#include "global.h"


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

/*
 * mqtt_msgPUBLISH() Create PUBLISH message
 *
 * @buf = Message buffer
 * @csTopic = Publish topic
 * @msgID = MessageID >0, if QOS != MQTT_QOS_ONCE
 * @Dup = Duplicate message
 * @QOS = QoS
 * @Retain = Retain message
 * @pData = Publish data into topic
 * @datlen = Publish data length
 * return: -1 error or >-1 message size for send
 */
int
mqtt_msgPUBLISH(mqtt_msg_t * __restrict buf, const char *csTopic, u_short msgID, 
		u_char Dup, u_char QOS, u_char Retain, const void *pData, u_short datlen)
{
	int siz = 0;
	struct mqtthdr *hdr;
	mqtthdr_var_t *topic;
	mqtt_v_t *mid;
	void *data;

	if (!buf || !csTopic)
		return -1;
	if (QOS > MQTT_QOS_EXACTLY) {
		mqtt_SetErr(EINVAL, "Error:: invalid QoS parameter");
		return -1;
	}
	if (!msgID && QOS != MQTT_QOS_ONCE) {
		mqtt_SetErr(EINVAL, "Error:: invalid MessageID parameter must be >0");
		return -1;
	}

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

	/* variable header */

	topic = (mqtthdr_var_t*) (buf->msg_base + siz);
	topic->var_sb.val = htons(strlen(csTopic));
	memcpy(topic->var_data, csTopic, ntohs(topic->var_sb.val));
	siz += MQTTHDR_VAR_SIZEOF(topic);

	mid = (mqtt_v_t*) (buf->msg_base + siz);
	mid->val = htons(msgID);
	siz += sizeof(mqtt_v_t);

	/* load with data */

	if (pData && datlen) {
		data = buf->msg_base + siz;
		memcpy(data, pData, datlen);
		siz += datlen;
	}

	/* fixed header */

	hdr->mqtt_msg.type = MQTT_TYPE_PUBLISH;
	hdr->mqtt_msg.qos = QOS;
	hdr->mqtt_msg.dup = Dup ? 1 : 0;
	hdr->mqtt_msg.retain = Retain ? 1 : 0;
	*hdr->mqtt_len = mqtt_encodeLen(siz - sizeof(struct mqtthdr));

	mqtt_msgRealloc(buf, siz);
	return siz;
}

static int
_mqtt_msgPUB_(mqtt_msg_t * __restrict buf, u_char cmd, u_short msgID)
{
	int siz = 0;
	struct mqtthdr *hdr;
	mqtt_v_t *v;

	if (!buf)
		return -1;

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

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

	/* MessageID */
	v->val = htons(msgID);

	return siz;
}

/*
 * mqtt_msgPUBACK() Create PUBACK message
 *
 * @buf = Message buffer
 * @msgID = MessageID
 * return: -1 error or >-1 message size for send
 */
inline int
mqtt_msgPUBACK(mqtt_msg_t * __restrict buf, u_short msgID)
{
	return _mqtt_msgPUB_(buf, MQTT_TYPE_PUBACK, msgID);
}

/*
 * mqtt_msgPUBREC() Create PUBREC message
 *
 * @buf = Message buffer
 * @msgID = MessageID
 * return: -1 error or >-1 message size for send
 */
inline int
mqtt_msgPUBREC(mqtt_msg_t * __restrict buf, u_short msgID)
{
	return _mqtt_msgPUB_(buf, MQTT_TYPE_PUBREC, msgID);
}

/*
 * mqtt_msgPUBREL() Create PUBREL message
 *
 * @buf = Message buffer
 * @msgID = MessageID
 * return: -1 error or >-1 message size for send
 */
inline int
mqtt_msgPUBREL(mqtt_msg_t * __restrict buf, u_short msgID)
{
	return _mqtt_msgPUB_(buf, MQTT_TYPE_PUBREL, msgID);
}

/*
 * mqtt_msgPUBCOMP() Create PUBCOMP message
 *
 * @buf = Message buffer
 * @msgID = MessageID
 * return: -1 error or >-1 message size for send
 */
inline int
mqtt_msgPUBCOMP(mqtt_msg_t * __restrict buf, u_short msgID)
{
	return _mqtt_msgPUB_(buf, MQTT_TYPE_PUBCOMP, msgID);
}