import imaplib, email, os

class IMAPConnector:
    _instance = None

    def __new__(cls, *args, **kwargs):
        if not cls._instance:
            cls._instance = super().__new__(cls)
        return cls._instance

    def __init__(self):
        if not hasattr(self, 'imap_connection'):
            IMAP_SERVER = os.environ.get('DGP_EML_HOST')
            IMAP_USER   = os.environ.get('DGP_EML_USER')
            IMAP_PASS   = os.environ.get('DGP_EML_PASS')

            if not all([IMAP_SERVER, IMAP_USER, IMAP_PASS]):
                raise ValueError("Please ensure DGP_EML_HOST, DGP_EML_USER and DGP_EML_PASS are defined in the environment")

            self.imap_connection = imaplib.IMAP4_SSL(IMAP_SERVER)
            self.imap_connection.login(IMAP_USER, IMAP_PASS)
            self.imap_connection.select('INBOX')

    def fetch_filtered_emails(self, sender_email):
        filtered_emails = []
        result, data = self.imap_connection.search(None, f'(FROM "{sender_email}")')
        if result == 'OK':
            for num in data[0].split():
                result, email_data = self.imap_connection.fetch(num, '(RFC822)')
                if result == 'OK':
                    raw_email = email_data[0][1]
                    email_message = email.message_from_bytes(raw_email)
                    filtered_emails.append(email_message)
        return filtered_emails


    def delete_emails_from_sender(self, sender_email):
        result, data = self.imap_connection.search(None, f'(FROM "{sender_email}")')
        if result == 'OK':
            for num in data[0].split():
                self.imap_connection.store(num, '+FLAGS', '\\Deleted')
            self.imap_connection.expunge()
            print(f"All messages from {sender_email} deleted successfully")