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#   http://www.apache.org/licenses/LICENSE-2.0
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"""This module contains SFTP sensor."""
from typing import Optional

from airflow.providers.sftp.hooks.sftp import SFTPHook
from airflow.sensors.base import BaseSensorOperator
from airflow.utils.decorators import apply_defaults
from paramiko import SFTP_NO_SUCH_FILE


class SFTPSensor(BaseSensorOperator):
    """
    Waits for a file or directory to be present on SFTP.

    :param path: Remote file or directory path
    :type path: str
    :param sftp_conn_id: The connection to run the sensor against
    :type sftp_conn_id: str
    """

    template_fields = ("path",)

    @apply_defaults
    def __init__(
        self, *, path: str, sftp_conn_id: str = "sftp_default", **kwargs
    ) -> None:
        super().__init__(**kwargs)
        self.path = path
        self.hook: Optional[SFTPHook] = None
        self.sftp_conn_id = sftp_conn_id

    def poke(self, context: dict) -> bool:
        self.hook = SFTPHook(self.sftp_conn_id)
        self.log.info("Poking for %s", self.path)
        try:
            self.hook.get_mod_time(self.path)
        except OSError as e:
            if e.errno != SFTP_NO_SUCH_FILE:
                raise e
            return False
        self.hook.close_conn()
        return True