#!/bin/bash
#steam-compatdata-symlinker
#by: Mouse
#Current build: Feb 11, 2023

###################
#user config:
###################

#the ln command with switches:
#change this command if you want this script to change how it creates links:
cmd="ln -sTf"

#directory filters:
#you can add your own filters here for the directories you want ignored.
#filters must be exact
#in other words, they're case sensitive and each game name or ID must be written here exactly as it appears in the directory name.
#example 1: the filter "Fallout" will not filter out the game Fallout: New Vegas
#example 2: the filter "Fallout: New Vegas" will not filter out any Fallout. Nor will it filter out the game it was intended to filter either, because the directory is named "Fallout New Vegas" and not "Fallout: New Vegas"
#note: filter checks aren't applied to broken symlinks
filter=("Steam Controller Configs" "0")

#custom directory overrides:
#put your custom directory overrides here.
#don't end paths with a slash ("/")
#use $HOME to reference your home directory
#example: commondir="$HOME/Games/mycustomsteamapps/common"
commondir=""
compatdatadir=""
shadercachedir=""

###################
#end of user config
###################

countlines(){
	grep "" -c "$1"
}

readline(){
	if [[ $1 && $2 ]]; then
		max="$(countlines "$1")"
		if (( $2 > $max )); then
			sed -n "${max}p" "$1"
		else
			sed -n "${2}p" "$1"
		fi
	fi
}

#this lets us look for a corresponding symlink to give us a hint as to what game this compatdata was originally for
lnsearchsub(){
	str="$2"
	linktarget="$(readlink -f "$1")"
	if [[ "$linktarget" == *"$str"* ]]; then
		echo "Found symlink for $(basename "$linktarget"). It's likely $(basename "$1")'s compatdata directory."
	fi
}

lnsearch(){
	if (( $# >= 2 )); then
		export -f lnsearchsub
		find "$2" -maxdepth 1 -type l -exec bash -c "lnsearchsub \"{}\" \"$1\"" \;
	else
		echo "Usage: $0 <string to search for> <dir to search in>"
	fi
}

isfiltered(){
	y=false
	for x in "${filter[@]}"; do
		if [[ "$x" == "$1" ]]; then
			y=true
			break
		fi
	done
	echo "$y"
}

lnfn(){
	counter=0
	for i in "$thedir/"*".acf"; do
		id="${i/"$thedir/appmanifest_"/""}"
		id="${id/".acf"/""}"
		if [[ "$(isfiltered "$id")" == "false" ]]; then
			if [[ -d "$compatdatadir/$id" ]]; then
				#line for undoing when $compatdatadir/$id/$id" was created by ln.
				#(I had to use -f and -T to prevent this. I had no idea ln behaved like this.)
#				if [[ -d "$compatdatadir/$id/$id" ]]; then
#					gio remove "$compatdatadir/$id/$id"
#				fi
				name="$(readline "$i" "5")"
				name="${name/"\"name\""/""}"
				name="${name//"	"/""}"
				name="${name//"\""/""}"
				if [[ "$name" =~ ^[0-9]+$ ]] && [[ -e "$compatdatadir/$name" ]] && ! [[ -L "$compatdatadir/$name" ]]; then
					echo
					echo "WARNING: $compatdatadir/$name already exists, is all numbers, and isn't a symlink. This seems like the rare situation where a game, who's name is all numbers, can conflict with compatdata directories and the symlinks this script creates."
					echo "As a precaution, this script will only report the conflict. It's on you to create a symlink, if you really want one."
					echo "To stop getting warnings about $name, add it to the filter list at the top of this script."
					echo "Skipping $name."
					echo
				else
					if [[ "$1" == "test" ]]; then
						echo "$cmd \"$compatdatadir/$id\" \"$compatdatadir/$name\""
					fi
					if [[ "$1" == "run" ]]; then
						$cmd "$compatdatadir/$id" "$compatdatadir/$name"
					fi
				fi
				counter=$(( counter + 1 ))
#			else
				#I guess it's technically an error but steam downloads appmanifest files for all of a game's subdepo's, so I guess we don't need to report on every single one. Or really any of them.
#				echo "ERROR: Missing target directory for ($name): $compatdatadir/$id"
#				echo "Skipping."
			fi
		fi
	done
}

usage(){
	echo "Usage: $0 [ \"steamapps directory\" ]"
	echo "This will automatically make symlinks for all directories in the supplied /steamapps/compatdata/ directory."
	echo "This makes it easier to find the right compatdata directory without needing to look up the game's Steam ID."
	echo "Run this script again to create symlinks for new game installs, and clean up old uninstalls."
	echo "This script will also check for unused compatdata, shadercache, and common directories, left behind from uninstalls and moved installs."
	echo "-h for this dialog."
	echo "-e for a longer explanation on these unused directories."
}

longexplain(){
	echo "There are multiple reasons why unused directories would exist, such as the game was uninstalled or moved to a different drive, another program made changes, a user made changes, etc etc."
	echo "But the important part is, as far as any directories reported by this script goes, Steam would be unaware of their existence and wouldn't be doing anything with them."
	echo
	echo "If you would like to know what game a directory is tied to, type the full name of the folder (the number(which is the steamid)) into your Steam library. It will automatically show you the game."
	echo
	echo "Whether or not these directories should be deleted is left to your discretion. But be aware your user data could be inside of them, including save files. So I advise at least looking around in the directory for valuable data first before deleting it."
	echo
	echo "If it's a compatdata directory, then look in the program files and steamuser directories."
	echo "If it's a steamapps/common directory, then obviously just look in the game's install directory."
	echo "If it's a shadercache directory, then you can safely delete that directory, unless you plan on reinstalling that game, on that same steamapps drive, sometime in the near future. This could save Steam from recompiling the shader cache. But even then, Steam may choose to do it anyways, so it's left to your discretion."
	echo
	echo "NOTE: This script doesn't support non-Steam games. To find which compatdata directory holds the non-Steam game in question, run this:"
	echo "find ~/path/to/your/steamapps/compatdata/ -iname *game*name*here* 2>/dev/null"
	echo
	echo "NOTE: Every steamapps directory has its own common, compatdata, and shadercache directories. If you have games installed on multiple drives, even moving a game from one drive to another can leave behind some of these directories. So just because Steam says a game is installed doesn't mean it's installed to the specific steamapps directory you supplied, which would mean these directories are still quite likely not in use. Again, this is all left to your discretion."
}

if (( $# >= 1 )); then
	while getopts "he" OPTION; do
		case "${OPTION}" in
			h)
				usage
				exit
				;;
			e)
				longexplain
				exit
				;;
			\?)
				exit
				;;
		esac
	done
	shift "$((OPTIND -1))"

	thedir="$(realpath "$1")"
	if [[ "$compatdatadir" == "" ]]; then
		compatdatadir="$thedir/compatdata"
	fi
	if [[ "$commondir" == "" ]]; then
		commondir="$thedir/common"
	fi
	if [[ "$shadercachedir" == "" ]]; then
		shadercachedir="$thedir/shadercache"
	fi

	if [[ -d "$compatdatadir" ]]; then
		echo "The following commands will run:"
		lnfn "test"
		echo
		echo "$counter symlinks will be created."
		echo "Continue? [ y / n ]"
		read -e input
		if [[ "${input,,}" == "y"* ]]; then
			lnfn "run"
			echo
			echo "Done!"
			echo "$counter symlinks created."
			echo

		else
			echo "Canceled!"
			echo
		fi

		#now let's find broken symlinks
		asdf="$(find "$compatdatadir/" -maxdepth 1 -xtype l)"
		if [[ "$asdf" == "" ]]; then
			echo "No broken symlinks found."
		else
			echo "--------------------------------"
			echo "Broken symlinks found:"
			echo "$asdf"
			echo "--------------------------------"
			echo
		fi

		unaccountedfound=0

		#now let's look for unused compatdata directories
		found=0
		for number in "$compatdatadir/"*; do
			if [[ -d "$number" ]] && ! [[ -L "$number" ]]; then
				numberbn="$(basename "$number")"
				if [[ "$(isfiltered "$numberbn")" == "false" ]]; then
					if ! [[ -e "$thedir/appmanifest_""$numberbn"".acf" ]]; then
						if [[ $found == 0 ]]; then
							found=1
							unaccountedfound=1
							echo "--------------------------------"
							echo "Unused compatdata directory(s) found:"
						fi
						echo "$number (link: https://steamdb.info/app/$numberbn)"
						lnsearch "$number" "$compatdatadir/"
					fi
				fi
			fi
		done
		if [[ $found == 1 ]]; then
			echo "--------------------------------"
			echo
		else
			echo "No unused compatdata directories found."
		fi

		#let's look for unused ../steamapps/common directories too while we're at it.
		if [[ -d "$commondir" ]]; then
			found=0
			for d in "$commondir/"*; do
				if [[ -d "$d" ]] && ! [[ -L "$d" ]]; then
					asdf="$(basename "$d")"
					if [[ "$(isfiltered "$asdf")" == "false" ]]; then
						if ! [[ "$(grep -ie "$asdf" "$thedir/app"*)" == *"$asdf"* ]]; then
							if [[ $found == 0 ]]; then
								found=1
								unaccountedfound=1
								echo "--------------------------------"
								echo "Unused common directory(s) found:"
							fi
							echo "$commondir/$asdf ($asdf)"
						fi
					fi
				fi
			done
			if [[ $found == 1 ]]; then
				echo "--------------------------------"
				echo
			else
				echo "No unused common directories found."
			fi
		else
			echo "ERROR: An invalid common directory has been set:"
			echo "'$commondir': $commondir"
			echo "Skipping."
			echo
		fi

		#and, what the hell, let's look for unused shader directories too I guess. we might as well since we're already wiping all of these other butts.
		if [[ -d "$shadercachedir" ]]; then
			found=0
			for number in "$shadercachedir/"*; do
				if [[ -d "$number" ]] && ! [[ -L "$number" ]]; then
					numberbn="$(basename "$number")"
					if [[ "$(isfiltered "$numberbn")" == "false" ]]; then
						if ! [[ -e "$thedir/appmanifest_""$numberbn"".acf" ]]; then
							if [[ $found == 0 ]]; then
								found=1
								unaccountedfound=1
								echo "--------------------------------"
								echo "Unused shadercache directory(s) found:"
							fi
							echo "$number (link: https://steamdb.info/app/$numberbn)"
						fi
					fi
				fi
			done
			if [[ $found == 1 ]]; then
				echo "--------------------------------"
				echo
			else
				echo "No unused shadercache directories found."
			fi
		else
			echo "ERROR: An invalid shadercache directory has been set:"
			echo "'$shadercachedir': $shadercachedir"
			echo "Skipping."
			echo
		fi

		if [[ $unaccountedfound == 1 ]]; then
			echo "These unused directories seem to have no configuration files and are likely not in use."
			echo "For a longer explanation, run:"
			echo "$0 -e"
		fi

	else
		echo "ERROR: compatdata directory not found."
		echo "Ensure you are supplying a valid steamapps directory."
		echo "Exiting."
	fi

else
	usage
fi