import os
import socket as _socket

from typing import Dict, List
from dataclasses import dataclass, field


@dataclass
class ProxyConfig:
    port: int = 1443
    host: str = '127.0.0.1'
    secret: str = field(default_factory=lambda: os.urandom(16).hex())
    dc_redirects: Dict[int, str] = field(default_factory=lambda: {2: '149.154.167.220', 4: '149.154.167.220'})
    buffer_size: int = 256 * 1024
    pool_size: int = 4
    fallback_cfproxy: bool = True
    fallback_cfproxy_priority: bool = True
    fallback_cfproxy_domain: str = 'pclead.co.uk'


proxy_config = ProxyConfig()


def parse_dc_ip_list(dc_ip_list: List[str]) -> Dict[int, str]:
    dc_redirects: Dict[int, str] = {}
    for entry in dc_ip_list:
        if ':' not in entry:
            raise ValueError(
                f"Invalid --dc-ip format {entry!r}, expected DC:IP")
        dc_s, ip_s = entry.split(':', 1)
        try:
            dc_n = int(dc_s)
            _socket.inet_aton(ip_s)
        except (ValueError, OSError):
            raise ValueError(f"Invalid --dc-ip {entry!r}")
        dc_redirects[dc_n] = ip_s
    return dc_redirects