"""VPN management service for OpenVPN operations.

This service provides basic OpenVPN management interface communication.
For PKI/certificate management, use CertificateService.
For VPN server management, use VPNServerService.
"""

import socket
from ..config import get_settings

settings = get_settings()


class VPNService:
    """Service for OpenVPN management interface operations."""

    def __init__(self, host: str = None, port: int = None):
        self.management_host = host or settings.openvpn_management_host
        self.management_port = port or settings.openvpn_management_port

    def _send_management_command(self, command: str) -> str:
        """Send command to OpenVPN management interface."""
        try:
            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            sock.settimeout(5)
            sock.connect((self.management_host, self.management_port))

            # Read welcome message
            sock.recv(1024)

            # Send command
            sock.send(f"{command}\n".encode())

            # Read response
            response = b""
            while True:
                data = sock.recv(4096)
                if not data:
                    break
                response += data
                if b"END" in data or b"SUCCESS" in data or b"ERROR" in data:
                    break

            sock.close()
            return response.decode()
        except Exception as e:
            return f"ERROR: {str(e)}"

    def get_connected_clients(self) -> list[dict]:
        """Get list of currently connected VPN clients."""
        response = self._send_management_command("status")
        clients = []

        if "ERROR" in response:
            return clients

        # Parse status output
        in_client_list = False
        for line in response.split('\n'):
            if line.startswith("ROUTING TABLE"):
                in_client_list = False
            elif line.startswith("Common Name"):
                in_client_list = True
                continue
            elif in_client_list and ',' in line:
                parts = line.split(',')
                if len(parts) >= 5:
                    clients.append({
                        "common_name": parts[0],
                        "real_address": parts[1],
                        "bytes_received": int(parts[2]) if parts[2].isdigit() else 0,
                        "bytes_sent": int(parts[3]) if parts[3].isdigit() else 0,
                        "connected_since": parts[4]
                    })

        return clients

    def disconnect_client(self, common_name: str) -> bool:
        """Disconnect a specific VPN client."""
        response = self._send_management_command(f"kill {common_name}")
        return "SUCCESS" in response

    def get_server_status(self) -> dict:
        """Get OpenVPN server status."""
        response = self._send_management_command("state")

        if "ERROR" in response:
            return {"status": "error", "message": response}

        # Parse state
        for line in response.split('\n'):
            if 'CONNECTED' in line:
                return {"status": "running", "message": "Server is running"}

        return {"status": "unknown", "message": response}