#!/bin/bash

# Exit out if the same script is already running in the background
pidof -sq -o %PPID -x "$(basename "$0")" && exit

# Set the directory paths
flatpak_themes_dir="$HOME/.themes"
flatpak_icons_dir="$HOME/.icons"

# Create flatpak icons & themes directories if they don't exist
mkdir -p "$flatpak_themes_dir" "$flatpak_icons_dir" ||
	{ echo "failed to make directories $flatpak_themes_dir & $flatpak_icons_dir"; exit 1; }

xdg_directory_lookup() {
	# Go through each item in $XDG_DATA_DIRS and find the subdirectory $1
	while read -r dir; do
		subdir="${dir%/}/$1"
		if [ -d "$subdir" ]; then
			echo "$subdir"
			break
		fi
	done < <(printf '%s:%s\n' "$HOME/.local/share" "$XDG_DATA_DIRS" | tr ':' '\n')
}

hdpi_theme_fix() {
	# Get the current window scaling factor (highDPI setting)
	current_scaling=$(xfconf-query -c xsettings -p /Gdk/WindowScalingFactor)
	# Get the current XFWM theme
	current_xfwm_theme=$(xfconf-query -c xfwm4 -p /general/theme)
	# Get the current mouse cursor size
	cursor_size=$(xfconf-query -c xsettings -p /Gtk/CursorThemeSize)

	if [ "$current_scaling" -eq '2' ]; then
		# Increase mouse cursor size if it's less than 45
		if [ "$cursor_size" -lt 45 ]; then
			xfconf-query -c xsettings -p /Gtk/CursorThemeSize -s '45'
			notify-send 'Mouse cursor size increased to 45' "Changed to a larger mouse cursor because you've enabled highDPI on your system"
		fi
		for variant in xhdpi hdpi; do
			# If this variant of the theme is already enabled then break out of the loop
			[ "${current_xfwm_theme##*-}" = "$variant" ] && break
			# Store the name for this variant of the theme in highDPI_theme variable
			highDPI_theme=$current_xfwm_theme-$variant
			# Find the directory where highDPI_theme is stored
			highDPI_theme_dir=$(xdg_directory_lookup "themes/$highDPI_theme")
			# If this directory exists then change to that theme for XFWM
			if [ -d "$highDPI_theme_dir" ]; then
				xfconf-query -c xfwm4 -p /general/theme -n -t string -s "$highDPI_theme"
				notify-send "XFWM theme changed to $highDPI_theme" "Changed to the highDPI variant of your chosen theme because you've enabled highDPI on your system"
				break
			fi
		done
	else
		# Decrease mouse cursor size if it's greater than or equal to 45
		if [ "$cursor_size" -ge 45 ]; then
			xfconf-query -c xsettings -p /Gtk/CursorThemeSize -s '25'
			notify-send 'Mouse cursor size decreased to 25' "Changed to a smaller mouse cursor because you've disabled highDPI on your system"
		fi
		for variant in xhdpi hdpi; do
			# Continue looping if this (highDPI) variant of the theme is not enabled
			[ "${current_xfwm_theme##*-}" != "$variant" ] && continue
			# Store the name for the normal variant of this theme in normal_theme variable
			normal_theme=${current_xfwm_theme%-"$variant"}
			# Find the directory where normal_theme is stored
			normal_theme_dir=$(xdg_directory_lookup "themes/$normal_theme")
			# If this directory exists then change to that theme for XFWM
			if [ -d "$normal_theme_dir" ]; then
				xfconf-query -c xfwm4 -p /general/theme -n -t string -s "$normal_theme"
				notify-send "XFWM theme changed to $normal_theme" "Changed to the normal variant of your chosen theme because you've disabled highDPI on your system"
				break
			fi
		done
	fi
}

sync_theme() {
	# Get the current system theme
	current_theme=$(xfconf-query -c xsettings -p /Net/ThemeName)

	# Enable syncing the current theme with XFWM theme if not already enabled
	[ "$(xfconf-query -c xsettings -p /Xfce/SyncThemes)" != 'true' ] && xfconf-query -c xsettings -p /Xfce/SyncThemes -n -t bool -s true
	# Apply the current theme with gsettings
	gsettings set org.gnome.desktop.interface gtk-theme "$current_theme"
	# Apply the current theme for GTK and Libadwaita apps on flatpak
	flatpak override --user --env=GTK_THEME="$current_theme"

	# Change XFWM theme and mouse cursor size according to the user's highDPI setting
	hdpi_theme_fix


	# Cleanup flatpak_themes_dir
	rm -rf "${flatpak_themes_dir:?}"/*

	# Find the directory where the current theme is stored
	current_theme_dir=$(xdg_directory_lookup "themes/$current_theme")
	# Copy/sync current_theme_dir to flatpak_themes_dir
	[ -d "$current_theme_dir" ] &&
		rsync -av --delete --progress "$current_theme_dir" "$flatpak_themes_dir"
}

sync_icons() {
	# Get the current icon theme
	current_icon_theme=$(xfconf-query -c xsettings -p /Net/IconThemeName)

	# Cleanup flatpak_icons_dir
	rm -rf "${flatpak_icons_dir:?}"/*

	# Find the directory where the current icon theme is stored
	current_icon_theme_dir=$(xdg_directory_lookup "icons/$current_icon_theme")
	# Copy/sync current_icon_theme_dir to flatpak_icons_dir
	[ -d "$current_icon_theme_dir" ] &&
		rsync -av --delete --progress "$current_icon_theme_dir" "$flatpak_icons_dir"
}

sync_font() {
	# Get the current system font
	font=$(xfconf-query -c xsettings -p /Gtk/FontName)
	# Apply the same font for the title of xfce windows
	xfconf-query -c xfwm4 -p /general/title_font -n -t string -s "$font"
}

# Initial synchronization
sync_theme
sync_icons
sync_font

# Monitor when the user changes their system theme or icons or font in XFCE and sync them as needed
while read -r line; do
	case "$line" in
		'set: /Net/ThemeName') sync_theme ;;
		'set: /Gdk/WindowScalingFactor') hdpi_theme_fix ;;
		'set: /Net/IconThemeName') sync_icons ;;
		'set: /Gtk/FontName') sync_font ;;
	esac
done < <(xfconf-query -c xsettings -m)