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"""This module contains SFTP hook."""
from __future__ import annotations

import datetime
import os
import stat
import warnings
from fnmatch import fnmatch
from typing import TYPE_CHECKING, Any, Callable

from airflow.exceptions import AirflowException, AirflowProviderDeprecationWarning
from airflow.providers.ssh.hooks.ssh import SSHHook

if TYPE_CHECKING:
    import paramiko


class SFTPHook(SSHHook):
    """Interact with SFTP.

    This hook inherits the SSH hook. Please refer to SSH hook for the input
    arguments.

    :Pitfalls::

        - In contrast with FTPHook describe_directory only returns size, type and
          modify. It doesn't return unix.owner, unix.mode, perm, unix.group and
          unique.
        - retrieve_file and store_file only take a local full path and not a
           buffer.
        - If no mode is passed to create_directory it will be created with 777
          permissions.

    Errors that may occur throughout but should be handled downstream.

    For consistency reasons with SSHHook, the preferred parameter is "ssh_conn_id".

    :param ssh_conn_id: The :ref:`sftp connection id<howto/connection:sftp>`
    :param ssh_hook: Optional SSH hook (included to support passing of an SSH hook to the SFTP operator)
    """

    conn_name_attr = "ssh_conn_id"
    default_conn_name = "sftp_default"
    conn_type = "sftp"
    hook_name = "SFTP"

    @classmethod
    def get_ui_field_behaviour(cls) -> dict[str, Any]:
        return {
            "hidden_fields": ["schema"],
            "relabeling": {
                "login": "Username",
            },
        }

    def __init__(
        self,
        ssh_conn_id: str | None = "sftp_default",
        ssh_hook: SSHHook | None = None,
        *args,
        **kwargs,
    ) -> None:
        self.conn: paramiko.SFTPClient | None = None

        # TODO: remove support for ssh_hook when it is removed from SFTPOperator
        self.ssh_hook = ssh_hook

        if self.ssh_hook is not None:
            warnings.warn(
                "Parameter `ssh_hook` is deprecated and will be removed in a future version.",
                AirflowProviderDeprecationWarning,
                stacklevel=2,
            )
            if not isinstance(self.ssh_hook, SSHHook):
                raise AirflowException(
                    f"ssh_hook must be an instance of SSHHook, but got {type(self.ssh_hook)}"
                )
            self.log.info("ssh_hook is provided. It will be used to generate SFTP connection.")
            self.ssh_conn_id = self.ssh_hook.ssh_conn_id
            return

        ftp_conn_id = kwargs.pop("ftp_conn_id", None)
        if ftp_conn_id:
            warnings.warn(
                "Parameter `ftp_conn_id` is deprecated. Please use `ssh_conn_id` instead.",
                AirflowProviderDeprecationWarning,
                stacklevel=2,
            )
            ssh_conn_id = ftp_conn_id

        kwargs["ssh_conn_id"] = ssh_conn_id
        self.ssh_conn_id = ssh_conn_id

        super().__init__(*args, **kwargs)

    def get_conn(self) -> paramiko.SFTPClient:  # type: ignore[override]
        """Opens an SFTP connection to the remote host."""
        if self.conn is None:
            # TODO: remove support for ssh_hook when it is removed from SFTPOperator
            if self.ssh_hook is not None:
                self.conn = self.ssh_hook.get_conn().open_sftp()
            else:
                self.conn = super().get_conn().open_sftp()
        return self.conn

    def close_conn(self) -> None:
        """Closes the SFTP connection."""
        if self.conn is not None:
            self.conn.close()
            self.conn = None

    def describe_directory(self, path: str) -> dict[str, dict[str, str | int | None]]:
        """Get file information in a directory on the remote system.

        The return format is ``{filename: {attributes}}``. The remote system
        support the MLSD command.

        :param path: full path to the remote directory
        """
        conn = self.get_conn()
        flist = sorted(conn.listdir_attr(path), key=lambda x: x.filename)
        files = {}
        for f in flist:
            modify = datetime.datetime.fromtimestamp(f.st_mtime).strftime("%Y%m%d%H%M%S")  # type: ignore
            files[f.filename] = {
                "size": f.st_size,
                "type": "dir" if stat.S_ISDIR(f.st_mode) else "file",  # type: ignore
                "modify": modify,
            }
        return files

    def list_directory(self, path: str) -> list[str]:
        """List files in a directory on the remote system.

        :param path: full path to the remote directory to list
        """
        conn = self.get_conn()
        files = sorted(conn.listdir(path))
        return files

    def mkdir(self, path: str, mode: int = 0o777) -> None:
        """Create a directory on the remote system.

        The default mode is ``0o777``, but on some systems, the current umask
        value may be first masked out.

        :param path: full path to the remote directory to create
        :param mode: int permissions of octal mode for directory
        """
        conn = self.get_conn()
        conn.mkdir(path, mode=mode)

    def isdir(self, path: str) -> bool:
        """Check if the path provided is a directory.

        :param path: full path to the remote directory to check
        """
        conn = self.get_conn()
        try:
            result = stat.S_ISDIR(conn.stat(path).st_mode)  # type: ignore
        except OSError:
            result = False
        return result

    def isfile(self, path: str) -> bool:
        """Check if the path provided is a file.

        :param path: full path to the remote file to check
        """
        conn = self.get_conn()
        try:
            result = stat.S_ISREG(conn.stat(path).st_mode)  # type: ignore
        except OSError:
            result = False
        return result

    def create_directory(self, path: str, mode: int = 0o777) -> None:
        """Create a directory on the remote system.

        The default mode is ``0o777``, but on some systems, the current umask
        value may be first masked out. Different from :func:`.mkdir`, this
        function attempts to create parent directories if needed, and returns
        silently if the target directory already exists.

        :param path: full path to the remote directory to create
        :param mode: int permissions of octal mode for directory
        """
        conn = self.get_conn()
        if self.isdir(path):
            self.log.info("%s already exists", path)
            return
        elif self.isfile(path):
            raise AirflowException(f"{path} already exists and is a file")
        else:
            dirname, basename = os.path.split(path)
            if dirname and not self.isdir(dirname):
                self.create_directory(dirname, mode)
            if basename:
                self.log.info("Creating %s", path)
                conn.mkdir(path, mode=mode)

    def delete_directory(self, path: str) -> None:
        """Delete a directory on the remote system.

        :param path: full path to the remote directory to delete
        """
        conn = self.get_conn()
        conn.rmdir(path)

    def retrieve_file(self, remote_full_path: str, local_full_path: str, prefetch: bool = True) -> None:
        """Transfer the remote file to a local location.

        If local_full_path is a string path, the file will be put
        at that location.

        :param remote_full_path: full path to the remote file
        :param local_full_path: full path to the local file
        :param prefetch: controls whether prefetch is performed (default: True)
        """
        conn = self.get_conn()
        conn.get(remote_full_path, local_full_path, prefetch=prefetch)

    def store_file(self, remote_full_path: str, local_full_path: str, confirm: bool = True) -> None:
        """Transfer a local file to the remote location.

        If local_full_path_or_buffer is a string path, the file will be read
        from that location.

        :param remote_full_path: full path to the remote file
        :param local_full_path: full path to the local file
        """
        conn = self.get_conn()
        conn.put(local_full_path, remote_full_path, confirm=confirm)

    def delete_file(self, path: str) -> None:
        """Remove a file on the server.

        :param path: full path to the remote file
        """
        conn = self.get_conn()
        conn.remove(path)

    def get_mod_time(self, path: str) -> str:
        """Get an entry's modification time.

        :param path: full path to the remote file
        """
        conn = self.get_conn()
        ftp_mdtm = conn.stat(path).st_mtime
        return datetime.datetime.fromtimestamp(ftp_mdtm).strftime("%Y%m%d%H%M%S")  # type: ignore

    def path_exists(self, path: str) -> bool:
        """Whether a remote entity exists.

        :param path: full path to the remote file or directory
        """
        conn = self.get_conn()
        try:
            conn.stat(path)
        except OSError:
            return False
        return True

    @staticmethod
    def _is_path_match(path: str, prefix: str | None = None, delimiter: str | None = None) -> bool:
        """Whether given path starts with ``prefix`` (if set) and ends with ``delimiter`` (if set).

        :param path: path to be checked
        :param prefix: if set path will be checked is starting with prefix
        :param delimiter: if set path will be checked is ending with suffix
        :return: bool
        """
        if prefix is not None and not path.startswith(prefix):
            return False
        if delimiter is not None and not path.endswith(delimiter):
            return False
        return True

    def walktree(
        self,
        path: str,
        fcallback: Callable[[str], Any | None],
        dcallback: Callable[[str], Any | None],
        ucallback: Callable[[str], Any | None],
        recurse: bool = True,
    ) -> None:
        """Recursively descend, depth first, the directory tree at ``path``.

        This calls discrete callback functions for each regular file, directory,
        and unknown file type.

        :param str path:
            root of remote directory to descend, use '.' to start at
            :attr:`.pwd`
        :param callable fcallback:
            callback function to invoke for a regular file.
            (form: ``func(str)``)
        :param callable dcallback:
            callback function to invoke for a directory. (form: ``func(str)``)
        :param callable ucallback:
            callback function to invoke for an unknown file type.
            (form: ``func(str)``)
        :param bool recurse: *Default: True* - should it recurse
        """
        conn = self.get_conn()
        for entry in self.list_directory(path):
            pathname = os.path.join(path, entry)
            mode = conn.stat(pathname).st_mode
            if stat.S_ISDIR(mode):  # type: ignore
                # It's a directory, call the dcallback function
                dcallback(pathname)
                if recurse:
                    # now, recurse into it
                    self.walktree(pathname, fcallback, dcallback, ucallback)
            elif stat.S_ISREG(mode):  # type: ignore
                # It's a file, call the fcallback function
                fcallback(pathname)
            else:
                # Unknown file type
                ucallback(pathname)

    def get_tree_map(
        self, path: str, prefix: str | None = None, delimiter: str | None = None
    ) -> tuple[list[str], list[str], list[str]]:
        """Get tuple with recursive lists of files, directories and unknown paths.

        It is possible to filter results by giving prefix and/or delimiter parameters.

        :param path: path from which tree will be built
        :param prefix: if set paths will be added if start with prefix
        :param delimiter: if set paths will be added if end with delimiter
        :return: tuple with list of files, dirs and unknown items
        """
        files: list[str] = []
        dirs: list[str] = []
        unknowns: list[str] = []

        def append_matching_path_callback(list_: list[str]) -> Callable:
            return lambda item: list_.append(item) if self._is_path_match(item, prefix, delimiter) else None

        self.walktree(
            path=path,
            fcallback=append_matching_path_callback(files),
            dcallback=append_matching_path_callback(dirs),
            ucallback=append_matching_path_callback(unknowns),
            recurse=True,
        )

        return files, dirs, unknowns

    def test_connection(self) -> tuple[bool, str]:
        """Test the SFTP connection by calling path with directory."""
        try:
            conn = self.get_conn()
            conn.normalize(".")
            return True, "Connection successfully tested"
        except Exception as e:
            return False, str(e)

    def get_file_by_pattern(self, path, fnmatch_pattern) -> str:
        """Get the first matching file based on the given fnmatch type pattern.

        :param path: path to be checked
        :param fnmatch_pattern: The pattern that will be matched with `fnmatch`
        :return: string containing the first found file, or an empty string if none matched
        """
        for file in self.list_directory(path):
            if fnmatch(file, fnmatch_pattern):
                return file

        return ""

    def get_files_by_pattern(self, path, fnmatch_pattern) -> list[str]:
        """Get all matching files based on the given fnmatch type pattern.

        :param path: path to be checked
        :param fnmatch_pattern: The pattern that will be matched with `fnmatch`
        :return: list of string containing the found files, or an empty list if none matched
        """
        matched_files = []
        for file in self.list_directory(path):
            if fnmatch(file, fnmatch_pattern):
                matched_files.append(file)

        return matched_files
