/**
 * @file can_driver.h
 * @brief CAN (Controller Area Network) driver interface
 * @note Supports classical CAN and CAN FD
 */

#ifndef CAN_DRIVER_H
#define CAN_DRIVER_H

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

/* CAN Configuration Constants */
#define CAN_MAX_MESSAGE_LENGTH      8    /* Classical CAN */
#define CAN_FD_MAX_MESSAGE_LENGTH   64   /* CAN FD */
#define CAN_MAX_FILTERS             32
#define CAN_MAX_TX_MAILBOXES        3
#define CAN_MAX_RX_FIFO_DEPTH       16

/* CAN Baudrates */
typedef enum {
    CAN_BAUD_125K = 125000,
    CAN_BAUD_250K = 250000,
    CAN_BAUD_500K = 500000,
    CAN_BAUD_1M   = 1000000,
    CAN_FD_BAUD_2M = 2000000,
    CAN_FD_BAUD_5M = 5000000
} CanBaudrate_t;

/* CAN Message Types */
typedef enum {
    CAN_FRAME_CLASSIC = 0,
    CAN_FRAME_FD = 1,
    CAN_FRAME_FD_BRS = 2  /* FD with Bit Rate Switch */
} CanFrameType_t;

/* CAN Frame Format */
typedef enum {
    CAN_FORMAT_STANDARD = 0,  /* 11-bit identifier */
    CAN_FORMAT_EXTENDED = 1   /* 29-bit identifier */
} CanFrameFormat_t;

/* CAN Message ID */
typedef struct {
    uint32_t id : 29;
    CanFrameFormat_t format : 1;
    bool is_remote : 1;
    bool is_extended : 1;
} CanMessageId_t;

/* CAN Message Structure */
typedef struct {
    CanMessageId_t id;
    CanFrameType_t type;
    uint8_t data[CAN_FD_MAX_MESSAGE_LENGTH];
    uint8_t length;
    uint32_t timestamp;
    bool is_rx;
} CanMessage_t;

/* CAN Filter Configuration */
typedef struct {
    uint32_t filter_id;
    uint32_t filter_mask;
    CanFrameFormat_t format;
    bool enable;
} CanFilterConfig_t;

/* CAN Statistics */
typedef struct {
    uint32_t tx_messages;
    uint32_t rx_messages;
    uint32_t tx_errors;
    uint32_t rx_errors;
    uint32_t bus_off_count;
    uint32_t error_warning_count;
    uint32_t error_passive_count;
    uint32_t tx_overflow;
    uint32_t rx_overflow;
} CanStatistics_t;

/* CAN Callbacks */
typedef void (*CanRxCallback_t)(const CanMessage_t* message);
typedef void (*CanTxCallback_t)(uint32_t mailbox, bool success);
typedef void (*CanErrorCallback_t)(uint32_t error_code);

/* CAN Configuration Structure */
typedef struct {
    CanBaudrate_t nominal_baudrate;
    CanBaudrate_t data_baudrate;  /* For CAN FD */
    CanFrameType_t frame_type;
    bool enable_fd;
    bool enable_automatic_retransmission;
    CanFilterConfig_t filters[CAN_MAX_FILTERS];
    uint8_t filter_count;
    CanRxCallback_t rx_callback;
    CanTxCallback_t tx_callback;
    CanErrorCallback_t error_callback;
} CanConfig_t;

/* CAN Driver Interface */
KernelStatus_t can_init(CanConfig_t* config);
KernelStatus_t can_deinit(void);
KernelStatus_t can_send_message(const CanMessage_t* message, uint32_t timeout_ms);
KernelStatus_t can_receive_message(CanMessage_t* message, uint32_t timeout_ms);
KernelStatus_t can_configure_filter(const CanFilterConfig_t* filter);
KernelStatus_t can_set_baudrate(CanBaudrate_t baudrate);
KernelStatus_t can_get_statistics(CanStatistics_t* stats);
KernelStatus_t can_clear_statistics(void);
bool can_is_bus_off(void);
KernelStatus_t can_recover_bus_off(void);
void can_process_interrupt(void);

/* CAN FD Specific Functions */
KernelStatus_t can_fd_set_data_baudrate(CanBaudrate_t baudrate);
KernelStatus_t can_fd_set_transmit_delay(uint16_t delay_us);
bool can_fd_is_enabled(void);

#endif /* CAN_DRIVER_H */