#!/usr/bin/env python3
# -*- coding: utf-8 -*-
'''
Criticality: High
Check that emails can be sent.
'''
import os
import subprocess
import sys
import random
import time
import imp

GREEN = '\033[92m'
RED = '\033[91m'
DEF = '\033[0m'

os.chdir(os.path.dirname(__file__))
if not os.path.isfile('../utils.py'):
    print('The envsetup configuration was not found.')
    sys.exit(1)
else:
    es_utils = imp.load_source('es_utils', '../utils.py')
    conf = es_utils.load_conf()


def print_color(txt, col):
    print('%s%s%s' % (col, txt, DEF))


def print_red(txt):
    print_color(txt, RED)


def print_green(txt):
    print_color(txt, GREEN)


def check_listening_port():
    # check that postfix listens the port 25 correctly
    status, out = subprocess.getstatusoutput('netstat -pant | grep master | grep 127.0.0.1:25')
    if status != 0:
        print_red('The port 25 is not listened by postfix "master" process.')
        return False
    else:
        print_green('Postfix is listening port 25 correctly.')
        return True

def check_spf(ip):
    status, output = subprocess.getstatusoutput('host -t TXT ubicast.eu')
    if ip in output:
        return True

def check_relay():
    print('Checking if SMTP relay conforms to conf.')
    status, out = subprocess.getstatusoutput('grep relayhost /etc/postfix/main.cf')
    if status == 0:
        configured_relay = out[len('relayhost'):].strip(' \t=')
    else:
        configured_relay = None
    if not configured_relay:
        # no relay configured, check relayless situations
        domain = '.'.join(conf.get('MS_SERVER_NAME').split('.')[-2:])
        ip = conf.get('NETWORK_IP')
        with open('/etc/mailname', 'r') as f:
            d = f.read()
            if domain != 'ubicast.tv' and domain not in d:
                print_red('/etc/mailname does not contain the server domain, emails will probably be treated as spam')
                return False
            if not check_spf(ip):
                print_red('ip %s is not in ubicast.eu SPF and emails sent from support@ubicast.eu will be treated as spam' % ip)
                return False
    conf_relay = conf.get('EMAIL_SMTP_SERVER')
    if conf_relay != configured_relay:
        print_red('Configured STMP relay (%s) does not match the expected value (%s).' % (configured_relay, conf_relay))
        return False
    else:
        print_green('STMP relay is properly set.')
        return True


def send_test_email():
    email = 'noreply+%s-%s@ubicast.eu' % (time.time(), random.randint(0, 1000))
    print('Sending test email to "%s".' % email)
    cmd = 'echo "This is a test email" | mail -s "Test email from `cat /etc/hostname`" %s' % email
    subprocess.getstatusoutput(cmd)
    time.sleep(3)
    cmd = 'grep "%s" /var/log/mail.log' % email
    status, out = subprocess.getstatusoutput(cmd)
    if status != 0:
        time.sleep(7)
        status, out = subprocess.getstatusoutput(cmd)
        if status != 0:
            print_red('Failed to send email.')
            print('No log entry found using command: %s' % cmd)
            return False
    if 'bounced' not in out or 'The email account that you tried to reach does not exist.' in out:
        print_green('Email sent.')
        return True
    else:
        print_red('Failed to send email.')
        print('Sending log line:\n%s' % out)
        return False


if not os.path.exists('/etc/postfix'):
    print_red('Postfix dir does not exists, please install postfix.')
    sys.exit(1)

all_ok = check_listening_port()
if all_ok:
    all_ok = all_ok and check_relay()
    all_ok = all_ok and send_test_email()

sys.exit(int(not all_ok))