#include "global.h"
#include "mqttd.h"
#include "utils.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;
	}

	ioDEBUG(7, "Send packet length %d for socket %d\n", AIT_LEN(p), (u_int) TASK_FD(task));

	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
search4send(struct tagSession * __restrict sess, const char *topic, int datlen, char qos)
{
	regex_t re;
	regmatch_t match;
	ait_val_t *p = NULL;
	struct tagSession *s = NULL;
	struct tagStore *st_, *st = NULL;
	char szStr[STRSIZ];
	int ret;

	assert(sess);

	TAILQ_FOREACH(s, &Sessions, sess_node) {
		SLIST_FOREACH_SAFE(st, &s->sess_subscr, st_node, st_) {
			/* check for QoS */
			if (st->st_subscr.sub_ret >= qos) {
				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, topic, 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;
}

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

void *
sendRetain(sched_task_t *task)
{
	mqtt_subscr_t *subs, *s;
	struct tagSession *sess;
	int siz;

	ioTRACE(2);

	assert(task);

	sess = TASK_ARG(task);
	assert(sess);

	if (!sess->sess_buf) {
		ioDEBUG(9, "WARNING! No allocated buffer!?!\n");
		return NULL;
	}

	subs = call.ReadPUB_topic(&cfg, pub, "%", "%", 1);
	if (!subs)
		return NULL;

	for (s = subs; s && s->sub_topic.msg_base; s++) {
		siz = s->sub_value.msg_len;
		memcpy(sess->sess_buf->msg_base, s->sub_value.msg_base, 
				MIN(sess->sess_buf->msg_len, s->sub_value.msg_len));
		ioDEBUG(7, "Sending retain message %d bytes, QoS %hhd topic '%s' data length %d\n", 
				siz, s->sub_ret, (char*) s->sub_topic.msg_base, s->sub_value.msg_len);
		if (siz > 0)
			search4send(sess, s->sub_topic.msg_base, siz, s->sub_ret);
	}

	mqtt_subFree(&subs);
	return NULL;
}

int
pubWill(struct tagSession * __restrict sess)
{
	int datlen;

	ioTRACE(2);

	/* prepare will packet */
	datlen = mqtt_msgPUBLISH(sess->sess_buf, sess->sess_will.topic, 0xDEAD, 0, 1, 0, 
			sess->sess_will.msg, sess->sess_will.msg ? strlen(sess->sess_will.msg) : 0);
	if (datlen == -1)
		return -1;	/* error */

	return search4send(sess, sess->sess_will.topic, datlen, MQTT_QOS_ACK);
}

static int
pubOnce(struct tagSession *sess, char * __restrict psTopic, int datlen)
{
	return search4send(sess, psTopic, datlen, MQTT_QOS_ONCE);
}

static int
pubAck(struct tagSession *sess, u_short mid, char * __restrict psTopic, int datlen)
{
	struct mqtthdr *hdr = (struct mqtthdr*) sess->sess_buf->msg_base;

	/* write topic to database */
	call.DeletePUB_topic(&cfg, pub, sess->sess_cid, mid, psTopic, sess->sess_user, 
			sess->sess_addr, hdr->mqtt_msg.retain);
	call.WritePUB_topic(&cfg, pub, sess->sess_cid, mid, psTopic, 
			sess->sess_buf->msg_base, datlen, sess->sess_user, sess->sess_addr, 
			hdr->mqtt_msg.qos, hdr->mqtt_msg.retain);

	search4send(sess, psTopic, datlen, MQTT_QOS_ACK);

	/* delete not retain message */
	call.DeletePUB_topic(&cfg, pub, sess->sess_cid, mid, psTopic, sess->sess_user, 
			sess->sess_addr, 0);
	return 0;
}

static int
pubExactly(struct tagSession *sess, u_short mid, char * __restrict psTopic, int datlen)
{
	struct mqtthdr *hdr = (struct mqtthdr*) sess->sess_buf->msg_base;

	/* write topic to database */
	call.DeletePUB_topic(&cfg, pub, sess->sess_cid, mid, psTopic, sess->sess_user, 
			sess->sess_addr, hdr->mqtt_msg.retain);
	call.WritePUB_topic(&cfg, pub, sess->sess_cid, mid, psTopic, 
			sess->sess_buf->msg_base, datlen, sess->sess_user, sess->sess_addr, 
			hdr->mqtt_msg.qos, hdr->mqtt_msg.retain);

	return search4send(sess, psTopic, datlen, MQTT_QOS_EXACTLY);
}


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;
	}

	/* delete not retain message */
	call.DeletePUB_topic(&cfg, pub, sess->sess_cid, mid, "%", sess->sess_user, 
			sess->sess_addr, 0);

	siz = mqtt_msgPUBCOMP(sess->sess_buf, mid);
	if (siz == -1) {
		ioDEBUG(5, "Error:: in msgPUBCOMP #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		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
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++) {
		store = io_malloc(sizeof(struct tagStore));
		if (!store) {
			ioSYSERR(0);
			continue;
		} else {
			store->st_msgid = mid;
			mqtt_subCopy(&store->st_subscr, &subs[i]);
			subs[i].sub_ret = MQTT_QOS_DENY;
		}

		/* 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());
		} else {
			ptr = realloc(store->st_subscr.sub_topic.msg_base, strlen(buf) + 1);
			if (!ptr) {
				ioSYSERR(0);
				continue;
			} 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);
			}

			/* store to db */
			call.WritePUB_subscribe(&cfg, pub, sess->sess_cid, mid, buf, 
					sess->sess_user, sess->sess_addr, store->st_subscr.sub_ret);
			/* subscribe pass */
			subs[i].sub_ret = MQTT_QOS_PASS;

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

	/* 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);

	schedCancelby(root, taskTIMER, CRITERIA_CALL, sendRetain, NULL);

	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.flag)
		pubWill(sess);

	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 */
}