#  _    __________________ 
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# | | / // // / __ / // /  
# | |/ // // /_/ // // /___
# |___/___/\____/___/_____/   
# © Uthmn 2025 under MIT license

import smtplib
from email.mime.text import MIMEText

from imaplib import IMAP4_SSL
from email import message_from_bytes

from dotenv import load_dotenv
from os import getenv
from os.path import dirname, join, exists
import time

# Exit if .env does not exist
if not exists(join(dirname(__file__), "../.env")):
    print("Please create a .env file in the root directory.")
    exit(1)

# Load environment variables from .env file
dotenv_path = join(dirname(__file__), "../.env")
load_dotenv(dotenv_path)

# SMTP server settings
SMTP_SERVER = getenv("SMTP_SERVER")
SMTP_PORT = getenv("SMTP_PORT")
SMTP_USERNAME = getenv("SMTP_USERNAME")
SMTP_PASSWORD = getenv("SMTP_PASSWORD")

# IMAP server settings
IMAP_SERVER = getenv("IMAP_SERVER")
IMAP_PORT = getenv("IMAP_PORT")
IMAP_USERNAME = getenv("IMAP_USERNAME")
IMAP_PASSWORD = getenv("IMAP_PASSWORD")

# Retry settings
MAX_RETRIES = 3
RETRY_DELAY = 2 # in seconds

# Check if all environment variables are set
if not SMTP_SERVER or not SMTP_PORT or not SMTP_USERNAME or not SMTP_PASSWORD or not IMAP_SERVER or not IMAP_PORT or not IMAP_USERNAME or not IMAP_PASSWORD:
    print("Please set all environment variables in .env file.")
    exit(1)

# Make sure SMTP and IMAP ports are integers
SMTP_PORT = int(SMTP_PORT)
IMAP_PORT = int(IMAP_PORT)

def connect_smtp_with_retry():
    """Connect to SMTP server with retry"""
    for attempt in range(MAX_RETRIES):
        try:
            server = smtplib.SMTP_SSL(SMTP_SERVER, SMTP_PORT)
            server.login(SMTP_USERNAME, SMTP_PASSWORD)
            return server
        except Exception as e:
            if attempt < MAX_RETRIES - 1:
                wait_time = RETRY_DELAY * (2 ** attempt)  # Exponential backoff
                print(f"SMTP connection attempt {attempt + 1} failed: {e}")
                print(f"Retrying in {wait_time} seconds...")
                time.sleep(wait_time)
            else:
                print(f"Failed to connect to SMTP after {MAX_RETRIES} attempts: {e}")
                raise

def connect_imap_with_retry():
    """Connect to IMAP server with retry"""
    for attempt in range(MAX_RETRIES):
        try:
            M = IMAP4_SSL(host=IMAP_SERVER, port=IMAP_PORT)
            M.login(IMAP_USERNAME, IMAP_PASSWORD)
            return M
        except Exception as e:
            if attempt < MAX_RETRIES - 1:
                wait_time = RETRY_DELAY * (2 ** attempt)  # Exponential backoff
                print(f"IMAP connection attempt {attempt + 1} failed: {e}")
                print(f"Retrying in {wait_time} seconds...")
                time.sleep(wait_time)
            else:
                print(f"Failed to connect to IMAP after {MAX_RETRIES} attempts: {e}")
                raise

# Test all connections
try:
    server = connect_smtp_with_retry()
    server.quit()
except Exception as e:
    print(f"Initial SMTP connection test failed: {e}")
    exit(1)
    
try:
    M = connect_imap_with_retry()
    M.logout()
except Exception as e:
    print(f"Initial IMAP connection test failed: {e}")
    exit(1)

def send_email(receiver_emails, subject, body):
    sender_email = SMTP_USERNAME

    # Create the email
    message = MIMEText(body, "html")
    message["Subject"] = subject
    message["From"] = sender_email
    message["To"] = ", ".join(receiver_emails)

    # Connect using SSL with retry
    try:
        server = connect_smtp_with_retry()
        try:
            server.sendmail(sender_email, receiver_emails, message.as_string())
            print("HTML email sent successfully!")
        finally:
            server.quit()
    except Exception as e:
        print(f"Failed to send email: {e}")

def receive_emails(folder="INBOX", limit=50):
    emails = {}

    try:
        M = connect_imap_with_retry()

        try:
            M.select(folder)

            # Get all message IDs
            typ, data = M.search(None, 'ALL')
            if typ != 'OK' or not data[0]:
                print("No messages found.")
                return emails

            all_ids = data[0].split()
            last_ids = all_ids[-limit:]  # Take only the last 'limit' messages

            for num in last_ids:
                typ, msg_data = M.fetch(num, '(RFC822)')
                if typ != 'OK':
                    print(f"Failed to fetch message {num}")
                    continue

                # Parse the email
                msg = message_from_bytes(msg_data[0][1])
                msg_id = msg.get('Message-ID') or num.decode()

                # Extract headers
                subject = msg.get('Subject', '')
                sender = msg.get('From', '')
                date = msg.get('Date', '')

                # Extract plain text and HTML
                body_text = ""
                body_html = ""
                if msg.is_multipart():
                    for part in msg.walk():
                        content_type = part.get_content_type()
                        content_disposition = str(part.get("Content-Disposition"))
                        if "attachment" in content_disposition:
                            continue
                        payload = part.get_payload(decode=True)
                        if payload:
                            payload = payload.decode(errors="ignore")
                            if content_type == "text/plain":
                                body_text = payload
                            elif content_type == "text/html":
                                body_html = payload
                else:
                    payload = msg.get_payload(decode=True)
                    if payload:
                        body_text = payload.decode(errors="ignore")

                emails[msg_id] = {
                    "subject": subject,
                    "from": sender,
                    "date": date,
                    "body_text": body_text,
                    "body_html": body_html
                }
        finally:
            M.close()
            M.logout()

    except Exception as e:
        print(f"Error receiving emails: {e}")

    return emails