remindme_caldav/alert_processor.py

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
import ssl
import humanfriendly
import slixmpp

class AlertProcessor:
    def __init__(self, config):
        self.config = config
        
    def _create_email(self, event, next_alert, next_event):
        # Set up the SMTP server details
        smtp_server = self.config["email"]["smtp_server"]
        port = self.config["email"]["port"]
        sender_email = self.config["email"]["username"]
        receiver_email = self.config["email"]["recipient"]
        password = self.config["email"]["password"]
        
        # Event details
        event_name, event_description, event_location, event_date, human_readable_time = self._get_event_details(event, next_alert, next_event)
        
        # Create a multipart message and set headers
        message = MIMEMultipart()
        message["From"] = sender_email
        message["To"] = receiver_email
        message["Subject"] = "Event Alert: '{}' @ {}".format(event_name, event_date)
        
        # Add body to email
        body = self._create_email_body(event_name, event_date, event_description, event_location, human_readable_time)
        message.attach(MIMEText(body, "plain"))
        text = message.as_string()
        
        return smtp_server, port, sender_email, receiver_email, password, text
    
    def _get_event_details(self, event, next_alert, next_event):
        # Event details
        event_name = event["summary"]
        event_description = event["description"]
        event_location = event["location"]
        event_date = next_event
        event_delta = next_event - next_alert
        total_seconds = event_delta.total_seconds()
        human_readable_time = humanfriendly.format_timespan(total_seconds)
        
        return event_name, event_description, event_location, event_date, human_readable_time
    
    def _create_email_body(self, event_name, event_date, event_description, event_location, human_readable_time):
        body = """\
        Hi,
        This is an event alert from remindme_caldav.

        Event details:
         ---------------------------------

            Event name: {}
            Date/time: {}
            Description: {}
            Location: {}
            Time until event: {}

          ---------------------------------
         """.format(event_name, event_date, event_description, event_location, human_readable_time)
        return body
    
    def send_email(self, event, next_alert, next_event):
        try:
            smtp_server, port, sender_email, receiver_email, password, text = self._create_email(event, next_alert, next_event)
            
            # Create a secure SSL context and connect to the server
            context = ssl.create_default_context()
            with smtplib.SMTP(smtp_server, port) as server:    # Use 'with' statement for automatic cleanup
                server.ehlo()  # Can be omitted
                server.starttls(context=context)     # Secure the connection
                server.login(sender_email, password)
                
                # Send email here
                server.sendmail(sender_email, receiver_email, text)
            return print("Message sent via email")
        except Exception as e:
             # Print any error messages to stdout
            print("An error occured when sending alert via email, please check your config. Message: {}".format(e))
    
    def _create_xmpp_bot(self, event, next_alert, next_event):
        class SendMsgBot(slixmpp.ClientXMPP):
            def __init__(self, jid, password, recipient, message):
                super().__init__(jid, password)
                self.recipient = recipient
                self.msg = message
                self.add_event_handler("session_start", self.start)

            def start(self, event):
                self.send_presence()
                self.get_roster()
                self.send_message(mto=self.recipient, mbody=self.msg, mtype='chat')
                self.disconnect()
        
        jid = self.config["xmpp"]["jid"]
        password = self.config["xmpp"]["password"]  # replace with your password
        recipient = self.config["xmpp"]["recipient"]

        event_name, event_description, event_location, event_date, human_readable_time = self._get_event_details(event, next_alert, next_event)
        
        message = self._create_email_body(event_name, event_date, event_description, event_location, human_readable_time)
        
        return SendMsgBot(jid, password, recipient, message)
    
    def send_xmpp(self, event, next_alert, next_event):
        try:
            bot = self._create_xmpp_bot(event, next_alert, next_event)
            
            bot.register_plugin('xep_0030')  # Service Discovery
            bot.register_plugin('xep_0199')  # XMPP Ping
            bot.connect()
            bot.process(forever=False)
            return print("Message sent via XMPP")
        except Exception as e:
            print("An error occured when sending alert via XMPP, please check your config. Message: {}".format(e))