret);
		free(msg.msg_base);
		memset(&msg, 0, sizeof msg);
	}

	ioDEBUG(1, "Close client %s with socket=%d", sess->sess_addr, sess->sess_sock);
	finiSession(sess, 0);
	return NULL;
}

/* ----------------------------------------------------------------------- */

static void *
thrSched(void *arg __unused)
{
	struct tagSession *sess;
	struct timespec pl = { 0, 10000000 };

	ioTRACE(1);

	schedPolling(root, &pl, NULL);
	schedRun(root, &Kill);

	TAILQ_FOREACH(sess, &Sessions, sess_node)
		if (sess->sess_tid)
			pthread_cancel(sess->sess_tid);
	ioDEBUG(5, "EXIT from Scheduler thread !!!");
	pthread_exit(NULL);
}

int
Run(int sock)
{
	io_sockaddr_t sa;
	socklen_t sslen = sizeof sa.ss;
	int cli;
	pthread_t tid;
	ait_val_t *v;
	char str[STRSIZ];

	ioTRACE(1);

	if (pthread_create(&tid, NULL, thrSched, NULL)) {
		ioSYSERR(0);
		return -1;
	} else
		pthread_detach(tid);
	ioDEBUG(2, "Run scheduler management thread");

	if (listen(sock, SOMAXCONN) == -1) {
		ioSYSERR(0);
		return -1;
	}

	while (!Kill) {
		if ((cli = accept(sock, &sa.sa, &sslen)) == -1) {
			if (!Kill)
				continue;
			ioSYSERR(0);
			break;
		}
		v = io_allocVar();
		if (!v) {
			ioLIBERR(mqtt);
			break;
		} else {
			memset(str, 0, sizeof str);
			snprintf(str, sizeof str, "%s:%hu", io_n2addr(&sa, v), io_n2port(&sa));
			AIT_SET_STR(v, str);
		}
		ioDEBUG(1, "Connected client with socket=%d from %s", cli, AIT_GET_STR(v));

		if (!schedRead(root, startSession, v, cli, NULL, 0)) {
			io_freeVar(v);
			close(cli);
			ioDEBUG(1, "Terminated client with socket=%d", cli);
		}
	}

	return 0;
}