import os
import asyncio
from aiosmtpd.controller import Controller
from email.parser import BytesParser
from email.policy import default
import telegram
import re
import httpx

# Configuration
TELEGRAM_API_KEY = os.getenv('TELEGRAM_API_KEY')
DEFAULT_CHAT_ID = os.getenv('TELEGRAM_CHAT_ID')  # Fallback chat ID
NTFY_TOKEN = os.getenv('NTFY_TOKEN')
NTFY_URL = os.getenv('NTFY_URL')

# SMTP configuration
SMTP_HOST = '0.0.0.0'  # Listen on all interfaces
SMTP_PORT = 2525  # Alternative SMTP port

class SMTPHandler:
    async def handle_RCPT(self, server, session, envelope, address, rcpt_options):
        envelope.rcpt_tos.append(address)
        return '250 OK'

    async def handle_DATA(self, server, session, envelope):
        parser = BytesParser(policy=default)
        message = parser.parsebytes(envelope.content)
        
        subject = message.get('subject', 'No subject')
        body = message.get_body(preferencelist=('plain', 'html')).get_content()
        full_message = f"Subject: {subject}\n\n{body}"
        
        # Extract destination from the recipient email address
        destination, service = self.extract_destination(envelope.rcpt_tos[0])
        
        if service == 'telegram':
            await self.send_telegram(destination, full_message)
        elif service == 'ntfy':
            await self.send_ntfy(destination, subject, body)
        else:
            print(f"Invalid service: {service}. Message not sent.")

        return '250 Message accepted for delivery'

    def extract_destination(self, email):
        match = re.match(r'(.+)@(telegram|ntfy)$', email)
        if match:
            return match.group(1), match.group(2)
        print(f"Invalid email format: {email}. Using default Telegram chat ID.")
        return DEFAULT_CHAT_ID, 'telegram'

    async def send_telegram(self, chat_id, message):
        bot = telegram.Bot(TELEGRAM_API_KEY)
        try:
            await bot.send_message(chat_id=chat_id, text=message)
            print(f"Message sent to Telegram chat ID: {chat_id}")
        except telegram.error.BadRequest as e:
            print(f"Failed to send message to Telegram chat ID: {chat_id}. Error: {str(e)}")
            print("Attempting to send to default Telegram chat ID.")
            await bot.send_message(chat_id=DEFAULT_CHAT_ID, text=message)

    async def send_ntfy(self, topic, subject, body):
        headers = {
            "Authorization": f"Bearer {NTFY_TOKEN}",
            "Title": subject,
            "Content-Type": "text/plain",
        }
        async with httpx.AsyncClient() as client:
            try:
                response = await client.post(f"{NTFY_URL}/{topic}", content=body, headers=headers)
                response.raise_for_status()
                print(f"Message sent to ntfy topic: {topic}")
            except httpx.HTTPStatusError as e:
                print(f"Failed to send message to ntfy topic: {topic}. Error: {str(e)}")

async def start_smtp_server():
    controller = Controller(SMTPHandler(), hostname=SMTP_HOST, port=SMTP_PORT)
    controller.start()

if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    loop.create_task(start_smtp_server())
    print(f"SMTP server started on {SMTP_HOST}:{SMTP_PORT}")
    loop.run_forever()