forward.py

import smtplib
import os
from dotenv import load_dotenv
load_dotenv()
from email.mime.multipart import MIMEMultipart
from email import encoders
from email.mime.base import MIMEBase
from email.mime.text import MIMEText
from email.header import decode_header
from email.message import EmailMessage
from .summarize import summarize_email

REDIRECT_URL = "http://localhost:3000"
LOGO_URL = "https://i.ibb.co/P60gmv3/EC-Footer-small.png"

def decode_subject(subject):
    """
    Decodes the subject header of an email message.

    Args:
        subject (str): The subject header of the email.

    Returns:
        str: Decoded subject.
    """
    decoded = decode_header(subject)
    decoded_subject = []
    for part, encoding in decoded:
        if isinstance(part, bytes):
            decoded_subject.append(part.decode(encoding or 'utf-8'))
        else:
            decoded_subject.append(part)
    return ''.join(decoded_subject)

def forward_email(email_message: EmailMessage, smtp_server: str, smtp_port: int, smtp_email: str, smtp_password: str, forward_to: str, cc_to: list = [], bcc_to: list = [], sentiment="") -> None:
    """
    Forwards an email message to the specified recipient using SMTP while maintaining the formatting of the original message.

    Args:
        email_message (email.message.EmailMessage): The email message to forward.
        smtp_server (str): SMTP server hostname.
        smtp_port (int): SMTP server port number.
        smtp_email (str): Sender's email address.
        smtp_password (str): Sender's email password.
        forward_to (str): Recipient's email address.
    """
    # email_message = message_from_string(email_message)
    # New email message
    forwarded_email = MIMEMultipart()
    forwarded_email['From'] = smtp_email
    forwarded_email['To'] = forward_to
    if cc_to:
        forwarded_email['CC'] = ', '.join(cc_to)
    forwarded_email['Subject'] = f"{decode_subject(email_message['Subject'])} - ({sentiment}) Fwd from EC" # EC = Email Classifier

    html_part = None
    for part in email_message.walk():
        if part.get_content_type() == 'text/html':
            html_part = part.get_payload(decode=True).decode(part.get_content_charset())
        elif part.get_content_disposition() == 'attachment':
            # Attachment
            new_part = MIMEBase(part.get_content_type().split('/')[0], part.get_content_type().split('/')[1])
            new_part.set_payload(part.get_payload(decode=True))
            encoders.encode_base64(new_part)
            new_part.add_header('Content-Disposition', 'attachment', filename=part.get_filename())
            forwarded_email.attach(new_part)
        else:
            continue

    try:
        summary = summarize_email(html_part if html_part else email_message.get_payload(decode=True).decode(email_message.get_content_charset()))
        summary_html = f"<p style='font-size: 1.2em; font-weight: bold; font-style: italic;'>Email Summary:<br>{summary}</p>"
        forwarded_email.attach(MIMEText(summary_html, 'html'))
    except:
        pass

    if html_part:
        forwarded_email.attach(MIMEText(html_part, 'html'))
    else:
        # If HTML part not found, use plain text
        text_part = email_message.get_payload(decode=True).decode(email_message.get_content_charset())
        forwarded_email.attach(MIMEText(text_part, 'plain'))

    # # Add a custom string to the email
    # custom_string = "\n\n-- This email was forwarded using the Email Classifier Service --"
    # forwarded_email.attach(MIMEText(custom_string, 'plain'))

    html_string = f"""
    <div style="margin: 0 auto; width: 50%;">
        <a href="{REDIRECT_URL}">
            <img src="{LOGO_URL}" alt="Barclays Logo" style="display: block; margin: 0 auto;">
        </a>
    </div>
    """
    forwarded_email.attach(MIMEText(html_string, 'html'))

    # TODO: Add a section for feedback on the basis of email sent (galti se bhej diya?)

    with smtplib.SMTP(smtp_server, smtp_port) as smtp:
        smtp.starttls()
        smtp.login(smtp_email, smtp_password)
        smtp.send_message(
            forwarded_email, 
            to_addrs=[forward_to] + (cc_to or []) + (bcc_to or [])
            # forward_to
        )