import reedsolo


def encode(text, n):
    rsc = reedsolo.RSCodec(n)
    encoded_bytes = rsc.encode(text)
    return encoded_bytes


def decode(encoded_text, n, original_length=None):
    rsc = reedsolo.RSCodec(n)
    try:
        decoded_bytes = rsc.decode(encoded_text)
        # Обрезаем декодированные данные до оригинального размера
        if original_length:
            primer = decoded_bytes[0][-original_length:]
            print(primer.decode('utf-8'))
            return bytes(primer)
        return decoded_bytes[0]
    except reedsolo.ReedSolomonError:
        return None


def split_text(text):
    length = len(text)
    part_length = length // 3
    part1 = text[:part_length]
    part2 = text[part_length:2 * part_length]
    part3 = text[2 * part_length:]
    return part1, part2, part3


text = b'This is a sample text for testing Reed-Solomon codes.'

part1, part2, part3 = split_text(text)
print(part1)
print(part2)
print(part3)
n = len(text)
# Кодируем каждую часть
encoded_part1 = encode(part1, n)
encoded_part2 = encode(part2, n)
encoded_part3 = encode(part3, n)

encoded_part2_corrupted = encoded_part2[:10] + b'corrupted' + encoded_part2[10:]
print(part2)
print(encoded_part2)
print(encoded_part2_corrupted)
data_len = len(part1)+2
recovered_part2 = decode(encoded_part2_corrupted, n, data_len)
encoded_part1 = decode(encoded_part1, n)
print(encoded_part1)
if recovered_part2 is not None:
    print("Original Part 2:", part2)
    print("Recovered Part 2:", recovered_part2)
else:
    print("Unable to recover Part 2.")