from typing import Optional, TYPE_CHECKING
from django.utils import timezone
import ipaddress

from board.models import Ban, RangeBan


if TYPE_CHECKING:
    from board.models import Board


def get_client_ip(request):
    "Get the IP address of a client-side request. Shamelessly copy/pasted from StackOverflow."
    x_forwarded_for = request.META.get("HTTP_X_FORWARDED_FOR")
    if x_forwarded_for:
        ip = x_forwarded_for.split(",")[0]
    else:
        ip = request.META.get("REMOTE_ADDR")
    return ip


def get_ip_bans(ip: str) -> list:
    bans = list(Ban.objects.filter(ip=ip))

    ip_addr = ipaddress.ip_address(ip)
    for rangeban in RangeBan.objects.all():
        start = ipaddress.ip_address(rangeban.start)
        end = ipaddress.ip_address(rangeban.end)
        if ip_addr.version != start.version or ip_addr.version != end.version:
            continue
        if start <= ip_addr <= end:  # type: ignore
            bans += [rangeban]
    return bans


def is_banned(ip: str, board: Optional["Board"]) -> bool:
    now = timezone.now()
    bans = [ban for ban in get_ip_bans(ip) if ban.board == board or not ban.board]
    if bans:
        active = [ban for ban in bans if ban.expires > now]
        expired = [ban for ban in bans if ban.expires <= now]
        # Delete expired bans
        for ban in expired:
            ban.delete()
        return bool(active)
    else:
        return False