"""Common Classes or Utilities for SSH Drivers."""

# Standard Library
from typing import Callable

# Project
from hyperglass.log import log
from hyperglass.exceptions import ScrapeError
from hyperglass.configuration import params
from hyperglass.compat._sshtunnel import BaseSSHTunnelForwarderError, open_tunnel
from hyperglass.execution.drivers._common import Connection


class SSHConnection(Connection):
    """Base class for SSH drivers."""

    def setup_proxy(self) -> Callable:
        """Return a preconfigured sshtunnel.SSHTunnelForwarder instance."""

        proxy = self.device.proxy

        def opener():
            """Set up an SSH tunnel according to a device's configuration."""
            try:
                return open_tunnel(
                    proxy._target,
                    proxy.port,
                    ssh_username=proxy.credential.username,
                    ssh_password=proxy.credential.password.get_secret_value(),
                    remote_bind_address=(self.device._target, self.device.port),
                    local_bind_address=("localhost", 0),
                    skip_tunnel_checkup=False,
                    gateway_timeout=params.request_timeout - 2,
                )

            except BaseSSHTunnelForwarderError as scrape_proxy_error:
                log.error(
                    f"Error connecting to device {self.device.name} via "
                    f"proxy {proxy.name}"
                )
                raise ScrapeError(
                    params.messages.connection_error,
                    device_name=self.device.display_name,
                    proxy=proxy.name,
                    error=str(scrape_proxy_error),
                )

        return opener