nxm-handler

#!/bin/bash

# This script tries to find an instance of Mod Organizer 2 running on Wine/Proton,
# then calls it again passing the nxm:// link so it starts downloading.

main() {
	local title
	local url
	local mo2_pid
	local mo2_cmdline
	local mo2_env_vars
	local success

	title=$(basename "$0")
	url=$1

	if [[ -z "$url" ]]; then
		message_box error 'No URL provided.'
		return 1
	fi

	mo2_pid=$(find_mo2)
	success=$?

	if [[ $success -ne 0 ]]; then
		message_box error \
		"Failed to find Mod Organizer 2, make sure it's running and try again!"
		return 1
	fi

	mo2_env_vars=$(get_env_vars_from_pid "$mo2_pid")
	mo2_cmdline=$(
		get_cmdline_from_pid "$mo2_pid" | \
		sed 's/waitforexitandrun/run/' # Hack to fix Proton.
	)

	export_env_var "$mo2_env_vars" STEAM_COMPAT_CLIENT_INSTALL_PATH
	export_env_var "$mo2_env_vars" STEAM_COMPAT_DATA_PATH
	#export_env_var "$mo2_env_vars" WINEPREFIX

	eval "WINEPREFIX=${STEAM_COMPAT_DATA_PATH}/pfx $mo2_cmdline '$url'"
}

find_mo2() {
	# Finds the first process id that started ModOrganizer.exe, which may be
	# Wine or Proton.

	local pid
	pid=$(pgrep -f ModOrganizer.exe | head -n 1)

	if [[ -z "$pid" ]]; then
		return 1
	fi

	echo "$pid"
}

get_cmdline_from_pid() {
	# Usage: get_cmdline_from_pid <process_id>
	#
	# Gets a sanitized command line for a given process id.
	# Spaces are escaped by quoting each argument.

	sed -E -e 's/.*--//g' < "/proc/$1/cmdline" | \
	strings -n 1 | \
	while read -r line; do
		printf "'%s' " "$line"
	done
}

get_env_vars_from_pid() {
	# Usage: get_env_vars_from_pid <process_id>
	#
	# Emits a list of environment variables for a given process id separated by
	# newlines.

	strings < "/proc/$1/environ"
}

export_env_var() {\
	# Usage: export_env_var <variables> <name>
	#
	# Takes a list of variable assignments split by newlines and exports the one
	# that matches a given name.

	local var=$2
	eval "$var=$(sed -nE -e "s/^$2=(.*)/\1/p" <<< "$1")"
	echo "$var=${!var}"
	export "${var?}"
}

message_box() {
	# Usage: message_box [info | error] <text>

	if [[ -z "$2" ]]; then
		set -- 'info' "$1"
	fi

	case "$XDG_CURRENT_DESKTOP" in
		'KDE' | 'LXQt')
			try_kdialog "$@" || try_zenity "$@" || console_log "$@"
			;;
		*)
			try_zenity "$@" || try_kdialog "$@" || console_log "$@"
			;;
	esac
}

try_kdialog() {
	if ! type kdialog &>/dev/null; then
		return 1
	fi

	read -ra flags < <(get_kdialog_flags "$1")
	kdialog --title "$title" "${flags[@]}" "$2"
}

get_kdialog_flags() {
	case "$1" in
		'error') echo '--error' ;;
		*) echo '--msgbox' ;;
	esac
}

try_zenity() {
	if type zenity &>/dev/null; then
		return 1
	fi

	read -ra flags < <(get_zenity_flags "$1")
	zenity --title "$title" "${flags[@]}" "$2"
}

get_zenity_flags() {
	case "$1" in
		'error') echo '--error --text' ;;
		*) echo '--info --text' ;;
	esac
}

console_log() {
	echo "$1: $2"
}

main "$@"