/**
 ******************************************************************************
 * @file    cdc.h
 * @brief   This is the USB Communication Device Class, Abstract Control Model
 * implementation module for the flatUSB project. The following standard
 * requestes are implemented: `SetLineCoding`, `GetLineCoding`,
 * `SetControlLineState` and `SendBreak`. Data transmission is performed by
 * calling `usb_acm_write()`. Ingress data is passed to the application through
 * the `usb_acm_read_callback()` function. A weak prototype is provided which
 * is expected to be overridden by the application. Supplying a BlockingFifo
 * is mandatory!
 *
 * If necessary, `USB_CDC_FIFO_MEM_SIZE` and `USB_CDC_PCKT_BUFSIZE` can be freely
 * overridden in the flatUSB configuration file.
 *
 * For more information about the USB CDC ACM class refer to the
 * <a href="https://www.usb.org/document-library/class-definitions-communication-devices-12" target="_blank">
 * USB CDC PSTN subclass</a>.
 *
 * @copyright András Wiesner, 2024-\showdate "%Y"
 ******************************************************************************
 */

#ifndef CORE_USB_CLASS_CDC
#define CORE_USB_CLASS_CDC

#include "../usb_callback_event.h"

/**
 * CDC request codes
 */
typedef enum {
    USB_ACM_SET_COMM_FEATURE = 0x2,        ///< SetCommFeature
    USB_ACM_GET_COMM_FEATURE = 0x3,        ///< GetCommFeature
    USB_ACM_CLEAR_COMM_FEATURE = 0x4,      ///< ClearCommFeature
    USB_ACM_SET_AUX_LINE_STATE = 0x10,     ///< SetAuxLineState
    USB_ACM_SET_HOOK_STATE = 0x11,         ///< SetHookState
    USB_ACM_PULSE_SETUP = 0x12,            ///< PulseSetup
    USB_ACM_SEND_PULSE = 0x13,             ///< SendPulse
    USB_ACM_SET_PULSE_TIME = 0x14,         ///< SetPulseTime
    USB_ACM_RING_AUX_JACK = 0x15,          ///< RingAuxJack
    USB_ACM_SET_LINE_CODING = 0x20,        ///< SetLineCoding
    USB_ACM_GET_LINE_CODING = 0x21,        ///< GetLineCoding
    USB_ACM_SET_CONTROL_LINE_STATE = 0x22, ///< SetControlLineState
    USB_ACM_SEND_BREAK = 0x23,             ///< SendBreak
    USB_ACM_SET_RINGER_PARMS = 0x30,       ///< SetRingerParms
    USB_ACM_GET_RINGER_PARMS = 0x31,       ///< GetRingerParms
    USB_ACM_SET_OPERATION_PARMS = 0x32,    ///< SetOperationParms
    USB_ACM_GET_OPERATION_PARMS = 0x33,    ///< GetOperationParms
    USB_ACM_SET_LINE_PARMS = 0x34,         ///< GetLineParms
} Usb_Acm_RequestCodes;

/**
 * ACM line coding structure
 */
typedef struct {
    uint32_t dwDTERate;  ///< data terminal rate, bits per second
    uint8_t bCharFormat; ///< character format
    uint8_t bParityType; ///< parity type
    uint8_t bDataBits;   ///< data bits
} Usb_Acm_LineCodingStruct;

/**
 * CDC control line state struct
 */
typedef struct {
    uint16_t D; ///< settings word
} Usb_Acm_ControlLineStateStruct;

// ----------------

/**
 * Endpoint assignments
 */
typedef struct {
    uint8_t control_ep : 4; ///< Control endpoint
    uint8_t data_ep : 4;    ///< Data endpoint
} Usb_Acm_EpAssignments;

typedef struct {
    Usb_Acm_EpAssignments ep_assignments;              ///< Endpoint assignments
    Usb_Acm_LineCodingStruct line_coding;              ///< Line Coding
    Usb_Acm_ControlLineStateStruct control_line_state; ///< Control Line State
    uint16_t interrupt_data;                           ///< Data sent though the next transfer on the notification element
    bool moduleInit;                                   ///< CDC module is initialized
    bool commInit;                                     ///< Communication protocol is initialized
} Usb_AcmState;

// ----------------

#define USB_ACM_INVALID_CONTROL_LINE_STATE (0xFFFF) ///< Invalid Control Line State

// ----------------

#ifndef USB_ACM_FIFO_MEM_SIZE
#define USB_ACM_FIFO_MEM_SIZE (3072) ///< CDC ACM FIFO memory size
#endif

#ifndef USB_ACM_PCKT_BUFSIZE
#define USB_ACM_PCKT_BUFSIZE (128) ///< Buffer size assigned to the data transfer endpoint
#endif

// ----------------

/**
 * Initialize CDC ACM module.
 *
 * @param as pointer to filled endpoint assignments object
 */
void usb_acm_init(const Usb_Acm_EpAssignments *as);

/**
 * Regular USB class process and return function.
 *
 * @param cbevt pointer to callback event emitted by the USB core
 * @return request is unprocessed if < 0
 */
int usb_acm_process_and_return(Usb_CallbackEvent *cbevt);

/**
 * Write to CDC ACM interface.
 *
 * @param data data to be sent through the interface
 * @param size length of the data
 */
void usb_acm_write(const uint8_t *data, uint32_t size);

#endif /* CORE_USB_CLASS_CDC */