#
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# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

import logging
from base64 import b64encode
from typing import Optional, Union

from winrm.exceptions import WinRMOperationTimeoutError

from airflow.configuration import conf
from airflow.exceptions import AirflowException
from airflow.models import BaseOperator
from airflow.providers.microsoft.winrm.hooks.winrm import WinRMHook

# Hide the following error message in urllib3 when making WinRM connections:
# requests.packages.urllib3.exceptions.HeaderParsingError: [StartBoundaryNotFoundDefect(),
#   MultipartInvariantViolationDefect()], unparsed data: ''
logging.getLogger('urllib3.connectionpool').setLevel(logging.ERROR)


class WinRMOperator(BaseOperator):
    """
    WinRMOperator to execute commands on given remote host using the winrm_hook.

    :param winrm_hook: predefined ssh_hook to use for remote execution
    :type winrm_hook: airflow.providers.microsoft.winrm.hooks.winrm.WinRMHook
    :param ssh_conn_id: connection id from airflow Connections
    :type ssh_conn_id: str
    :param remote_host: remote host to connect
    :type remote_host: str
    :param command: command to execute on remote host. (templated)
    :type command: str
    :param ps_path: path to powershell, `powershell` for v5.1- and `pwsh` for v6+.
        If specified, it will execute the command as powershell script.
    :type ps_path: str
    :param output_encoding: the encoding used to decode stout and stderr
    :type output_encoding: str
    :param timeout: timeout for executing the command.
    :type timeout: int
    """

    template_fields = ('command',)
    template_fields_renderers = {"command": "powershell"}

    def __init__(
        self,
        *,
        winrm_hook: Optional[WinRMHook] = None,
        ssh_conn_id: Optional[str] = None,
        remote_host: Optional[str] = None,
        command: Optional[str] = None,
        ps_path: Optional[str] = None,
        output_encoding: str = 'utf-8',
        timeout: int = 10,
        **kwargs,
    ) -> None:
        super().__init__(**kwargs)
        self.winrm_hook = winrm_hook
        self.ssh_conn_id = ssh_conn_id
        self.remote_host = remote_host
        self.command = command
        self.ps_path = ps_path
        self.output_encoding = output_encoding
        self.timeout = timeout

    def execute(self, context: dict) -> Union[list, str]:
        if self.ssh_conn_id and not self.winrm_hook:
            self.log.info("Hook not found, creating...")
            self.winrm_hook = WinRMHook(ssh_conn_id=self.ssh_conn_id)

        if not self.winrm_hook:
            raise AirflowException("Cannot operate without winrm_hook or ssh_conn_id.")

        if self.remote_host is not None:
            self.winrm_hook.remote_host = self.remote_host

        if not self.command:
            raise AirflowException("No command specified so nothing to execute here.")

        winrm_client = self.winrm_hook.get_conn()

        # pylint: disable=too-many-nested-blocks
        try:
            if self.ps_path is not None:
                self.log.info("Running command as powershell script: '%s'...", self.command)
                encoded_ps = b64encode(self.command.encode('utf_16_le')).decode('ascii')
                command_id = self.winrm_hook.winrm_protocol.run_command(  # type: ignore[attr-defined]
                    winrm_client, f'{self.ps_path} -encodedcommand {encoded_ps}'
                )
            else:
                self.log.info("Running command: '%s'...", self.command)
                command_id = self.winrm_hook.winrm_protocol.run_command(  # type: ignore[attr-defined]
                    winrm_client, self.command
                )

            # See: https://github.com/diyan/pywinrm/blob/master/winrm/protocol.py
            stdout_buffer = []
            stderr_buffer = []
            command_done = False
            while not command_done:
                try:
                    # pylint: disable=protected-access
                    (
                        stdout,
                        stderr,
                        return_code,
                        command_done,
                    ) = self.winrm_hook.winrm_protocol._raw_get_command_output(  # type: ignore[attr-defined]
                        winrm_client, command_id
                    )

                    # Only buffer stdout if we need to so that we minimize memory usage.
                    if self.do_xcom_push:
                        stdout_buffer.append(stdout)
                    stderr_buffer.append(stderr)

                    for line in stdout.decode(self.output_encoding).splitlines():
                        self.log.info(line)
                    for line in stderr.decode(self.output_encoding).splitlines():
                        self.log.warning(line)
                except WinRMOperationTimeoutError:
                    # this is an expected error when waiting for a
                    # long-running process, just silently retry
                    pass

            self.winrm_hook.winrm_protocol.cleanup_command(  # type: ignore[attr-defined]
                winrm_client, command_id
            )
            self.winrm_hook.winrm_protocol.close_shell(winrm_client)  # type: ignore[attr-defined]

        except Exception as e:
            raise AirflowException(f"WinRM operator error: {str(e)}")

        if return_code == 0:
            # returning output if do_xcom_push is set
            enable_pickling = conf.getboolean('core', 'enable_xcom_pickling')
            if enable_pickling:
                return stdout_buffer
            else:
                return b64encode(b''.join(stdout_buffer)).decode(self.output_encoding)
        else:
            error_msg = "Error running cmd: {}, return code: {}, error: {}".format(
                self.command, return_code, b''.join(stderr_buffer).decode(self.output_encoding)
            )
            raise AirflowException(error_msg)
