notification_service.py

import asyncio
import json
import logging
import os
import sys
from typing import Dict, Any
import aio_pika
import aiosmtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from dotenv import load_dotenv

load_dotenv()

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
    handlers=[logging.StreamHandler(sys.stdout)]
)
logger = logging.getLogger("notification_service")

RABBITMQ_URL = os.getenv("RABBITMQ_URL", "amqp://guest:guest@localhost:5672/")
SMTP_SERVER = os.getenv("SMTP_SERVER", "smtp.example.com")
SMTP_PORT = int(os.getenv("SMTP_PORT", "587"))
SMTP_USERNAME = os.getenv("SMTP_USERNAME", "user")
SMTP_PASSWORD = os.getenv("SMTP_PASSWORD", "password")
EMAIL_FROM = os.getenv("EMAIL_FROM", "noreply@example.com")

async def send_email(to: str, subject: str, body: str) -> None:
    """Send an email notification"""
    try:
        message = MIMEMultipart()
        message["From"] = EMAIL_FROM
        message["To"] = to
        message["Subject"] = subject
        message.attach(MIMEText(body, "html"))

        smtp = aiosmtplib.SMTP(hostname=SMTP_SERVER, port=SMTP_PORT, use_tls=True)
        await smtp.connect()
        await smtp.login(SMTP_USERNAME, SMTP_PASSWORD)
        await smtp.send_message(message)
        await smtp.quit()

        logger.info(f"Email sent to {to}")
    except Exception as e:
        logger.error(f"Failed to send email: {e}")

def get_notification_content(notification: Dict[str, Any]) -> tuple:
    """Generate email subject and body based on notification type"""
    notification_type = notification.get("type")
    patient_name = notification.get("patient_name", "Patient")
    doctor_name = notification.get("doctor_name", "Doctor")
    appointment_time = notification.get("appointment_time", "")

    if notification_type == "created":
        subject = "Appointment Confirmation"
        body = f"""
        <h2>Appointment Confirmation</h2>
        <p>Dear {patient_name},</p>
        <p>Your appointment with Dr. {doctor_name} has been scheduled for {appointment_time}.</p>
        <p>Please arrive 15 minutes before your appointment time.</p>
        <p>If you need to reschedule or cancel, please contact us at least 24 hours in advance.</p>
        <p>Thank you for choosing our healthcare services.</p>
        """
    elif notification_type == "updated":
        subject = "Appointment Update"
        body = f"""
        <h2>Appointment Update</h2>
        <p>Dear {patient_name},</p>
        <p>Your appointment with Dr. {doctor_name} has been updated to {appointment_time}.</p>
        <p>Please arrive 15 minutes before your appointment time.</p>
        <p>If you need to reschedule or cancel, please contact us at least 24 hours in advance.</p>
        <p>Thank you for choosing our healthcare services.</p>
        """
    elif notification_type == "cancelled":
        subject = "Appointment Cancellation"
        body = f"""
        <h2>Appointment Cancellation</h2>
        <p>Dear {patient_name},</p>
        <p>Your appointment with Dr. {doctor_name} scheduled for {appointment_time} has been cancelled.</p>
        <p>If you would like to reschedule, please contact our office.</p>
        <p>Thank you for choosing our healthcare services.</p>
        """
    elif notification_type == "status_updated":
        status = notification.get("status", "updated")
        subject = f"Appointment Status: {status.capitalize()}"
        body = f"""
        <h2>Appointment Status Update</h2>
        <p>Dear {patient_name},</p>
        <p>Your appointment with Dr. {doctor_name} scheduled for {appointment_time} has been marked as {status}.</p>
        <p>If you have any questions, please contact our office.</p>
        <p>Thank you for choosing our healthcare services.</p>
        """
    else:
        subject = "Healthcare Appointment Notification"
        body = f"""
        <h2>Appointment Notification</h2>
        <p>Dear {patient_name},</p>
        <p>This is a notification regarding your appointment with Dr. {doctor_name} scheduled for {appointment_time}.</p>
        <p>If you have any questions, please contact our office.</p>
        <p>Thank you for choosing our healthcare services.</p>
        """

    return subject, body

async def process_notification(notification: Dict[str, Any]) -> None:
    """Process a notification message"""
    try:
        patient_email = notification.get("patient_email")
        if not patient_email:
            logger.error("No patient email in notification")
            return

        subject, body = get_notification_content(notification)
        await send_email(patient_email, subject, body)

    except Exception as e:
        logger.error(f"Error processing notification: {e}")

async def main() -> None:
    """Main function to consume messages from RabbitMQ"""
    connection = await aio_pika.connect_robust(RABBITMQ_URL)

    async with connection:
        channel = await connection.channel()

        queue = await channel.declare_queue("notifications", durable=True)

        logger.info("Notification service started. Waiting for messages...")

        async with queue.iterator() as queue_iter:
            async for message in queue_iter:
                async with message.process():
                    try:
                        notification = json.loads(message.body.decode())
                        logger.info(f"Received notification: {notification}")
                        await process_notification(notification)
                    except Exception as e:
                        logger.error(f"Error processing message: {e}")

if __name__ == "__main__":
    asyncio.run(main())