#!/bin/sh

# Vars {{{
readonly PROGNAME=$(basename "${0}")
readonly PROGDIR=$(readlink -m $(dirname "${0}"))
readonly ARGS="${*}"
readonly NBARGS="${#}"
## Test if DEBUG is already defined (by parent script,…)
[ -z "${DEBUG}" ] && DEBUG=1

# If output message should be displayed
[ -z "${OUTPUT_MESSAGE}" ] && OUTPUT_MESSAGE=0

# Maco temp file
readonly MACO_TMP_FILE="/tmp/.maco.upgrade"
readonly MACO_TMP_URGENT_FILE="/tmp/.maco.urgent.upgrade"

# APT temp file to monitor
readonly APT_TMP_FILE="/tmp/.apt.upgrade"

# If the scrip need to check pending upgrade before enable a queue
CHECK_UPGRADE="0"

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

usage() {                                                       # {{{

	cat <<- EOF
usage: $PROGNAME [--help] [-d|-h|-q] [hostname]

Try to enable all SGE queues of the current host (default),
if no pending upgrades (Maco, APT) are present,
or to the one passed as first argument (no upgrades checking).

EXAMPLES :
    - Enable SGE's queue(s) of the current host
        ${PROGNAME}

    - Enable SGE's queue(s) of "marvin.domain.tld" host
        ${PROGNAME} marvin.domain.tld
        ${PROGNAME} -h marvin.domain.tld

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

    --help
        Print this help message.

    -h,--host,--hostname SGE_HOST_TO_MANAGE
        Manage SGE's queue(s) of "SGE_HOST_TO_MANAGE" host.

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

	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}"

}
# }}}
message() {                                                     # {{{

	local_message="${1}"

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

	return 0

}
# }}}
is_apt_upgrade_present() {                                      # {{{

	## No pending upgrade by default
	return_apt_upgrade_present="1"

	## If we need to watch for upgrades
	if [ "${CHECK_UPGRADE}" -eq "0" ]; then
		### Check if temp APT upgrade file exists
		if [ -f "${APT_TMP_FILE}" ]; then
			return_apt_upgrade_present="0"
			debug_message "is_apt_upgrade_absent − \
APT upgrade seems available for this system."
		else
			return_apt_upgrade_present="1"
			debug_message "is_apt_upgrade_absent − \
NO APT upgrade available for this system."
		fi
	fi

	return "${return_apt_upgrade_present}"

}
# }}}
is_maco_upgrade_present() {                                     # {{{

	## No pending upgrades by default
	return_maco_upgrade_present="1"

	## If we need to watch for upgrades
	if [ "${CHECK_UPGRADE}" -eq "0" ]; then
		## Check if temp Maco upgrade file is present
		if [ -f "${MACO_TMP_FILE}" ]; then
			return_maco_upgrade_present="0"
			debug_message "is_maco_upgrade_present − \
Maco upgrade seems available."

		## Check if temp Maco urgent upgrade file is present
		elif [ -f "${MACO_TMP_URGENT_FILE}" ]; then
			return_maco_upgrade_present="0"
			debug_message "is_maco_upgrade_present − \
Maco urgent upgrade seems available."
		else
			debug_message "is_maco_upgrade_present − \
No Maco upgrade require."
		fi
	fi

	return "${return_maco_upgrade_present}"

}
# }}}
is_queue_enable() {                                             # {{{

	local_queue_enable_hostname="${1}"
	local_queue_enable_name="${2}"
	## List all queues with 'disable' state and filter to the expected queue name
	## with a fake_user to avoid pending jobs for this queue
	### And count returned lines
	local_queue_enable_test=$(qstat -f -qs d -q "${local_queue_enable_name:=/dev/null}@${local_queue_enable_hostname:=/dev/null}" -u fake_user \
		| wc -l)

	case "${local_queue_enable_test}" in
		0 ) ## No result so the queue is enable
			local_sge_queue_state="enable"
			return_queue_enable="0"
			;;
		3 ) ## Results (header + queue name) so the queue is disable
			local_sge_queue_state="disable"
			return_queue_enable="1"
			;;
		* ) ## Unexpected result
			printf '%b\n' "${RED}Not able to determine the state of ${local_sge_queue_name:=/dev/null}@${local_queue_enable_hostname:=/dev/null} queue (command return ${local_queue_enable_test} lines).${RESET}"
			exit 2
			;;
esac

	## Simple debug message to valid current variables
	debug_message "is_queue_enable − \
SGE queue: ${RED}${local_queue_enable_name:=/dev/null}${COLOR_DEBUG} \
state is: ${RED}${local_sge_queue_state:=/dev/null}${COLOR_DEBUG}."

	return "${return_queue_enable}"

}
# }}}
is_queue_disable() {                                            # {{{

	local_queue_disable_hostname="${1}"
	local_queue_disable_name="${2}"
	## List all queues with 'disable' state and filter to the expected queue name
	## add a fake_user to avoid pending jobs for this queue
	### And count returned lines
	local_queue_disable_test=$(qstat -f -qs d -q "${local_queue_disable_name:=/dev/null}@${local_queue_disable_hostname:=/dev/null}" -u fake_user \
		| wc -l)

	case "${local_queue_disable_test}" in
		0 ) ## No result so the queue is enable
			local_sge_queue_state="enable"
			return_queue_disable="1"
			;;
		3 ) ## Results (header + queue name) so the queue is disable
			local_sge_queue_state="disable"
			return_queue_disable="0"
			;;
		* ) ## Unexpected result
			printf '%b\n' "${RED}Not able to determine the state of ${local_queue_disable_name:=/dev/null}@${local_queue_disable_hostname:=/dev/null} queue (command return ${local_queue_disable_test} lines).${RESET}"
			exit 3
			;;
esac

	## Simple debug message to valid current variables
	debug_message "is_queue_disable − \
SGE queue: ${RED}${local_queue_disable_name:=/dev/null}${COLOR_DEBUG} \
state is: ${RED}${local_sge_queue_state:=/dev/null}${COLOR_DEBUG}."

	return "${return_queue_disable}"

}
# }}}
is_all_queue_enable() {                                         # {{{

	local_all_queue_enable_hostname="${1}"
	local_all_queue_enable_name="${2}"

	## By default, all queues are enable
	return_all_queue_enable="0"

	## Test all queues one by one
	for loop_enable_queue in ${local_all_queue_enable_name}; do

		### If a queue is not enable
		#### Change the return value
		is_queue_enable "${local_all_queue_enable_hostname}" "${loop_enable_queue}" \
			|| return_all_queue_enable="1"

	done

	return "${return_all_queue_enable}"

}
# }}}
enable_sge_queue() {                                            # {{{

	local_sge_hostname="${1}"
	local_sge_queue_name="${2}"

	local_sge_disable="/etc/.sge.${local_sge_queue_name}.disable"

	## If the queue was previously disabled by another script
	if [ -f "${local_sge_disable}" ]; then
		debug_message "enable_sge_queue − \
Try to enable SGE queue: ${RED}${local_sge_queue_name:=/dev/null}@${local_sge_hostname:=/dev/null}${COLOR_DEBUG}."
		## SGE command to enable the queue
		qmod --enable "${local_sge_queue_name}@${local_sge_hostname}" \
			&& return_enable_queue="${?}"
	else
		message "SGE queue: ${RED}${local_sge_queue_name:=/dev/null}@${local_sge_hostname:=/dev/null}${RESET} was manually disabled, please re-enable it ${RED}manually${RESET}."
		return_enable_queue="1"
	fi

	return "${return_enable_queue}"

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

	sge_queues_name="$(qhost -h "${sge_hostname:=/dev/null}" -q -xml \
		| grep "queue name" \
		| cut -d"'" -f2 )"
	sge_queues_name_print="$(qhost -h "${sge_hostname:=/dev/null}" -q -xml \
		| grep "queue name" \
		| cut -d"'" -f2 \
		| tr -s '\n' ' ' )"


	## If APT package upgrade is available
	### Exit (wait for APT upgrade to be applied)
	is_apt_upgrade_present \
		&& exit 0

	## If Maco upgrade is present
	### Exit (wait for Maco upgrade to be applied)
	is_maco_upgrade_present \
		&& exit 0


	## Simple debug message with color to valid current variables
	debug_message "main − Try to manage \
SGE queue(s): ${RED}${sge_queues_name_print:=/dev/null}${COLOR_DEBUG}\
for host: ${RED}${sge_hostname:=/dev/null}${COLOR_DEBUG}."

	## If the queue(s) are already enable
	### Exit
	is_all_queue_enable "${sge_hostname}" "${sge_queues_name}" \
		&& exit 0

	## Test all queues one by one
	for loop_queue in ${sge_queues_name}; do

		## If the queue is disable
		### Try to enable it
		is_queue_disable "${sge_hostname}" "${loop_queue}" \
			&& enable_sge_queue "${sge_hostname}" "${loop_queue}"

		## If the queue is still disable
		### Exit with error
		is_queue_disable "${sge_hostname}" "${loop_queue}" \
			&& printf '%b\n' "${RED}ERROR ${loop_queue}@${sge_hostname} is still disable.${RESET}" \
			&& exit 4

	done

}
# }}}

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

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

	manage_arg="0"

	## If the first argument is not an option
	if ! printf -- '%s' "${1}" | grep -q -E -- "^-*";
	then
		## Use this argument for sge_hostname
		sge_hostname="${1}"

		## No way to monitor pending upgrades on a remote host
		CHECK_UPGRADE="1"

		## Switch to the next argument
		shift
		manage_arg=$((manage_arg+1))
	else
		## Use local host for sge_hostname
		sge_hostname="$(hostname -f)"
	fi

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

	case "${1}" in
		-d|--debug )           ## debug
			DEBUG=0
			;;
		--help )               ## help
			usage
			## Exit after help informations
			exit 0
			;;
		-h|--host|--hostname ) ## Specify a different host to manage
			## Move to the next argument
			shift
			## Override previous definition of sge_hostname
			sge_hostname="${1}"
			;;
		-q|--quiet )           ## Silent mode
			## Avoid to display any message on standard output
			OUTPUT_MESSAGE=1
			;;
		-- )                   ## End of options list
			## End the while loop
			break
			;;
		* )                    ## unknow option
			printf '%b\n' "${RED}Invalid option: ${1}${RESET}"
			printf '%b\n' "---"
			usage
			exit 1
			;;
	esac

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

	## Move to the next argument
	shift
	manage_arg=$((manage_arg+1))

	done

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

	## Use local host for sge_hostname
	sge_hostname="$(hostname -f)"
fi

# }}}

main

exit 0