# a micro library of helper functions for the power scripts

umask 022

PATH=$PATH:/usr/bin/X11
POWERSTATE=/var/lib/acpi-support/powerstate

# getXuser: get the user for the specified X display, or if none is
# specified, then the user for whatever X display we find.
# input: $displaynum: the X display to query
# output: $XAUTHORITY: the path to the xauth data used for connecting to the
#                      detected X display.
#         $XUSER: the username of the user who owns the display.
getXuser() {
	local plist display uid user startx pid userhome IFS

	if [ "$displaynum" ]; then
		display=:$displaynum
	else
		display=.+
	fi

	user=
	if [ -x /usr/bin/ck-list-sessions ]; then
		uid=$(ck-list-sessions | awk 'BEGIN { unix_user = ""; } /^Session/ { unix_user = ""; } /unix-user =/ { gsub(/'\''/,"",$3); unix_user = $3; } /x11-display = '\'$display\''/ { print unix_user; exit (0); }')

		if [ "$uid" ]; then
			IFS=:
			set -- $(getent passwd $uid)
			user=$1
			unset IFS
		fi
	else
		plist=$(pinky -fw) || pwf_error "pinky lost"
		while read l; do
			set -- $l
			eval lastpp=\$$#
			for ds in $2 $lastpp; do
				case $ds in
					$display)
						user=$1
						break
						;;
				esac
			done
			[ -z "$user" ] || break
			for ds in $2 $lastpp; do
				case $ds in
					$display.0)
						user=$1
						break
						;;
				esac
			done
			[ -z "$user" ] || break
		done <<-EOF
			$plist
		EOF
	fi

	if [ -z "$user" ]; then
		startx=$(pgrep -n startx || :)
		[ -z "$startx" ] || user=$(ps -o user --no-headers $startx || :)
	fi

	if [ x"$user" != x ]; then
        	for pid in `ps -U "$user" -o pid=`; do
			if grep -z -q XAUTHORITY /proc/$pid/environ; then
				XAUTHORITY="$(grep -z XAUTHORITY /proc/$pid/environ | cut -d= -f2-)"
				export XAUTHORITY
				break
			fi
		done
		if [ -z "$XAUTHORITY" ]; then
			userhome="$(getent passwd "$user" | cut -d: -f6)"
			XAUTHORITY="$userhome/.Xauthority"
			export XAUTHORITY
		fi
	else
		export XAUTHORITY=
	fi
	XUSER="$user"
	export XUSER
}

# getXconsole: get the information for the active X console, if any.
# 	calls getXuser to get information related to the logged-in user.
# input: none
# output: $XAUTHORITY: the path to the xauth data used for connecting to the
#                      detected X display.
#         $DISPLAY: the X display
#         $XUSER: the username of the user who owns the display.
getXconsole() {
	local displaynum

	displaynum=$(ck-list-sessions | awk 'BEGIN { active = 0; } /^Session/ { active = 0; } /active = TRUE/ { active = 1; } active && /x11-display = '\':.+\''/ { gsub(/'\':*'/,"",$3); print $3; exit (0); }')

	if [ "$displaynum" ]; then
		DISPLAY=":$displaynum"
		export DISPLAY
		getXuser
	fi
}

# getState side effect: sets global variable STATE
getState() {
        /usr/bin/on_ac_power
        if [ $? -eq 1 ]; then
                STATE=BATTERY
        else
                STATE=AC
        fi
}

#check our state has actually changed
checkStateChanged() {
	local OLDSTATE

# do we have our state stashed?
# XXX:	if vaiable STATE is unset, set it to the null string
	: ${STATE=${STATE:-}}
# XXX:	make sure variable STATE has a non-null value
	[ "$STATE" ] || getState
        if [ -f "$POWERSTATE" ]; then
# XXX:	unset or empty variable STATE and an existing but empty POWERSTATE file
#	and the function will probably have undesired side effects
                read OLDSTATE <$POWERSTATE || :
                if [ "$STATE" = "$OLDSTATE" ]; then
                       exit 0
                else
#stash the new state
# XXX:	unset or empty variable STATE, will create an empty POWERSTATE file
                        echo "$STATE" > $POWERSTATE
                fi
        else
#we need to stash the new state
# XXX:	unset or empty variable STATE, will create an empty POWERSTATE file
                echo "$STATE" > $POWERSTATE
        fi
}

HDPARM='/sbin/hdparm -q'

LIDSTATE=/var/lib/acpi-support/lidstate