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


static inline ait_val_t *
mkPkt(void * __restrict data, int dlen)
{
	ait_val_t *p = NULL;

	if (!(p = io_allocVar())) {
		ioDEBUG(7, "Error:: in send packet prepare #%d - %s", io_GetErrno(), io_GetError());
		return NULL;
	}

	if (data && dlen > 0)
		AIT_SET_BUF(p, data, dlen);

	return p;
}

static inline void
freePkt(ait_val_t ** __restrict p)
{
	if (!p)
		return;

	io_freeVar(p);
}

static void *
sendPacket(sched_task_t *task)
{
	ait_val_t *p = TASK_ARG(task);
	register int n, slen;
	u_char *pos;

	if (!p || AIT_ISEMPTY(p)) {
		ioDEBUG(9, "Error:: invalid packet or found empty content ...");
		return NULL;
	}

	for (slen = AIT_LEN(p), pos = AIT_GET_BUF(p); slen > 0; slen -= n, pos += n) {
		n = send(TASK_FD(task), pos, slen, MSG_NOSIGNAL);
		if (n == -1) {
			ioSYSERR(0);
			break;
		}
	}

	freePkt(&p);
	return NULL;
}

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

static int
pubOnce(struct tagSession *sess, char * __restrict psTopic, int datlen)
{
	ait_val_t *p = NULL;
	struct tagSession *s = NULL;
	struct tagStore *st = NULL;
	regex_t re;
	regmatch_t match;
	int ret;
	char szStr[STRSIZ];

	TAILQ_FOREACH(s, &Sessions, sess_node) {
		SLIST_FOREACH(st, &s->sess_subscr, st_node) {
			if ((ret = regcomp(&re, st->st_subscr.sub_topic.msg_base, REG_EXTENDED))) {
				regerror(ret, &re, szStr, sizeof szStr);
				regfree(&re);
				ioDEBUG(3, "Error:: regcomp(%s) %s\n", (char*)
						st->st_subscr.sub_topic.msg_base, szStr);
			}
			if (!regexec(&re, psTopic, 1, &match, 0)) {
				/* MATCH */
				p = mkPkt(sess->sess_buf->msg_base, datlen);
				schedWrite(root, sendPacket, p, s->sess_sock, NULL, 0);
			}

			regfree(&re);
		}
	}

	return 0;
}

static int
pubAck(struct tagSession *sess, u_short mid, char * __restrict psTopic, int datlen)
{
	ait_val_t *p = NULL;
	struct tagSession *s = NULL;
	struct tagStore *st = NULL;
	regex_t re;
	regmatch_t match;
	int ret, flg = 0;
	char szStr[STRSIZ];
	struct mqtthdr *hdr;

	p = mkPkt(sess->sess_buf->msg_base, datlen);
	hdr = (struct mqtthdr*) sess->sess_buf->msg_base;

	/* write topic to database */
	call.WritePUB_topic(&cfg, pub, sess->sess_cid, mid, psTopic, AIT_GET_BUF(p), AIT_LEN(p), 
			sess->sess_user, sess->sess_addr, hdr->mqtt_msg.retain);

	TAILQ_FOREACH(s, &Sessions, sess_node) {
		SLIST_FOREACH(st, &s->sess_subscr, st_node) {
			if ((ret = regcomp(&re, st->st_subscr.sub_topic.msg_base, REG_EXTENDED))) {
				regerror(ret, &re, szStr, sizeof szStr);
				regfree(&re);
				ioDEBUG(3, "Error:: regcomp(%s) %s\n", (char*)
						st->st_subscr.sub_topic.msg_base, szStr);
			}
			if (!regexec(&re, psTopic, 1, &match, 0)) {
				flg = 1;	/* MATCH */
				schedWrite(root, sendPacket, p, s->sess_sock, NULL, 0);
			}

			regfree(&re);
		}
	}

	/* if subscriber not found then free packet */
	if (!flg)
		freePkt(&p);

	call.DeletePUB_topic(&cfg, pub, sess->sess_cid, mid, psTopic, sess->sess_user, sess->sess_addr, -1);
	return 0;
}

static int
pubExactly(struct tagSession *sess, u_short mid, char * __restrict psTopic, int datlen)
{
	return 0;
}


int
cmdPUBLISH(void *srv, int len, void *arg)
{
	struct mqtthdr *hdr;
	struct tagSession *sess = (struct tagSession*) arg;
	char szTopic[STRSIZ] = { 0 };
	int siz = 0;
	u_short mid = 0;
	ait_val_t *p = NULL;

	ioTRACE(2);

	if (!sess)
		return -1;

	ioDEBUG(5, "Exec PUBLISH session");
	siz = mqtt_readPUBLISH(sess->sess_buf, szTopic, sizeof szTopic, &mid, NULL);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in readPUBLISH #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		return 0;
	}

	hdr = (struct mqtthdr*) sess->sess_buf->msg_base;
	switch (hdr->mqtt_msg.qos) {
		case MQTT_QOS_ACK:
			if (pubAck(sess, mid, szTopic, mqtt_pktLen(hdr)))
				return 0;
			siz = mqtt_msgPUBACK(sess->sess_buf, mid);
			if (siz == -1) {
				ioDEBUG(5, "Error:: in msgPUBACK #%d - %s", 
						mqtt_GetErrno(), mqtt_GetError());
				return 0;
			}
			break;
		case MQTT_QOS_EXACTLY:
			if (pubExactly(sess, mid, szTopic, mqtt_pktLen(hdr)))
				return 0;
			siz = mqtt_msgPUBREC(sess->sess_buf, mid);
			if (siz == -1) {
				ioDEBUG(5, "Error:: in msgPUBREC #%d - %s", 
						mqtt_GetErrno(), mqtt_GetError());
				return 0;
			}
			break;
		case MQTT_QOS_ONCE:
			pubOnce(sess, szTopic, mqtt_pktLen(hdr));
		default:
			return 0;
	}

	p = mkPkt(sess->sess_buf->msg_base, siz);
	memset(sess->sess_buf->msg_base, 0, sess->sess_buf->msg_len);
	schedWrite(root, sendPacket, p, sess->sess_sock, NULL, 0);
	return 0;
}

int
cmdPUBREL(void *srv, int len, void *arg)
{
	struct tagSession *sess = (struct tagSession*) arg;
	int siz = 0;
	u_short mid = 0;
	ait_val_t *p = NULL;

	ioTRACE(2);

	if (!sess)
		return -1;

	ioDEBUG(5, "Exec PUBREL session");
	mid = mqtt_readPUBREL(sess->sess_buf);
	if (mid == (u_short) -1) {
		ioDEBUG(5, "Error:: in readPUBREL #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		return 0;
	}

	// TODO:: Delete from database topic

	siz = mqtt_msgPUBCOMP(sess->sess_buf, mid);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in msgPUBCOMP #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		return 0;
	} else {
		p = mkPkt(sess->sess_buf->msg_base, siz);
		memset(sess->sess_buf->msg_base, 0, sess->sess_buf->msg_len);
	}

	schedWrite(root, sendPacket, p, sess->sess_sock, NULL, 0);
	return 0;
}

int
cmdSUBSCRIBE(void *srv, int len, void *arg)
{
	struct tagSession *sess = (struct tagSession*) arg;
	mqtt_subscr_t *subs = NULL;
	int siz = 0;
	u_short mid = 0;
	register int i;
	struct tagStore *store;
	char buf[BUFSIZ];
	void *ptr;
	ait_val_t *p = NULL;

	ioTRACE(2);

	if (!sess)
		return -1;

	ioDEBUG(5, "Exec SUBSCRIBE session");
	siz = mqtt_readSUBSCRIBE(sess->sess_buf, &mid, &subs);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in readSUBSCRIBE #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		return 0;
	}

	/* add to db */
	for (i = 0; i < siz; i++, subs[i].sub_ret = MQTT_QOS_DENY) {
		/* convert topic to sql search statement */
		if (mqtt_sqlTopic(subs[i].sub_topic.msg_base, buf, sizeof buf) == -1) {
			ioDEBUG(5, "Error:: in db #%d - %s", mqtt_GetErrno(), mqtt_GetError());
			continue;
		}
		if (call.WritePUB_subscribe(&cfg, pub, sess->sess_cid, mid, buf, 
				sess->sess_user, sess->sess_addr, subs[i].sub_ret) > 0) {
			store = io_malloc(sizeof(struct tagStore));
			if (!store) {
				ioSYSERR(0);
				continue;
			} else {
				store->st_msgid = mid;
				mqtt_subCopy(&store->st_subscr, &subs[i]);
			}

			/* add to cache */
			SLIST_INSERT_HEAD(&sess->sess_subscr, store, st_node);

			/* convert topic to regexp */
			if (mqtt_expandTopic(subs[i].sub_topic.msg_base, buf, sizeof buf, 1, 1) == -1) {
				ioDEBUG(5, "Error:: in regexp #%d - %s", mqtt_GetErrno(), mqtt_GetError());

				subs[i].sub_ret = MQTT_QOS_DENY;
			} else {
				ptr = realloc(store->st_subscr.sub_topic.msg_base, strlen(buf) + 1);
				if (!ptr)
					ioSYSERR(0);
				else {
					store->st_subscr.sub_topic.msg_base = ptr;
					store->st_subscr.sub_topic.msg_len = strlen(buf) + 1;
					memcpy(store->st_subscr.sub_topic.msg_base, buf, 
							store->st_subscr.sub_topic.msg_len);
				}

				call.LOG(logg, "Added [%s] SUBSCRIBE '%s'(%d) from %s\n", sess->sess_cid, 
						store->st_subscr.sub_topic.msg_base, 
						store->st_subscr.sub_topic.msg_len, sess->sess_addr);

				subs[i].sub_ret = MQTT_QOS_PASS;
			}
		}
	}

	/* send acknowledge */
	siz = mqtt_msgSUBACK(sess->sess_buf, subs, mid);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in msgSUBACK #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		goto end;
	} else {
		p = mkPkt(sess->sess_buf->msg_base, siz);
		memset(sess->sess_buf->msg_base, 0, sess->sess_buf->msg_len);
	}

	schedWrite(root, sendPacket, p, sess->sess_sock, NULL, 0);
end:
	mqtt_subFree(&subs);
	return 0;
}

int
cmdUNSUBSCRIBE(void *srv, int len, void *arg)
{
	struct tagSession *sess = (struct tagSession*) arg;
	mqtt_subscr_t *subs = NULL;
	int siz = 0;
	u_short mid = 0;
	register int i;
	struct tagStore *store, *tmp;
	ait_val_t *p = NULL;

	ioTRACE(2);

	if (!sess)
		return -1;

	ioDEBUG(5, "Exec UNSUBSCRIBE session");
	siz = mqtt_readUNSUBSCRIBE(sess->sess_buf, &mid, &subs);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in readUNSUBSCRIBE #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		return 0;
	}

	/* del from db */
	for (i = 0; i < siz; i++) {
		SLIST_FOREACH_SAFE(store, &sess->sess_subscr, st_node, tmp) {
			if (store->st_subscr.sub_ret == subs[i].sub_ret && 
					store->st_subscr.sub_topic.msg_base && 
					!strcmp(store->st_subscr.sub_topic.msg_base, 
						subs[i].sub_topic.msg_base)) {
				SLIST_REMOVE(&sess->sess_subscr, store, tagStore, st_node);

				if (store->st_subscr.sub_topic.msg_base)
					free(store->st_subscr.sub_topic.msg_base);
				if (store->st_subscr.sub_value.msg_base)
					free(store->st_subscr.sub_value.msg_base);
				io_free(store);
			}
		}

		call.DeletePUB_subscribe(&cfg, pub, sess->sess_cid, subs[i].sub_topic.msg_base, 
				sess->sess_user, "%");
	}

	/* send acknowledge */
	siz = mqtt_msgUNSUBACK(sess->sess_buf, mid);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in msgUNSUBACK #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		goto end;
	} else {
		p = mkPkt(sess->sess_buf->msg_base, siz);
		memset(sess->sess_buf->msg_base, 0, sess->sess_buf->msg_len);
	}

	schedWrite(root, sendPacket, p, sess->sess_sock, NULL, 0);
end:
	mqtt_subFree(&subs);
	return 0;
}

int
cmdPINGREQ(void *srv, int len, void *arg)
{
	struct tagSession *sess = (struct tagSession*) arg;
	int siz = 0;
	ait_val_t *p = NULL;

	ioTRACE(2);

	if (!sess)
		return -1;

	ioDEBUG(5, "Exec PINGREQ session");
	siz = mqtt_msgPINGRESP(sess->sess_buf);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in msgPINGRESP #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		return 0;
	} else {
		p = mkPkt(sess->sess_buf->msg_base, siz);
		memset(sess->sess_buf->msg_base, 0, sess->sess_buf->msg_len);
	}

	schedWrite(root, sendPacket, p, sess->sess_sock, NULL, 0);
	return 0;
}

int
cmdCONNECT(void *srv, int len, void *arg)
{
	struct tagStore *store;
	struct tagSession *sess = (struct tagSession*) arg;

	ioTRACE(2);

	if (!sess)
		return -1;

	ioDEBUG(5, "Exec CONNECT session");
	TAILQ_REMOVE(&Sessions, sess, sess_node);

	if (sess->sess_clean) {
		if (call.FiniSessPUB)
			call.FiniSessPUB(&cfg, pub, sess->sess_cid, sess->sess_user, "%");
		if (call.DeletePUB_subscribe)
			call.DeletePUB_subscribe(&cfg, pub, sess->sess_cid, "%", sess->sess_user, "%");
		if (call.WipePUB_topic)
			call.WipePUB_topic(&cfg, pub, sess->sess_cid, sess->sess_user, -1);
	}

	while ((store = SLIST_FIRST(&sess->sess_subscr))) {
		SLIST_REMOVE_HEAD(&sess->sess_subscr, st_node);

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

		io_free(store);
	}

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

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

	return -3;	/* reconnect client */
}

int
cmdDISCONNECT(void *srv, int len, void *arg)
{
	struct tagSession *sess = (struct tagSession*) arg;

	ioTRACE(2);

	if (!sess)
		return -1;

	ioDEBUG(5, "Exec DISCONNECT session");

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

	return -2;	/* must terminate dispatcher */
}