from __future__ import unicode_literals

import time
import re

from netmiko.base_connection import BaseConnection


class DellIsilonSSH(BaseConnection):
    def set_base_prompt(self, pri_prompt_terminator='$',
                        alt_prompt_terminator='#', delay_factor=1):
        """Determine base prompt."""
        return super(DellIsilonSSH, self).set_base_prompt(
            pri_prompt_terminator=pri_prompt_terminator,
            alt_prompt_terminator=alt_prompt_terminator,
            delay_factor=delay_factor)

    def strip_ansi_escape_codes(self, string_buffer):
        """Remove Null code"""
        output = re.sub(r'\x00', '', string_buffer)
        return super(DellIsilonSSH, self).strip_ansi_escape_codes(output)

    def session_preparation(self):
        """Prepare the session after the connection has been established."""
        self.ansi_escape_codes = True
        self.zsh_mode()
        self.find_prompt(delay_factor=1)
        self.set_base_prompt()
        # Clear the read buffer
        time.sleep(.3 * self.global_delay_factor)
        self.clear_buffer()

    def zsh_mode(self, delay_factor=1, prompt_terminator="$"):
        """Run zsh command to unify the environment"""
        delay_factor = self.select_delay_factor(delay_factor)
        self.clear_buffer()
        command = self.RETURN + "zsh" + self.RETURN
        self.write_channel(command)
        time.sleep(1 * delay_factor)
        self.set_prompt()
        self.clear_buffer()

    def set_prompt(self, prompt_terminator="$"):
        prompt = "PROMPT='%m{}'".format(prompt_terminator)
        command = self.RETURN + prompt + self.RETURN
        self.write_channel(command)

    def disable_paging(self, *args, **kwargs):
        """Isilon doesn't have paging by default."""
        pass

    def check_enable_mode(self, *args, **kwargs):
        """No enable mode on Isilon."""
        pass

    def enable(self, *args, **kwargs):
        """No enable mode on Isilon."""
        pass

    def exit_enable_mode(self, *args, **kwargs):
        """No enable mode on Isilon."""
        pass

    def check_config_mode(self, check_string='#'):
        return super(DellIsilonSSH, self).check_config_mode(check_string=check_string)

    def config_mode(self, config_command='sudo su'):
        """Attempt to become root."""
        delay_factor = self.select_delay_factor(delay_factor=1)
        output = ""
        if not self.check_config_mode():
            output += self.send_command_timing(config_command, strip_prompt=False,
                                               strip_command=False)
            if 'Password:' in output:
                output = self.write_channel(self.normalize_cmd(self.secret))
            self.set_prompt(prompt_terminator="#")
            time.sleep(1 * delay_factor)
            self.set_base_prompt()
            if not self.check_config_mode():
                raise ValueError("Failed to configuration mode")
        return output

    def exit_config_mode(self, exit_config='exit'):
        """Exit enable mode."""
        return super(DellIsilonSSH, self).exit_config_mode(exit_config=exit_config)
