"""Flask Request Utils.

Utils for parsing request values.
"""

from collections import namedtuple

import flask

from vectororder.constants import pagination

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


def get_pagination(request: flask.Request) -> Pagination:
    """Parse 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: int | str, default_value: int) -> int:
    """Convert 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:
        result = int(value)
        if result < 0:
            raise ValueError
        return result
    except ValueError:
        return default_value