#!/usr/bin/python3

from mastodon import Mastodon
import configparser
import xdg.BaseDirectory

def fetch_user_ids(func, idval=user_id):
    user_ids = []
    # This reads like it discards the first page of results, but fetch_remaining includes the
    # original results as well as the titular "remaining" ones.
    fetched_users = mastodon.fetch_remaining(func(idval))
    for user in fetched_users:
        user_ids.append(user['id'])
    return user_ids

config_file_path = '%s/masto-mutuals/config.txt' % xdg.BaseDirectory.xdg_config_home
config = configparser.ConfigParser()
config.read(config_file_path)
# TODO: if config file is empty, this should write defaults into the file and throw an errorS
# correctly.

if not config['ACCOUNT_DATA']['access_token']:
    print('Error: An access token is required.')
    exit()

if not config['ACCOUNT_DATA']['instance_url']:
    print('Error: An instance url is required.')
    exit()

if config['ACCOUNT_DATA']['list_name']:
    list_name = config['ACCOUNT_DATA']['list_name']
else:
    list_name = 'mutuals'

mastodon = Mastodon(
    access_token = config['ACCOUNT_DATA']['access_token'],
    api_base_url = config['ACCOUNT_DATA']['instance_url']
)

user_id = mastodon.me()['id']

print("Getting following list.")
followed_ids = fetch_user_ids(mastodon.account_following)
print('You follow %s accounts.' % str(len(followed_ids)))
print("Getting followed list.")
follower_ids = fetch_user_ids(mastodon.account_followers)
print('You are followed by %s accounts.' % str(len(follower_ids)))
mutual_ids = [i for i in followed_ids if i in followed_ids and i in follower_ids]

list_id = None
for l in mastodon.lists():
    if l['title'] == list_name:
        list_id = l['id']
    if list_id is not None:
        break
if list_id is None:
    l = mastodon.list_create(list_name)
    list_id = l['id']

list_ids = fetch_user_ids(mastodon.list_accounts, idval=list_id)
toadd_ids = [i for i in mutual_ids if i not in list_ids]
torm_ids = [i for i in list_ids if i not in mutual_ids]

list_changed = False
if len(toadd_ids) > 0:
    list_changed = True
    mastodon.list_accounts_add(list_id, toadd_ids)

if len(torm_ids) > 0:
    list_changed = True
    mastodon.list_accounts_delete(list_id, torm_ids)

if list_changed:
    print('%s list updated.' % list_name)
else:
    print('%s list unchanged.' % list_name)