remindme.py

   1 import os
   2 import sys
   3 from smtplib import SMTP_SSL
   4 import email
   5 import datetime
   6
   7 from imapclient import IMAPClient, SEEN
   8 from dateutil.parser import parse
   9 from cron_descriptor import get_description
  10 from croniter import croniter
  11
  12
  13 IMAP_USER = os.environ["REMINDME_IMAP_USER"]
  14 IMAP_PASS = os.environ["REMINDME_IMAP_PASS"]
  15 IMAP_HOST = os.environ["REMINDME_IMAP_HOST"]
  16 SMTP_USER = os.environ.get("REMINDME_SMTP_USER", IMAP_USER)
  17 SMTP_PASS = os.environ.get("REMINDME_IMAP_PASS", IMAP_PASS)
  18 SMTP_HOST = os.environ.get("REMINDME_IMAP_HOST", IMAP_HOST)
  19
  20 USAGE = ""
  21
  22 __iclient = None
  23
  24
  25 def iclient():
  26     global __iclient
  27     if not __iclient:
  28         __iclient = IMAPClient(IMAP_HOST, use_uid=True)
  29         __iclient.login(IMAP_USER, IMAP_PASS)
  30
  31     __iclient.select_folder("INBOX")
  32     return __iclient
  33
  34
  35 def make_reply(orig, subject, body):
  36     reply = email.message.Message()
  37     reply["Subject"] = subject
  38     reply["In-Reply-To"] = orig["Message-ID"]
  39     reply["References"] = orig["Message-ID"]
  40     reply.set_payload(body)
  41     reply["From"] = "remindme@friedersdorff.com"
  42     reply["To"] = orig["From"]
  43     return reply
  44
  45
  46 def ls(msg, reminders):
  47     reply_lines = []
  48     for uid, reminder in reminders:
  49         body = reminder.get_payload().strip()
  50         if body.startswith("repeat"):
  51             parsed = get_description(body[6:].strip())
  52             reply_lines.append(f"({uid}) {reminder['subject']}: {body} ; {parsed}")
  53             pass
  54         else:
  55             reply_lines.append(f"({uid}) {reminder['subject']}: {body}")
  56
  57     return make_reply(msg, "Your current reminders", "\n".join(reply_lines))
  58
  59
  60 def ack_reminder(uid, reminder):
  61     body = reminder.get_payload().strip()
  62     if body.startswith("repeat"):
  63         parsed = get_description(body[6:].strip())
  64         reply_body = f"({uid}) {reminder['subject']}: {body} ; {parsed}"
  65         pass
  66     else:
  67         reply_body = f"({uid}) {reminder['subject']}: {body}"
  68
  69     return make_reply(reminder, f"Received Reminder: {reminder['subject']}", reply_body)
  70
  71
  72 def remind(last_time, start_time, reminder):
  73     f_line = reminder.get_payload().strip().splitlines()[0]
  74     if f_line.lower().startswith("repeat"):
  75         cron_payload = f_line[6:].strip()
  76         it = croniter(cron_payload, last_time)
  77         next_time = it.get_next(datetime.datetime)
  78         if next_time > last_time and next_time <= start_time:
  79             return (
  80                 True,
  81                 make_reply(
  82                     reminder, f"Re: {reminder['subject']} now", reminder.get_payload()
  83                 ),
  84             )
  85         else:
  86             return False, None
  87     else:
  88         try:
  89             parsed_time = parse(f_line, fuzzy=True)
  90         except ValueError:
  91             return False, None
  92
  93         if not parsed_time.tzinfo:
  94             send_date = email.utils.parsedate_to_datetime(reminder["Date"])
  95             sender_tz = send_date.tzinfo or datetime.timezone.utc
  96             parsed_time = parsed_time.replace(tzinfo=sender_tz)
  97
  98         if datetime.datetime.now(datetime.timezone.utc) > parsed_time:
  99             return (
 100                 True,
 101                 make_reply(
 102                     reminder, f"Re: {reminder['subject']} now", reminder.get_payload()
 103                 ),
 104             )
 105
 106
 107 def main(last_time, start_time):
 108     msgs = iclient().search(["ALL"])
 109     new_rems, old_rems, metas, to_delete, to_send = [], [], [], [], []
 110     for uid, data in iclient().fetch(msgs, ["BODY.PEEK[]", "FLAGS"]).items():
 111         mail = email.message_from_bytes(data[b"BODY[]"])
 112         if mail.is_multipart():
 113             to_delete.append(uid)
 114
 115         payload = mail.get_payload().strip()
 116         if payload.lower().startswith("help") or payload.lower().startswith("list"):
 117             metas.append(mail)
 118             to_delete.append(uid)
 119         else:
 120             if SEEN in data[b"FLAGS"]:
 121                 old_rems.append((uid, mail))
 122             else:
 123                 new_rems.append((uid, mail))
 124
 125     for meta in metas:
 126         if meta.get_payload().strip().startswith("help"):
 127             to_send.append(make_reply(meta, "Remindme Help", USAGE))
 128         elif meta.get_payload().strip().startswith("list"):
 129             to_send.append(ls(meta, old_rems + new_rems))
 130
 131     for uid, reminder in new_rems:
 132         to_send.append(ack_reminder(uid, reminder))
 133
 134     for uid, reminder in old_rems + new_rems:
 135         done, reply = remind(last_time, start_time, reminder)
 136         if reply:
 137             to_send.append(reply)
 138         if done:
 139             to_delete.append(uid)
 140
 141     iclient().delete_messages(to_delete)
 142     iclient().expunge()
 143     iclient().add_flags([u[0] for u in new_rems], SEEN)
 144
 145     with SMTP_SSL(SMTP_HOST) as smtp:
 146         smtp.login(SMTP_USER, SMTP_PASS)
 147         for reply in to_send:
 148             smtp.send_message(reply)
 149
 150
 151 if __name__ == "__main__":
 152     last_time = datetime.datetime.fromtimestamp(
 153         float(sys.argv[1]), datetime.timezone.utc
 154     )
 155     start_time = datetime.datetime.now(datetime.timezone.utc)
 156     main(last_time, start_time)
 157     print(start_time.timestamp())