#pragma once

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

#include "esp_err.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef enum {
    ROBOT_CMD_UP = 0,
    ROBOT_CMD_DOWN,
    ROBOT_CMD_LEFT,
    ROBOT_CMD_RIGHT,
    ROBOT_CMD_STOP,
    ROBOT_CMD_INVALID,
} robot_cmd_dir_t;

typedef struct {
    bool ok;
    uint32_t seq;
    const char *type;   /* "cmd" or "msg" */
    const char *dir;    /* for cmd */
    const char *text;   /* for msg */
    const char *fwd;    /* "ack" now; later "i2c" / "fail" */
    const char *error;  /* set when ok=false */
} robot_ack_t;

void robot_link_init(void);

robot_cmd_dir_t robot_link_parse_dir(const char *dir);

/* Accept a drive command. Fills ack; does not yet talk to RP2040. */
esp_err_t robot_link_handle_cmd(const char *dir, robot_ack_t *ack);

/* Accept a free-text message. Fills ack; does not yet talk to RP2040. */
esp_err_t robot_link_handle_msg(const char *text, size_t len, robot_ack_t *ack);

/* Format ack as a compact JSON object into buf. Returns bytes written (excl NUL). */
int robot_link_format_ack(const robot_ack_t *ack, char *buf, size_t buflen);

#ifdef __cplusplus
}
#endif