#!/bin/sh
# Purpose {{{
## Create a temp file (to monitor) if an upgrade is available for Gitea
## project on Github.
## It based on gitea's binary available in $PATH or give as first argument.
## How-to use {{{
### 1. Needs releasetags script, in the same directory
### cf. https://git.ipr.univ-rennes1.fr/cellinfo/scripts/src/master/github/releasetags
# wget https://git.ipr.univ-rennes1.fr/cellinfo/scripts/raw/master/github/releasetags
### 2. Create a cron job, eg.
#00 20 * * * root /opt/repos/ipr.scripts/github/check_gitea_update
### 2-1 Create a cron job with a specific path for gitea bin, eg.
#00 20 * * * root /opt/repos/ipr.scripts/github/check_gitea_update /srv/bin/gitea
### 3. Monitor the temp file : /tmp/.github.gitea.upgrade
# Or enable MAILTO in cronjob and edit the script to print a message.
# Or send a mail.
# …
## }}}
# }}}

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

check.gitea.update  --
Compare current version of an installed Gitea and the last available.

EXAMPLE :
    - Compare the current version of Gitea with bin available in \$PATH
        check.gitea.update

    - Compare the current version of Gitea at a specific place
        check.gitea.update /srv/bin/gitea

HELP

	exit 1

fi
# }}}

# Vars {{{
DEBUG=1

script_wd=$(dirname "${0}")

gitea_repo_url="https://github.com/go-gitea/gitea"
gitea_new_version=$("${script_wd}"/releasetags "${gitea_repo_url}" | grep -vE -- '(dev|rc)' | head -n1 | sed 's/v//')

gitea_new_version_file="/tmp/.github.gitea.upgrade"

if [ $# -eq 1 ]  ## If an argument was gave
then
	gitea_bin_path="${1}"

	### Define new version URL and path only if Gitea's absolut path was given
	gitea_new_version_url="https://github.com/go-gitea/gitea/releases/download/v${gitea_new_version}/gitea-${gitea_new_version}-linux-amd64"
	gitea_new_bin_path="${gitea_bin_path}.to.upgrade.v${gitea_new_version}"
else
	gitea_bin_path="gitea"
	fi

gitea_current_version=$("${gitea_bin_path}" -v | cut -d' ' -f3)

# }}}

# Check if the current version is the last one {{{
if [ "${gitea_current_version}" != "${gitea_new_version}" ]; then
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Test version — Current version (${gitea_current_version}) and new one (${gitea_new_version}) seems to be different."

	## Create a temp file to monitor
	touch -- "${gitea_new_version_file}"
	printf '\e[1;35m%-6s\e[m\n' "An upgrade is available for Gitea (current : ${gitea_current_version}) : ${gitea_new_version}." >> "${gitea_new_version_file}"

	## If the variables were defined
	if [ -n "${gitea_new_version_url}" ] && [ -n "${gitea_new_bin_path}" ]; then
		### Download and prepare the new bin {{{
		[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Download Gitea binary from Gitea repository on Github to ${gitea_new_bin_path} ."
		wget --quiet "${gitea_new_version_url}" --output-document="${gitea_new_bin_path}"
		chmod +x -- "${gitea_new_bin_path}"
		### }}}
	fi

else
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6s\e[m\n' "DEBUG : Test version — The current version is up-to-date."
	rm -f -- "${gitea_new_version_file}"
fi
# }}}

exit 0