developer.intra2net.com Git - imap-fix-internaldate/blob - date_interpreter.py

   1 '''
   2 date_interpreter.py - The module contains the MailIterator class.
   3
   4 Copyright (c) 2012 Intra2net AG
   5 Author: Plamen Dimitrov
   6
   7 This program is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 Add '-t' argument when running the module for a test mode.
  18 For a detailed list of each message with a date conflict change
  19 the 'log_level' in the configuration file from '30' to '20'.
  20 '''
  21
  22 import datetime
  23 import re
  24 import time
  25
  26 #reg expressions
  27 RECEIVED_DATE = re.compile(r'(0?[1-9]|[1-2][0-9]|3[01])\s+([A-Z][a-z][a-z])\s+'
  28         r'(19[0-9]{2}|[2-9][0-9]{3}|[0-9]{2})\s+(2[0-3]|[0-1][0-9]):([0-5][0-9])(?::(60|[0-5][0-9]))?\s*'
  29         r'(?:([-\+])([0-9]{2})([0-5][0-9]))*')
  30 INTERNAL_DATE = re.compile(r'(?P<day>[ 0123][0-9])-(?P<mon>[A-Z][a-z][a-z])-(?P<year>[0-9][0-9][0-9][0-9])'
  31         r' (?P<hour>[0-9][0-9]):(?P<min>[0-9][0-9]):(?P<sec>[0-9][0-9])'
  32         r' (?P<zonen>[-+])(?P<zoneh>[0-9][0-9])(?P<zonem>[0-9][0-9])')
  33 CONTROL_SYMBOLS = re.compile(r'[\n\r\t]')
  34
  35 class DateInterpreter:
  36     """This class extracts dates from imap server responses and compares them."""
  37
  38     def __init__(self):
  39         return
  40
  41     @classmethod
  42     def extract_internal_date(cls, fetchresult):
  43         """Extracts the internal date from INTERNALDATE, returns datetime."""
  44         return datetime.datetime.fromtimestamp(time.mktime(fetchresult))
  45
  46     @classmethod
  47     def extract_received_date(cls, fetchresult):
  48         """Extracts the first date from RECEIVED, returns datetime."""
  49         fetchresult = CONTROL_SYMBOLS.sub('', fetchresult[0][1].decode("utf-8"))
  50         received_dates = RECEIVED_DATE.findall(fetchresult)
  51         if(len(received_dates)==0):
  52             return ""
  53         else: received_date = received_dates[0]
  54         #print("Retrieved date ", received_date, " from header ", fetchresult)
  55         month = datetime.datetime.strptime(received_date[1],'%b').month
  56
  57         if(received_date[3]!=""):
  58             hours = int(received_date[3])
  59         else: hours = 0
  60         if(received_date[4]!=""):
  61             minutes = int(received_date[4])
  62         else: minutes = 0
  63         if(received_date[5]!=""):
  64             seconds = int(received_date[5])
  65         else: seconds = 0
  66
  67         if(received_date[6]!=""):
  68             zonen = received_date[6]
  69         else: zonen = b'+'
  70         if(received_date[7]!=""):
  71             zoneh = int(received_date[7])
  72         else: zoneh = 0
  73         if(received_date[8]!=""):
  74             zonem = int(received_date[8])
  75         else: zonem = 0
  76         # subtract time zone to get unified time
  77         zone = (zoneh * 60 + zonem) * 60
  78         if(zonen == b'-'):
  79             zone = -zone
  80
  81         time_tuple = (int(received_date[2]), month, int(received_date[0]), hours, minutes, seconds, -1, -1, -1)
  82         #'mktime' assumes arg in local timezone, so add timezone/altzone
  83         utc = time.mktime(time_tuple)
  84         #adjust to DST
  85         if(time.daylight and time.localtime(utc)[-1]):
  86             zone = zone + time.altzone
  87         else:
  88             zone = zone + time.timezone
  89
  90         received_time_tuple = time.localtime(utc - zone)
  91         converted_received_date = datetime.datetime.fromtimestamp(time.mktime(received_time_tuple))
  92         return converted_received_date
  93
  94     @classmethod
  95     def compare_dates(cls, date1, date2, tolerance=1800):
  96         """Compares datetime objects for deviation given certain tolerance."""
  97         """Returns 1 if there is a significant difference."""
  98         #print(date1, "<>", date2)
  99         timedelta = abs(date1 - date2)
 100         if(timedelta.total_seconds()>tolerance):
 101             return 1
 102         else:
 103             return 0