#ifndef _DATASERVER_MESSAGE_H_
#define _DATASERVER_MESSAGE_H_

#include "stdint.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Message head
 */
typedef struct {
    int magic;
    #define DS_MAGIC ((int)('d'<<24|'a'<<16|'s'<<8|'r'))

    int type;
    #define DS_T_DATA 0
    #define DS_T_CNTL 1
    #define DS_T_RESP 2
    #define DS_T_EVNT 3

    /**
     * Specifies the number of bytes of the body.
     */
    int size;

    /**
     * Contains the different types of message content, as defined below.
     */
    uint8_t body[0];
} ds_msg_head_t;

/**
 * @brief Message data
 */
typedef struct {
    /**
     * The data size is specified by field "size" in ds_msg_head_t.
     * Details of different device data will be defined in "dataserver_data_xxx.h"
     */
    uint8_t data[0];
} ds_msg_data_t;

/**
 * @brief Message control
 */
typedef struct {
    /**
     * A NULL terminated string.
     * Detailed commands definition can be found in "dataserver_cmd_resp.h".
     */
    uint8_t cmd[0];
} ds_msg_cntl_t;

/**
 * @brief Message response (common)
 */
typedef struct {
    /**
     * A simple reply of state, "ok" or "ko".
     */
    uint8_t resp[3];
} ds_msg_resp_comm_t;

/**
 * @brief Message event
 */
typedef struct {
    /**
     * A NULL terminated string.
     * Specifies the name of the event.
     * Details of events can be found in "dataserver_event.h"
     */
    uint8_t event[0];
} ds_msg_evnt_t;

#ifdef __cplusplus
}
#endif

#endif