#!/bin/bash
data="$HOME"/.local/share/applications/tweaked-desktop-files
detectfiles() {
	for file in "$HOME"/.local/share/applications/*.desktop; do
		[ -d "$file" ] || grep -xq "$file" "$data" && continue
		name=$(basename "$file") || continue
		[ -f /usr/share/applications/"$name" ] ||
			ls /var/lib/flatpak/app/*/current/active/files/share/applications/"$name" >/dev/null 2>&1 ||
			[ -f /var/lib/snapd/desktop/applications/"$name" ] &&
			echo "$file" >> "$data"
	done
}

fixfiles() {
	lastmod=$(stat -c "%Y" "$data")
	tmp="$(mktemp -u)"
	[ -f "$data" ] && cp "$data" "$tmp" && copied='true'
	[ "$copied" = 'true' ] && while IFS= read -r file; do
		[ -f "$file" ] || { sed -i "/^$file$/d" "$tmp" ; continue; }
		name=$(basename "$file") || continue
		[ -f /usr/share/applications/"$name" ] ||
			ls /var/lib/flatpak/app/*/current/active/files/share/applications/"$name" >/dev/null 2>&1 ||
			[ -f /var/lib/snapd/desktop/applications/"$name" ] ||
			mv "$file" "$file.bak"
	done < "$data"

	[ "$copied" = 'true' ] && [ "$(stat -c '%Y' "$data")" = "$lastmod" ] && mv "$tmp" "$data"

	for bakfile in "$HOME"/.local/share/applications/*.desktop.bak; do
		origfile="${bakfile/%.bak}"
		[ -f "$origfile" ] && continue
		name=$(basename "$origfile") || continue
		[ -f /usr/share/applications/"$name" ] ||
			ls /var/lib/flatpak/app/*/current/active/files/share/applications/"$name" >/dev/null 2>&1 ||
			[ -f /var/lib/snapd/desktop/applications/"$name" ] &&
			mv "$bakfile" "$origfile"
	done
}

pidof -q -o %PPID -x fix-tweaked-desktop-files && exit

while :; do
	local_new=$(ls -ad "$HOME"/.local/share/applications/*.desktop 2>/dev/null)
	pacman_new=$(ls -ad /usr/share/applications/*.desktop 2>/dev/null)
	flatpak_new=$(ls -ad /var/lib/flatpak/app/*/current/active/files/share/applications/*.desktop 2>/dev/null)
	snap_new=$(ls -ad /var/lib/snapd/desktop/applications/*.desktop 2>/dev/null)
	[ "$local_new" != "$local_old" ] && detectfiles
	[ "$pacman_new" != "$pacman_old" ] ||
		[ "$flatpak_new" != "$flatpak_old" ] ||
		[ "$snap_new" != "$snap_old" ] && fixfiles
	local_old=$local_new
	pacman_old=$pacman_new
	flatpak_old=$flatpak_new
	snap_old=$snap_new
	sleep 5
done