discorss/discorss.py

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# SPDX-License-Identifier: MPL-2.0
# SPDX-FileCopyrightText: © 2025 A.M. Rowsell <https://frzn.dev/~amr>

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# DiscoRSS: A simple RSS feed reader for Discord. Takes RSS feeds and then sends them to
# webhooks. Intended to run using systemd timers.

import requests
import feedparser
import hashlib
from pathlib import Path
import json
import time
import os
import sys
import re

config_dir = os.environ.get("XDG_CONFIG_HOME")
home_dir = Path.home()
if config_dir is None:
    config_file_path = str(home_dir) + "/.config/discorss/discorss.conf"
    config_dir = str(home_dir) + "/.config/discorss"
else:
    config_file_path = config_dir + r"/discorss/discorss.conf"
log_dir = r"/var/log/discorss"
log_file_path = r"/app.log"
# Yes, I know you "can't parse HTML with regex", but
# just watch me.
html_filter = re.compile(r"\<\/?([A-Za-z \:\.\/\"\=])*\>")
success_codes = ["200", "201", "202", "203", "204", "205", "206"]
app_config = {}


# This function gets and formats the brief excerpt that goes in the embed
# Different feeds put summaries in different fields, so we pick the best
# one and limit it to 250 characters.
# TODO: make the character limit smarter, as to split at a natural point
def get_description(feed):
    try:
        temporary_string = str(feed.entries[0]["summary_detail"]["value"])
        temporary_string = html_filter.sub("", temporary_string)
        desc = (
            temporary_string[:250] if len(temporary_string) > 250 else temporary_string
        )
    except KeyError:
        temporary_string = str(feed.entries[0]["description"])
        temporary_string = html_filter.sub("", temporary_string)
        desc = (
            temporary_string[:250] if len(temporary_string) > 250 else temporary_string
        )
    return desc


def main():
    os.environ["TZ"] = "America/Toronto"
    time.tzset()
    # Check for log and config files/paths, create empty directories if needed
    # TODO: make this cleaner
    try:
        Path(log_file_path).mkdir(parents=True, exist_ok=True)
    except FileExistsError:
        print(
            "The logfile path {} already exists and is not a directory!".format(
                log_file_path
            )
        )
    if not Path(config_file_path).exists():
        print(
            "No config file at {}! Snarf.\n{} was created for you.".format(
                config_file_path, config_dir
            )
        )
        Path(config_dir).mkdir(parents=True, exist_ok=True)
        return
    with open(config_file_path, "r") as config_file:
        app_config = json.load(config_file)
    now = time.mktime(time.localtime())
    try:
        last_check = app_config["lastupdate"]
    except KeyError:
        last_check = now - 21600  # first run, no lastupdate, check up to 6 hours ago
    for i, hook in enumerate(app_config["feeds"]):
        # Get the feed
        print("Parsing feed {}...".format(hook["name"]))
        feed = feedparser.parse(hook["url"])
        try:
            published_time = time.mktime(feed.entries[0]["published_parsed"])
            published_time = published_time + hook["offset"]
        except KeyError:
            published_time = now - 10  # Not sure what a sensible default here is
        # Hash the title of the latest post and use that to determine if it's been posted
        new_hash = hashlib.sha3_512(
            bytes(feed.entries[0]["title"], "utf-8")
        ).hexdigest()
        try:
            if hook["lasthash"] != new_hash:
                app_config["feeds"][i]["lasthash"] = new_hash
            else:
                continue
        except KeyError:
            app_config["feeds"][i]["lasthash"] = new_hash
        # Generate the webhook
        webhook = {
            "embeds": [
                {
                    "title": str(feed.entries[0]["title"]),
                    "url": str(feed.entries[0]["link"]),
                    "color": 216128,
                    "footer": {
                        "name": "DiscoRSS",
                        # "url": "https://git.frzn.dev/amr/discorss",
                    },
                    "author": {
                        "name": str(hook["name"]),
                        "url": str(hook["siteurl"]),
                    },
                    "fields": [
                        {
                            "name": "Excerpt from post:",
                            "value": get_description(feed),
                        }
                    ],
                }
            ],
            "attachments": [],
        }
        custom_header = {
            "user-agent": "DiscoRSS (https://git.frzn.dev/amr/discorss, 0.2rc2)",
            "content-type": "application/json",
        }
        webhook_string = json.dumps(webhook)

        if published_time > last_check:
            r = requests.post(
                hook["webhook"], data=webhook_string, headers=custom_header
            )
            if r.status_code not in success_codes:
                print(
                    "Error {} while trying to post {}".format(
                        r.status_code, hook["webhook"]
                    )
                )
        app_config["lastupdate"] = now
        with open(config_file_path, "w") as config_file:
            json.dump(app_config, config_file, indent=4)

    return


if __name__ == "__main__":
    main()