import os.path
import base64
import imaplib
import email
from email.header import decode_header
import google.auth
from google.oauth2.credentials import Credentials
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request
from bs4 import BeautifulSoup  # Import BeautifulSoup for parsing HTML
from datetime import datetime

# If modifying these SCOPES, delete the file token.json.
SCOPES = ['https://mail.google.com/']

def authenticate_gmail():
    """Shows basic usage of the Gmail API.
    Lists the user's Gmail labels.
    """
    creds = None
    # The file token.json stores the user's access and refresh tokens, and is
    # created automatically when the authorization flow completes for the first
    # time.
    
    token = r'/data/token.json'
    if os.path.isfile(token) is False:
        token = r'x:\substack\token.json'
        
    cred = r'/data/client_secret_396578640529-o4dsukvomuo43j5d4j0bogg17e3e8l7f.apps.googleusercontent.com.json'
    if os.path.isfile(cred) is False:
        cred = r'x:\substack\client_secret_396578640529-o4dsukvomuo43j5d4j0bogg17e3e8l7f.apps.googleusercontent.com.json'        
    
    if os.path.exists(token):
        creds = Credentials.from_authorized_user_file(token, SCOPES)
    # If there are no (valid) credentials available, let the user log in.
    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(cred, SCOPES)
            creds = flow.run_local_server(port=0)
        # Save the credentials for the next run
        with open(token, 'w') as token:
            token.write(creds.to_json())

    return creds

def generate_oauth2_string(username, access_token):
    return f"user={username}\1auth=Bearer {access_token}\1\1"

def decode_mime_words(s):
    return ''.join(
        word.decode(encoding or 'utf-8') if isinstance(word, bytes) else word
        for word, encoding in decode_header(s)
    )

def get_verification_link(email_user, sender_email, start_time):
    creds = authenticate_gmail()
    auth_string = generate_oauth2_string(email_user, creds.token)

    mail = imaplib.IMAP4_SSL("imap.gmail.com")
    #mail.debug = 4  # Enable IMAP debug output for more detailed logs

    try:
        mail.authenticate('XOAUTH2', lambda x: auth_string)
    except imaplib.IMAP4.error as e:
        print(f"IMAP authentication error: {e}")
        return None

    mail.select("inbox")

    result, data = mail.search(None, f'(FROM "{sender_email}" SUBJECT "Finish signing in to Substack")')
    mail_ids = data[0]
    id_list = mail_ids.split()
    
    for num in reversed(id_list):  # Check the most recent emails first
        result, data = mail.fetch(num, "(RFC822)")
        raw_email = data[0][1]
        msg = email.message_from_bytes(raw_email)
        # Decode and print the email subject
        subject = decode_mime_words(msg["Subject"])
        # Get email date
        email_date_tuple = email.utils.parsedate_tz(msg["Date"])
        email_timestamp = email.utils.mktime_tz(email_date_tuple)
        print(subject, start_time, email_timestamp)

        if abs(email_timestamp - start_time) > 12 * 3600:
            continue
        
        if msg.is_multipart():
            for part in msg.walk():
                if part.get_content_type() == "text/plain":
                    body = part.get_payload(decode=True).decode()
                    for line in body.split("\n"):
                        if "http" in line:
                            return line.strip()
        else:
            print("-----")
            body = msg.get_payload(decode=True).decode()
            soup = BeautifulSoup(body, 'html.parser')
            link = soup.find('a', href=True, text="Connectez-vous dès maintenant")
            if link:
                return link['href']
    
    return None

if __name__ == "__main__":
    email_user = "gael.honorez@gmail.com"
    sender_email = "no-reply@substack.com"
    verification_link = get_verification_link(email_user, sender_email)
    if verification_link:
        print("Verification link found:", verification_link)
    else:
        print("No verification link found.")