#!/usr/bin/python

import sys
import mailbox
import os

def error(message):
    sys.stderr.write(message)
    sys.exit(1)

if len(sys.argv) != 4:
    error("Usage: %s <mbox> <number> <out>\n" % os.path.basename(sys.argv[0]))

mbox=sys.argv[1]
num = 0
out=sys.argv[3]

os.path.isfile(mbox) or error("File %s not found.\n" % mbox)

try:
    num=int(sys.argv[2])
except Exception, e:
    error("Can't convert %s to an int. %s\n" % (sys.argv[2], str(e)))

if num <= 0:
    error("Please supply a positive number.\n")

os.path.isdir(out) and error("Directory %s exists. Please remove it.\n" % out)

try:
    os.mkdir(out)
except Exception, e:
    error("Can't create directory %s. %s\n" % (out, str(e)))

counter = 0
cur = mailbox.mbox(os.path.join(out, str(counter)))
for (key, message) in mailbox.mbox(mbox).items():
    if counter == num:
        counter = 0
        cur = mailbox.mbox(os.path.join(out, str(key)))
    cur.add(message)
    counter += 1