#!/usr/bin/python3

# mdmv -- safely move messages between maildirs

# Copyright (C) 2017-2018 Sean Whitton
#
# 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 3 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, see <http://www.gnu.org/licenses/>.

import os
import sys
import time
import shutil
import socket

def eprint(*args, **kwargs):
    print(*args, file=sys.stderr, **kwargs)

us = os.path.basename(sys.argv[0])

if len(sys.argv) < 3:
    eprint(us + ": usage: " + us + " MSG [MSG..] DEST")
    sys.exit(1)

dest = sys.argv[-1]

for msg in sys.argv[1:-1]:
    if not os.path.isfile(msg):
        eprint(us + ": " + msg + " does not exist")
        sys.exit(1)

for d in [os.path.join(dest, "cur"), os.path.join(dest, "new"), os.path.join(dest, "tmp")]:
    if not os.path.isdir(d):
        eprint(us + ": " + dest + " doesn't look like a Maildir")
        sys.exit(1)

counter = 0

for msg in sys.argv[1:-1]:
    # annex/ subdir is readonly; avoid errors by skipping over
    if ".fmail/annex" in msg:
        print("skipping", msg)
        continue

    msg_name = os.path.basename(msg)
    parts = msg_name.split(':')
    if len(parts) == 2:
        flags = parts[1]
    else:
        flags = None
    name_prefix = "%d.%d_%d.%s" % (int(time.time()), os.getpid(),
                                   counter, socket.gethostname())

    if flags:
        msg_dest = os.path.join(os.path.join(dest, 'cur'), name_prefix + ':' + flags)
    else:
        msg_dest = os.path.join(os.path.join(dest, 'cur'), name_prefix)

    if os.path.exists(msg_dest):
        eprint(us + ": somehow, dest " + msg_dest + " already exists")
        sys.exit(1)
    else:
        shutil.move(msg, msg_dest)

    counter = counter + 1