#!/bin/sh
LINES=16
# width of menu is a third of the screen; use that to centre X and use number
# of lines to centre Y
Z=$(echo "$(xrandr --current | grep '*' | awk '{print $1}' | cut -d 'x' -f1)/3" | bc)
X=$(echo "($(xrandr --current | grep '*' | awk '{print $1}' | cut -d 'x' -f1)-$Z)/2" | bc)
Y=$(echo "$(xrandr --current | grep '*' | awk '{print $1}' | cut -d 'x' -f2)/2-(8*$LINES)" | bc)

if [ $# -eq 0 ]; then
  IMG_DIR="$HOME/Pictures/albums/"
else
  IMG_DIR="$1"
fi

# remove directory prefix from list
ALBUM="$(find "$IMG_DIR" -not -path '*/.*' -type f -printf "%p\n" |
  sed "s:$IMG_DIR::" | sort | sed '1 i\random' |
  dmenu -i -l $LINES -x $X -y $Y -z $Z -p "album?")"
if [ $ALBUM == "random" ]; then
  ./rand_wall.sh
else
  # replace prefix so correct path passed
  ALBUM="$(printf "%s/%s" "$IMG_DIR" "$ALBUM")"
  wall_gen.sh "$ALBUM"
fi