mailcheck

#!/bin/env python3

from os import path, getenv, mkdir
from glob import iglob
import subprocess
import shlex
import uuid
from argparse import ArgumentParser
from email.parser import HeaderParser
from email.header import decode_header

UUID_NAMESPACE = uuid.UUID("becc6078-fd0c-4660-9a55-c25af9cef0d0")
NOTIFY_TITLE = "New mail from {author}"
NOTIFY_BODY = "{subject}"


def get_new_mail(maildir, mailbox):
    """ get list of mail messages for mailbox folders """
    glob_iter = iglob(path.join(maildir, mailbox, 'new', '*'))
    return {message for message in glob_iter}


def get_decoded(msg, key, default='unknown'):
    decoded_parts = []
    parts = decode_header(msg.get(key, default))
    for part in parts:
        try:
            if isinstance(part[0], bytes):
                try:
                    decoded_parts.append(part[0].decode(part[1]))
                except TypeError:
                    decoded_parts.append(part[0].decode())
            else:
                decoded_parts.append(part[0])
        except IndexError:
            decoded_parts.append("unknown")
    return " ".join(decoded_parts)


def main():
    """ main logic """
    parser = ArgumentParser()
    parser.add_argument("-d", dest="maildir", metavar="MAILDIR",
                        default="~/Mail", help="Specify maildir path")
    parser.add_argument("-c", dest="command", metavar="COMMAND",
                        help="Specify a command to be run before checking")
    parser.add_argument("-b", dest="i3blocks", action="store_true",
                        help="Output as i3blocks format")
    parser.add_argument(dest="mailboxes", metavar="MAILBOX", nargs="*",
                        default=["INBOX"], help="List mailboxes to check")
    args = parser.parse_args()

    xdg_cache_path = getenv("XDG_CACHE_HOME") or path.expanduser(path.join("~", ".cache"))
    cache_dir = path.join(xdg_cache_path, "mailcheck")
    if not path.exists(cache_dir):
        mkdir(cache_dir)

    count = 0
    for mailbox in args.mailboxes:
        cache_name = str(uuid.uuid5(UUID_NAMESPACE, args.maildir + mailbox))
        cache_path = path.join(cache_dir, cache_name)
        new_before = None
        if path.isfile(cache_path):
            with open(cache_path, "r") as fd:
                new_before = set(fd.read().splitlines())
        elif args.command:
            new_before = get_new_mail(args.maildir, mailbox)

        if args.command:
            subprocess.call(shlex.split(args.command))

        new_after = get_new_mail(args.maildir, mailbox)
        count += len(new_after)

        with open(cache_path, "w") as fd:
            fd.write("\n".join(new_after))

        if new_before is None:
            continue

        just_came = new_after - new_before
        for message in just_came:
            parser = HeaderParser()
            with open(message) as fp:
                msg = parser.parse(fp=fp)
            subprocess.call(['notify-send',
                             NOTIFY_TITLE.format(author=get_decoded(msg, 'from', 'unknown')),
                             NOTIFY_BODY.format(subject=get_decoded(msg, 'subject', 'unknown'))])

    print(count)

    if args.i3blocks:
        print(count)
        print("#FFFFFF")


if __name__ == "__main__":
    main()