update_hostname() {
    uci set system.@system[0].hostname=$1
    echo $1 > /proc/sys/kernel/hostname
}

update_geo() {
    local auto=$1
    local public=$2
    local del=$3
    uci -q batch <<EOF
set system.position.automatic=$auto
set system.position.public=$public
EOF
    if $del; then
	    uci -q batch <<EOF
delete system.position.lon
delete system.position.lat
delete system.position.street
EOF
    fi
    if $auto && have_internet; then
	# geolocate may fail (e.g. if another instance was running or
	# the position could not be determined)
	/usr/sbin/geolocate || true
        # close previously aquired lock
	exec 667>&-
    fi
}

update_node_db() {
    true # TODO
}

use_router_pos=false
# the POST input is given to this loop via HEREDOC to allow
# manipulating variables in the current scope (especially for lazy
# execution)
while read key val; do
    case "$key" in 
	router_name)
	    [ "$val" == "$(echo "$val" | tr -dc 'a-zA-Z0-9_')" ] \
		|| fail 400 'Unerlaubte Zeichen verwendet'
	    router_name=$val
	    lazy 10 update_hostname $router_name
	    lazy 90 update_node_db
	    lazy 99 uci commit system
	    ;;
	router_qos|router_vpn|router_filter_wan)
	    fail 403 'Diese Funktion ist noch nicht fertig'
	    ;;
	router_password)
	    fail 403 'Diese Funktion ist noch nicht fertig'
	    ;;
	router_geo)
	    router_geo="$val"
	    case "$router_geo" in
		private)
		    lazy 00 update_geo false false true
		    ;;
		manual)
		    lazy 00 update_geo false true false
		    use_router_pos=true
		    ;;
		automatic)
		    # only delete current position if we have internet
		    # to immediately get the new position
		    if have_internet; then
			lazy 00 update_geo true true true
    	                # obtain writing lock until geolocate obtains
			# the same lock to close race cond; ignore
			# failure to lock (prefer to process the
			# request instead (-:)
			exec 667>>/tmp/lock/geolocate
			flock -n -x 667 || true
		    else
			lazy 00 update_geo true true false
		    fi
		    ;;
		*)
		    fail
		    ;;
	    esac
	    lazy 90 update_node_db
	    lazy 99 uci commit system
	    ;;
	router_pos_lon|router_pos_lat)
	    if $use_router_pos; then
		true
	    fi
	    ;;
	router_pos_street)
	    if $use_router_pos; then
		true
	    fi
	    ;;
	esac
done <<EOF
$(tr '=&' ' \n' | sort)
EOF