# from http://www.thinkwiki.org/wiki/Xorg_RandR_1.2
# and http://www.thinkwiki.org/wiki/Sample_Fn-F7_script

INTERNAL_OUTPUT="LVDS"
EXTERNAL_OUTPUT1="HDMI-0"
EXTERNAL_OUTPUT2="VGA-0"
EXTERNAL_LOCATION="above"

case "$EXTERNAL_LOCATION" in
       left|LEFT)
               EXTERNAL_LOCATION="--left-of $INTERNAL_OUTPUT"
               ;;
       right|RIGHT)
               EXTERNAL_LOCATION="--right-of $INTERNAL_OUTPUT"
               ;;
       top|TOP|above|ABOVE)
               EXTERNAL_LOCATION="--above $INTERNAL_OUTPUT"
               ;;
       bottom|BOTTOM|below|BELOW)
               EXTERNAL_LOCATION="--below $INTERNAL_OUTPUT"
               ;;
       *)
               EXTERNAL_LOCATION="--left-of $INTERNAL_OUTPUT"
               ;;
esac

# Figure out current state
INTERNAL_STATE=$(xrandr | grep ^$INTERNAL_OUTPUT | grep " con" | sed "s/.*connected//" | sed "s/ //" | sed "s/ .*//g"| sed "s/(normal//g" )
EXTERNAL_STATE=$(xrandr | grep ^$EXTERNAL_OUTPUT2 | grep "disconnected" )
if [ -z "$EXTERNAL_STATE" ]; then
    EXTERNAL_OUTPUT=$EXTERNAL_OUTPUT2
    xrandr --output $EXTERNAL_OUTPUT1 --off
else
    EXTERNAL_OUTPUT=$EXTERNAL_OUTPUT1
    xrandr --output $EXTERNAL_OUTPUT2 --off
fi
EXTERNAL_STATE=$(xrandr | grep ^$EXTERNAL_OUTPUT | grep " con" | sed "s/.*connected//" | sed "s/ //" | sed "s/ .*//g"| sed "s/(normal//g" )

if [ -z "$INTERNAL_STATE" ]; then
    STATE="external"
elif [ -z "$EXTERNAL_STATE" ]; then
    STATE="internal"
else
    INTERNAL_STATE=$(echo $INTERNAL_STATE | sed "s/[0-9]*x[0-9]*//")
    EXTERNAL_STATE=$(echo $EXTERNAL_STATE | sed "s/[0-9]*x[0-9]*//")
    if [ "$INTERNAL_STATE" = "$EXTERNAL_STATE" ]; then
        STATE="mirror"
    else
        STATE="both"
    fi
fi

# Set new state
case "$STATE" in
    internal)
        # both
        xrandr --output $INTERNAL_OUTPUT --auto
        xrandr --output $EXTERNAL_OUTPUT --auto $EXTERNAL_LOCATION
        ;;
    both)
        # external
        xrandr --output $INTERNAL_OUTPUT --off
        xrandr --output $EXTERNAL_OUTPUT --auto
        ;;
    external)
        # mirror
        xrandr --output $INTERNAL_OUTPUT --auto
        xrandr --output $EXTERNAL_OUTPUT --auto --same-as $INTERNAL_OUTPUT
        ;;
    mirror)
        # internal
        xrandr --output $EXTERNAL_OUTPUT --off
        xrandr --output $INTERNAL_OUTPUT --auto
        ;;
    *)
        # internal
        xrandr --output $EXTERNAL_OUTPUT --off
        xrandr --output $INTERNAL_OUTPUT --auto
        ;;
esac