#!/bin/ksh
#
# Uptime Atomic v20230603
# https://git.high5.nl/uptimeatomic/
#
export PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin
CONFIGFILE="uptimeatomic.conf"
WORKDIR=$(cd -P -- "$(dirname -- "$(command -v -- "$0")")" && pwd -P)

usage() {
        echo "usage: ${0##*/} [-c checksfile] [-i incidentsfile] [-p pastincidentsfile] [-o htmlfile]" 1>&2
        exit
}

date_rss() {
	if [ -n "${1}" ]; then
		date -uj '+%a, %d %b %Y %H:%M:%S %z' ${1}
	else
		date -uj '+%a, %d %b %Y %H:%M:%S %z'
	fi
}
date_incident() {
	if [ -n "${1}" ]; then
		date -uj '+%F %H:%M %Z' ${1}
	else
		date -uj '+%F %H:%M %Z'
	fi
}

get_element() {
	echo "${2}" | awk -v col="${1}" -F',' '{gsub(/^[ \t]+|[ \t]+$/, "", $col); print $col}'
}

incidents() {
	_date=${1}
	_type=${2}
	_description=${3}
	[[ ${_type} == "Incident" ]] && color="failed"
	[[ ${_type} == "Maintenance" ]] && color="maint"
	echo "<p>$(date_incident ${_date}) - <b class='${color}'>${_type}</b><br />${_description}</p>" >> ${_HTMLFILE}
	if [ -n "${_RSSFILE}" ]; then
cat << EOF >> ${_RSSFILE}
<item>
<title>${_type}</title>
<link>${RSS_URL}/rss.xml</link>
<guid>${RSS_URL}/rss.xml?$(date -j '+%s' $(echo "${_date}"))</guid>
<pubDate>$(date_rss "${_date}")</pubDate>
<description><![CDATA[ ${_description} ]]></description>
</item>
EOF
	fi
}

notify() {
	_name="${1}"
	_status="${2}"
	_priority="${3}"

	if [ ${_priority} == "ko" ]; then
		echo "${_status}." | mail -r "${TITLE} <${SENDER}>" -s "${_name} DOWN" ${RECIPIENT}
		${PUSHOVER} -c ${PUSHOVER_CONF} -t "${TITLE}" -m "${_name} DOWN ${_status}." -p 1 >/dev/null 2>&1
		touch "${PUSHOVER_STATUS}/${_name}"
	fi
	if [ ${_priority} == "ok" ]; then
		_seconds=$(expr $(date +%s) - $(stat -r "${PUSHOVER_STATUS}/${_name}" | awk '{print $11}'))
		_downtime=$(date -r${_seconds} -u +%H:%M:%S)

		echo "${_status} - down for ${_downtime}" | mail -r "${TITLE} <${SENDER}>" -s "${_name} OK" ${RECIPIENT}
		${PUSHOVER} -c ${PUSHOVER_CONF} -t "${TITLE}" -m "${_name} OK ${_status} - down for ${_downtime}" >/dev/null 2>&1
		rm -rf "${PUSHOVER_STATUS}/${_name}"
	fi
}

check() {
	_ctype="${1}"
	_expectedcode="${2}"
	_name="${3}"
	_host="${4}"
	_timeout="${5}"
	IPv="${_ctype#(http|ping|port)}"
	[[ -n "${_timeout}" ]] && TIMEOUT=${_timeout}

	case "${_ctype}" in
		http*)
			statuscode="$(curl -${IPv}sSkLo /dev/null -H "${USERAGENT}" -m "${TIMEOUT}" -w "%{http_code}" "${_host}" 2> "${_TMP}/ko/${_name}.error")"
			if [ "${statuscode}" -ne "${_expectedcode}" ]; then
				if [ -s "${_TMP}/ko/${_name}.error" ]; then
					sed -e 's,curl: ([0-9]*) ,,' "${_TMP}/ko/${_name}.error" > "${_TMP}/ko/${_name}.status"
				else
					echo "Status code: ${statuscode}" > "${_TMP}/ko/${_name}.status"
				fi
			else
				echo "Status code: ${statuscode}" > "${_TMP}/ok/${_name}.status"
			fi
			;;
		ping*)
			ping -${IPv}w "${TIMEOUT}" -c 1 "${_host}" >/dev/null 2>&1
			statuscode=$?
			if [ "${statuscode}" -ne "${_expectedcode}" ]; then
				echo "Host unreachable" > "${_TMP}/ko/${_name}.status"
			else
				echo "Host reachable" > "${_TMP}/ok/${_name}.status"
			fi
			;;
		port*)
			error="$(nc -${IPv}w "${TIMEOUT}" -zv ${_host} 2>&1)"
			statuscode=$?
			if [ "${statuscode}" -ne "${_expectedcode}" ]; then
				echo "Connection refused" > "${_TMP}/ko/${_name}.status"
			else
				echo "Connection succeeded" > "${_TMP}/ok/${_name}.status"
			fi
			;;
		maint*)
			echo "Maintenance" > "${_TMP}/maint/${_name}.status"
			;;
	esac
}

process_status() {
	_status_files=${1}

	ls ${_TMP}/${_status_files}/*.status 2>/dev/null | sort -V | while read file; do
		[ -e "${file}" ] || continue
		_name="$(basename "${file%.status}")"
		_status="$(cat "${file}")"
		
		if [ ${_status_files} == "ko" ]; then
			echo "<li>${_name} <span class='small failed'>(${_status})</span><span class='status failed'>Disrupted</span></li>" >> ${_HTMLFILE}
			if [ ! -e "${PUSHOVER_STATUS}/${_name}" ]; then
				notify "${_name}" "${status}" "${_status_files}"
			fi
		fi
		if [ ${_status_files} == "maint" ]; then
			echo "<li>${_name} <span class='status maint'>Maintenance</span></li>" >> ${_HTMLFILE}
		fi
		if [ ${_status_files} == "ok" ]; then
			echo "<li>${_name} <span class='status success'>Operational</span></li>" >> ${_HTMLFILE}
			if [ -e "${PUSHOVER_STATUS}/${_name}" ]; then
				notify "${_name}" "${_status}" "${_status_files}"
			fi
		fi
	done
}

parse_file() {
	_file=${1}
	while IFS="$(printf '\n')" read -r line; do
		_col1="$(get_element 1 "${line}")"
		_col2="$(get_element 2 "${line}")"
		_col3="$(get_element 3 "${line}")"
		_col4="$(get_element 4 "${line}")"
		_col5="$(get_element 5 "${line}")"
		if [[ ${_file} == *".csv" ]]; then
			check "${_col1}" "${_col2}" "${_col3}" "${_col4}" "${_col5}" &
		else
			incidents "${_col1}" "${_col2}" "${_col3}"
		fi
	done < "${_file}"
	wait
}

cd ${WORKDIR}
if [ -e "${CONFIGFILE}" ]; then
	. ${WORKDIR}/${CONFIGFILE}
else
	echo "Configfile ${WORKDIR}/${CONFIGFILE} doesn't exist."
	exit
fi

while getopts c:i:o:r:h arg; do
	case ${arg} in
	c)      CHECKFILE=${OPTARG};;
	i)      INCIDENTSFILE=${OPTARG};;
	p)      PASTINCIDENTSFILE=${OPTARG};;
	o)      HTMLFILE=${OPTARG};;
	r)      RSS_FILE=${OPTARG};;
	h)      usage;;
	*)      usage;;
	esac
done

if [ ! -e "${CHECKFILE}" ]; then
	echo "Checkfile ${WORKDIR}/${CHECKFILE} doesn't exist."
	exit
fi

_TMP="$(mktemp -d)"
mkdir -p "${_TMP}/ok" "${_TMP}/ko" "${_TMP}/maint" || exit 1
_HTMLFILE="${_TMP}/${HTMLFILE}"
[[ -n "${RSS_FILE}" ]] && _RSSFILE="${_TMP}/${RSS_FILE}"

parse_file "${CHECKFILE}"

#
# HTML
#
cat << EOF > ${_HTMLFILE}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="refresh" content="${REFRESH}">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<title>${TITLE}</title>
<style>
body { font-family: segoe ui,Roboto,Oxygen-Sans,Ubuntu,Cantarell,helvetica neue,Verdana,sans-serif; }
h1 { margin-top: 30px; }
ul { padding: 0px; }
li { list-style: none; margin-bottom: 2px; padding: 5px; border-bottom: 1px solid #ddd;  }
.container { max-width: 600px; width: 100%; margin: 15px auto; }
.panel { text-align: center; padding: 10px; border: 0px; border-radius: 5px; }
.failed-bg  { color: white; background-color: #E25D6A; }
.success-bg { color: white; background-color: #52B86A; }
.maint-bg { color: white; background-color: #5DADE2; }
.failed  { color: #E25D6A; }
.success { color: #52B86A; }
.maint { color: #5DADE2; }
.small { font-size: 80%; }
.status { float: right; }
@media (prefers-color-scheme: dark) {
  a, a:link, a:visited { color: #ffe489; }
  body, html { background-color: #111111; color: #888888; }
  pre { background-color: #111111; color: #aaaaaa; }
  li { border-bottom: 1px solid #333333 }
  .clean { background-color: #111111; color: #aaaaaa; }
}
</style>
</head>
<body>
<div class='container'>
<h1>${HEADER}</h1>
EOF

#
# RSS
#
if [ -n "${_RSSFILE}" ]; then
cat << EOF > ${_RSSFILE}
<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
<channel>
<atom:link href="${RSS_URL}/rss.xml" rel="self" type="application/rss+xml" />
<title>${TITLE}</title>
<description>${RSS_DESCRIPTION}</description>
<link>${RSS_URL}</link>
<lastBuildDate>$(date_rss)</lastBuildDate>
EOF
fi

_outage_count="$(find "${_TMP}/ko" -mindepth 1 | grep -c 'status$')"
_maint_count="$(find "${_TMP}/maint" -mindepth 1 | grep -c 'status$')"
if [ "${_outage_count}" -ne 0 ]; then
	echo "<ul><li class='panel failed-bg'>${_outage_count} Outage(s)</li></ul>" >> ${_HTMLFILE}
fi
if [ "${_maint_count}" -ne 0 ]; then
	echo "<ul><li class='panel maint-bg'>${_maint_count} Maintenance</li></ul>" >> ${_HTMLFILE}
fi
if [[ "${_outage_count}" -eq 0 && "${_maint_count}" -eq 0 ]]; then
	echo "<ul><li class='panel success-bg'>All Systems Operational</li></ul>" >> ${_HTMLFILE}
fi

if [ -s "${INCIDENTSFILE}" ]; then
	echo '<h2>Incidents / Maintenance</h2>' >> ${_HTMLFILE}
	parse_file "${INCIDENTSFILE}"
fi

echo "<h1>Services</h1>" >> ${_HTMLFILE}
echo "<ul>" >> ${_HTMLFILE}

process_status "ko"
process_status "maint"
process_status "ok"

echo "</ul>" >> ${_HTMLFILE}
echo "<p class=small>Last check: $(date -u '+%FT%T %Z')</p>" >> ${_HTMLFILE}

if [ -s "${PASTINCIDENTSFILE}" ]; then
	echo '<h3>Past Incidents / Maintenance</h3>' >> ${_HTMLFILE}
	parse_file "${PASTINCIDENTSFILE}"
fi

#
# END HTML
#
cat << EOF >> ${_HTMLFILE}
<p class=small>
<a href="https://git.high5.nl/uptimeatomic/">Uptime Atomic</a> loosely based on <a href="https://github.com/bderenzo/tinystatus">Tinystatus</a>
EOF
[[ -n "${_RSSFILE}" ]] && echo " - <a href='${RSS_URL}/${RSS_FILE}'>RSS</a>" >> ${_HTMLFILE}
cat << EOF >> ${_HTMLFILE}
</p>
</div>
</body>
</html>
EOF

#
# END RSS
#
if [ -n "${_RSSFILE}" ]; then
cat << EOF >> ${_RSSFILE}
</channel>
</rss>
EOF
fi

if [[ -f "${HTMLDIR}/${RSS_FILE}" ]]; then
	_diff=$(diff "${_RSSFILE}" "${HTMLDIR}/${RSS_FILE}" | wc -l)
	if [ "${_diff}" -ne "4" ]; then
		cp ${_RSSFILE} ${HTMLDIR}/${RSS_FILE}
	fi
elif [ -n "${RSS_FILE}" ]; then
	cp ${_RSSFILE} ${HTMLDIR}/${RSS_FILE}
fi

cp ${_HTMLFILE} ${HTMLDIR}/${HTMLFILE}
rm -r "${_TMP}" 2>/dev/null