#  Copyright (c) 2015-2018 Cisco Systems, Inc.
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#  The above copyright notice and this permission notice shall be included in
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import os
import sys
from base64 import b64decode

try:
    from cryptography.hazmat.backends import default_backend
    from cryptography.hazmat.primitives.asymmetric.padding import PKCS1v15
    from cryptography.hazmat.primitives.serialization import load_pem_private_key

    HAS_CRYPTOGRAPHY = True
except ImportError:
    HAS_CRYPTOGRAPHY = False

try:
    import boto3

    HAS_BOTO3 = True
except ImportError:
    HAS_BOTO3 = False

from molecule import logger, util
from molecule.api import Driver

LOG = logger.get_logger(__name__)


class EC2(Driver):
    """
    The class responsible for managing `EC2`_ instances.  `EC2`_
    is ``not`` the default driver used in Molecule.

    Molecule leverages Ansible's `ec2_module`_, by mapping variables from
    ``molecule.yml`` into ``create.yml`` and ``destroy.yml``.

    .. _`ec2_module`: https://docs.ansible.com/ansible/latest/ec2_module.html

    .. code-block:: yaml

        driver:
          name: ec2
        platforms:
          - name: instance

    Some configuration examples:

    .. code-block:: yaml

        driver:
          name: ec2
        platforms:
          - name: instance
            image: ami-0311dc90a352b25f4
            instance_type: t2.micro
            vpc_subnet_id: subnet-1cb17175

    If you don't know the AMI code or want to avoid hardcoding it:

    .. code-block:: yaml

        driver:
          name: ec2
        platforms:
          - name: instance
            image_owner: 099720109477
            image_name: ubuntu/images/hvm-ssd/ubuntu-bionic-18.04-amd64-server-20190320
            instance_type: t2.micro
            vpc_subnet_id: subnet-1cb17175

    Use wildcards for getting the latest image. For example, the latest Ubuntu bionic image:

    .. code-block:: yaml

        driver:
          name: ec2
        platforms:
          - name: instance
            image_owner: 099720109477
            image_name: ubuntu/images/hvm-ssd/ubuntu-bionic-18.04-amd64-server-*
            instance_type: t2.micro
            vpc_subnet_id: subnet-1cb17175

    Windows EC2 instances can be used as well:

    .. code-block:: yaml

        driver:
          name: ec2
        platforms:
          - name: instance
            image: ami-06a0d33fc8d328de0
            instance_type: t3a.medium
            vpc_subnet_id: subnet-1cb17175
            connection_options:
              sudo: False
              ansible_user: Administrator
              # Specify a password to override the automatic lookup
              # or omit to retrieve automatically
              # (requires boto3 & cryptography packages)
              # ansible_password: hunter2
              ansible_port: 5986
              ansible_connection: winrm
              ansible_winrm_scheme: https
              ansible_winrm_server_cert_validation: ignore

    .. code-block:: bash

        $ pip install 'molecule[ec2]'

    Change the options passed to the ssh client.

    .. code-block:: yaml

        driver:
          name: ec2
          ssh_connection_options:
            - '-o ControlPath=~/.ansible/cp/%r@%h-%p'

    .. important::

        Molecule does not merge lists, when overriding the developer must
        provide all options.

    Provide a list of files Molecule will preserve, relative to the scenario
    ephemeral directory, after any ``destroy`` subcommand execution.

    .. code-block:: yaml

        driver:
          name: ec2
          safe_files:
            - foo

    .. _`EC2`: https://aws.amazon.com/ec2/
    """

    def __init__(self, config=None) -> None:
        super().__init__(config)
        self._name = "ec2"

    @property
    def name(self):
        return self._name

    @name.setter
    def name(self, value):
        self._name = value

    @property
    def login_cmd_template(self):
        if self._config.command_args.get("host"):
            hostname = self._config.command_args["host"]
        elif len(self._config.platforms.instances) == 1:
            hostname = self._config.platforms.instances[0]["name"]
        else:
            LOG.error("Please specify instance via '--host'")
            sys.exit(1)

        ansible_connection_options = self.ansible_connection_options(hostname)
        if ansible_connection_options.get("ansible_connection") == "winrm":
            return (
                "xfreerdp "
                '"/u:{}" '
                '"/p:{}" '
                "/v:{} "
                "/cert-tofu "
                "+clipboard "
                "/grab-keyboard".format(
                    ansible_connection_options["ansible_user"],
                    ansible_connection_options["ansible_password"],
                    ansible_connection_options["ansible_host"],
                )
            )

        else:  # normal ssh connection
            connection_options = " ".join(self.ssh_connection_options)

            return (
                "ssh {{address}} "
                "-l {{user}} "
                "-p {{port}} "
                "-i {{identity_file}} "
                "{}"
            ).format(connection_options)

    @property
    def default_safe_files(self):
        return [self.instance_config]

    @property
    def default_ssh_connection_options(self):
        return self._get_ssh_connection_options()

    def login_options(self, instance_name):
        d = {"instance": instance_name}

        return util.merge_dicts(d, self._get_instance_config(instance_name))

    def ansible_connection_options(self, instance_name):
        try:
            d = self._get_instance_config(instance_name)
            plat_conn_opts = next(
                (
                    item
                    for item in self._config.config.get("platforms", [])
                    if item["name"] == instance_name
                ),
                {},
            ).get("connection_options", {})
            conn_opts = util.merge_dicts(
                {
                    "ansible_user": d["user"],
                    "ansible_host": d["address"],
                    "ansible_port": d["port"],
                    "ansible_private_key_file": d["identity_file"],
                    "connection": "ssh",
                    "ansible_ssh_common_args": " ".join(self.ssh_connection_options),
                },
                plat_conn_opts,
            )
            if conn_opts.get("ansible_connection") == "winrm" and (
                not conn_opts.get("ansible_password")
            ):
                conn_opts["ansible_password"] = self._get_windows_instance_pass(
                    d["instance_ids"][0],
                    d["identity_file"],
                )
            return conn_opts
        except StopIteration:
            return {}
        except OSError:
            # Instance has yet to be provisioned , therefore the
            # instance_config is not on disk.
            return {}

    def _get_instance_config(self, instance_name):
        instance_config_dict = util.safe_load_file(self._config.driver.instance_config)

        return next(
            item for item in instance_config_dict if item["instance"] == instance_name
        )

    def _get_windows_instance_pass(self, instance_id, key_file):
        if not HAS_BOTO3:
            LOG.error("boto3 required when using Windows instances")
            sys.exit(1)
        if not HAS_CRYPTOGRAPHY:
            LOG.error("cryptography package required when using Windows instances")
            sys.exit(1)
        ec2_client = boto3.client("ec2")
        data_response = ec2_client.get_password_data(InstanceId=instance_id)
        decoded = b64decode(data_response["PasswordData"])
        with open(key_file, "rb") as f:
            key = load_pem_private_key(f.read(), None, default_backend())
        return key.decrypt(decoded, PKCS1v15()).decode("utf-8")

    def sanity_checks(self):
        # FIXME(decentral1se): Implement sanity checks
        pass

    def template_dir(self):
        """Return path to its own cookiecutterm templates. It is used by init
        command in order to figure out where to load the templates from.
        """
        return os.path.join(os.path.dirname(__file__), "cookiecutter")
