#!/bin/sh

. /lib/functions.sh
. /lib/netifd/netifd-proto.sh
. /usr/share/ModemManager/modemmanager.common

trap_with_arg() {
	func="$1" ; shift
	for sig ; do
		# shellcheck disable=SC2064
		trap "$func $sig" "$sig"
	done
}

func_trap() {
	local monitor_cache_line object

	logger "ModemManager-monitor[$$]" "Sending signal ${1} ..."

	# Set all configured logical interfaces to unavailable
	while IFS= read -r monitor_cache_line; do
		object=$(echo "${monitor_cache_line}" | awk '{print $1}')
		mm_monitor_cache_remove "$object"
	done < ${MODEMMANAGER_MONITOR_CACHE}

	kill "-${1}" "$CHILD" 2>/dev/null
}

mm_monitor_get_sysfspath() {
	local object="$1"

	# If no monitor cache file, we're done
	[ -f "${MODEMMANAGER_MONITOR_CACHE}" ] || return

	awk -v object="${object}" '!/^#/ && $0 ~ object { print $2 }' "${MODEMMANAGER_MONITOR_CACHE}"
}

mm_monitor_cache_remove() {
	local object="$1"

	local device cfg

	device=$(mm_monitor_get_sysfspath "${object}")

	cfg=$(mm_get_modem_config "${device}")
	if [ -n "${cfg}" ]; then
		mm_log "debug" "interface '${cfg}' set '${device}' state unavailable"
		proto_set_available "${cfg}" 0
	fi

	mm_log "debug" "delete object '$object' from monitore cache"

	# On monitor remove event, remove old events from cache
	# Also substitute object path '/org/freedesktop/ModemManager1/Modem/<number>'
	# all '/' with '\/' to make sed happy with shell expansion
	sed -i "/${object//\//\\/}/d" "${MODEMMANAGER_MONITOR_CACHE}"
}

mm_monitor_cache_add() {
	local object="$1"
	local modemstatus device sysfspath cfg

	modemstatus="$(mmcli --modem="${object}" --output-keyvalue)"

	device=$(modemmanager_get_field "${modemstatus}" "modem.generic.device")
	[ -n "${device}" ] || {
		mm_log "err" "No 'device' for object '$object' not found..."
		return 1
	}

	sysfspath=$(modemmanager_get_field "${modemstatus}" "modem.generic.physdev")
	[ -n "${sysfspath}" ] || {
		mm_log "err" "No 'sysfspath' for object '$object' not found..."
		return 2
	}

	mm_log "debug" "add object '$object' to monitore cache (device=${device},sysfspath=${sysfspath})"

	# On monitor add event, store event details in cache (if not exists yet)
	grep -qs "${sysfspath}" "${MODEMMANAGER_MONITOR_CACHE}" || \
		echo "${object} ${device} ${sysfspath}" >> "${MODEMMANAGER_MONITOR_CACHE}"

	cfg=$(mm_get_modem_config "${device}")
	if [ -n "${cfg}" ]; then
		mm_log "info" "interface '${cfg}' set '${device}' state available"
		proto_set_available "${cfg}" 1
	fi
}

mm_monitor_cache_del() {
	local object="$1"

	mm_monitor_cache_remove "$object"
}

mm_monitor_cache() {
	local line="$1"
	local event object modemstatus device pyhsdev

	event="$(echo "$line" | cut -d " " -f 1)"
	object="$(echo "$line" | cut -d " " -f 2)"

	case "$event" in
		"(+)")
			mm_monitor_cache_add "$object"
			;;
		"(-)")
			mm_monitor_cache_del "$object"
			;;
	esac
}

main() {

	local n=60
	local step=1
	local mmrunning=0

	trap_with_arg func_trap INT TERM KILL

	mkdir -p "${MODEMMANAGER_RUNDIR}"
	chmod 0755 "${MODEMMANAGER_RUNDIR}"

	# Wait for ModemManager to be available in the bus
	while [ $n -ge 0 ]; do
		sleep $step
		mm_log "info" "Checking if ModemManager is available..."

		if ! /usr/bin/mmcli -L >/dev/null 2>&1; then
			mm_log "info" "ModemManager not yet available"
		else
			mmrunning=1
			break
		fi
		n=$((n-step))
	done

	[ ${mmrunning} -eq 1 ] || {
		mm_log "error" "couldn't report initial kernel events: ModemManager not running"
		return
	}

	/usr/bin/mmcli -M | {
		local line
		while read -r line; do
			mm_log "debug" "Monitor cache line: ${line}"
			mm_monitor_cache "$line"
		done
	} &
	CHILD="$!"

	wait $CHILD
}

main "$@"