#!/bin/bash

# (c) Michael Honkoop <mhonkoop@comsolve.nl>

# License: GNU General Public License v2

# Version 0.1:
# - initial release
# Version 0.2
# - adapted state for checking required packages for the check

# Current active version of the script
SCRIPT_VERSION=0.2

# Installation:
# This file should be placed on a/the host running SimpleSamlPHP in /usr/lib/check_mk_agent/local
#
# (reccomended) if you want the check to run on a different schedule (like once per hour) put it in a subdirectory of above path
# named to the number of seconds of the interval wanted, so 3600/ for once an hour, 86400/ for once per day.
# Suggestion for this check is to run this once a day to minimize processing cost.
#
# Also do not forget to make this file executable with chmod +x /usr/lib/check_mk_agent/local/simplesaml_version_check

##########################################################################
# Global definitions for the script - change if needed to fit your needs #
##########################################################################

# Define path to where SimpleSalmPHP is installed
BASEPATH="/opt/simplesamlphp"

# Version (json) file reference
VERSION_FILE="composer.json"

# url to check releases against
RELEASEURL="https://api.github.com/repos/simplesamlphp/simplesamlphp/releases"

# Service Name to be shown in Check_MK
SERVICE="SimpleSAMLphp_Version"


#####################################################################
# DO NOT CHANGE BELOW UNLESS YOU EXACTLY KNOW WHAT YOU ARE DOING    #
#####################################################################

# Check if jq package is present on the system (required for this check)
if ! command -v jq >/dev/null 2>&1; then
    echo "3 \"$SERVICE\" - $SERVICE localcheck requires jq package to be installed"
    exit 0
fi

# Check if curl package is present on the system (required for this check)
if ! command -v curl >/dev/null 2>&1; then
    echo "3 \"$SERVICE\" - $SERVICE localcheck requires curl package to be installed"
    exit 0
fi

# Check presence of SimpleSAMLPhp and report if not found
if [[ ! -f "$BASEPATH/$VERSION_FILE" ]]; then
    echo "3 \"$SERVICE\" - No local version information found in: $$BASEPATH/$VERSION_FILE check localcheck configuration."
    exit 0
fi
# Get installed version information via composer.json or version file
if [ -f "$BASEPATH/$VERSION_FILE" ]; then
    INSTALLED_VERSION=$(jq -r '.version // empty' "$BASEPATH/$VERSION_FILE")
    INSTALLED_VERSION="${INSTALLED_VERSION#v}"
else
    # Fallback to checking directory name if version isn't in composer.json
    INSTALLED_VERSION="Unknown"
fi

# Get latest avaiable version information from github.
AVAILABLE_VERSION=$(curl -fsSL -H 'Accept: application/vnd.github+json' --connect-timeout 5 --max-time 15 "$RELEASEURL" | jq -r '.[] | select(.draft == false and .prerelease == false) | .tag_name' | sed 's/^v//' | sort -V | tail -n1)

# Error handling / Evaluate results
if [ -z "$AVAILABLE_VERSION" ]; then
    # Issue Warn state when failing to fetch data from GitHub.
    echo "1 \"$SERVICE\" - Could not fetch the latest version from GitHub API."
    exit 0
elif [ "$VERSION_FILE" = "Unknown" ]; then
    # Issue Warn state when local/installed version could not be determined.
    echo "1 \"$SERVICE\" - Cannot detect installed version at $VERSION_FILE."
    exit 0
elif [ "$INSTALLED_VERSION" = "$AVAILABLE_VERSION" ]; then
    # Set OK state when installed and latest release version match.
    echo "0 \"$SERVICE\" - SimpleSAMLphp is up to date ($VERSION_FILE)."
    exit 0
else
    # WARN: Update available
    echo "1 \"$SERVICE\" - Update available! Installed: $INSTALLED_VERSION, Available: $AVAILABLE_VERSION."
    exit 0
fi