"""MRV Communications Driver (OptiSwitch)."""
import time
import re
from typing import Optional

from netmiko.cisco_base_connection import CiscoSSHConnection


class MrvOptiswitchSSH(CiscoSSHConnection):
    """MRV Communications Driver (OptiSwitch)."""

    def session_preparation(self) -> None:
        """Prepare the session after the connection has been established."""
        self._test_channel_read(pattern=r"[>#]")
        self.set_base_prompt()
        self.enable()
        self.disable_paging(command="no cli-paging")
        # Clear the read buffer
        time.sleep(0.3 * self.global_delay_factor)
        self.set_base_prompt()
        self.clear_buffer()

    def enable(
        self,
        cmd: str = "enable",
        pattern: str = r"#",
        enable_pattern: Optional[str] = None,
        check_state: bool = True,
        re_flags: int = re.IGNORECASE,
    ) -> str:
        """Enable mode on MRV uses no password."""
        output = ""
        if check_state and self.check_enable_mode():
            return output

        self.write_channel(self.normalize_cmd(cmd))
        output += self.read_until_prompt_or_pattern(
            pattern=pattern, re_flags=re_flags, read_entire_line=True
        )
        if not self.check_enable_mode():
            msg = (
                "Failed to enter enable mode. Please ensure you pass "
                "the 'secret' argument to ConnectHandler."
            )
            raise ValueError(msg)
        return output

    def save_config(
        self,
        cmd: str = "save config flash",
        confirm: bool = False,
        confirm_response: str = "",
    ) -> str:
        """Saves configuration."""
        return super().save_config(
            cmd=cmd, confirm=confirm, confirm_response=confirm_response
        )