import json
import base64
import struct


def to_bytes(x, charset='utf-8', errors='strict'):
    if x is None:
        return None
    if isinstance(x, bytes):
        return x
    if isinstance(x, str):
        return x.encode(charset, errors)
    if isinstance(x, (int, float)):
        return str(x).encode(charset, errors)
    return bytes(x)


def to_unicode(x, charset='utf-8', errors='strict'):
    if x is None or isinstance(x, str):
        return x
    if isinstance(x, bytes):
        return x.decode(charset, errors)
    return str(x)


def to_native(x, encoding='ascii'):
    if isinstance(x, str):
        return x
    return x.decode(encoding)


def json_loads(s):
    return json.loads(s)


def json_dumps(data, ensure_ascii=False):
    return json.dumps(data, ensure_ascii=ensure_ascii, separators=(',', ':'))


def urlsafe_b64decode(s):
    s += b'=' * (-len(s) % 4)
    return base64.urlsafe_b64decode(s)


def urlsafe_b64encode(s):
    return base64.urlsafe_b64encode(s).rstrip(b'=')


def base64_to_int(s):
    data = urlsafe_b64decode(to_bytes(s, charset='ascii'))
    buf = struct.unpack('%sB' % len(data), data)
    return int(''.join(["%02x" % byte for byte in buf]), 16)


def int_to_base64(num):
    if num < 0:
        raise ValueError('Must be a positive integer')

    s = num.to_bytes((num.bit_length() + 7) // 8, 'big', signed=False)
    return to_unicode(urlsafe_b64encode(s))


def json_b64encode(text):
    if isinstance(text, dict):
        text = json_dumps(text)
    return urlsafe_b64encode(to_bytes(text))