#!/bin/sh

# This script will check if Maco require an upgrade and
# will prepare the host in order to apply upgrade :
#   1. Disable SGE queue
#   2. Create a temp file (${MACO_LOCAL_DIR}/.maco.upgrade or ${MACO_LOCAL_DIR}/.maco.urgent.upgrade)

# This script can be call by a cronjob (eg. weekly)
# Another script should try to apply upgrades also with cron (eg. hourly)

# Vars {{{
readonly PROGNAME=$(basename "${0}")
readonly PROGDIR=$(readlink -m $(dirname "${0}"))
readonly ARGS="${*}"
readonly NBARGS="${#}"

[ -z "${DEBUG}" ] && DEBUG=1
## Export DEBUG for sub-script
export DEBUG

# If output message should be displayed
[ -z "${OUTPUT_MESSAGE}" ] && OUTPUT_MESSAGE=0
## Export OUTPUT_MESSAGE for sub-script
export OUTPUT_MESSAGE

# If modifications should be applied
[ -z "${SIMULATE_MODE}" ] && SIMULATE_MODE=1

# If only urgent upgrade should be checked
[ -z "${URGENT_ONLY_MODE}" ] && URGENT_ONLY_MODE=1

## Colors
readonly PURPLE='\033[1;35m'
readonly RED='\033[0;31m'
readonly RESET='\033[0m'
readonly COLOR_DEBUG="${PURPLE}"

## Maco
readonly MACO_LOCAL_DIR="/opt/maco"
readonly MACO_INSTALL_DIR="/mnt/store.ipr/InstallProgs/ipr/maco"
readonly MACO_TMP_FILE="${MACO_LOCAL_DIR}/.maco.upgrade"
readonly MACO_TMP_URGENT_FILE="${MACO_LOCAL_DIR}/.maco.urgent.upgrade"
# }}}

usage() {                                                       # {{{

	cat <<- EOF
usage: $PROGNAME [-d|-h|-q|-s|-u]

Compare current version of Maco script with the latest and
 the urgent versions then try to prepare the host by:
	* Disabling SGE queue

EXAMPLES:
    - Verify Maco's upgrade and prepare the current host
        ${PROGNAME}

    - Verify only urgent upgrade for Maco and prepare the current host
        ${PROGNAME} --urgent

OPTIONS :
    -d,--debug
        Enable debug messages.

    -h,--help
        Print this help message.

    -q,--quiet
        Disable messages on standard output (except for error).

    -s,--simulate
        Only display messages and don't manage temp files.

    -u,--urgent
        Check only for urgent upgrade.
EOF


}
# }}}
debug_message() {                                               # {{{

	local_debug_message="${1}"

	## Print message if DEBUG is enable (=0)
	[ "${DEBUG}" -eq "0" ] && printf '\e[1;35m%-6b\e[m\n' "DEBUG − ${PROGNAME}: ${local_debug_message}"

	return 0
}
# }}}
message() {                                                     # {{{

	local_message="${1}"

	## Print message if OUTPUT_MESSAGE is enable (=0)
	[ "${OUTPUT_MESSAGE}" -eq "0" ] && printf '%b\n' "${local_message}"

	return 0

}
# }}}
is_var_empty() {                                                # {{{

	## Return False by default
	return_var_empty="1"
	## Total number of variables to test
	local_total_var="${#}"

	loop_count_var_empty="0"

	## While it remains a variable to test
	while [ "${local_total_var}" -gt "${loop_count_var_empty}" ]; do
		debug_message "is_var_empty − \
Test var: ${1}."
		### Test if this is empty and set return value to True
		[ -z "${1}" ] && return_var_empty="0"

		### Increase the number of tested variables
		loop_count_var_empty=$((loop_count_var_empty+1))

		### Shift to the next variable
		shift
	done

	return "${return_var_empty}"

}
# }}}
is_sge_master_available() {                                     # {{{

	## Check with Netcat if SGE master (sge_qmaster) is reachable from this host.
	### -z: Only scan for listening daemons, without sending any data to them.
	### -w 10: Timeout the test after 10 seconds.
	if nc -z -w 10 "${sge_master_uri}" "${sge_master_port}"; then
		return_is_sge_master_available="0"
		debug_message "is_sge_master_available − \
SGE Master (${sge_master_uri}:${sge_master_port}) is reachable from this host."
	else
		return_is_sge_master_available="1"
		debug_message "is_sge_master_available − \
SGE Master (${sge_master_uri}:${sge_master_port}) is not reachable from this host."
	fi

	return "${return_is_sge_master_available}"

}
# }}}
is_maco_urgent_upgrade_require() {                              # {{{

	return_urgent_upgrade=""

	if [ "${URGENT_TIMESTAMP}" -gt "${CURRENT_TIMESTAMP}" ]; then
		debug_message "is_maco_urgent_upgrade_require − \
Urgent Maco upgrade is available (from version ${CURRENT_MACO_VERSION} to ${URGENT_MACO_VERSION})."
		message "Urgent Maco upgrade is available (from version ${CURRENT_MACO_VERSION} to ${URGENT_MACO_VERSION})."
		return_urgent_upgrade="0"

		## If SIMULATE_MODE is not enable
		if [ ! "${SIMULATE_MODE}" -eq 0 ]; then
			### Also create an urgent temp file that can be monitored
			### touch and append to keep existing content
			touch "${MACO_TMP_URGENT_FILE}" && echo "Urgent Maco upgrade is available (from version ${CURRENT_MACO_VERSION} to ${URGENT_MACO_VERSION})." >> "${MACO_TMP_URGENT_FILE}"
		fi

	else
		debug_message "is_maco_urgent_upgrade_require − \
Local Maco (${CURRENT_MACO_VERSION}) is newer than urgent upgrade (${URGENT_MACO_VERSION})."
		return_urgent_upgrade="1"
		## If SIMULATE_MODE is not enable
		if [ ! "${SIMULATE_MODE}" -eq 0 ]; then
			## Ensure urgent temp file is not present
			rm -f -- "${MACO_TMP_URGENT_FILE}"
		fi
	fi

	return "${return_urgent_upgrade}"

}
# }}}
is_maco_upgrade_require() {                                     # {{{

	return_upgrade=""

	if [ "${LATEST_TIMESTAMP}" -gt "${CURRENT_TIMESTAMP}" ]; then
		debug_message "is_maco_upgrade_require − \
Latest Maco upgrade is available (from version ${CURRENT_MACO_VERSION} to ${LATEST_MACO_VERSION})."
		message "Latest Maco upgrade is available (from version ${CURRENT_MACO_VERSION} to ${LATEST_MACO_VERSION})."
		return_upgrade="0"

		## If SIMULATE_MODE is not enable
		if [ ! "${SIMULATE_MODE}" -eq 0 ]; then
			### Also create a temp file that can be monitored
			### touch and append to keep existing content
			touch "${MACO_TMP_FILE}" && echo "Latest Maco upgrade is available (from version ${CURRENT_MACO_VERSION} to ${LATEST_MACO_VERSION})." >> "${MACO_TMP_FILE}"
		fi

	else
		debug_message "is_maco_upgrade_require − \
Local Maco (${CURRENT_MACO_VERSION}) seems up to date (latest: ${LATEST_MACO_VERSION})."
		return_upgrade="1"
		## If SIMULATE_MODE is not enable
		if [ ! "${SIMULATE_MODE}" -eq 0 ]; then
			## Ensure temp file is not present
			rm -f -- "${MACO_TMP_FILE}"
		fi
	fi

	return "${return_upgrade}"

}
# }}}
is_maco_uptodate() {                                            # {{{

	return_uptodate=""

	if [ "${CURRENT_TIMESTAMP}" = "${LATEST_TIMESTAMP}" ]; then
		debug_message "is_maco_uptodate − \
Local Maco (${CURRENT_MACO_VERSION}) is up to date (latest: ${LATEST_MACO_VERSION})."
		message "Local Maco (${CURRENT_MACO_VERSION}) is up to date (latest: ${LATEST_MACO_VERSION})."
		return_uptodate="0"
		## If SIMULATE_MODE is not enable
		if [ ! "${SIMULATE_MODE}" -eq 0 ]; then
			## Ensure to remove temp files
			rm -f -- "${MACO_TMP_FILE}" "${MACO_TMP_URGENT_FILE}"
		fi
	else
		debug_message "is_maco_uptodate − \
Local Maco version (${CURRENT_MACO_VERSION}) is different from latest version (${LATEST_MACO_VERSION})."
		return_uptodate="1"
	fi

	return "${return_uptodate}"

}
# }}}
prepare_host_for_upgrade() {                                    # {{{

	sge_disable_host_queue_script="${PROGDIR}/sge.disable.host.queue.sh"

	## If SIMULATE_MODE is enable
	if [ "${SIMULATE_MODE}" -eq 0 ]; then
		return 0
	else

		debug_message "prepare_host_for_upgrade − \
Disable SGE queue."
		sh "${sge_disable_host_queue_script}"

		return "${?}"
	fi

}
# }}}
main() {                                                        # {{{

	## If sge_master_uri wasn't defined (environment variable,…)
	if [ -z "${sge_master_uri}" ]; then
		## Use local host for sge_master_uri
		sge_master_uri="physix-master.ipr.univ-rennes1.fr"
	fi

	## If sge_master_port wasn't defined (environment variable,…)
	if [ -z "${sge_master_port}" ]; then
		## Use local host for sge_master_port
		sge_master_port="6444"
	fi
	## If SGE Master is not reachable from this host {{{
	### Exit
	is_sge_master_available \
		|| exit 0
	## }}}

	## Get all Maco's versions (date)
	readonly CURRENT_MACO_VERSION=$(< "${MACO_LOCAL_DIR}/maco-version.txt" awk -v FS=. '{ print $1 "-" $2 "-" $3 "T" $4 ":" $5 ":" $6 }' )
	readonly LATEST_MACO_VERSION=$(< "${MACO_INSTALL_DIR}/maco-version.txt" awk -v FS=. '{ print $1 "-" $2 "-" $3 "T" $4 ":" $5 ":" $6 }' )
	readonly URGENT_MACO_VERSION=$(< "${MACO_INSTALL_DIR}/urgent-maco-version.txt" awk -v FS=. '{ print $1 "-" $2 "-" $3 "T" $4 ":" $5 ":" $6 }' )
	## Convert version to timestamp
	readonly CURRENT_TIMESTAMP=$(date -d "${CURRENT_MACO_VERSION}" "+%s")
	readonly LATEST_TIMESTAMP=$(date -d "${LATEST_MACO_VERSION}" "+%s")
	readonly URGENT_TIMESTAMP=$(date -d "${URGENT_MACO_VERSION}" "+%s")

	## If a variable is empty
	##  Exit with error code
	is_var_empty "${CURRENT_MACO_VERSION}" "${LATEST_MACO_VERSION}" "${URGENT_MACO_VERSION}" "${CURRENT_TIMESTAMP}" "${LATEST_TIMESTAMP}" "${URGENT_TIMESTAMP}" \
		&& exit 1

	is_maco_uptodate \
		&& exit 0

	## If URGENT_ONLY_MODE is set
	if [ "${URGENT_ONLY_MODE}" -eq "0"  ]; then
		### Check only for urgent upgrade {{{
		is_maco_urgent_upgrade_require \
			&& prepare_host_for_upgrade \
			&& exit 0
		### }}}

	else
		### Check for latest upgrade {{{
		is_maco_upgrade_require \
			&& prepare_host_for_upgrade \
			&& exit 0
		### }}}

		### Check for urgent upgrade {{{
		is_maco_urgent_upgrade_require \
			&& prepare_host_for_upgrade \
			&& exit 0
		### }}}

	fi

}
# }}}

# Manage arguments                                              # {{{
# This code can't be in a function due to arguments

if [ ! "${NBARGS}" -eq "0" ]; then

	manage_arg="0"
	# Parse all options (start with a "-") one by one
	while printf -- '%s' "${1}" | grep -q -E -- "^-+"; do

	case "${1}" in
		-h|--help )     ## help
			usage
			## Exit after help informations
			exit 0
			;;
		-d|--debug )    ## debug
			DEBUG=0
			## Re-export new DEBUG value
			export DEBUG
			;;
		-q|--quiet )    ## Silent mode
			## Avoid to display any message on standard output
			OUTPUT_MESSAGE=1
			;;
		-s|--simulate ) ## Simulate mode
			## Only display messages
			SIMULATE_MODE=0
			;;
		-u|--urgent )   ## Urgent upgrade only
			## Check only for urgent upgrade
			URGENT_ONLY_MODE=0
			;;
		-- )            ## End of options list
			## End the while loop
			break
			;;
		* )
			printf '%b\n' "${RED}Invalid option: ${1}${RESET}"
			printf '%b\n' "---"
			usage
			exit 1
			;;
	esac

	debug_message "Arguments management − \
${1} option managed."

	## Next arg
	shift
	manage_arg=$((manage_arg+1))

	done

	debug_message "Arguments management − \
${manage_arg} argument(s) successfully managed."
else
	debug_message "Arguments management − \
No arguments/options to manage."
fi

# }}}

main

exit 255