#!/usr/bin/python3
"""
Icinga/Nagios plugin to check Forgejo instance upgrade status.

Copyright (c) 2023 Benjamin Renard <brenard@zionetrix.net>

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License version 3
as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
"""

import argparse
import logging
import re
import subprocess  # nosec
import sys

import requests
import xmltodict

parser = argparse.ArgumentParser()

parser.add_argument("-d", "--debug", action="store_true")
parser.add_argument("-p", "--path", type=str, help="Forgejo bin path", default="forgejo")
parser.add_argument(
    "-U",
    "--url",
    type=str,
    help="Forgejo releases RSS URL",
    default="https://forgejo.org/releases/rss.xml",
)
parser.add_argument(
    "--rc",
    action="store_true",
    dest="include_rc",
    help="Allow release candidate (default: only stable release are considered)",
)
parser.add_argument(
    "-t", "--timeout", type=int, help="Specify timeout for HTTP requests (default: 20)", default=20
)

options = parser.parse_args()

logging.basicConfig(level=logging.DEBUG if options.debug else logging.WARNING)

CURRENT = None

cmd = [options.path, "--version"]
logging.debug("Command use to retrieve current version of Forgejo: %s", " ".join(cmd))
OUTPUT = None
EXCEPTION = None
try:
    OUTPUT = subprocess.check_output(cmd)  # nosec
    logging.debug("Output:\n%s", OUTPUT)
    m = re.search("version ([^ ]+) built", OUTPUT.decode("utf8", errors="ignore"))
    if m:
        CURRENT = m.group(1)
except Exception as err:  # pylint: disable=broad-except
    EXCEPTION = err
logging.debug("Current version: %s", CURRENT)

if not CURRENT:
    print("UNKNOWN - Fail to retrieve current Forgejo")
    print(f'Command: {" ".join(cmd)}')
    print("Output:")
    print(OUTPUT if OUTPUT else "")
    print("Exception:")
    print(EXCEPTION if EXCEPTION else "")
    sys.exit(3)

CURRENT = CURRENT.replace("+", "-")
logging.debug("Cleaned current version: %s", CURRENT)

LATEST = None
LATEST_INT = None
try:
    logging.debug("Get releases RSS feed from %s...", options.url)
    r = requests.get(options.url, timeout=options.timeout)
    logging.debug("Data retrieve:\n%s", r.text)
    data = xmltodict.parse(r.text)
    versions = {}
    for item in data["rss"]["channel"]["item"]:
        version = re.sub("^v", "", item["title"])
        if not options.include_rc and "-rc" in version:
            logging.debug("Ignore release candidate %s", version)
            continue
        version_int = int(re.sub(r"[\.-]", "000", version))
        logging.debug("Found version %s (%s)", version, version_int)
        if not LATEST_INT or LATEST_INT < version_int:
            if LATEST:
                logging.debug(
                    "Version %s considered as newer than %s, override latest version",
                    version,
                    LATEST,
                )
            LATEST = version
            LATEST_INT = version_int
        else:
            logging.debug("Version %s considered as oldest than %s", version, LATEST)
except Exception:  # pylint: disable=broad-except  # nosec
    pass
logging.debug("Latest version: %s", LATEST)

if not LATEST:
    print("UNKNOWN - Fail to retrieve latest Forgejo release from the project RSS feed")
    print(f"Current version: {CURRENT}")
    sys.exit(3)

if LATEST == CURRENT:
    print(f"OK - The latest release of Forgejo is currently used ({LATEST})")
    sys.exit(0)

print(
    "WARNING - The version of Forgejo currently used is not the latest " f"({CURRENT} vs {LATEST})"
)
sys.exit(1)