#include <stdint.h>
#include <string.h>
#include <malloc.h>

typedef unsigned char byte;

typedef struct {
    uint8_t  just_a_byte;
    int16_t  int16_with_sign;
    uint8_t  text_length;
    char     *text;
} data_t;

void serialize(const data_t *data, byte *dst) {
    unsigned int p = 0;
    dst[p++] = data->just_a_byte;
    dst[p++] = (int8_t)(data->int16_with_sign >> 8);
    dst[p++] = (uint8_t)(data->int16_with_sign & 0xff);
    dst[p++] = data->text_length;
    strcpy((char *)(dst + p), data->text);
}

void deserialize(const byte *array, data_t *data) {
    unsigned int p = 0;
    data->just_a_byte     = array[p++];
    data->int16_with_sign = (array[p++] << 8);
    data->int16_with_sign |= array[p++];
    data->text_length     = array[p++];
    data->text            = (char *)malloc(data->text_length);
    memcpy(data->text, (char *)(array + p), data->text_length);
}

int main()
{
    data_t data = {
        .just_a_byte = 0x12,
        .int16_with_sign = -4567,  // = 0xEE29
        .text_length = 6,
        .text = (char *)malloc(6)
    };
    strcpy(data.text, "kissa");

    // Serialize
    byte serialized[16] = { 0 };
    serialize(&data, serialized);
    for (unsigned int i = 0; i < 16; i++)
        printf("%02x ", serialized[i]);

    // Deserialize
    data_t new_data;
    deserialize(serialized, &new_data);
    printf("\njust_a_byte: %x, int16_with_sign: %d, text: %s\n",
        new_data.just_a_byte, new_data.int16_with_sign, new_data.text);

    return 0;
}