from datetime import datetime
import http
import urllib
import urllib.request

HTTPRequest = urllib.request.Request
HTTPResponse = http.client.HTTPResponse
HTTPException = http.client.HTTPException


def parse_iso(iso: str) -> datetime:
    return datetime.fromisoformat(iso.replace("Z", "+00:00"))


def send_with_retry(request: HTTPRequest, retries: int) -> HTTPResponse:
    """
    Send an HTTP request and retry in case of failure.

    :param request: request to try sending
    :param retries: number of retries
    :returns: response sent by the server
    :throws HTTPException: if the number of retries is exceeded
    """
    last_err = HTTPException()

    while retries:
        try:
            return urllib.request.urlopen(request, timeout=3)
        except HTTPException as err:
            retries -= 1
            last_err = err

    raise last_err