"""Basic utils."""

import base64
import binascii
from collections import namedtuple
import hashlib
import hmac
import json

from users import constants

Pagination = namedtuple('Pagination', ['offset', 'limit'])


def sign_token(token, shared_secret):
    """Sign token with secret key.

    Args:
        token (bytes): the token to be signed
        shared_secret (bytes): the secret key to sign the token
    Returns:
          bytes: The signed token represented as hex
    """
    token = hmac.new(shared_secret, token, hashlib.sha1).digest()
    return base64.b64encode(binascii.hexlify(token))


def get_pagination(request):
    """Parse pagination information.

    Args:
        request (Flask.request): The request object.

    Returns:
        Pagination (namedtuple): pagination information.

    """
    page_offset = request.args.get('page_offset', constants.PAGE_OFFSET_DEFAULT)
    page_offset = _get_int(page_offset, constants.PAGE_OFFSET_DEFAULT)

    page_limit = request.args.get('page_limit', constants.PAGE_LIMIT_DEFAULT)
    page_limit = _get_int(page_limit, constants.PAGE_LIMIT_DEFAULT)

    return Pagination(page_offset, page_limit)


def _get_int(value, default_value):
    """Methos to covert value in int.

    Args:
        value (str or int): The value to convert to int.
        default_value (int): The default value to use if value cannot be
            converted.

    Returns:
        int: value converted to int.

    """
    try:
        return int(value)
    except Exception:
        return default_value


def get_mock_response(profile_id, action_name):
    """Get mock response for this profile_id from json files."""
    filename = f'{profile_id}_{action_name}.json'
    json_file = f'{constants.MOCK_RESPONSE_FOLDER}{filename}'
    with open(json_file) as json_file:
        data = json.load(json_file)
        return data