libmp/include/mptp.h

#pragma once
#include "types.h"
#include <stdint.h>

// clang-format off

/*

 0 1 2 3 4 5 6 7
 ###############
 #   FLAGS     #
 ###############
 #    SIZE     #
 #             #
 ###############
 #    DATA     #
 #.............#

 [8 bits] FLAGS
 ---------------------------------------------------------
 4 bits used for specifying the version
 ---------------------------------------------------------
 1 bit used to specify if this is a request or response

 0- it's a request
 1- it's a response
 ---------------------------------------------------------
 2 bits used for request/response codes

 We have 4 types of different requests
 1- PING: checks if the server is avaliable
 2- INFO: gets information about the pool(s) the server is hosting
 3- LIST: requests the package list for certain pool
 4- PULL: requests a certain package from a certain pool

 And 4 types of responses
 1- PONG: response for the ping request
 2- COOL: everything is fine, here's the data you requested
 3- BRUH: cannot access to the data you requested, or version mismatch
 4- WHAT: bad request
 ---------------------------------------------------------
 1 bit used to specify if this the last request/response

 0- no stay connected, im not done responsing/requesting yet
 1- yes, im done, disconnect
 ---------------------------------------------------------

 [16 bits] SIZE
 ---------------------------------------------------------
 All bits used for specifying the DATA size, in bytes
 ---------------------------------------------------------

 [...] DATA
 ---------------------------------------------------------
 Plaintext data used for that specific request/response,
 max value for SIZE is 65535, so this section may have
 65535 bytes total
 ---------------------------------------------------------

*/

// clang-format on

#define MPTP_VERSION_SUPPORTED 0
#define MPTP_VERSION_MAX       15 // 4 bits
#define MPTP_CODE_MAX          4  // 2 bits

typedef enum lm_mptp_request {
  MPTP_C2S_PING = 0,
  MPTP_C2S_INFO = 1,
  MPTP_C2S_LIST = 2,
  MPTP_C2S_PULL = 3,
} lm_mptp_request_t;

typedef enum lm_mptp_response {
  MPTP_S2C_PONG = 0,
  MPTP_S2C_COOL = 1,
  MPTP_S2C_BRUH = 2,
  MPTP_S2C_WHAT = 3,
} lm_mptp_response_t;

typedef struct lm_mptp {
  uint8_t  flags;
  uint16_t size;
  char    *data;
} lm_mptp_t;

void lm_mptp_flags_set(lm_mptp_t *packet, uint8_t version, bool is_request, uint8_t code, bool is_last);
#define MPTP_FLAGS_VERSION(m)    (m->flags >> 4) & 15
#define MPTP_FLAGS_IS_REQUEST(m) ((m->flags >> 3) & 1) == 0
#define MPTP_FLAGS_TYPE(m)       (m->flags >> 1) & 3
#define MPTP_FLAGS_IS_LAST(m)    (m->flags & 1) == 1

int  lm_mptp_connect(lm_url_t *url);
bool lm_mptp_recv(int socket, lm_mptp_t *packet);
bool lm_mptp_send(int socket, lm_mptp_t *packet);
void lm_mptp_disconnect(int socket);