import smtplib
import os

def send_email(host, port, username, password, mail_from, mail_to, subject, body):
    message = """From: %s\nTo: %s\nSubject: %s\n\n%s""" % (mail_from, mail_to, subject, body)
    print (message)
    try:
        server = smtplib.SMTP(host, port)
        server.ehlo()
        server.starttls()
        server.login(username, password)
        server.sendmail(mail_from, mail_to, message)
        server.close()
        return True
    except Exception as ex:
        print (ex)
        return False

def get_recipient():
    # separate multiple recipient by comma. eg: "abc@gmail.com, xyz@gmail.com"
    return os.environ['MAIL_TO']

def lambda_handler(event, context):
    username = os.environ['USERNAME']
    password = os.environ['PASSWORD']
    host = os.environ['SMTPHOST']
    port = os.environ['SMTPPORT']

    response = { "isBase64Encoded": False }
    to = get_recipient()
    subject = event['queryStringParameters']['subject']
    body = event['body']

    success = send_email(host, port, username, password, username, to, subject, body)
    if success:
        response["statusCode"] = 200
        response["body"] = "message sent"
    else:
        response["statusCode"] = 400
        response["body"] = "message sending failed"
    return response