#!/usr/bin/env python3

from datetime import datetime, timedelta
from dateutil import parser
import itertools
import json
import os
import re
import sys
import requests
import time
import argparse
import uuid

argparser=argparse.ArgumentParser()

argparser.add_argument('--server', required=True, help="Required: The name of your server (e.g. `mstdn.thms.uk`)")
argparser.add_argument('--access-token', action="append", required=True, help="Required: The access token can be generated at https://<server>/settings/applications, and must have read:search, read:statuses and admin:read:accounts scopes. You can supply this multiple times, if you want tun run it for multiple users.")
argparser.add_argument('--reply-interval-in-hours', required = False, type=int, default=0, help="Fetch remote replies to posts that have received replies from users on your own instance in this period")
argparser.add_argument('--home-timeline-length', required = False, type=int, default=0, help="Look for replies to posts in the API-Key owner's home timeline, up to this many posts")
argparser.add_argument('--user', required = False, default='', help="Use together with --max-followings or --max-followers to tell us which user's followings/followers we should backfill")
argparser.add_argument('--max-followings', required = False, type=int, default=0, help="Backfill posts for new accounts followed by --user. We'll backfill at most this many followings' posts")
argparser.add_argument('--max-followers', required = False, type=int, default=0, help="Backfill posts for new accounts following --user. We'll backfill at most this many followers' posts")
argparser.add_argument('--max-follow-requests', required = False, type=int, default=0, help="Backfill posts of the API key owners pending follow requests. We'll backfill at most this many requester's posts")
argparser.add_argument('--max-bookmarks', required = False, type=int, default=0, help="Fetch remote replies to the API key owners Bookmarks. We'll fetch replies to at most this many bookmarks")
argparser.add_argument('--from-notifications', required = False, type=int, default=0, help="Backfill accounts of anyone appearing in your notifications, during the last hours")
argparser.add_argument('--remember-users-for-hours', required=False, type=int, default=24*7, help="How long to remember users that you aren't following for, before trying to backfill them again.")
argparser.add_argument('--http-timeout', required = False, type=int, default=5, help="The timeout for any HTTP requests to your own, or other instances.")
argparser.add_argument('--backfill-with-context', required = False, type=int, default=1, help="If enabled, we'll fetch remote replies when backfilling profiles. Set to `0` to disable.")
argparser.add_argument('--backfill-mentioned-users', required = False, type=int, default=1, help="If enabled, we'll backfill any mentioned users when fetching remote replies to timeline posts. Set to `0` to disable.")
argparser.add_argument('--lock-hours', required = False, type=int, default=24, help="The lock timeout in hours.")
argparser.add_argument('--lock-file', required = False, default=None, help="Location of the lock file")
argparser.add_argument('--state-dir', required = False, default="artifacts", help="Directory to store persistent files and possibly lock file")
argparser.add_argument('--on-done', required = False, default=None, help="Provide a url that will be pinged when processing has completed. You can use this for 'dead man switch' monitoring of your task")
argparser.add_argument('--on-start', required = False, default=None, help="Provide a url that will be pinged when processing is starting. You can use this for 'dead man switch' monitoring of your task")
argparser.add_argument('--on-fail', required = False, default=None, help="Provide a url that will be pinged when processing has failed. You can use this for 'dead man switch' monitoring of your task")

def get_notification_users(server, access_token, known_users, max_age):
    since = datetime.now(datetime.now().astimezone().tzinfo) - timedelta(hours=max_age)
    notifications = get_paginated_mastodon(f"https://{server}/api/v1/notifications", since, headers={
        "Authorization": f"Bearer {access_token}",
    })
    notification_users = []
    for notification in notifications:
        notificationDate = parser.parse(notification['created_at'])
        if(notificationDate >= since and notification['account'] not in notification_users):
            notification_users.append(notification['account'])

    new_notification_users = filter_known_users(notification_users, known_users)

    log(f"Found {len(notification_users)} users in notifications, {len(new_notification_users)} of which are new")

    return new_notification_users

def get_bookmarks(server, access_token, max):
    return get_paginated_mastodon(f"https://{server}/api/v1/bookmarks", max, {
        "Authorization": f"Bearer {access_token}",
    })

def add_user_posts(server, access_token, followings, know_followings, all_known_users, seen_urls):
    for user in followings:
        if user['acct'] not in all_known_users and not user['url'].startswith(f"https://{server}/"):
            posts = get_user_posts(user, know_followings, server)

            if(posts != None):
                count = 0
                failed = 0
                for post in posts:
                    if post['reblog'] == None and post['url'] != None and post['url'] not in seen_urls:
                        added = add_post_with_context(post, server, access_token, seen_urls)
                        if added is True:
                            seen_urls.add(post['url'])
                            count += 1
                        else:
                            failed += 1
                log(f"Added {count} posts for user {user['acct']} with {failed} errors")
                if failed == 0:
                    know_followings.add(user['acct'])
                    all_known_users.add(user['acct'])

def add_post_with_context(post, server, access_token, seen_urls):
    added = add_context_url(post['url'], server, access_token)
    if added is True:
        seen_urls.add(post['url'])
        if (post['replies_count'] or post['in_reply_to_id']) and arguments.backfill_with_context > 0:
            parsed_urls = {}
            parsed = parse_url(post['url'], parsed_urls)
            if parsed == None:
                return True
            known_context_urls = get_all_known_context_urls(server, [post],parsed_urls)
            add_context_urls(server, access_token, known_context_urls, seen_urls)
        return True
    
    return False

def get_user_posts(user, know_followings, server):
    parsed_url = parse_user_url(user['url'])

    if parsed_url == None:
        # We are adding it as 'known' anyway, because we won't be able to fix this.
        know_followings.add(user['acct'])
        return None
    
    if(parsed_url[0] == server):
        log(f"{user['acct']} is a local user. Skip")
        know_followings.add(user['acct'])
        return None
    
    try:
        user_id = get_user_id(parsed_url[0], parsed_url[1])
    except Exception as ex:
        log(f"Error getting user ID for user {user['acct']}: {ex}")
        return None
    
    try:
        url = f"https://{parsed_url[0]}/api/v1/accounts/{user_id}/statuses?limit=40"
        response = get(url)

        if(response.status_code == 200):
            return response.json()
        elif response.status_code == 404:
            raise Exception(
                f"User {user['acct']} was not found on server {parsed_url[0]}"
            )
        else:
            raise Exception(
                f"Error getting URL {url}. Status code: {response.status_code}"
            )
    except Exception as ex:
        log(f"Error getting posts for user {user['acct']}: {ex}")
        return None
    
def get_new_follow_requests(server, access_token, max, known_followings):
    """Get any new follow requests for the specified user, up to the max number provided"""

    follow_requests = get_paginated_mastodon(f"https://{server}/api/v1/follow_requests", max, {
        "Authorization": f"Bearer {access_token}",
    })

    # Remove any we already know about    
    new_follow_requests = filter_known_users(follow_requests, known_followings)
    
    log(f"Got {len(follow_requests)} follow_requests, {len(new_follow_requests)} of which are new")
        
    return new_follow_requests

def filter_known_users(users, known_users):
    return list(filter(
        lambda user: user['acct'] not in known_users,
        users
    ))

def get_new_followers(server, user_id, max, known_followers):
    """Get any new followings for the specified user, up to the max number provided"""
    followers = get_paginated_mastodon(f"https://{server}/api/v1/accounts/{user_id}/followers", max)

    # Remove any we already know about    
    new_followers = filter_known_users(followers, known_followers)
    
    log(f"Got {len(followers)} followers, {len(new_followers)} of which are new")
        
    return new_followers

def get_new_followings(server, user_id, max, known_followings):
    """Get any new followings for the specified user, up to the max number provided"""
    following = get_paginated_mastodon(f"https://{server}/api/v1/accounts/{user_id}/following", max)

    # Remove any we already know about    
    new_followings = filter_known_users(following, known_followings)
    
    log(f"Got {len(following)} followings, {len(new_followings)} of which are new")
        
    return new_followings
    

def get_user_id(server, user = None, access_token = None):
    """Get the user id from the server, using a username"""

    headers = {}

    if user != None and user != '':
        url = f"https://{server}/api/v1/accounts/lookup?acct={user}"
    elif access_token != None:
        url = f"https://{server}/api/v1/accounts/verify_credentials"
        headers = {
            "Authorization": f"Bearer {access_token}",
        }
    else:
        raise Exception('You must supply either a user name or an access token, to get an user ID')
    
    response = get(url, headers=headers)

    if response.status_code == 200:
        return response.json()['id'] 
    elif response.status_code == 404:
        raise Exception(
            f"User {user} was not found on server {server}."
        )
    else:
        raise Exception(
            f"Error getting URL {url}. Status code: {response.status_code}"
        )


def get_timeline(server, access_token, max):
    """Get all post in the user's home timeline"""

    url = f"https://{server}/api/v1/timelines/home"

    try:
    
        response = get_toots(url, access_token)

        if response.status_code == 200:
            toots = response.json()
        elif response.status_code == 401:
            raise Exception(
                f"Error getting URL {url}. Status code: {response.status_code}. "
                "Ensure your access token is correct"
            )
        elif response.status_code == 403:
            raise Exception(
                f"Error getting URL {url}. Status code: {response.status_code}. "
                "Make sure you have the read:statuses scope enabled for your access token."
            )
        else:
            raise Exception(
                f"Error getting URL {url}. Status code: {response.status_code}"
            )

        # Paginate as needed
        while len(toots) < max and 'next' in response.links:
            response = get_toots(response.links['next']['url'], access_token)
            toots = toots + response.json()
    except Exception as ex:
        log(f"Error getting timeline toots: {ex}")
        raise

    log(f"Found {len(toots)} toots in timeline")

    return toots
    
def get_toots(url, access_token):
    response = get( url, headers={
        "Authorization": f"Bearer {access_token}",
    })

    if response.status_code == 200:
        return response
    elif response.status_code == 401:
        raise Exception(
            f"Error getting URL {url}. Status code: {response.status_code}. "
            "It looks like your access token is incorrect."
        )
    elif response.status_code == 403:
        raise Exception(
            f"Error getting URL {url}. Status code: {response.status_code}. "
            "Make sure you have the read:statuses scope enabled for your access token."
        )
    else:
        raise Exception(
            f"Error getting URL {url}. Status code: {response.status_code}"
        )
    
def get_active_user_ids(server, access_token, reply_interval_hours):
    """get all user IDs on the server that have posted a toot in the given
       time interval"""
    since = datetime.now() - timedelta(days=reply_interval_hours / 24 + 1)
    url = f"https://{server}/api/v1/admin/accounts"
    resp = get(url, headers={
        "Authorization": f"Bearer {access_token}",
    })
    if resp.status_code == 200:
        for user in resp.json():
            last_status_at = user["account"]["last_status_at"]
            if last_status_at is not None:
                last_active = datetime.strptime(last_status_at, "%Y-%m-%d")
                if last_active > since:
                    log(f"Found active user: {user['username']}")
                    yield user["id"]
    elif resp.status_code == 401:
        raise Exception(
            f"Error getting user IDs on server {server}. Status code: {resp.status_code}. "
            "Ensure your access token is correct"
        )
    elif resp.status_code == 403:
        raise Exception(
            f"Error getting user IDs on server {server}. Status code: {resp.status_code}. "
            "Make sure you have the admin:read:accounts scope enabled for your access token."
        )
    else:
        raise Exception(
            f"Error getting user IDs on server {server}. Status code: {resp.status_code}"
        )


def get_all_reply_toots(
    server, user_ids, access_token, seen_urls, reply_interval_hours
):
    """get all replies to other users by the given users in the last day"""
    replies_since = datetime.now() - timedelta(hours=reply_interval_hours)
    reply_toots = list(
        itertools.chain.from_iterable(
            get_reply_toots(
                user_id, server, access_token, seen_urls, replies_since
            )
            for user_id in user_ids
        )
    )
    log(f"Found {len(reply_toots)} reply toots")
    return reply_toots


def get_reply_toots(user_id, server, access_token, seen_urls, reply_since):
    """get replies by the user to other users since the given date"""
    url = f"https://{server}/api/v1/accounts/{user_id}/statuses?exclude_replies=false&limit=40"

    try:
        resp = get(url, headers={
            "Authorization": f"Bearer {access_token}",
        })
    except Exception as ex:
        log(
            f"Error getting replies for user {user_id} on server {server}: {ex}"
        )
        return []

    if resp.status_code == 200:
        toots = [
            toot
            for toot in resp.json()
            if toot["in_reply_to_id"] is not None
            and toot["url"] not in seen_urls
            and datetime.strptime(toot["created_at"], "%Y-%m-%dT%H:%M:%S.%fZ")
            > reply_since
        ]
        for toot in toots:
            log(f"Found reply toot: {toot['url']}")
        return toots
    elif resp.status_code == 403:
        raise Exception(
            f"Error getting replies for user {user_id} on server {server}. Status code: {resp.status_code}. "
            "Make sure you have the read:statuses scope enabled for your access token."
        )

    raise Exception(
        f"Error getting replies for user {user_id} on server {server}. Status code: {resp.status_code}"
    )


def get_all_known_context_urls(server, reply_toots,parsed_urls):
    """get the context toots of the given toots from their original server"""
    known_context_urls = set(
        filter(
            lambda url: not url.startswith(f"https://{server}/"),
            itertools.chain.from_iterable(
                get_toot_context(*parse_url(toot["url"] if toot["reblog"] is None else toot["reblog"]["url"],parsed_urls), toot["url"])
                for toot in filter(
                    lambda toot: toot_has_parseable_url(toot,parsed_urls),
                    reply_toots
                )            
            ),
        )
    )
    log(f"Found {len(known_context_urls)} known context toots")
    return known_context_urls


def toot_has_parseable_url(toot,parsed_urls):
    parsed = parse_url(toot["url"] if toot["reblog"] is None else toot["reblog"]["url"],parsed_urls)
    if(parsed is None) :
        return False
    return True
                

def get_all_replied_toot_server_ids(
    server, reply_toots, replied_toot_server_ids, parsed_urls
):
    """get the server and ID of the toots the given toots replied to"""
    return filter(
        lambda x: x is not None,
        (
            get_replied_toot_server_id(server, toot, replied_toot_server_ids, parsed_urls)
            for toot in reply_toots
        ),
    )


def get_replied_toot_server_id(server, toot, replied_toot_server_ids,parsed_urls):
    """get the server and ID of the toot the given toot replied to"""
    in_reply_to_id = toot["in_reply_to_id"]
    in_reply_to_account_id = toot["in_reply_to_account_id"]
    mentions = [
        mention
        for mention in toot["mentions"]
        if mention["id"] == in_reply_to_account_id
    ]
    if len(mentions) == 0:
        return None

    mention = mentions[0]

    o_url = f"https://{server}/@{mention['acct']}/{in_reply_to_id}"
    if o_url in replied_toot_server_ids:
        return replied_toot_server_ids[o_url]

    url = get_redirect_url(o_url)

    if url is None:
        return None

    match = parse_url(url,parsed_urls)
    if match is not None:
        replied_toot_server_ids[o_url] = (url, match)
        return (url, match)

    log(f"Error parsing toot URL {url}")
    replied_toot_server_ids[o_url] = None
    return None

def parse_user_url(url):
    match = parse_mastodon_profile_url(url)
    if match is not None:
        return match
    
    match = parse_pleroma_profile_url(url)
    if match is not None:
        return match

    match = parse_pixelfed_profile_url(url)
    if match is not None:
        return match

    log(f"Error parsing Profile URL {url}")
    
    return None

def parse_url(url, parsed_urls):
    if url not in parsed_urls:
        match = parse_mastodon_url(url)
        if match is not None:
            parsed_urls[url] = match
    
    if url not in parsed_urls:
        match = parse_pleroma_url(url)
        if match is not None:
            parsed_urls[url] = match

    if url not in parsed_urls:
        match = parse_pixelfed_url(url)
        if match is not None:
            parsed_urls[url] = match

    if url not in parsed_urls:
        log(f"Error parsing toot URL {url}")
        parsed_urls[url] = None
    
    return parsed_urls[url]

def parse_mastodon_profile_url(url):
    """parse a Mastodon Profile URL and return the server and username"""
    match = re.match(
        r"https://(?P<server>.*)/@(?P<username>.*)", url
    )
    if match is not None:
        return (match.group("server"), match.group("username"))
    return None

def parse_mastodon_url(url):
    """parse a Mastodon URL and return the server and ID"""
    match = re.match(
        r"https://(?P<server>.*)/@(?P<username>.*)/(?P<toot_id>.*)", url
    )
    if match is not None:
        return (match.group("server"), match.group("toot_id"))
    return None


def parse_pleroma_url(url):
    """parse a Pleroma URL and return the server and ID"""
    match = re.match(r"https://(?P<server>.*)/objects/(?P<toot_id>.*)", url)
    if match is not None:
        server = match.group("server")
        url = get_redirect_url(url)
        if url is None:
            return None
        
        match = re.match(r"/notice/(?P<toot_id>.*)", url)
        if match is not None:
            return (server, match.group("toot_id"))
        return None
    return None

def parse_pleroma_profile_url(url):
    """parse a Pleroma Profile URL and return the server and username"""
    match = re.match(r"https://(?P<server>.*)/users/(?P<username>.*)", url)
    if match is not None:
        return (match.group("server"), match.group("username"))
    return None

def parse_pixelfed_url(url):
    """parse a Pixelfed URL and return the server and ID"""
    match = re.match(
        r"https://(?P<server>.*)/p/(?P<username>.*)/(?P<toot_id>.*)", url
    )
    if match is not None:
        return (match.group("server"), match.group("toot_id"))
    return None

def parse_pixelfed_profile_url(url):
    """parse a Pixelfed Profile URL and return the server and username"""
    match = re.match(r"https://(?P<server>.*)/(?P<username>.*)", url)
    if match is not None:
        return (match.group("server"), match.group("username"))
    return None


def get_redirect_url(url):
    """get the URL given URL redirects to"""
    try:
        resp = requests.head(url, allow_redirects=False, timeout=5,headers={
            'User-Agent': 'FediFetcher (https://go.thms.uk/mgr)'
        })
    except Exception as ex:
        log(f"Error getting redirect URL for URL {url}. Exception: {ex}")
        return None

    if resp.status_code == 200:
        return url
    elif resp.status_code == 302:
        redirect_url = resp.headers["Location"]
        log(f"Discovered redirect for URL {url}")
        return redirect_url
    else:
        log(
            f"Error getting redirect URL for URL {url}. Status code: {resp.status_code}"
        )
        return None


def get_all_context_urls(server, replied_toot_ids):
    """get the URLs of the context toots of the given toots"""
    return filter(
        lambda url: not url.startswith(f"https://{server}/"),
        itertools.chain.from_iterable(
            get_toot_context(server, toot_id, url)
            for (url, (server, toot_id)) in replied_toot_ids
        ),
    )


def get_toot_context(server, toot_id, toot_url):
    """get the URLs of the context toots of the given toot"""
    url = f"https://{server}/api/v1/statuses/{toot_id}/context"
    try:
        resp = get(url)
    except Exception as ex:
        log(f"Error getting context for toot {toot_url}. Exception: {ex}")
        return []

    if resp.status_code == 200:
        try:
            res = resp.json()
            log(f"Got context for toot {toot_url}")
            return (toot["url"] for toot in (res["ancestors"] + res["descendants"]))
        except Exception as ex:
            log(f"Error parsing context for toot {toot_url}. Exception: {ex}")
        return []
    elif resp.status_code == 429:
        reset = datetime.strptime(resp.headers['x-ratelimit-reset'], '%Y-%m-%dT%H:%M:%S.%fZ')
        log(f"Rate Limit hit when getting context for {toot_url}. Waiting to retry at {resp.headers['x-ratelimit-reset']}")
        time.sleep((reset - datetime.now()).total_seconds() + 1)
        return get_toot_context(server, toot_id, toot_url)

    log(
        f"Error getting context for toot {toot_url}. Status code: {resp.status_code}"
    )
    return []


def add_context_urls(server, access_token, context_urls, seen_urls):
    """add the given toot URLs to the server"""
    count = 0
    failed = 0
    for url in context_urls:
        if url not in seen_urls:
            added = add_context_url(url, server, access_token)
            if added is True:
                seen_urls.add(url)
                count += 1
            else:
                failed += 1

    log(f"Added {count} new context toots (with {failed} failures)")


def add_context_url(url, server, access_token):
    """add the given toot URL to the server"""
    search_url = f"https://{server}/api/v2/search?q={url}&resolve=true&limit=1"

    try:
        resp = get(search_url, headers={
            "Authorization": f"Bearer {access_token}",
        })
    except Exception as ex:
        log(
            f"Error adding url {search_url} to server {server}. Exception: {ex}"
        )
        return False

    if resp.status_code == 200:
        log(f"Added context url {url}")
        return True
    elif resp.status_code == 403:
        log(
            f"Error adding url {search_url} to server {server}. Status code: {resp.status_code}. "
            "Make sure you have the read:search scope enabled for your access token."
        )
        return False
    elif resp.status_code == 429:
        reset = datetime.strptime(resp.headers['x-ratelimit-reset'], '%Y-%m-%dT%H:%M:%S.%fZ')
        log(f"Rate Limit hit when adding url {search_url}. Waiting to retry at {resp.headers['x-ratelimit-reset']}")
        time.sleep((reset - datetime.now()).total_seconds() + 1)
        return add_context_url(url, server, access_token)
    else:
        log(
            f"Error adding url {search_url} to server {server}. Status code: {resp.status_code}"
        )
        return False
    
def get_paginated_mastodon(url, max, headers = {}, timeout = 0, max_tries = 5):
    """Make a paginated request to mastodon"""
    if(isinstance(max, int)):
        furl = f"{url}?limit={max}"
    else:
        furl = url

    response = get(furl, headers, timeout, max_tries)

    if response.status_code != 200:
        if response.status_code == 401:
            raise Exception(
                f"Error getting URL {url}. Status code: {response.status_code}. "
                "Ensure your access token is correct"
            )
        elif response.status_code == 403:
            raise Exception(
                f"Error getting URL {url}. Status code: {response.status_code}. "
                "Make sure you have the correct scopes enabled for your access token."
            )
        else:
            raise Exception(
                f"Error getting URL {url}. Status code: {response.status_code}"
            )

    result = response.json()

    if(isinstance(max, int)):
        while len(result) < max and 'next' in response.links:
            response = get(response.links['next']['url'], headers, timeout, max_tries)
            result = result + response.json()
    else:
        while parser.parse(result[-1]['created_at']) >= max and 'next' in response.links:
            response = get(response.links['next']['url'], headers, timeout, max_tries)
            result = result + response.json()
    
    return result


def get(url, headers = {}, timeout = 0, max_tries = 5):
    """A simple wrapper to make a get request while providing our user agent, and respecting rate limits"""
    h = headers.copy()
    if 'User-Agent' not in h:
        h['User-Agent'] = 'FediFetcher (https://go.thms.uk/mgr)'

    if timeout == 0:
        timeout = arguments.http_timeout
        
    response = requests.get( url, headers= h, timeout=timeout)
    if response.status_code == 429:
        if max_tries > 0:
            reset = parser.parse(response.headers['x-ratelimit-reset'])
            now = datetime.now(datetime.now().astimezone().tzinfo)
            wait = (reset - now).total_seconds() + 1
            log(f"Rate Limit hit requesting {url}. Waiting {wait} sec to retry at {response.headers['x-ratelimit-reset']}")
            time.sleep(wait)
            return get(url, headers, timeout, max_tries - 1)
        
        raise Exception(f"Maximum number of retries exceeded for rate limited request {url}")
    return response

def log(text):
    print(f"{datetime.now()} {datetime.now().astimezone().tzinfo}: {text}")

class OrderedSet:
    """An ordered set implementation over a dict"""

    def __init__(self, iterable):
        self._dict = {}
        if isinstance(iterable, dict):
            for item in iterable:
                if isinstance(iterable[item], str):
                    self.add(item, parser.parse(iterable[item]))
                else:
                    self.add(item, iterable[item])
        else:
            for item in iterable:
                self.add(item)

    def add(self, item, time = None):
        if item not in self._dict:
            if(time == None):
                self._dict[item] = datetime.now(datetime.now().astimezone().tzinfo)
            else:
                self._dict[item] = time

    def pop(self, item):
        self._dict.pop(item)
    
    def get(self, item):
        return self._dict[item]

    def update(self, iterable):
        for item in iterable:
            self.add(item)

    def __contains__(self, item):
        return item in self._dict

    def __iter__(self):
        return iter(self._dict)

    def __len__(self):
        return len(self._dict)
    
    def toJSON(self):
        return json.dump(self._dict, f, default=str)


if __name__ == "__main__":
    start = datetime.now()

    log(f"Starting FediFetcher")

    arguments = argparser.parse_args()

    runId = uuid.uuid4()

    if(arguments.on_start != None and arguments.on_start != ''):
        try:
            get(f"{arguments.on_start}?rid={runId}")
        except Exception as ex:
            log(f"Error getting callback url: {ex}")

    if arguments.lock_file is None:
        arguments.lock_file = os.path.join(arguments.state_dir, 'lock.lock')
    LOCK_FILE = arguments.lock_file

    if( os.path.exists(LOCK_FILE)):
        log(f"Lock file exists at {LOCK_FILE}")

        try:
            with open(LOCK_FILE, "r", encoding="utf-8") as f:
                lock_time = parser.parse(f.read())

            if (datetime.now() - lock_time).total_seconds() >= arguments.lock_hours * 60 * 60: 
                os.remove(LOCK_FILE)
                log(f"Lock file has expired. Removed lock file.")
            else:
                log(f"Lock file age is {datetime.now() - lock_time} - below --lock-hours={arguments.lock_hours} provided.")
                if(arguments.on_fail != None and arguments.on_fail != ''):
                    try:
                        get(f"{arguments.on_fail}?rid={runId}")
                    except Exception as ex:
                        log(f"Error getting callback url: {ex}")
                sys.exit(1)

        except Exception:
            log(f"Cannot read logfile age - aborting.")
            if(arguments.on_fail != None and arguments.on_fail != ''):
                try:
                    get(f"{arguments.on_fail}?rid={runId}")
                except Exception as ex:
                    log(f"Error getting callback url: {ex}")
            sys.exit(1)

    with open(LOCK_FILE, "w", encoding="utf-8") as f:
        f.write(f"{datetime.now()}")

    try:

        SEEN_URLS_FILE = os.path.join(arguments.state_dir, "seen_urls")
        REPLIED_TOOT_SERVER_IDS_FILE = os.path.join(arguments.state_dir, "replied_toot_server_ids")
        KNOWN_FOLLOWINGS_FILE = os.path.join(arguments.state_dir, "known_followings")
        RECENTLY_CHECKED_USERS_FILE = os.path.join(arguments.state_dir, "recently_checked_users")


        seen_urls = OrderedSet([])
        if os.path.exists(SEEN_URLS_FILE):
            with open(SEEN_URLS_FILE, "r", encoding="utf-8") as f:
                seen_urls = OrderedSet(f.read().splitlines())

        replied_toot_server_ids = {}
        if os.path.exists(REPLIED_TOOT_SERVER_IDS_FILE):
            with open(REPLIED_TOOT_SERVER_IDS_FILE, "r", encoding="utf-8") as f:
                replied_toot_server_ids = json.load(f)

        known_followings = OrderedSet([])
        if os.path.exists(KNOWN_FOLLOWINGS_FILE):
            with open(KNOWN_FOLLOWINGS_FILE, "r", encoding="utf-8") as f:
                known_followings = OrderedSet(f.read().splitlines())

        recently_checked_users = OrderedSet({})
        if os.path.exists(RECENTLY_CHECKED_USERS_FILE):
            with open(RECENTLY_CHECKED_USERS_FILE, "r", encoding="utf-8") as f:
                recently_checked_users = OrderedSet(json.load(f))

        # Remove any users whose last check is too long in the past from the list
        for user in list(recently_checked_users):
            lastCheck = recently_checked_users.get(user)
            userAge = datetime.now(lastCheck.tzinfo) - lastCheck
            if(userAge.total_seconds() > arguments.remember_users_for_hours * 60 * 60):
                recently_checked_users.pop(user)    

        parsed_urls = {}

        all_known_users = OrderedSet(list(known_followings) + list(recently_checked_users))

        for token in arguments.access_token:

            if arguments.reply_interval_in_hours > 0:
                """pull the context toots of toots user replied to, from their
                original server, and add them to the local server."""
                user_ids = get_active_user_ids(arguments.server, token, arguments.reply_interval_in_hours)
                reply_toots = get_all_reply_toots(
                    arguments.server, user_ids, token, seen_urls, arguments.reply_interval_in_hours
                )
                known_context_urls = get_all_known_context_urls(arguments.server, reply_toots,parsed_urls)
                seen_urls.update(known_context_urls)
                replied_toot_ids = get_all_replied_toot_server_ids(
                    arguments.server, reply_toots, replied_toot_server_ids, parsed_urls
                )
                context_urls = get_all_context_urls(arguments.server, replied_toot_ids)
                add_context_urls(arguments.server, token, context_urls, seen_urls)


            if arguments.home_timeline_length > 0:
                """Do the same with any toots on the key owner's home timeline """
                timeline_toots = get_timeline(arguments.server, token, arguments.home_timeline_length)
                known_context_urls = get_all_known_context_urls(arguments.server, timeline_toots,parsed_urls)
                add_context_urls(arguments.server, token, known_context_urls, seen_urls)

                # Backfill any post authors, and any mentioned users
                if arguments.backfill_mentioned_users > 0:
                    mentioned_users = []
                    cut_off = datetime.now(datetime.now().astimezone().tzinfo) - timedelta(minutes=60)
                    for toot in timeline_toots:
                        these_users = []
                        toot_created_at = parser.parse(toot['created_at'])
                        if len(mentioned_users) < 10 or (toot_created_at > cut_off and len(mentioned_users) < 30):
                            these_users.append(toot['account'])
                            if(len(toot['mentions'])):
                                these_users += toot['mentions']
                            if(toot['reblog'] != None):
                                these_users.append(toot['reblog']['account'])
                                if(len(toot['reblog']['mentions'])):
                                    these_users += toot['reblog']['mentions']
                        for user in these_users:
                            if user not in mentioned_users and user['acct'] not in all_known_users:
                                mentioned_users.append(user)

                    add_user_posts(arguments.server, token, filter_known_users(mentioned_users, all_known_users), recently_checked_users, all_known_users, seen_urls)

            if arguments.max_followings > 0:
                log(f"Getting posts from last {arguments.max_followings} followings")
                user_id = get_user_id(arguments.server, arguments.user, token)
                followings = get_new_followings(arguments.server, user_id, arguments.max_followings, all_known_users)
                add_user_posts(arguments.server, token, followings, known_followings, all_known_users, seen_urls)
            
            if arguments.max_followers > 0:
                log(f"Getting posts from last {arguments.max_followers} followers")
                user_id = get_user_id(arguments.server, arguments.user, token)
                followers = get_new_followers(arguments.server, user_id, arguments.max_followers, all_known_users)
                add_user_posts(arguments.server, token, followers, recently_checked_users, all_known_users, seen_urls)

            if arguments.max_follow_requests > 0:
                log(f"Getting posts from last {arguments.max_follow_requests} follow requests")
                follow_requests = get_new_follow_requests(arguments.server, token, arguments.max_follow_requests, all_known_users)
                add_user_posts(arguments.server, token, follow_requests, recently_checked_users, all_known_users, seen_urls)

            if arguments.from_notifications > 0:
                log(f"Getting notifications for last {arguments.from_notifications} hours")
                notification_users = get_notification_users(arguments.server, token, all_known_users, arguments.from_notifications)
                add_user_posts(arguments.server, token, notification_users, recently_checked_users, all_known_users, seen_urls)

            if arguments.max_bookmarks > 0:
                log(f"Pulling replies to the last {arguments.max_bookmarks} bookmarks")
                bookmarks = get_bookmarks(arguments.server, token, arguments.max_bookmarks)
                known_context_urls = get_all_known_context_urls(arguments.server, bookmarks,parsed_urls)
                add_context_urls(arguments.server, token, known_context_urls, seen_urls)

        with open(KNOWN_FOLLOWINGS_FILE, "w", encoding="utf-8") as f:
            f.write("\n".join(list(known_followings)[-10000:]))

        with open(SEEN_URLS_FILE, "w", encoding="utf-8") as f:
            f.write("\n".join(list(seen_urls)[-10000:]))

        with open(REPLIED_TOOT_SERVER_IDS_FILE, "w", encoding="utf-8") as f:
            json.dump(dict(list(replied_toot_server_ids.items())[-10000:]), f)

        with open(RECENTLY_CHECKED_USERS_FILE, "w", encoding="utf-8") as f:
            recently_checked_users.toJSON()

        os.remove(LOCK_FILE)

        if(arguments.on_done != None and arguments.on_done != ''):
            try:
                get(f"{arguments.on_done}?rid={runId}")
            except Exception as ex:
                log(f"Error getting callback url: {ex}")

        log(f"Processing finished in {datetime.now() - start}.")

    except Exception as ex:
        os.remove(LOCK_FILE)
        log(f"Job failed after {datetime.now() - start}.")
        if(arguments.on_fail != None and arguments.on_fail != ''):
            try:
                get(f"{arguments.on_fail}?rid={runId}")
            except Exception as ex:
                log(f"Error getting callback url: {ex}")
        raise