# -*- coding: utf-8 -*-
# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4

# Copyright (c) 2012 dput authors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.    See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.
"""
FTP Uploader implementation.
"""

import ftplib
import os.path

from dput.core import logger
from dput.uploader import AbstractUploader
from dput.exceptions import UploadException


class FtpUploadException(UploadException):
    """
    Thrown in the event of a problem connecting, uploading to or
    terminating the connection with the remote server. This is
    a subclass of :class:`dput.exceptions.UploadException`.
    """
    pass


class FtpUploader(AbstractUploader):
    """
    Provides an interface to upload files through FTP. Supports anonymous
    uploads only for the time being.

    This is a subclass of :class:`dput.uploader.AbstractUploader`
    """

    def initialize(self, **kwargs):
        """
        See :meth:`dput.uploader.AbstractUploader.initialize`
        """
        logger.debug("Logging into %s as %s" % (
            self._config["fqdn"],
            self._config["login"]
        ))

        conf = self._config['ftp'] if 'ftp' in self._config else {}
        timeout = conf['timeout'] if 'timeout' in conf else 10
        use_tls = kwargs.get("use_tls")

        try:
            self._ftp = ftplib.FTP_TLS() if use_tls else ftplib.FTP()
            host, dummy, port = self._config["fqdn"].partition(":")
            self._ftp.connect(host, 0 if port == "" else int(port), timeout)
            if use_tls:
                self._ftp.auth()
                self._ftp.prot_p()
            self._ftp.login(self._config["login"])
        except Exception as e:
            raise FtpUploadException(
                "Could not establish FTP connection to %s: %s" % (
                    self._config['fqdn'],
                    e
                )
            )

        if self._config["passive_ftp"] or kwargs['passive_mode']:
            logger.debug("Enable PASV mode")
            self._ftp.set_pasv(True)
        if self._config["incoming"]:
            logger.debug("Change directory to %s" % (
                self._config["incoming"]
            ))
            try:
                self._ftp.cwd(self._config["incoming"])
            except ftplib.error_perm as e:
                raise FtpUploadException(
                    "Could not change directory to %s: %s" % (
                        self._config["incoming"],
                        e
                    )
                )

    def upload_file(self, filename, upload_filename=None):
        """
        See :meth:`dput.uploader.AbstractUploader.upload_file`
        """

        if not upload_filename:
            upload_filename = os.path.basename(filename)

        try:
            basename = "STOR %s" % (upload_filename)
            with open(filename, 'rb') as f:
                self._ftp.storbinary(basename, f)
        except ftplib.error_perm as e:
            self.upload_write_error(e)
        except Exception as e:
            raise FtpUploadException("Could not upload file %s: %s" % (
                upload_filename,
                e
            ))

    def shutdown(self):
        """
        See :meth:`dput.uploader.AbstractUploader.shutdown`
        """
        self._ftp.quit()
