from config.settings import MAIL, MAIL_PASSWORD
import smtplib
from email.message import EmailMessage
from logging import getLogger
from contextlib import contextmanager
from typing import Optional
logger = getLogger(__name__)

email_sender = None
class EmailSender:
    def __init__(self, email: str, password: str):
        self.email = email
        self.password = password
        self._smtp: Optional[smtplib.SMTP_SSL] = None
        logger.debug(f"EmailSender initialized with {self.email}")

    @contextmanager
    def get_connection(self):
        if self._smtp is None:
            logger.info("Establishing new SMTP connection.")
            try:
                self._smtp = smtplib.SMTP_SSL('smtp.gmail.com', 465)
                self._smtp.login(self.email, self.password)
                logger.info("SMTP connection established and logged in.")
            except Exception as e:
                logger.error(f"Failed to establish SMTP connection: {e}")
                raise
        try:
            yield self._smtp
        except Exception as e:
            logger.error(f"Error during SMTP operation: {e}")
            self.close_connection()
            raise e

    def close_connection(self):
        if self._smtp:
            try:
                logger.info("Closing SMTP connection.")
                self._smtp.quit()
                logger.info("SMTP connection closed.")
            except Exception as e:
                logger.warning(f"Error closing SMTP connection: {e}")
            finally:
                self._smtp = None

    def send_email(self, subject: str, body: str, to: list[str], **kwargs):
        logger.debug(f"Preparing to send email to: {to} with subject: '{subject}' and kwargs: {kwargs}")
        
        msg = EmailMessage()
        msg['Subject'] = subject
        msg['From'] = self.email
        msg['To'] = ", ".join(to)
        msg.set_content('Este correo tiene contenido HTML.')
        msg.add_alternative(body.format(**kwargs), subtype='html')
        
        try:
            with self.get_connection() as smtp:
                smtp.send_message(msg)
                logger.info(f"Email sent to {to} with subject '{subject}'.")
        except Exception as e:
            logger.error(f"Failed to send email to {to}: {e}")
            raise


def initialize_email_sender():
    global email_sender
    if email_sender is None:
        email_sender = EmailSender(MAIL, MAIL_PASSWORD)
        logger.info("EmailSender initialized globally.")
    return email_sender

def send_email(subject: str, body: str, to: list[str], **kwargs):
    email_sender = initialize_email_sender()
    email_sender.send_email(subject, body, to, **kwargs)