#!/bin/env bash
#
## Calculate DPI, update settings if necessary, then start desktop apps

REGEX_XRANDR='^.* ([0-9]+)x([0-9]+)\+[0-9]+\+[0-9]+.* ([0-9]+)mm x ([0-9]+)mm.*$'

echo -n "Getting display details... "

# Get screen data
xrandr_str="$(xrandr | grep mm | head -1)"
width_px="$(echo "${xrandr_str}" | sed -r "s/${REGEX_XRANDR}/\1/")"
height_px="$(echo "${xrandr_str}" | sed -r "s/${REGEX_XRANDR}/\2/")"
width_mm="$(echo "${xrandr_str}" | sed -r "s/${REGEX_XRANDR}/\3/")"
height_mm="$(echo "${xrandr_str}" | sed -r "s/${REGEX_XRANDR}/\4/")"

# Convert to in
width_in="$(echo "${width_mm} * 0.03937" | bc)"
height_in="$(echo "${height_mm} * 0.03937" | bc)"

# Calculate diagonals
diag_px="$(echo "sqrt(${width_px}^2 + ${height_px}^2)" | bc)"
diag_in="$(echo "sqrt(${width_in}^2 + ${height_in}^2)" | bc)"

# Calculate DPI
dpi="$(echo "${diag_px} / ${diag_in}" | bc 2>/dev/null || True)"
dpi="${dpi:-0}"

# Save data
echo "width_px=$width_px" > "$HOME/.screen_data"
echo "height_px=$height_px" >> "$HOME/.screen_data"
echo "dpi=$dpi" >> "$HOME/.screen_data"

echo "Done"

# Update settings if necessary
if [[ "${dpi}" -ge 192 ]]; then
  echo -n "Updating settings for HiDPI... "

  # Conky
  sed -i 's/default_graph_height = 24/default_graph_height = 48/' "${HOME}/.config/conky/base.conf"
  sed -i 's/gap_x = 20/gap_x = 40/' "${HOME}/.config/conky/base.conf"
  sed -i 's/gap_y = 24/gap_y = 48/' "${HOME}/.config/conky/base.conf"
  sed -i 's/maximum_width = 180/maximum_width = 360/' "${HOME}/.config/conky/base.conf"
  sed -i 's/minimum_width = 180/minimum_width = 360/' "${HOME}/.config/conky/base.conf"

  # Fonts
  sed -i 's/!Xft.dpi: 192/Xft.dpi: 192/' "${HOME}/.Xresources"

  # GDK
  export GDK_SCALE=2
  export GDK_DPI_SCALE=0.5

  # Rofi
  sed -i -r 's/Noto Sans 12/Noto Sans 24/' "${HOME}/.config/rofi/config"

  # Tint2
  sed -i 's/panel_size = 100% 30/panel_size = 100% 60/' \
    "${HOME}/.config/tint2/tint2rc"
  sed -i 's/Hack 10/Hack 20/g' \
    "${HOME}/.config/tint2/tint2rc"
  sed -i 's/Hack 12/Hack 24/g' \
    "${HOME}/.config/tint2/tint2rc"
  sed -i 's/systray_icon_size = 24/systray_icon_size = 48/' \
    "${HOME}/.config/tint2/tint2rc"

  # Done
  echo "Done"
fi

# Update conky
echo -n "Updating conky... "
$HOME/.update_conky
echo "Done"

# Update X
echo -n "Updating X... "
xset s off
xset -dpms
xrdb -merge $HOME/.Xresources
echo "Done"

# Set wallpaper
echo -n "Setting wallpaper... "
feh --bg-fill "$HOME/.wallpaper"
echo "Done"