#!/usr/bin/env python3
import argparse
import logging
import sys
from datetime import datetime
from pathlib import Path

import humanize
import yaml
from sdnotify import SystemdNotifier

from iarchiver.database import EmailDatabase
from iarchiver.email import unix_timestamp_since_to_imap_timestamp
from iarchiver.mail_conn import MailConnection


def main(args):
    logging.basicConfig()
    logger = logging.getLogger('iarchiver')
    logger.setLevel(logging.INFO)
    with open(args.config) as f:
        config = yaml.safe_load(f)

    exclude_folders = config.get('exclude_folders', [])

    if not config.get('server') or not config.get('username') or not config.get('password') or not config.get('database_path') or not config.get('attachments_path'):
        logger.critical('Bad config file.')
        sys.exit(1)

    save_inline_attachments = config.get('save_inline_attachments', False)
    if save_inline_attachments:
        logger.info('Saving inline attachments as well')

    attachments_dir = Path(config['attachments_path'])
    attachments_dir.mkdir(parents=True, exist_ok=True)

    notifier = SystemdNotifier()
    database = EmailDatabase(Path(config['database_path']))
    mail = MailConnection(config['server'], config['username'], config['password'], attachments_dir, save_inline_attachments=save_inline_attachments)
    mail.load_folders()

    if config['server'] == 'imap.gmail.com':
        mail.folder_structure.remove('INBOX')  # We will use "'[Gmail]/All Mail'" instead
        mail.folder_structure.remove('[Gmail]')
    num_folders_to_sync = len(mail.folder_structure)
    logger.info(f'Syncing {num_folders_to_sync} folders...')

    last_refresh_imap_date = None
    if args.full:
        last_refresh = None
        logger.info('Performing full sync...')
    else:
        last_refresh = database.have_we_done_a_full_sync_at_all()
    if last_refresh:
        last_refresh_imap_date = unix_timestamp_since_to_imap_timestamp(last_refresh)
        logger.info(f'Syncing emails received after {last_refresh_imap_date}')

    new_emails = 0
    new_attachments = 0
    did_full_sync = False
    sync_start_time = datetime.now()

    for folder_name in mail.folder_structure:
        if folder_name in exclude_folders:
            # Exclude folder
            continue
        logger.info(folder_name)
        if last_refresh:
            search_criterion = ['(SINCE "' + last_refresh_imap_date + '")']
        else:
            did_full_sync = True
            search_criterion = ['ALL']

        for email in mail.fetch_folder(folder_name, search_criterion=search_criterion):
            timestamp, to_email, from_email, subject, raw_content, attachments = email
            is_new_email = database.insert_email(folder_name, timestamp, subject, raw_content, to_email, from_email, attachments)
            if is_new_email:
                new_emails += 1
            if len(attachments):
                new_attachments += 1
            notifier.notify("WATCHDOG=1")

    elapsed = datetime.now() - sync_start_time
    database.finish_sync('refresh' if not did_full_sync else 'full', new_emails, new_attachments, int(elapsed.total_seconds()))
    logger.info(f'Finished email {"refresh" if not did_full_sync else "sync"} in {humanize.naturaldelta(elapsed)} and added {new_emails} new emails and {new_attachments} attachments.')


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Sync and archive your IMAP server.')
    parser.add_argument('--config', default='config.yml', help='Path to config file.')
    parser.add_argument('--full', action='store_true', help='Perform a full sync.')
    args = parser.parse_args()
    main(args)