Source code for intranet.apps.emerg.views

import logging
import time
from typing import Tuple

import requests
from bs4 import BeautifulSoup
from django.conf import settings
from django.core.cache import cache
from django.utils import timezone

from ...utils.html import get_domain_name, safe_fcps_emerg_html

logger = logging.getLogger(__name__)


def check_emerg():
    """Fetch from FCPS emergency announcement pages.

    URLs defined in settings.FCPS_EMERGENCY_PAGE

    Request timeout defined in settings.FCPS_EMERGENCY_TIMEOUT

    """
    fcps_page = settings.FCPS_EMERGENCY_PAGE
    announcements = []

    if settings.EMERGENCY_MESSAGE:
        return True, settings.EMERGENCY_MESSAGE
    if not fcps_page:
        return None, None

    timeout = settings.EMERGENCY_TIMEOUT

    try:
        r = requests.get(f"{fcps_page}?{int(time.time() // 60)}", timeout=timeout)
    except requests.exceptions.Timeout:
        return False, None

    res = r.text

    # Keep this list up to date with whatever wording FCPS decides to use each time...
    bad_strings = [
        "There are no emergency announcements at this time",
        "There are no emergency messages at this time",
        "There are no emeregency annoncements at this time",  # codespell: ignore
        "There are no major announcements at this time.",
        "There are no major emergency announcements at this time.",
        "There are no emergencies at this time.",
        "Site under maintenance",  # We don't want to get people's attention like this just to tell them that fcps.edu is under maintenance
        "502 Bad Gateway",
    ]

    status = True
    for b in bad_strings:
        if b in res:
            status = False
            break

    soup = BeautifulSoup(res, "xml")
    if soup.title and status:
        title = soup.title.text
        body = soup.find("content").text

        title = safe_fcps_emerg_html(title, fcps_page)
        body = safe_fcps_emerg_html(body, fcps_page)

        announcements.append({"title": f"<a target='_blank' href=\"{get_domain_name(fcps_page)}\">{title}</a>", "body": body})

    message = "".join(
        [
            f"<h3><i class='fas fa-exclamation-triangle'></i>&nbsp; {announcement['title']}</h3><hr />{announcement['body']}\n"
            for announcement in announcements
        ]
    )

    return status, message


def get_emerg_result(*, custom_logger=None):
    """Run the fetch command from FCPS."""
    if custom_logger is None:
        custom_logger = logger

    status, message = check_emerg()
    custom_logger.debug("Fetched emergency info from FCPS")
    return {"status": status, "message": message}


def get_emerg():
    """Get the cached FCPS emergency page, or check it again.

    Timeout defined in settings.CACHE_AGE["emerg"]

    """
    key = f"emerg:{timezone.localdate()}"
    cached = cache.get(key)
    if cached:
        return cached
    else:
        # We have a Celery task updating the cache periodically, so this normally won't run.
        # However, if Celery stops working, we still want it to update, so we fall back on
        # updating it here.
        result = get_emerg_result()
        cache.set(key, result, timeout=settings.CACHE_AGE["emerg"])
        return result


def update_emerg_cache(*, custom_logger=None) -> None:
    """Updates the cached contents of FCPS emergency page.

    This forces a cache update, regardless of whether or not the cache has
    expired. However, it does set the cache entry to expire in
    ``settings.CACHE_AGE["emerg"]`` seconds.

    Args:
        custom_logger: A custom ``logging.Logger`` instance to use for log
            messages relating to the cache update.

    """
    key = f"emerg:{timezone.localdate()}"
    result = get_emerg_result(custom_logger=custom_logger)
    cache.set(key, result, timeout=settings.CACHE_AGE["emerg"])


def get_csl_status() -> Tuple[str, bool]:
    """Get the cached status of the TJCSL status page.

    Returns:
        Tuple with a string consisting of the aggregate status
        of the TJ computer systems lab and a bool indicating whether
        the status cache was updated

        The string of the tuple will be one of the following: "error" (parse error), "operational", "downtime", "degraded", "maintenance"
    """

    status = cache.get("emerg:csl_status")
    updated = False

    if not status:
        response = requests.get(settings.CSL_STATUS_PAGE)
        if response.status_code != 200:
            status = "error"
            logger.error("Could not fetch status page")

        else:
            try:
                status = response.json()["data"]["attributes"]["aggregate_state"]
                updated = True
            except KeyError as e:
                status = "error"
                logger.error("Unexpected status page JSON format. %s", e)

        cache.set("emerg:csl_status", status, settings.CACHE_AGE["csl_status"])

    return status, updated