#!/usr/bin/env python3
"""
SMTP webhook server
"""

import os
import json
import smtplib
import sys
import time
from email.header import Header
from email.mime.text import MIMEText

import cherrypy
import logging

logging.basicConfig(filename='app.log', filemode='w',
                    format='%(name)s - %(levelname)s - %(message)s')


class SMTPWebhookApp:
    """
    SMTP webhook server
    """

    def _send_mail(self):

        if not cherrypy.request.headers.get('Content-Length'):
            logging.error("To: {}, error: Invalid content length.".format(
                        TO_MAIL))
            return {"status": 400, "message": "Invalid content length."}

        cl = cherrypy.request.headers['Content-Length']
        rawbody = cherrypy.request.body.read(int(cl))
        req_body = json.loads(rawbody)

        if not req_body.get('subject') or req_body.get('subject') == '':
            logging.error("To: {}, error: body field is required.".format(
                        TO_MAIL))
            return {"status": 400, "message": "subject field is required."}

        if not req_body.get('body') or req_body.get('body') == '':
            logging.error("To: {}, error: body field is required.".format(
                        TO_MAIL))
            return {"status": 400, "message": "body field is required."}

        subject = req_body['subject']
        body = req_body['body']

        try:
            client = smtplib.SMTP(host=SMTP_SERVER_HOST, port=SMTP_SERVER_PORT)
        except Exception as e:
            time.sleep(0.2)
            logging.error("To: {}, error: {}".format(TO_MAIL, e))
            return {"status": 400, "message": "SMTP client error: {}.".format(
                    e)}

        msg = MIMEText(body, 'plain', 'utf-8')
        msg['Subject'] = Header(subject, 'utf-8')
        msg['From'] = FROM_MAIL
        msg['To'] = TO_MAIL
        try:
            client.ehlo()
            client.starttls()
            client.ehlo()
            client.login(msg["From"], FROM_MAIL_PASSWORD)
            client.sendmail(msg['From'], msg['To'], msg.as_string())
            response = {"status": 200, "message": "mail sent successfully"}
            logging.info("To: {}, mail sent successfully".format(TO_MAIL))
        except smtplib.SMTPException as e:
            time.sleep(0.2)
            logging.error("To: {}, error: {}".format(TO_MAIL, e))
            response = {"status": 500, "message": "some error: {}".format(e)}
        finally:
            client.quit()
            return response

    @cherrypy.expose
    def send_mail(self):
        """
        api endpoint for send mail
        """
        data = self._send_mail()
        cherrypy.response.status = data["status"]
        cherrypy.response.headers["Content-Type"] = "application/json"
        return json.dumps(data["status"]).encode()


ROOT = SMTPWebhookApp()

SMTP_SERVER_PORT = 587
CHERRYPY_SERVER_HOST = "0.0.0.0"
CHERRYPY_SERVER_PORT = 8081

if __name__ == "__main__":
    try:
        SMTP_SERVER_HOST = os.environ["SMTP_SERVER_HOST"]
        TO_MAIL = os.environ["TO_MAIL"]
        FROM_MAIL = os.environ["FROM_MAIL"]
        FROM_MAIL_PASSWORD = os.environ["FROM_MAIL_PASSWORD"]
    except KeyError:
        raise KeyError("Please check missing environment variables: "
                       "SMTP_SERVER_HOST, TO_MAIL, FROM_MAIL, "
                       "FROM_MAIL_PASSWORD")

    cherrypy.server.socket_host = CHERRYPY_SERVER_HOST
    cherrypy.server.socket_port = CHERRYPY_SERVER_PORT
    ENGINE = cherrypy.engine

    cherrypy.tree.mount(ROOT, config={})

    try:
        ENGINE.start()
    except Exception:  # pylint: disable=broad-except
        sys.exit(1)
    else:
        ENGINE.block()