#!/bin/sh

twoscreen() {
  mirror=$(printf "no\\nyes" | dmenu -c -l 2 -i)
  if [ "$mirror" = "yes" ]; then
    external=$(echo "$screens" | dmenu -c -l 2 -i)
    internal=$(echo "$screens" | grep -v "$external")
    res_external=$(xrandr --query | sed -n "/^$external/,/\+/p" | \
      tail -n 1 | awk '{print $1}')
    res_internal=$(xrandr --query | sed -n "/^$internal/,/\+/p" | \
      tail -n 1 | awk '{print $1}')
    res_ext_x=$(echo "$res_external" | sed 's/x.*//')
    res_ext_y=$(echo "$res_external" | sed 's/.*x//')
    res_int_x=$(echo "$res_internal" | sed 's/x.*//')
    res_int_y=$(echo "$res_internal" | sed 's/.*x//')
    scale_x=$(echo "$res_ext_x / $res_int_x" | bc -l)
    scale_y=$(echo "$res_ext_y / $res_int_y" | bc -l)
    xrandr --output "$external" --auto --scale 1.0x1.0 \
      --output "$internal" --auto --same-as "$external" \
      --scale "$scale_x"x"$scale_y"
  else
    primary=$(echo "$screens" | dmenu -c -l 50 -i)
    secondary=$(echo "$screens" | grep -v "$primary")
    direction=$(printf "left\\nright" | dmenu -c -l 2 -i)
    xrandr --output "$primary" --auto --scale 1.0x1.0 --output "$secondary" --"$direction"-of "$primary" --auto --scale 1.0x1.0
  fi
}

onescreen() {
  if [ "$2" = "native" ]; then
    xrandr --output "$1" --auto --scale 1.0x1.0 $(echo "$allposs" | grep -v "\b$1" | awk '{print "--output", $1, "--off"}' | paste -sd ' ' -)
  else
    scale=$(printf "native\\n0.75\\n0.5" | dmenu -c -l 3 -i) &&
    case "$scale" in
      "native") xrandr --output "$1" --auto --scale 1.0x1.0 $(echo "$allposs" | grep -v "\b$1" | awk '{print "--output", $1, "--off"}' | paste -sd ' ' -);;
      *) xrandr --output "$1" --auto --scale ${scale}x${scale} $(echo "$allposs" | grep -v "\b$1" | awk '{print "--output", $1, "--off"}' | paste -sd ' ' -);;
    esac
  fi
}

postrun() {
  feh --no-fehbg --bg-scale ~/.local/share/wallpaper
  { killall dunst ; setsid -f dunst ;} >/dev/null 2>&1 # Restart dunst to ensure proper location on screen
  kill -46 $(pidof dwmblocks)
}

# Get all possible displays
allposs=$(xrandr -q | grep "connected")

# Get all connected screens.
screens=$(echo "$allposs" | awk '/ connected/ {print $1}')

# If there's only one screen
[ "$(echo "$screens" | wc -l)" -lt 2 ] &&
  { onescreen "$screens" "native"; postrun; dunstify -u critical "💻 no device to switch";  exit ;}

# Get user choice including both and manual selection:
chosen=$(printf -- "%s\\nmulti" "$screens" | dmenu -c -l 5 -i) &&
case "$chosen" in
  "multi") twoscreen ;;
  *) onescreen "$chosen" ;;
esac

postrun