/**
 * @file se050_tai64n_hw.h
 * @brief TAI64N using SE050 Hardware Monotonic Counter
 * 
 * Uses SE050's built-in monotonic counter for replay prevention.
 * Object ID: SE05X_OBJ_ID_MONOTONIC_COUNTER (0x7FFF0203)
 */

#ifndef SE050_TAI64N_HW_H
#define SE050_TAI64N_HW_H

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

#ifdef __cplusplus
extern "C" {
#endif

#define TAI64N_HW_SIZE 12
#define SE050_MONOTONIC_COUNTER_ID 0x7FFF0203

/* Session handle type (opaque) */
typedef void* se050_session_t;

/* Mock session for testing */
typedef struct {
    uint32_t counter;
} mock_session_t;

/**
 * @brief Read SE050 monotonic counter and encode as TAI64N
 * @param session SE050 session handle
 * @param out Output buffer (12 bytes)
 * @return 0 on success, -1 on error
 */
int se050_tai64n_hw_now(void *session, uint8_t out[12]);

/**
 * @brief Read SE050 monotonic counter only (32-bit)
 * @param session SE050 session handle
 * @param counter Output counter value
 * @return 0 on success, -1 on error
 */
int se050_tai64n_hw_read_counter(void *session, uint32_t *counter);

/**
 * @brief Increment SE050 monotonic counter
 * @param session SE050 session handle
 * @return 0 on success, -1 on error
 */
int se050_tai64n_hw_increment(void *session);

/**
 * @brief Check if timestamp is within acceptable window
 * @param timestamp Received TAI64N timestamp
 * @param current Current TAI64N timestamp
 * @param window Acceptable window in seconds
 * @return 1 if valid, 0 if expired/replay, -1 on error
 */
int se050_tai64n_hw_check_window(const uint8_t timestamp[12],
                                 const uint8_t current[12],
                                 uint32_t window);

#ifdef __cplusplus
}
#endif

#endif /* SE050_TAI64N_HW_H */