"""A conversion module for googletrans"""
import json
import re


def build_params(query, src, dest, token, override):
    params = {
        'client': 'webapp',
        'sl': src,
        'tl': dest,
        'hl': dest,
        'dt': ['at', 'bd', 'ex', 'ld', 'md', 'qca', 'rw', 'rm', 'ss', 't'],
        'ie': 'UTF-8',
        'oe': 'UTF-8',
        'otf': 1,
        'ssel': 0,
        'tsel': 0,
        'tk': token,
        'q': query,
    }

    if override is not None:
        for key, value in get_items(override):
            params[key] = value

    return params


def legacy_format_json(original):
    # save state
    states = []
    text = original

    # save position for double-quoted texts
    for i, pos in enumerate(re.finditer('"', text)):
        # pos.start() is a double-quote
        p = pos.start() + 1
        if i % 2 == 0:
            nxt = text.find('"', p)
            states.append((p, text[p:nxt]))

    # replace all wiered characters in text
    while text.find(',,') > -1:
        text = text.replace(',,', ',null,')
    while text.find('[,') > -1:
        text = text.replace('[,', '[null,')

    # recover state
    for i, pos in enumerate(re.finditer('"', text)):
        p = pos.start() + 1
        if i % 2 == 0:
            j = int(i / 2)
            nxt = text.find('"', p)
            # replacing a portion of a string
            # use slicing to extract those parts of the original string to be kept
            text = text[:p] + states[j][1] + text[nxt:]

    converted = json.loads(text)
    return converted


def get_items(dict_object):
    for key in dict_object:
        yield key, dict_object[key]


def format_json(original):
    try:
        converted = json.loads(original)
    except ValueError:
        converted = legacy_format_json(original)

    return converted


def rshift(val, n):
    """python port for '>>>'(right shift with padding)
    """
    return (val % 0x100000000) >> n
