#!/usr/bin/env python

"""
Usage:
    cat email | incspam increment [comment]
    ex. incspam 2 "keyword: viagra" < email.file

Description:
pipe in an email on stdin, argument is how many X to add to X-Spam-Level
dumps new msg to stdout, used by procmail

:0 fw
* some condition
| incmail 2 comment

Caveat:
This process may change some cr/lf and header spacing/breaking but should be email client safe
"""


import os,sys
import re
import subprocess
import email
from cStringIO import StringIO
from email.Generator import Generator

def msg_to_string(msg):

    fp = StringIO()
    g = Generator(fp, mangle_from_=False)
    g.flatten(msg,True)
    return fp.getvalue()

try:

    if len(sys.argv) < 2:
        raise
    else:
        inc=int(sys.argv[1])

    if inc < 1:     # we don't want to mess with headers if we aren't going do anything worthwhile
        raise       # we may want to have the ability to subract from the score in the future

    try:
        comment=sys.argv[2]
    except IndexError:
        comment=""

    orig_msg=sys.stdin.read()
    msg=email.message_from_string(orig_msg)

    h_level="X-Spam-Level"
    h_flag="X-Spam-Flag"
    h_comment="X-Spam-Inc"

    for header in (h_level, h_flag, h_comment):
        if not msg.has_key(header):
            msg.add_header(header, "")

    msg.replace_header(h_flag,"YES")

    # set the number of X's
    level=len(msg.get(h_level)) + inc
    msg.replace_header(h_level,"X"*level)

    # add a note saying how this msg is getting incremented
    t_comment=msg.get(h_comment)
    if len(t_comment):
        t_comment= t_comment + ", "

    t_comment +=  comment + " +" + str(inc)
    msg.replace_header(h_comment,t_comment)

    h_subject="Subject"
    subject=msg.get(h_subject)

    re_spam=re.compile("\[spam\+?\] ")

    if re_spam.match(subject):              # strip out [spam+?] from subject
        pos=subject.find(" ") + 1           # find then skip space
        subject = subject[pos:] 

    subject="[spam+] " + subject            # prepend [spam+] to subject
    msg.replace_header(h_subject,subject)

    print msg_to_string(msg)

except: # if anything bad happens then just print out original stdin
    try:
        print orig_msg
    except NameError:               # orig_msg doesn't exist yet
        print sys.stdin.read()