#!/usr/bin/env python3

import argparse
import sys
import datetime
import secretstorage
import functools


def datetime_from_ss(ts):
    datetime.datetime.fromtimestamp(int(ts) / 10000000)


@functools.total_ordering
class StoredPassword:
    def __init__(self, item):
        self.item = item
        self.url = item.get_label()
        self.password = item.get_secret().decode()
        attributes = item.get_attributes()
        self.realm = attributes['signon_realm']
        self.username = attributes['username_value']
        self.created = datetime_from_ss(attributes['date_created'])
        self.synced = datetime_from_ss(attributes['date_synced'])

    def __id__(self):
        return id(self.item)

    def __eq__(self, other):
        return self.item == other.item

    def __hash__(self):
        return hash(self.item)

    def __lt__(self, other):
        return (self.created, self.synced) < (other.created, other.synced)

    def __repr__(self):
        date_format = '%Y-%m-%d'
        return 'StoredPassword(%s %s %s %s %s)' % (
            self.realm, self.username, self.password,
            self.created.strftime(date_format),
            self.synced.strftime(date_format))


def get_all_passwords():
    print('Loading passwords...')
    bus = secretstorage.dbus_init()
    collection = secretstorage.get_default_collection(bus)
    collection.ensure_not_locked()
    return [StoredPassword(item)
            for item in collection.get_all_items()
            if item.get_attributes()['xdg:schema'] ==
            'chrome_libsecret_password_schema']


def password_for_site_matching(pattern, all_passwords):
    matching = [item for item in all_passwords if pattern in item.realm]
    pws = set(m.password for m in matching)
    if len(pws) > 1:
        print('Found %d passwords across %d password manager entries:')
        for m in matching:
            print('  %s  %s' % (m.username, m.url))
        print('Use a more specific match.')
        sys.exit(1)
    return pws.pop()


def find_matching_passwords(password, site_pattern, all_passwords):
    reuse = [item
             for item in all_passwords
             if item.password == password and (site_pattern is None or site_pattern not in item.realm)]
    reuse.sort(key=lambda pw: pw.realm)
    if len(reuse):
        print('Found password. It is reused across %d sites:' % len(reuse))
        username_width = max(len(item.username) for item in reuse)
        for item in reuse:
            print('{:{width}} {}'.format(item.username,
                                         item.realm,
                                         width=username_width))


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Find reused passwords')
    parser.add_argument(
        '--site',
        type=str,
        help='Find sites reusing a the password from this site')
    parser.add_argument('--password',
                        type=str,
                        help='Find sites using this password')
    args = parser.parse_args()

    if not args.site and not args.password:
        parser.print_help()
        sys.exit(1)

    if args.site and args.password:
        parser.print_help()
        print()
        print('You can only pass one of --site and --password')
        sys.exit(1)

    all_passwords = get_all_passwords()
    if args.site:
        password = password_for_site_matching(args.site, all_passwords)
    else:
        password = args.password
    find_matching_passwords(password, args.site, all_passwords)