# Copyright 2011 - 2019 Patrick Ulbrich <zulu99@gmx.net>
# Copyright 2016 Timo Kankare <timo.kankare@iki.fi>
# Copyright 2016 Thomas Haider <t.haider@deprecate.de>
# Copyright 2011 Ralf Hersel <ralf.hersel@gmx.net>
# Copyright 2019 razer <razerraz@free.fr>
#
# 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.
#

"""Implementation for POP3 mailbox connection."""

import email
import logging
import poplib

from Mailnag.backends.base import MailboxBackend
from Mailnag.common.exceptions import InvalidOperationException


class POP3MailboxBackend(MailboxBackend):
	"""Implementation of POP3 mail boxes."""
	
	def __init__(self, name = '', user = '', password = '', oauth2string = '',
				 server = '', port = '', ssl = True, **kw):
		self.name = name
		self.user = user
		self.password = password
		self.oauth2string = oauth2string
		self.server = server
		self.port = port
		self.ssl = ssl # bool
		self._conn = None


	def open(self):
		if self._conn != None:
			raise InvalidOperationException("Account is aready open")
				
		conn = None
		
		try:
			if self.ssl:
				if self.port == '':
					conn = poplib.POP3_SSL(self.server)
				else:
					conn = poplib.POP3_SSL(self.server, int(self.port))
			else:
				if self.port == '':
					conn = poplib.POP3(self.server)
				else:
					conn = poplib.POP3(self.server, int(self.port))
				
				try:
					conn.stls()
				except:
					logging.warning("Using unencrypted connection for account '%s'" % self.name)
				
			conn.getwelcome()
			conn.user(self.user)
			conn.pass_(self.password)
		except:
			try:
				if conn != None:
					conn.quit()
			except:	pass
			raise # re-throw exception
		
		self._conn = conn


	def close(self):
		if self._conn != None:
			self._conn.quit()
			self._conn = None


	def is_open(self):
		return (self._conn != None) and \
				('sock' in self._conn.__dict__)


	def list_messages(self):
		self._ensure_open()
		
		conn = self._conn
		folder = ''
		
		# number of mails on the server
		mail_total = len(conn.list()[1])
		for i in range(1, mail_total + 1): # for each mail
			try:
				# header plus first 0 lines from body
				message = conn.top(i, 0)[1]
			except:
				logging.debug("Couldn't get POP message.")
				continue
			
			# convert list to byte sequence
			message_bytes = b'\n'.join(message)
			
			try:
				# put message into email object and make a dictionary
				msg = dict(email.message_from_bytes(message_bytes))
			except:
				logging.debug("Couldn't get msg from POP message.")
				continue
			yield (folder, msg)


	def request_folders(self):
		raise NotImplementedError("POP3 does not support folders")


	def notify_next_change(self, callback=None, timeout=None):
		raise NotImplementedError("POP3 does not support notifications")


	def cancel_notifications(self):
		raise NotImplementedError("POP3 does not support notifications")


	def _ensure_open(self):
		if not self.is_open():
			raise InvalidOperationException("Account is not open")