#!/usr/bin/env python

# (c) 2004 -- Benjamin Mako Hill <mako@bork.hampshire.edu>

__copyright__ = "Copyright (c) 2004 Benjamin Mako Hill"
__author__ = "Benjamin Mako Hill <mako@debian.org>" 

import sys
import os
import re
import email

# location of the sendmail binary
sendmail = "/usr/sbin/sendmail"

# list of mimetype which are, for the sake of this program, not
# attachments
ignored_types = ( "applica/pgp-signat", "application/pgp-signature" ) 

def send_message(): 
    mailpipe = os.popen("%s -t" % sendmail, 'w')
    mailpipe.write( message_string )
    sys.exit( mailpipe.close() )

# get the mail from stdin
message_string = sys.stdin.read()
message = email.message_from_string( message_string )

attachment_expected = False
attachment_seen = False
text_seen = False

for part in message.walk():

    # check to see if this part is a plain text entry
    if part.get_content_type() == "text/plain":

        # if this is the second text block, we should interrate
        # through things
        if text_seen:
            attachment_seen = True
        # otherwise, mark that we've now seen one text field
        else:
            text_seen = True

        # search for the word "attach" or "attached" or "attachment"
        # in the body of the message
        if re.search( r'\battach(ed|ment)?\b(?im)',
                      part.get_payload() ):
            attachment_expected = True

    # check to see if this mime-type is something we can ignore
    elif ( re.match( r'message/(?m)', part.get_content_type() ) or
           re.match( r'multipart/(?m)', part.get_content_type() ) or
           part.get_content_type() in ignored_types ):
        continue

    # if it's not text and it's an ignored type, it's a seen attachment
    else:
        attachment_seen = True

# now check to see if we are expecting an attachment
if attachment_expected:

    # if we are expecting an attachment and we've seen one, we should
    # send the file and be done with things
    if attachment_seen:
        send_message()

    # if we are expected have not seen it, we need to check to see if
    # the mail has been confirmed

    else:
        # check for the confirmation

        if re.search( r'Subject: CONFIRM', message_string ):

            message_string = re.sub( r'(Subject: )(CONFIRM )(.*?)\n',
                                     r'\1\3\n', message_string )
            send_message()

        else:
            print >>sys.stderr, "Your message mentions attachments but does not include any."
            print >>sys.stderr
            print >>sys.stderr, "Either add an attachment or add \"CONFIRM\" (in ALLCAPS)"
            print >>sys.stderr, "to beginning of the subject of the message and resend."
            print >>sys.stderr
            print >>sys.stderr, "\"CONFIRM\" will be stripped from your message subject before"
            print >>sys.stderr, "the message is sent."
            sys.exit( 1 )

##    else:
##        answer = ''
##        while not answer:

##            answer = 'n'
##            answer = raw_input( "No attachment detected.\n"
##                                "Are you sure you want to send this?"
##                                " [Y/N]: " )

                
##            # send the mail without the attachment
##             if answer == "y":
##                 send_message()

##             # go back and let us reattach the message
##             elif answer == "n":
##                 sys.exit( 1 )

##             # no good answer ask again
##             else:
##                 answer = ''


# if we are not expecting anything more, we should send the message
else:
    send_message()