/* File: state_machine.h */
/**
 * @file state_machine.h
 * @brief State machine interface for the beverage dispenser core program.
 *
 * This module drives a keypad‐and‐LCD UI to select beverage types (A–D),
 * choose quantities, confirm orders, detect door events, and edit stock levels.
 *
 * @authors
 *      Frederik Beimgraben
 *      Minh Dan Cam
 *      Luis Meyer
 * @date 2025-07-03
 */

#ifndef STATE_MACHINE_H
#define STATE_MACHINE_H

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

/**
 * @enum State_t
 * @brief All possible states of the UI state machine.
 */
typedef enum {
    STATE_IDLE,                  /**< Waiting for user input */
    STATE_SEL_COUNT,             /**< Selecting order quantity */
    STATE_CONFIRMED,             /**< Order confirmed */
    STATE_OPEN,                  /**< Door is open */
    STATE_UNAUTHORIZED,          /**< Unauthorized door opening */
    STATE_NONE_SELECTED,         /**< No beverage selected at confirm */
    STATE_RESET,                 /**< Transient “reset” display */
    STATE_EDIT_STOCK_SELECT,     /**< Select which beverage’s stock to edit */
    STATE_EDIT_STOCK_SET,        /**< Enter new stock value */
    STATE_EDIT_STOCK_CONFIRMED   /**< Stock update confirmed */
} State_t;

/**
 * @enum SelectedBev_t
 * @brief Identifiers for the four beverage types.
 */
typedef enum {
    BEV_A, /**< Beverage A */
    BEV_B, /**< Beverage B */
    BEV_C, /**< Beverage C */
    BEV_D  /**< Beverage D */
} SelectedBev_t;

/**
 * @brief Initialize the state machine, keypad, door sensor, and LCD.
 */
void sm_init(void);

/**
 * @brief Enter the state‐machine’s main loop (low‐power + interrupts).
 */
void sm_loop(void);

#endif // STATE_MACHINE_H