#!/bin/sh
# Purpose {{{
## Create a temp file (to monitor) if an upgrade is available for Pi-hole
## from official repository − https://github.com/pi-hole/pi-hole
## It's based on the pihole binary to check versions.
## How-to use {{{
### 1. Create a cron job, eg :
#00 20 * * * root /opt/repos/ipr.scripts/app/check.pihole.update
### 2-1 Create a cron job to compare the version available in an APT repository :
#00 20 * * * root /opt/repos/ipr.scripts/app/check.pihole.update repo
### 2. Monitor the temp file : /tmp/.pihole.upgrade
# Or enable MAILTO in cronjob and edit the script to print a message.
# Or send a mail.
# …
## }}}
# }}}

# Expect maximum 1 argument {{{
if [ $# -gt 1 ]
then
	cat << HELP

check.pihole.update    --
Compare current version of an installed Pi-hole and the last available.

EXAMPLE :
    - Compare the current version from pihole binary informations.
        check.pihole.update

HELP

	exit 1
fi
# }}}

# Vars {{{
DEBUG=1

pihole_current_status=$(pihole updatePihole --check-only)

pihole_new_version_file="/tmp/.pihole.upgrade"
# }}}

# Check the current status with pihole subcommand {{{
if printf -- '%s' "${pihole_current_status}" | grep -q -- "Everything is up to date"; then
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Pi-hole seems up to date."
	## Ensure to remove any temp file
	rm --force -- "${pihole_new_version_file}"
else
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : An update seems available for Pi-hole."
	## Create a temp file to monitor
	touch -- "${pihole_new_version_file}"
	printf '\e[1;35m%-6s\e[m\n' "An upgrade is available for Pi-hole, result of 'pihole updatePihole --check-only' command :" >> "${pihole_new_version_file}"
	pihole updatePihole --check-only >> "${pihole_new_version_file}"
fi
# }}}

exit 0