#!/usr/bin/python

import argparse
import smtplib
import random
import string
import quopri
import time
import sys
import os
import email.utils

from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

"""
check out http://blog.magiksys.net/generate-and-send-mail-with-python-tutorial
for a real professional solution
"""

eol = "\r\n"
emails = []
dictionary = '/'.join(__file__.split('/')[:-1]) + "/dictionary.txt"
checkpoint_for_newline = 300


def create_random_string(len=60):
    return ''.join(random.choice(string.uppercase + string.digits) for i in range(len))


def create_msg(words, size=10000):
    msg_text = ""
    msg_size = 0
    new_line_checkpoint = checkpoint_for_newline

    while msg_size < size:
        choice = random.SystemRandom().choice
        s = str(choice(words)).replace('\n', ' ')
        msg_text += s
        msg_size += len(s)
        if msg_size > new_line_checkpoint:
            new_line_checkpoint += checkpoint_for_newline
            msg_text += eol + eol

    return msg_text


def create_text_mime_part(text, charset, encoding, boundary):
    part = ""

    part += "--" + boundary + eol
    part += "Content-Type: text/plain; charset=\"" + charset + "\"" + eol
    part += "Content-Transfer-Encoding: " + encoding + eol
    part += eol
    part += text + eol + eol

    return part
 

def create_headers(args, boundary):
    hdr = ""

    hdr += "Content-Type: multipart/alternative;" + eol
    hdr += "   boundary=\"" + boundary + "\"" + eol
    hdr += "MIME-Version: 1.0" + eol
    hdr += "Subject: " + args.subject + eol
    hdr += "From: " + args.sender + eol
    hdr += "To: " + ', ' . join(args.rcpt) + eol
    hdr += "Date: " + email.utils.formatdate(time.time(), localtime=True) + eol
    hdr += "Message-ID: " + "<" + create_random_string(40) + "@" + args.helo + ">" + eol
    hdr += eol + eol

    return hdr


def create_message(words, args):
    msg = ""

    boundary = '_' + create_random_string() + '_'

    msg += create_headers(args, boundary)

    the_text = create_msg(words, args.msglen)
    the_text = quopri.encodestring(the_text)

    msg += create_text_mime_part(the_text, "iso-8859-2", "quoted-printable", boundary)
    msg += "--" + boundary + eol

    return msg


def read_emails_from_dir(directory):
    for dir, dirs, files in os.walk(directory):
        for file in files:
            emails.append(os.path.join(dir, file))

    args.count = len(emails)


def get_next_email_text():
    if emails == []: return ''

    filename = emails.pop()
    with open(filename) as f:
        return f.read()


parser = argparse.ArgumentParser()

parser.add_argument("--helo", type=str, help="ehlo hostname", default="myhost.aaa.fu")
parser.add_argument("-f", "--sender", type=str, help="sender email", default="sender@aaa.fu")
parser.add_argument("-r", "--rcpt", type=str, nargs='+', help="recipient email(s)", default=["archive@aaa.fu"])
parser.add_argument("-c", "--count", type=int, help="number of emails to send", default=1)
parser.add_argument("-d", "--debug", type=int, help="debug level", default=0)
parser.add_argument("--session", type=int, help="number of emails to send in one smtp transaction", default=1)
parser.add_argument("-s", "--server", type=str, help="smtp server", required=True)
parser.add_argument("-p", "--port", type=int, help="smtp port", default=25)
parser.add_argument("--subject", type=str, help="subject", default="This is test subject")
parser.add_argument("-l", "--msglen", type=int, help="message length (approx.)", default=20000)
parser.add_argument("--starttls", help="use STARTTLS", action="store_true")
parser.add_argument("--pem", type=str, help="pem file for starttls", default="")
parser.add_argument("--dir", type=str, help="directory to send emails (must be eml files) from", default="")

args = parser.parse_args()


if args.starttls and args.pem == "":
    sys.exit("make a pem file for starttls")


i = 0
total_count = 0

if args.dir:
    read_emails_from_dir(args.dir)
else:
    with open(dictionary) as f:
        words = f.readlines()


while i < args.count:
    server = smtplib.SMTP(args.server, args.port, args.helo, 10)

    if args.starttls:
        server.starttls(args.pem, args.pem)

    k = 0

    while i < args.count and k < args.session:

        if args.dir:
            message = get_next_email_text()
        else:
            message = create_message(words, args)

        server.set_debuglevel(args.debug)
        server.sendmail(args.sender, args.rcpt, message)

        k += 1
        total_count += 1
 
        if args.debug == 0:
            sys.stdout.write('%s\r' % str(total_count))
            sys.stdout.flush()

    server.quit()
    i += 1


if args.debug == 0:
    print('')