path: root/serve.py

#!/usr/bin/env python3
"""
Copyright (c) 2023-present Arjun Satarkar <me@arjunsatarkar.net>.
Licensed under the GNU Affero General Public License v3.0. See LICENSE.txt in
the root of this repository for the text of the license.
"""
import bottle
import schedule

import argparse
import logging
import math
import pathlib
import threading
import time
import typing

import tagrss

MAX_PER_PAGE_ENTRIES = 1000
DEFAULT_PER_PAGE_ENTRIES = 50
MAX_TAGS = 100

logging.basicConfig(
    format='%(levelname)s:%(name)s:"%(asctime)s":%(message)s',
    datefmt="%Y-%m-%d %H:%M:%S %z",
    level=logging.INFO,
)

parser = argparse.ArgumentParser()
parser.add_argument("--host", default="localhost")
parser.add_argument("--port", default=8000, type=int)
parser.add_argument("--storage-path", required=True)
parser.add_argument("--update-seconds", default=3600, type=int)
args = parser.parse_args()

storage_path: pathlib.Path = pathlib.Path(args.storage_path)

core_lock = threading.RLock()
core = tagrss.TagRss(storage_path=storage_path)


def parse_space_separated_tags(inp: str) -> list[str]:
    tags: set[str] = set()
    tag = ""
    escaped = False
    for c in inp:
        match c:
            case "\\":
                if not escaped:
                    escaped = True
                    continue
            case " ":
                if not escaped:
                    tags.add(tag)
                    tag = ""
                    continue
        escaped = False
        tag += c
    if tag:
        tags.add(tag)
    return list(sorted(tags))


def serialise_tags(tags: list[str]) -> str:
    result = ""
    for i, tag in enumerate(tags):
        if i > 0:
            result += " "
        result += (tag.replace("\\", "\\\\")).replace(" ", "\\ ")
    return result


@bottle.get("/")
def index():
    per_page: int = min(MAX_PER_PAGE_ENTRIES, int(bottle.request.query.get("per_page", DEFAULT_PER_PAGE_ENTRIES)))  # type: ignore
    page_num = int(bottle.request.query.get("page_num", 1))  # type: ignore
    offset = (page_num - 1) * per_page
    included_feeds_str: typing.Optional[str] = bottle.request.query.get("included_feeds", None)  # type: ignore
    included_feeds: typing.Optional[list[int]] = None
    if included_feeds_str:
        try:
            included_feeds = [int(feed_id) for feed_id in included_feeds_str.split(" ")]
        except ValueError:
            pass
    included_tags_str: typing.Optional[str] = bottle.request.query.get("included_tags", None)  # type: ignore
    included_tags: typing.Optional[list[str]] = None
    if included_tags_str:
        included_tags = parse_space_separated_tags(included_tags_str)
    with core_lock:
        total_pages: int = max(
            1,
            math.ceil(
                core.get_entry_count(
                    included_feeds=included_feeds, included_tags=included_tags
                )
                / per_page
            ),
        )
        entries = core.get_entries(
            limit=per_page,
            offset=offset,
            included_feeds=included_feeds,
            included_tags=included_tags,
        )
    referenced_feed_ids = list({entry["feed_id"] for entry in entries})
    with core_lock:
        referenced_feeds_list = core.get_feeds(
            limit=len(referenced_feed_ids),
            included_feeds=referenced_feed_ids,
            get_tags=True,
        )
    referenced_feeds = {}
    for feed in referenced_feeds_list:
        referenced_feeds[feed["id"]] = {k: feed[k] for k in feed if k != "id"}
    return bottle.template(
        "index",
        entries=entries,
        offset=offset,
        page_num=page_num,
        total_pages=total_pages,
        per_page=per_page,
        max_per_page=MAX_PER_PAGE_ENTRIES,
        included_feeds=included_feeds,
        included_tags=included_tags,
        included_feeds_str=included_feeds_str,
        included_tags_str=included_tags_str,
        referenced_feeds=referenced_feeds
    )


@bottle.get("/list_feeds")
def list_feeds():
    per_page: int = min(MAX_PER_PAGE_ENTRIES, int(bottle.request.query.get("per_page", DEFAULT_PER_PAGE_ENTRIES)))  # type: ignore
    page_num = int(bottle.request.query.get("page_num", 1))  # type: ignore
    offset = (page_num - 1) * per_page
    with core_lock:
        total_pages: int = max(1, math.ceil(core.get_feed_count() / per_page))
        feeds = core.get_feeds(limit=per_page, offset=offset, get_tags=True)
        return bottle.template(
            "list_feeds",
            feeds=feeds,
            offset=offset,
            page_num=page_num,
            total_pages=total_pages,
            per_page=per_page,
            max_per_page=MAX_PER_PAGE_ENTRIES,
        )


@bottle.get("/add_feed")
def add_feed_view():
    return bottle.template("add_feed")


@bottle.post("/add_feed")
def add_feed_effect():
    feed_source: str = bottle.request.forms.get("feed_source")  # type: ignore
    tags = parse_space_separated_tags(bottle.request.forms.get("tags"))  # type: ignore

    if len(tags) > MAX_TAGS:
        raise bottle.HTTPError(400, f"A feed cannot have more than {MAX_TAGS} tags.")

    already_present: bool = False

    parsed, epoch_downloaded = tagrss.fetch_parsed_feed(feed_source)
    with core_lock:
        try:
            feed_id = core.add_feed(
                feed_source=feed_source,
                parsed_feed=parsed,
                epoch_downloaded=epoch_downloaded,
                tags=tags,
            )
            logging.info(f"Added feed {feed_id} (source: {feed_source}).")
        except tagrss.FeedAlreadyAddedError:
            already_present = True
        # TODO: handle FeedFetchError too
    return bottle.template(
        "add_feed",
        after_add=True,
        feed_source=feed_source,
        already_present=already_present,
    )


@bottle.get("/manage_feed")
def manage_feed_view():
    try:
        feed_id_raw: str = bottle.request.query["feed"]  # type: ignore
        feed_id: int = int(feed_id_raw)
    except KeyError:
        raise bottle.HTTPError(400, "Feed ID not given.")
    feed: dict[str, typing.Any] = {}
    feed["id"] = feed_id
    with core_lock:
        feed["source"] = core.get_feed_source(feed_id)
        feed["title"] = core.get_feed_title(feed_id)
        feed["tags"] = core.get_feed_tags(feed_id)
    feed["serialised_tags"] = serialise_tags(feed["tags"])
    return bottle.template("manage_feed", feed=feed)


@bottle.post("/manage_feed")
def manage_feed_effect():
    feed: dict[str, typing.Any] = {}
    feed["id"] = int(bottle.request.forms["id"])  # type: ignore
    feed["source"] = bottle.request.forms["source"]  # type: ignore
    feed["title"] = bottle.request.forms["title"]  # type: ignore
    feed["tags"] = parse_space_separated_tags(bottle.request.forms["tags"])  # type: ignore
    feed["serialised_tags"] = bottle.request.forms["tags"]  # type: ignore
    if len(feed["tags"]) > MAX_TAGS:
        raise bottle.HTTPError(400, f"A feed cannot have more than {MAX_TAGS} tags.")
    with core_lock:
        core.set_feed_source(feed["id"], feed["source"])
        core.set_feed_title(feed["id"], feed["title"])
        core.set_feed_tags(feed["id"], feed["tags"])
    logging.info(f"Edited details of feed {feed['id']}.")
    return bottle.template("manage_feed", feed=feed, after_update=True)


@bottle.post("/delete_feed")
def delete_feed():
    feed_id: int = int(bottle.request.forms["id"])  # type: ignore
    with core_lock:
        core.delete_feed(feed_id)
    logging.info(f"Deleted feed {feed_id}.")
    return bottle.template("delete_feed")


@bottle.get("/static/<path:path>")
def serve_static(path):
    return bottle.static_file(path, "static")


def update_feeds(run_event: threading.Event):
    def inner_update():
        logging.info("Updating all feeds...")
        limit = 100
        with core_lock:
            feed_count = core.get_feed_count()
        for i in range(math.ceil(feed_count / limit)):
            with core_lock:
                feeds = core.get_feeds(limit=limit, offset=limit * i)
            for feed in feeds:
                parsed_feed, epoch_downloaded = tagrss.fetch_parsed_feed(feed["source"])
                logging.debug(f"Fetched feed {feed['id']} (source {feed['source']}).")
                with core_lock:
                    try:
                        core.store_feed_entries(
                            feed["id"], parsed_feed, epoch_downloaded
                        )
                    except tagrss.StorageConstraintViolationError:
                        logging.warning(
                            f"Failed to update feed {feed['id']} with source {feed['source']} "
                            "due to constraint violation (feed already deleted?)."
                        )
        logging.info("Finished updating all feeds.")

    inner_update()
    schedule.every(args.update_seconds).seconds.do(inner_update)
    while run_event.is_set():
        schedule.run_pending()
        time.sleep(1)


feed_update_run_event = threading.Event()
feed_update_run_event.set()
threading.Thread(target=update_feeds, args=(feed_update_run_event,)).start()

bottle.run(host=args.host, port=args.port, server="cheroot")
logging.info("Exiting...")
feed_update_run_event.clear()
with core_lock:
    core.close()