/*******************************************************************************
 * Copyright (c) 2014 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 *
 * The Eclipse Public License is available at
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Ian Craggs - initial API and implementation and/or initial documentation
 *    Xiang Rong - 442039 Add makefile to Embedded C client
 *******************************************************************************/

#ifndef MQTTPACKET_H_
#define MQTTPACKET_H_

#if defined(__cplusplus) /* If this is a C++ compiler, use C linkage */
extern "C" {
#endif

#if defined(WIN32_DLL) || defined(WIN64_DLL)
#define DLLImport __declspec(dllimport)
#define DLLExport __declspec(dllexport)
#elif defined(LINUX_SO)
#define DLLImport extern
#define DLLExport __attribute__((visibility("default")))
#else
#define DLLImport
#define DLLExport
#endif

enum errors {
    MQTTPACKET_BUFFER_TOO_SHORT = -2,
    MQTTPACKET_READ_ERROR = -1,
    MQTTPACKET_READ_COMPLETE
};

/* CPT, control packet type */
enum msgTypes {
    MQTT_CPT_RESERVED = 0,
    CONNECT = 1,
    CONNACK,
    PUBLISH,
    PUBACK,
    PUBREC,
    PUBREL,
    PUBCOMP,
    SUBSCRIBE,
    SUBACK,
    UNSUBSCRIBE,
    UNSUBACK,
    PINGREQ,
    PINGRESP,
    DISCONNECT
};

#define MQTT_HEADER_BIT_MASK_TYPE    (0xF0)
#define MQTT_HEADER_BIT_MASK_DUP     (0x08)
#define MQTT_HEADER_BIT_MASK_QOS     (0x06)
#define MQTT_HEADER_BIT_MASK_RETAIN  (0x01)

#define MQTT_HEADER_GET_TYPE(head)   ((head & 0xF0) >> 4)
#define MQTT_HEADER_GET_DUP(head)    ((head & 0x08) >> 3)
#define MQTT_HEADER_GET_QOS(head)    ((head & 0x06) >> 1)
#define MQTT_HEADER_GET_RETAIN(head) (head & 0x01)

#define MQTT_HEADER_SET_TYPE(head, type) \
    do {                                 \
        head |= ((type << 4) & 0xF0);    \
    } while (0)
#define MQTT_HEADER_SET_DUP(head, dup) \
    do {                               \
        head |= ((dup << 3) & 0x08);   \
    } while (0)
#define MQTT_HEADER_SET_QOS(head, qos) \
    do {                               \
        head |= ((qos << 1) & 0x06);   \
    } while (0)
#define MQTT_HEADER_SET_RETAIN(head, retain) \
    do {                                     \
        head |= (retain & 0x01);             \
    } while (0)

/**
 * Bitfields for the MQTT header byte.
 */
typedef union {
    unsigned char byte; /**< the whole byte */
} MQTTHeader;

typedef struct {
    int len;
    char *data;
} MQTTLenString;

typedef struct {
    char *cstring;
    MQTTLenString lenstring;
} MQTTString;

#define MQTTString_initializer \
    {                          \
        NULL, { 0, NULL }      \
    }

int MQTTstrlen(MQTTString mqttstring);

#include "MQTTConnect.h"
#include "MQTTPublish.h"
#include "MQTTSubscribe.h"
#include "MQTTUnsubscribe.h"

int MQTTSerialize_ack(unsigned char *buf, int buflen, unsigned char type,
                      unsigned char dup, unsigned short packetid);
int MQTTDeserialize_ack(unsigned char *packettype, unsigned char *dup,
                        unsigned short *packetid, unsigned char *buf,
                        int buflen);

int MQTTPacket_len(int rem_len);
int MQTTPacket_equals(MQTTString *a, char *b);

int MQTTPacket_encode(unsigned char *buf, int length);
int MQTTPacket_decode(int (*getcharfn)(unsigned char *, int), int *value);
int MQTTPacket_decodeBuf(unsigned char *buf, int *value);

int readInt(unsigned char **pptr);
char readChar(unsigned char **pptr);
void writeChar(unsigned char **pptr, char c);
void writeInt(unsigned char **pptr, int anInt);
int readMQTTLenString(MQTTString *mqttstring, unsigned char **pptr,
                      unsigned char *enddata);
void writeCString(unsigned char **pptr, const char *string);
void writeMQTTString(unsigned char **pptr, MQTTString mqttstring);

typedef struct {
    int (*getfn)(void *, unsigned char *,
                 int); /* must return -1 for error, 0 for call again, or the
                          number of bytes read */
    void *sck;         /* pointer to whatever the system may use to identify the
                          transport */
    int multiplier;
    int rem_len;
    int len;
    char state;
} MQTTTransport;

#ifdef __cplusplus /* If this is a C++ compiler, use C linkage */
}
#endif

#endif /* MQTTPACKET_H_ */