#ifndef NALL_CRC16_HPP
#define NALL_CRC16_HPP

#include <nall/stdint.hpp>

namespace nall {

inline uint16_t crc16_adjust(uint16_t crc16, uint8_t data) {
  for(unsigned n = 0; n < 8; n++) {
    if((crc16 & 1) ^ (data & 1)) crc16 = (crc16 >> 1) ^ 0x8408;
    else crc16 >>= 1;
    data >>= 1;
  }
  return crc16;
}

inline uint16_t crc16_calculate(const uint8_t* data, unsigned length) {
  uint16_t crc16 = ~0;
  for(unsigned n = 0; n < length; n++) {
    crc16 = crc16_adjust(crc16, data[n]);
  }
  return ~crc16;
}

}

#endif