#!/usr/bin/env python

import sys
import argparse
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

# Edit these defaults, as needed
# If you want to get your defaults from environment variables, and/or if you want to hardcode a new default
# edit this code like:
# ```
# import os
#
# DEFAULT_FROM = os.environ.get("EMAIL_FROM_ADDRESS") or "example@example.com"
# ```

DEFAULT_HOST = "smtp.mailgun.org"
DEFAULT_PORT = 587
DEFAULT_USER = None
DEFAULT_PASSWORD = None
DEFAULT_FROM = None

DEFAULT_SUBJECT = None
DEFAULT_TO = None
DEFAULT_CC = None
DEFAULT_BCC = None
DEFAULT_HTML_FILE = None
DEFAULT_PLAIN_FILE = None

VERBOSITY_NONE = 0
VERBOSITY_LOW = 1
VERBOSITY_HIGH = 2

DESCRIPTION = """Send SMTP email from the command line"""

EPILOG = """Thank you for using the software"""

def main():
    argParser = argparse.ArgumentParser(description=DESCRIPTION, epilog=EPILOG, formatter_class=argparse.RawDescriptionHelpFormatter)

    argParser.add_argument("-H", "--host", help="Sets the 'host' field. Default to '{0}'".format(DEFAULT_HOST if DEFAULT_HOST is not None else ""), default=DEFAULT_HOST)
    argParser.add_argument("-p", "--port", type=int, help="Sets the 'port' field. Default to '{0}'".format(DEFAULT_PORT if DEFAULT_PORT is not None else ""), default=DEFAULT_PORT)
    argParser.add_argument("-u", "--user", help="Sets the 'userName' field. Default to '{0}'".format(DEFAULT_USER if DEFAULT_USER is not None else ""), default=DEFAULT_USER)
    argParser.add_argument("-P", "--password", help="Sets the 'password' field. Default to '{0}'".format(DEFAULT_PASSWORD if DEFAULT_PASSWORD is not None else ""), default=DEFAULT_PASSWORD)
    argParser.add_argument("-f", "--fromAddress", help="Sets the 'fromAddress' field. Default to '{0}'".format(DEFAULT_FROM if DEFAULT_FROM is not None else ""), default=DEFAULT_FROM)
    argParser.add_argument("-s", "--subject", help="Sets the 'subject' field. Default to '{0}'".format(DEFAULT_SUBJECT if DEFAULT_SUBJECT is not None else ""), default=DEFAULT_SUBJECT)
    argParser.add_argument("-t", "--to", help="Sets the 'toList' field. Formatted as a comma-separated list of emails. Default to '{0}'".format(DEFAULT_TO if DEFAULT_TO is not None else ""), default=DEFAULT_TO)
    argParser.add_argument("-c", "--cc", help="Sets the 'ccList' field. Formatted as a comma-separated list of emails. Default to '{0}'".format(DEFAULT_CC if DEFAULT_CC is not None else ""), default=DEFAULT_CC)
    argParser.add_argument("-b", "--bcc", help="Sets the 'bccList' field. Formatted as a comma-separated list of emails. Default to '{0}'".format(DEFAULT_BCC if DEFAULT_BCC is not None else ""), default=DEFAULT_BCC)
    argParser.add_argument("-n", "--htmlFile", help="Sets the 'htmlFile' field. Default to '{0}'".format(DEFAULT_HTML_FILE if DEFAULT_HTML_FILE is not None else ""), default=DEFAULT_HTML_FILE)
    argParser.add_argument("-N", "--plainFile", help="Sets the 'plainFile' field. Default to '{0}'".format(DEFAULT_PLAIN_FILE if DEFAULT_PLAIN_FILE is not None else ""), default=DEFAULT_PLAIN_FILE)

    argParser.add_argument("-v", "--verbosity", type=int, help="write info messages to standard output", default=VERBOSITY_NONE)
    argParser.add_argument("-d", "--dryRun", help="Program runs normally, only mail is not sent", action="store_true")

    args = argParser.parse_args()

    verbosity = args.verbosity
    dryRun = args.dryRun

    host = args.host
    port = args.port

    userName = args.user
    password = args.password

    if (userName and not password) or (not userName and password):
        print "Username and Password must be specified together"
        sys.exit(1)

    subject = args.subject
    if subject is None:
        print "Subject must be specified"
        sys.exit(1)

    fromAddress = args.fromAddress
    if fromAddress is None:
        print "From Address must be specified"
        sys.exit(1)

    toList = args.to.split(",") if args.to is not None else []
    ccList = args.cc.split(",") if args.cc is not None else []
    bccList = args.bcc.split(",") if args.bcc is not None else []

    recipents = toList + ccList + bccList

    if len(recipents) < 1:
        print "No recipents specified"
        sys.exit(1)

    htmlFile = args.htmlFile
    htmlPart = None
    try:
        if htmlFile:
            with open(htmlFile, "r") as fp:
                html = fp.read()
                htmlPart = MIMEText(html, "html")
    except Exception as e:
        print "Could not read HTML file"
        if verbosity >= VERBOSITY_LOW:
            print e
        sys.exit(1)

    plainFile = args.plainFile
    plainPart = None
    try:
        if plainFile:
            with open(plainFile, "r") as fp:
                plain = fp.read()
                plainPart = MIMEText(plain, "plain")
    except Exception as e:
        print "Could not read plain file"
        if verbosity >= VERBOSITY_LOW:
            print e
        sys.exit(1)

    if not htmlPart and not plainPart:
        print "No message (html or plain) specified"
        sys.exit(1)

    msg = MIMEMultipart("alternative")
    msg["Subject"] = subject
    msg["From"] = fromAddress
    msg["To"] = ",".join(toList)
    msg["Cc"] = ",".join(ccList)
    msg["Bcc"] = ",".join(bccList)

    if htmlPart:
        msg.attach(htmlPart)
    if plainPart:
        msg.attach(plainPart)

    s = smtplib.SMTP(host, port)

    if verbosity >= VERBOSITY_HIGH:
        s.set_debuglevel(1)

    try:
        if userName and password:
            s.login(userName, password)

        if not dryRun:
            s.sendmail(fromAddress, recipents, msg.as_string())
    except Exception as e:
        print "Error sending email"
        if verbosity >= VERBOSITY_LOW:
            print e

    s.quit()

if __name__ == "__main__":
    main()