"""
Flask Request Utils
===================

Utils for parsing request values.
"""

from collections import namedtuple

from ows_accounting.constants import header
from ows_accounting.constants import pagination


Pagination = namedtuple('Pagination', ['offset', 'limit'])
GrassAccount = namedtuple('GrassAccount', ['type', 'id'])


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

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

    Returns:
        Pagination (namedtuple): pagination information.
    """

    page_offset = request.args.get(
        'page_offset') or pagination.PAGE_OFFSET_DEFAULT
    page_offset = _get_int(page_offset, pagination.PAGE_OFFSET_DEFAULT)

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

    return Pagination(page_offset, page_limit)


def _get_int(value, default_value):
    """Helper method to convert a value to 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: # noqa
        return default_value


def get_account_from_grass_headers(request):
    """Parses Grass Account information.

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

    Returns:
        GrassAccount (namedtuple): grass account information.
    """

    header_account_type = request.headers.get(header.GRASS_ACCOUNT_TYPE)
    header_account_id = request.headers.get(header.GRASS_ACCOUNT_ID)
    return GrassAccount(header_account_type, header_account_id)