#ifndef UBUS_H
#define UBUS_H

#include <ArduinoRS485.h>
#include <util/crc16.h>

extern unsigned long _hdlc_start;

#define HDLC_START 0x7E
#define HDLC_ESC 0x7D
#define HDLC_BUF_SIZE 32
#define CRC16_CCITT_INIT_VAL 0xFFFF

class UBus: public RS485Class {
public:
    enum MessageType : uint8_t {
        SYS_StatusPoll = 0x00,
        SYS_Identify = 0x01,
        SYS_SupportedCommands = 0x02,

        GPIO_Write = 0x10,
        GPIO_Read = 0x11,
        GPIO_WS2812 = 0x12,

        PERI_NFC = 0x20,
    };

    uint8_t addr = 0;
    uint32_t identify_ts = 0;

    bool escape = false;

    uint8_t buf_pos = 0;
    uint8_t buffer[HDLC_BUF_SIZE];
    uint16_t checksum = CRC16_CCITT_INIT_VAL;

    UBus(): RS485Class(Serial, 1, 3, 2) { }

    void begin();

    void sendByte(uint8_t b);
    void send(uint8_t msg_type, uint8_t* buf, size_t size);
    void sendResponse(uint8_t msg_type, uint8_t* buf, size_t size);

    void handleRequest();

    void poll();
    void parse(uint8_t c);
};
#endif