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


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 = io_malloc(sizeof(struct tagSession));
	if (!sess) {
		ioSYSERR(0);
		return NULL;
	} else
		memset(sess, 0, sizeof(struct tagSession));

	SLIST_INIT(&sess->sess_subscr);

	str = cfg_getAttribute(&cfg, "mqttd", "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) {
		ioLIBERR(mqtt);
		io_free(sess);
		return NULL;
	}

	/* init server actor */
	sess->sess_srv = mqtt_srv_cliInit(sock, sess->sess_buf, sess->sess_ka, 1);
	if (!sess->sess_srv) {
		ioDEBUG(3, "Error:: in srv_Init #%d - %s", mqtt_GetErrno(), mqtt_GetError());
		mqtt_msgFree(&sess->sess_buf, 42);
		io_free(sess);
		return NULL;
	} else {
		mqtt_srv_setCmd(sess->sess_srv, MQTT_TYPE_CONNECT, cmdCONNECT);
		mqtt_srv_setCmd(sess->sess_srv, MQTT_TYPE_PUBLISH, cmdPUBLISH);
		mqtt_srv_setCmd(sess->sess_srv, MQTT_TYPE_PUBREL, cmdPUBREL);
		mqtt_srv_setCmd(sess->sess_srv, MQTT_TYPE_SUBSCRIBE, cmdSUBSCRIBE);
		mqtt_srv_setCmd(sess->sess_srv, MQTT_TYPE_UNSUBSCRIBE, cmdUNSUBSCRIBE);
		mqtt_srv_setCmd(sess->sess_srv, MQTT_TYPE_PINGREQ, cmdPINGREQ);
		mqtt_srv_setCmd(sess->sess_srv, MQTT_TYPE_DISCONNECT, cmdDISCONNECT);
	}

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

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

	ioTRACE(5);

	if (!sess)
		return;

	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)
		srv_Will(sess);

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

	if (sess->sess_sock > STDERR_FILENO)
		srv_Close(sess->sess_sock);

	mqtt_srv_cliFini(&sess->sess_srv);
	mqtt_msgFree(&sess->sess_buf, 42);

	io_free(sess);
}

static void *
leaveClient(sched_task_t *task)
{
	struct tagSession *sess;
	int ret;

	ioTRACE(4);

	assert(task);

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

	TAILQ_REMOVE(&Sessions, sess, sess_node);

	ret = mqtt_msgDISCONNECT(sess->sess_buf);
	send(TASK_FD(task), sess->sess_buf->msg_base, ret, MSG_NOSIGNAL);

	ioDEBUG(1, "Close socket=%ld", (long) TASK_FD(task));
	call.LOG(logg, "Session %s stopped from %s for user %s.\n", sess->sess_cid, 
			sess->sess_addr, sess->sess_user);

	finiSession(sess);
	return NULL;
}

static void *
dispatchSession(sched_task_t *task)
{
	int ret, len = 0;
	struct tagSession *sess;

	ioTRACE(2);

	assert(task);

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

	/* receive & decode packet */
	if ((ret = recv(TASK_FD(task), 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));
		TAILQ_REMOVE(&Sessions, sess, sess_node);
		finiSession(sess);
		return NULL;
	} else if (!ret) {
		ioDEBUG(4, "Session %s EOF received.", sess->sess_cid);
		TAILQ_REMOVE(&Sessions, sess, sess_node);
		finiSession(sess);
		return NULL;
	}

	do {
		/* dispatch message type */
		if ((len = mqtt_srv_cliDispatch(sess->sess_srv, ret, sess)) < 0) {
			if (len == -1) {
				ioLIBERR(mqtt);
				finiSession(sess);
			} else if (len == -2) {
				TAILQ_REMOVE(&Sessions, sess, sess_node);
				finiSession(sess);
			} else if (len == -3)
				schedEvent(root, startSession, NULL, (u_long) TASK_FD(task), sess, ret);
		} else
			ret -= len;
	} while (len > 0 && ret > 0);

	if (len >= 0 && !schedRead(root, dispatchSession, TASK_ARG(task), TASK_FD(task), NULL, 0)) {
		ioLIBERR(sched);
		TAILQ_REMOVE(&Sessions, sess, sess_node);
		finiSession(sess);
	}
	return NULL;
}

static int
loadSubscribes(struct tagSession * __restrict sess, mqtt_subscr_t * __restrict subs)
{
	register int i;
	struct tagStore *store;

	if (!subs)
		return -1;

	for (i = 0; subs[i].sub_topic.msg_base; i++) {
		store = io_malloc(sizeof(struct tagStore));
		if (!store) {
			ioSYSERR(0);
			continue;
		} else {
			store->st_msgid = 0;
			mqtt_subCopy(&store->st_subscr, &subs[i]);
		}

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

	return 0;
}

void *
startSession(sched_task_t *task)
{
	u_char basebuf[USHRT_MAX];
	mqtt_msg_t buf = { basebuf, sizeof basebuf };
	mqtthdr_connflgs_t flg;
	mqtthdr_connack_t cack;
	ait_val_t *v;
	struct tagSession *s, *sess = NULL;
	int ret, wlen;
	mqtt_subscr_t *subs;

	ioTRACE(4);

	assert(task);

	if (!TASK_DATA(task)) {
		v = TASK_ARG(task);
		/* flow from accept new clients */
		sess = initSession(TASK_FD(task), v);
		io_freeVar(&v);
		if (!sess) {
			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);
			return NULL;
		}
	} else {
		sess = TASK_DATA(task);
		assert(sess);

		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;

		sess->sess_srv->timeout = sess->sess_ka;
	}

	/* 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;
	}

	/* db management */
	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! */
				schedCancelby(root, taskMAX, CRITERIA_FD, (void*) s->sess_sock, NULL);
				schedWrite(root, leaveClient, s, s->sess_sock, NULL, 0);
				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;
	}
	/* clean/load session if requested */
	if (sess->sess_clean) {
		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);
	} else if (call.ReadPUB_subscribe) {
		subs = call.ReadPUB_subscribe(&cfg, pub, sess->sess_cid, "%");
		loadSubscribes(sess, subs);
		mqtt_subFree(&subs);
	}

	/* Start session task OK ... */
	if (!schedRead(root, dispatchSession, sess, TASK_FD(task), NULL, 0)) {
		ioLIBERR(sched);
		ret = MQTT_RETCODE_DENIED;
	} else
		TAILQ_INSERT_TAIL(&Sessions, sess, sess_node);

	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);
end:	/* close client connection */
	wlen = mqtt_msgCONNACK(sess->sess_buf, ret);
	if ((wlen = send(TASK_FD(task), sess->sess_buf->msg_base, wlen, 0)) == -1) {
		ioDEBUG(3, "Error:: send(%ld) #%d - %s", (long) TASK_FD(task), errno, strerror(errno));
	} else
		ioDEBUG(5, "Sended %d bytes", wlen);

	if (ret != MQTT_RETCODE_ACCEPTED) {
		ioDEBUG(1, "Close client %s with socket=%ld", sess->sess_addr, (long) TASK_FD(task));
		finiSession(sess);
	}
	return NULL;
}

static void *
acceptClient(sched_task_t *task)
{
	int cli;
	io_sockaddr_t sa;
	socklen_t sslen = sizeof sa.ss;
	ait_val_t *v;
	char str[STRSIZ];

	ioTRACE(4);

	assert(task);

	if ((cli = accept(TASK_FD(task), &sa.sa, &sslen)) == -1)
		goto end;

	v = io_allocVar();
	if (!v) {
		ioLIBERR(io);
		close(cli);
		goto end;
	} else {
		memset(str, 0, sizeof str);
		snprintf(str, sizeof str, "%s:%hu", io_n2addr(&sa, v), io_n2port(&sa));
		AIT_FREE_VAL(v);
		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);
	}
end:
	if (!schedRead(root, acceptClient, NULL, TASK_FD(task), NULL, 0))
		ioLIBERR(sched);
	return NULL;
}

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

int
Run(int sock)
{
	struct tagSession *sess;
	struct timespec pl = { 0, 100000000 };

	ioTRACE(1);

	if (mqtt_srv_Listen(sock, 0, 1) == -1) {
		ioLIBERR(mqtt);
		return -1;
	}

	/* state machine - accept new connections */
	if (!schedRead(root, acceptClient, NULL, sock, NULL, 0)) {
		ioLIBERR(sched);
		return -1;
	}

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

	/* free all undeleted elements into lists */
	TAILQ_FOREACH(sess, &Sessions, sess_node) {
		TAILQ_REMOVE(&Sessions, sess, sess_node);

		finiSession(sess);
	}
	return 0;
}