import socket
from typing import Union
from urllib.parse import urlparse
from ipaddress import ip_address, ip_network, IPv4Address

class UrlValidator:
    @staticmethod
    def is_internal_address(ip: Union[IPv4Address]) -> bool:
        return any([
            ip.is_private,
            ip.is_unspecified,
            ip.is_reserved,
            ip.is_loopback,
            ip.is_multicast,
            ip.is_link_local,
        ])

    @classmethod
    def validate(cls, url: str):
        DEFAULT_PORT_WHITELIST = {80, 81, 8080, 443, 8443, 8000}
        DEFAULT_SCHEME_WHITELIST = {'http', 'https'}
        DEFAULT_HOST_BLACKLIST = {'192.0.0.192', '169.254.169.254', '100.100.100.200', 'metadata.packet.net', 'metadata.google.internal'}
        DEFAULT_CHARACTER_WHITELIST = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789:/-_.?&='

        if url is None:
            return False

        whitelist_set = set(DEFAULT_CHARACTER_WHITELIST)
        if any(c not in whitelist_set for c in url):
            return False

        try:
            ip = ip_address(url)
        except ValueError:
            try:
                host = urlparse(url).hostname
                ip = ip_address(str(socket.gethostbyname(host)))
            except:
                return False

        port_whitelist = DEFAULT_PORT_WHITELIST.copy()
        scheme_whitelist = DEFAULT_SCHEME_WHITELIST.copy()
        host_blacklist = DEFAULT_HOST_BLACKLIST.copy()

        try:
            port, scheme = urlparse(url).port, urlparse(url).scheme
        except:
            return False

        if scheme_whitelist and scheme is not None and scheme not in scheme_whitelist:
            return False

        if host_blacklist and host is not None and host in host_blacklist:
            return False

        if port_whitelist and port is not None and port not in port_whitelist:
            return False

        if ip.version == 4:
            if not ip.is_private:
                # CGNAT IPs do not set `is_private` so `not is_global` added
                if not ip_network(ip).is_global:
                    return False
        else:
            return False

        if cls.is_internal_address(ip):
            return False

        return True