/* rpc.h - versioned length-prefixed control protocol and command registry. */
#ifndef NAUT_RPC_H
#define NAUT_RPC_H

#include "naut/common.h"
#include "naut/event.h"

#include <jansson.h>

#define NAUT_RPC_VERSION 1
#define NAUT_RPC_MAX_PAYLOAD (1u << 20)

typedef enum {
    NAUT_RPC_REQUEST = 1,
    NAUT_RPC_RESPONSE = 2,
    NAUT_RPC_EVENT = 3,
} naut_rpc_frame_type;

typedef struct naut_rpc_registry naut_rpc_registry;
typedef json_t *(*naut_rpc_handler)(void *context, const json_t *params,
                                    naut_err *error);

naut_rpc_registry *naut_rpc_registry_create(void);
void naut_rpc_registry_destroy(naut_rpc_registry *registry);
naut_err naut_rpc_register(naut_rpc_registry *registry, const char *method,
                           naut_rpc_handler handler, void *context);
void naut_rpc_unregister(naut_rpc_registry *registry, const char *method);
json_t *naut_rpc_dispatch(naut_rpc_registry *registry, const char *method,
                          const json_t *params, naut_err *error);

naut_err naut_rpc_send_json(int fd, naut_rpc_frame_type type,
                            const json_t *payload);
naut_err naut_rpc_recv_json(int fd, naut_rpc_frame_type *type,
                            json_t **payload);

int naut_rpc_connect_unix(const char *socket_path);

/* Connect to a UNIX socket and perform one request/response exchange. */
naut_err naut_rpc_call(const char *socket_path, const char *method,
                       const json_t *params, json_t **response);

/* Convert an event into the stable JSON event representation. */
json_t *naut_rpc_event_json(const naut_event *event);

#endif /* NAUT_RPC_H */