#include "global.h"


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

/*
 * mqtt_msgCONNECT() Create CONNECT message
 *
 * @buf = Message buffer
 * @csConnID = ConnectID
 * @csUser = Username if !=NULL
 * @csPass = Password for Username, only if csUser is set
 * @csWillTopic = Will Topic if !=NULL Will Flags set into message
 * @csWillMessage = Will Message, may be NULL
 * @ClrSess = Clear Session subscriptions after disconnect
 * @WillQOS = Will QOS if csWillTopic is set
 * @WillRetain = Will Retain Will Message if csWillTopic is set
 * return: -1 error or >-1 message size for send
 */
int
mqtt_msgCONNECT(mqtt_msg_t * __restrict buf, const char *csConnID, 
		const char *csUser, const char *csPass, 
		const char *csWillTopic, const char *csWillMessage, 
		u_char ClrSess, u_char WillQOS, u_char WillRetain)
{
	int siz = 0;
	struct mqtthdr *hdr;
	mqtthdr_var_t *var, *cid, *topic, *wmsg, *user, *pass;
	mqtthdr_protover_t *proto;
	mqtthdr_connflgs_t *flags;
	mqtt_v_t *ka;

	if (!buf || !csConnID)
		return -1;
	if (strlen(csConnID) > 23) {
		mqtt_SetErr(EINVAL, "Error:: invalid argument ConnID is too long (max 23 bytes)");
		return -1;
	}
	if (csUser && strlen(csUser) > 12) {
		mqtt_SetErr(EINVAL, "Error:: invalid argument Username is too long (max 12 bytes)");
		return -1;
	}
	if (csPass && strlen(csPass) > 12) {
		mqtt_SetErr(EINVAL, "Error:: invalid argument Password is too long (max 12 bytes)");
		return -1;
	}
	if (WillQOS > MQTT_QOS_EXACTLY) {
		mqtt_SetErr(EINVAL, "Error:: invalid argument WillQOS - unknown QOS value");
		return -1;
	}

	if (mqtt_msgRealloc(buf, BUFSIZ) == -1)
		return -1;
	else {
		hdr = (struct mqtthdr *) (buf->msg_base + siz);
		siz += sizeof(struct mqtthdr);
		var = (mqtthdr_var_t*) (buf->msg_base + siz);
		siz += 8;
		proto = buf->msg_base + siz;
		siz++;
		flags = (mqtthdr_connflgs_t*) (buf->msg_base + siz);
		siz++;
		ka = (mqtt_v_t*) (buf->msg_base + siz);
		siz += sizeof(mqtt_v_t);
	}

	/* fixed header */
	MQTTHDR_MSGINIT(hdr);
	hdr->mqtt_msg.type = MQTT_TYPE_CONNECT;
	*hdr->mqtt_len = 0;

	/* variable header */
	var->var_sb.sb.l = 6;
	memcpy(var->var_data, MQTT_CONN_STR, 6);

	*proto = MQTT_PROTO_VER;

	/* CONNECT header */
	flags->clean_sess = ClrSess ? 1 : 0;
	if (csUser) {
		flags->username = 1;
		flags->password = csPass ? 1 : 0;
	} else {
		flags->username = 0;
		flags->password = 0;
	}
	if (csWillTopic) {
		flags->will_flg = 1;
		flags->will_qos = WillQOS;
		flags->will_retain = WillRetain ? 1 : 0;
	} else {
		flags->will_flg = 0;
		flags->will_qos = 0;
		flags->will_retain = 0;
	}

	ka->sb.l = MQTT_KEEPALIVE;

	/* ConnID */
	cid = (mqtthdr_var_t*) (buf->msg_base + siz);
	cid->var_sb.val = htons(strlen(csConnID));
	siz += MQTTHDR_VAR_SIZEOF(cid);
	memcpy(cid->var_data, csConnID, ntohs(cid->var_sb.val));

	/* If Will Flags setup */
	if (csWillTopic) {
		topic = (mqtthdr_var_t*) (buf->msg_base + siz);
		topic->var_sb.val = htons(strlen(csWillTopic));
		memcpy(topic->var_data, csWillTopic, ntohs(topic->var_sb.val));
		siz += MQTTHDR_VAR_SIZEOF(topic);

		wmsg = (mqtthdr_var_t*) (buf->msg_base + siz);
		if (csWillMessage) {
			wmsg->var_sb.val = htons(strlen(csWillMessage));
			memcpy(wmsg->var_data, csWillMessage, ntohs(wmsg->var_sb.val));
		} else
			wmsg->var_sb.val = 0;
		siz += MQTTHDR_VAR_SIZEOF(wmsg);
	}

	/* If defined Username & Password */
	if (csUser) {
		user = (mqtthdr_var_t*) (buf->msg_base + siz);
		user->var_sb.val = htons(strlen(csUser));
		memcpy(user->var_data, csUser, ntohs(user->var_sb.val));
		siz += MQTTHDR_VAR_SIZEOF(user);

		if (csPass) {
			pass = (mqtthdr_var_t*) (buf->msg_base + siz);
			pass->var_sb.val = htons(strlen(csPass));
			memcpy(pass->var_data, csPass, ntohs(pass->var_sb.val));
			siz += MQTTHDR_VAR_SIZEOF(pass);
		}
	}

	*hdr->mqtt_len = mqtt_encodeLen(siz - sizeof(struct mqtthdr));
	mqtt_msgRealloc(buf, siz);
	return siz;
}

/*
 * mqtt_msgCONNACK() Create CONNACK message
 *
 * @buf = Message buffer
 * @retcode = Return code
 * return: -1 error or >-1 message size for send
 */
int
mqtt_msgCONNACK(mqtt_msg_t * __restrict buf, u_char retcode)
{
	int siz = 0;
	struct mqtthdr *hdr;
	mqtthdr_connack_t *ack;

	if (!buf)
		return -1;
	if (retcode > MQTT_RETCODE_DENIED) {
		mqtt_SetErr(EINVAL, "Error:: invalid retcode");
		return -1;
	}

	if (mqtt_msgRealloc(buf, sizeof(struct mqtthdr) + sizeof(mqtthdr_connack_t)) == -1)
		return -1;
	else {
		hdr = (struct mqtthdr *) (buf->msg_base + siz);
		siz += sizeof(struct mqtthdr);
		ack = (mqtthdr_connack_t*) (buf->msg_base + siz);
		siz += sizeof(mqtthdr_connack_t);
	}

	/* fixed header */
	MQTTHDR_MSGINIT(hdr);
	hdr->mqtt_msg.type = MQTT_TYPE_CONNACK;
	*hdr->mqtt_len = sizeof(mqtthdr_connack_t);

	/* CONNACK header */
	ack->reserved = 0;
	ack->retcode = retcode;

	return siz;
}

static int
_mqtt_msgSIMPLE_(mqtt_msg_t * __restrict buf, u_char cmd)
{
	int siz = 0;
	struct mqtthdr *hdr;

	if (!buf)
		return -1;

	if (mqtt_msgRealloc(buf, sizeof(struct mqtthdr)) == -1)
		return -1;
	else {
		hdr = (struct mqtthdr *) (buf->msg_base + siz);
		siz += sizeof(struct mqtthdr);
	}

	/* fixed header */
	MQTTHDR_MSGINIT(hdr);
	hdr->mqtt_msg.type = cmd;
	*hdr->mqtt_len = 0;

	return siz;
}

/*
 * mqtt_msgPINGREQ() Create PINGREQ message
 *
 * @buf = Message buffer
 * return: -1 error or >-1 message size for send
 */
int
mqtt_msgPINGREQ(mqtt_msg_t * __restrict buf)
{
	return _mqtt_msgSIMPLE_(buf, MQTT_TYPE_PINGREQ);
}

/*
 * mqtt_msgPINGRESP() Create PINGRESP message
 *
 * @buf = Message buffer
 * return: -1 error or >-1 message size for send
 */
int
mqtt_msgPINGRESP(mqtt_msg_t * __restrict buf)
{
	return _mqtt_msgSIMPLE_(buf, MQTT_TYPE_PINGRESP);
}

/*
 * mqtt_msgDISCONNECT() Create DISCONNECT message
 *
 * @buf = Message buffer
 * return: -1 error or >-1 message size for send
 */
int
mqtt_msgDISCONNECT(mqtt_msg_t * __restrict buf)
{
	return _mqtt_msgSIMPLE_(buf, MQTT_TYPE_DISCONNECT);
}