from __future__ import annotations

from typing import TYPE_CHECKING

import paramiko # type: ignore # error: Library stubs not installed for "paramiko"

from ...log import *
from ...ExecContext import Result
from ..SSHClient import SSHClient as Base

from .util import join_cmd

class Paramiko(Base):

    def __init__(self, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs)
        self.__timeout: float|None = None # Untested
        self.___ssh: Any|None = None

    def __ssh_connect(self):
        ret = paramiko.SSHClient()
        ret.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        try:
            ret.connect(
                hostname=self.hostname,
                username=self.username,
                allow_agent=True
            )
        except Exception as e:
            log(ERR, f'Failed to connect to {self.hostname} ({str(e)})')
            raise
        s = ret.get_transport().open_session()
        # set up the agent request handler to handle agent requests from the server
        paramiko.agent.AgentRequestHandler(s)
        return ret

    @property
    def __ssh(self):
        if self.___ssh is None:
            self.___ssh = self.__ssh_connect()
        return self.___ssh

    @property
    def __scp(self):
        return SCPClient(self.__ssh.get_transport())

    async def _run_ssh(self, cmd: list[str], cmd_input: str|None, *args, **kwargs) -> Result:
        try:
            stdin, stdout, stderr = self.__ssh.exec_command(join_cmd(cmd), timeout=self.__timeout)
        except Exception as e:
            log(ERR, f'Command failed for {self.uri}: "{join_cmd(cmd)}"')
            raise
        if cmd_input is not None:
            stdin.write(cmd_input)
        exit_status = stdout.channel.recv_exit_status()
        return Result(stdout.read(), stderr.read(), exit_status)