import platform
import subprocess
import os

import paramiko
from paramiko.ssh_exception import SSHException, PasswordRequiredException

import config

SUPPORTED_SYSTEMS = [
    'Linux',
    'MacOS',
    'BSD',
]

KEYSDIR = os.path.join(config.CONFIG_BASEDIR, "keys")
KEYFILE_PATH = os.path.join(config.CONFIG_BASEDIR, "keys", "mdt.key")


class Keystore:
    def __init__(self):
        if not os.path.exists(config.CONFIG_BASEDIR):
            os.makedirs(CONFIG_BASEDIR, mode=0o700)
        if not os.path.exists(KEYSDIR):
            os.makedirs(KEYSDIR, mode=0o700)
        if not os.path.exists(KEYFILE_PATH):
            self.pkey = None
        else:
            try:
                self.pkey = paramiko.rsakey.RSAKey.from_private_key_file(KEYFILE_PATH)
            except IOError as e:
                print("Unable to read private key from file: {0}".format(e))
                sys.exit(1)
            except PasswordRequiredException as e:
                print("Unable to load in private key: {0}".format(e))
                sys.exit(1)

    def generateKey(self):
        self.pkey = paramiko.rsakey.RSAKey.generate(bits=4096)

        try:
            self.pkey.write_private_key_file(KEYFILE_PATH)
        except IOError as e:
            print("Unable to write private key to disk: {0}".format(e))
            return False
        else:
            return True

    def key(self):
        return self.pkey


class GenKey:
    def run(self, args):
        if os.path.exists(KEYFILE_PATH):
            os.unlink(KEYFILE_PATH)
        keystore = Keystore()
        if not keystore.generateKey():
            return 1
        return 0