"""Parse gmail account for control codes."""
import email
import imaplib

from integration_scripts import logger
from integration_scripts.constants.service import CONTROL_CODE, SENDER_USERNAME


def control_from_gmail(process_name, smtp_server, email_address, password):
    """Check gail for a message witha given subject for control codes."""
    try:
        mail = imaplib.IMAP4_SSL(smtp_server)
        mail.login(email_address, password)
        mail.select('inbox')

        type, data = mail.search(None, 'ALL')
        mail_ids = data[0]

        id_list = mail_ids.split()
        # first_email_id = int(id_list[0])
        if id_list:
            latest_email_id = int(id_list[-1])
        else:
            return

        typ, data = mail.fetch(str(latest_email_id), '(RFC822)')

        for response_part in data:
            if isinstance(response_part, tuple):
                msg = email.message_from_bytes(response_part[1])
                email_subject = msg['subject']
                email_from = msg['from']
                controls = email_subject.split('::')
                if CONTROL_CODE in email_subject \
                        and SENDER_USERNAME in email_from:
                    if controls[2] == 'all' or controls[2] == process_name:
                        return_val = controls[3]
                        mail.store(str(latest_email_id), '+FLAGS', '\\Deleted')
                        return return_val

    except Exception as e:
        return 'Error checking email:\n{}'.format(str(e))

    return None


def process_control_email(name, smtp_server, email_login, email_pwd):
    """Process control emails to start or stop the system"""
    # *** DISABLED - Too risky/potentially slow
    # Turn off if email control received.
    control = control_from_gmail(name, smtp_server, email_login, email_pwd)

    if control == 'off':
        logger.info('Terminating process {} from remote email control.', name)
        raise InterruptedError('Process received interrupt signal.')
    elif control:
        logger.info('Non-terminal remote email control message '
                    'received. \n{}', control)