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