import random
import bchlib

ECC_POLY = 8219
ECC_BITS = 16  # 16-bit ECC encoder
bch = bchlib.BCH(ECC_BITS, prim_poly=ECC_POLY)

# 待编码数据
text = 'hello world ' * 30

# 转 bytearray
data = bytearray('hello world ' * 30, 'utf-8')

# 创建一个包含数据和错误校正码的数据包
ecc = bch.encode(data)
packet = data + ecc

# 展示原始数据包
print('original packet: %s' % packet)


# 模拟在数据包上引入错误
def bit_flip(packet):
    byte_num = random.randint(0, len(packet) - 1)
    bit_num = random.randint(0, 7)
    packet[byte_num] ^= (1 << bit_num)


# 引入5个错误
for _ in range(5):
    bit_flip(packet)

# 展示引入错误后的数据包
print('corrupt packet: %s' % packet)

# 解码并纠正数据包
data, ecc = packet[:-bch.ecc_bytes], packet[-bch.ecc_bytes:]
bitflips = bch.decode(data, ecc)

if bitflips >= 0:
    print('bitflips: %d' % bitflips)
else:
    print('unrecoverable error')

bch.correct(data, ecc)
print('corrected packet: %s' % (data + ecc))