

#ifndef __PN532_INTERFACE_H__
#define __PN532_INTERFACE_H__

#include <stdint.h>

#define PN532_PREAMBLE                (0x00)
#define PN532_STARTCODE1              (0x00)
#define PN532_STARTCODE2              (0xFF)
#define PN532_POSTAMBLE               (0x00)

#define PN532_HOSTTOPN532             (0xD4)
#define PN532_PN532TOHOST             (0xD5)

#define PN532_ACK_WAIT_TIME           (10)  // ms, timeout of waiting for ACK

#define PN532_INVALID_ACK             (-1)
#define PN532_TIMEOUT                 (-2)
#define PN532_INVALID_FRAME           (-3)
#define PN532_NO_SPACE                (-4)

#define REVERSE_BITS_ORDER(b)         b = (b & 0xF0) >> 4 | (b & 0x0F) << 4; \
    b = (b & 0xCC) >> 2 | (b & 0x33) << 2; \
    b = (b & 0xAA) >> 1 | (b & 0x55) << 1

class PN532Interface {
  public:
    virtual void begin() = 0;
    virtual void wakeup() = 0;

    /**
        @brief    write a command and check ack
        @param    header  packet header
        @param    hlen    length of header
        @param    body    packet body
        @param    blen    length of body
        @return   0       success
                not 0   failed
    */
    virtual int8_t writeCommand(const uint8_t* header, uint8_t hlen, const uint8_t* body = 0, uint8_t blen = 0) = 0;

    /**
        @brief    read the response of a command, strip prefix and suffix
        @param    buf     to contain the response data
        @param    len     lenght to read
        @param    timeout max time to wait, 0 means no timeout
        @return   >=0     length of response without prefix and suffix
                <0      failed to read response
    */
    virtual int16_t readResponse(uint8_t buf[], uint8_t len, uint16_t timeout = 1000) = 0;
};

#endif

