"""NAPALM driver for Example switches over SSH.

Optional args
-------------
port : int
    SSH port (default 22).
"""

from __future__ import annotations

import logging
from typing import Any, Protocol

from napalm.base.exceptions import ConnectionException
from napalm.base.models import FactsDict
from napalm_device_types import SwitchDriver

from napalm_example.parsers import parse_version

LOG = logging.getLogger(__name__)

VENDOR = "Example"
DEFAULT_PORT = 22


class Transport(Protocol):
    def command(self, line: str) -> str: ...

    def close(self) -> None: ...


class ExampleDriver(SwitchDriver):
    """A switch that answers line commands over SSH."""

    def __init__(
        self,
        hostname: str,
        username: str,
        password: str,
        timeout: int = 60,
        optional_args: dict[str, Any] | None = None,
    ) -> None:
        self.hostname = hostname
        self.username = username
        self.password = password
        self.timeout = timeout
        self.port = int((optional_args or {}).get("port", DEFAULT_PORT))
        self.transport: Transport | None = None

    def open(self) -> None:  # pragma: no cover - live I/O
        from netmiko import ConnectHandler

        session = ConnectHandler(
            device_type="generic",
            host=self.hostname,
            port=self.port,
            username=self.username,
            password=self.password,
            timeout=self.timeout,
        )

        class _Netmiko:
            def command(self, line: str) -> str:
                return str(session.send_command(line))

            def close(self) -> None:
                session.disconnect()

        self.transport = _Netmiko()

    def close(self) -> None:
        if self.transport is not None:
            self.transport.close()
            self.transport = None

    def _command(self, line: str) -> str:
        if self.transport is None:
            raise ConnectionException(f"{self.hostname}: not connected; call open() first")
        LOG.debug("%s: %s", self.hostname, line)
        return self.transport.command(line)

    def get_facts(self) -> FactsDict:
        version = parse_version(self._command("show version"))
        return {
            "vendor": VENDOR,
            "model": version["model"],
            "hostname": version["hostname"],
            "fqdn": version["hostname"],
            "os_version": version["os_version"],
            "serial_number": version["serial_number"],
            "uptime": version["uptime"],
            "interface_list": [],
        }