#!/bin/bash

################
# CHANGE THESE #
################

# path to your build_info.json file; include the file name
DISCORD_BUILD_INFO_PATH="/usr/share/discord/resources/build_info.json"

# for debian-based linux distributions (.deb installers)
DISCORD_PLATFORM="linux"
DISCORD_FORMAT="deb"

###########################
# DON'T CHANGE THIS STUFF #
###########################

# check for sudo
if [ $(id -g) -ne 0 ]; then
	echo "Please run as sudo"
	exit 2
fi

apt-get update && apt-get install -y jq

# get currently installed version of Discord
ver_current=$(jq -r ".version" "$DISCORD_BUILD_INFO_PATH")
echo "Discord version $ver_current installed"

# check latest available Discord version by looking at the headers of the latest Discord download URL
pre_ver_available=$(curl -s -I "https://discord.com/api/download?platform=$DISCORD_PLATFORM&format=$DISCORD_FORMAT" | grep location)

# trim everything before and after the version number
ver_available="${pre_ver_available#*linux/}"
ver_available="${ver_available%/*}"

echo "Discord version $ver_available available"

if [ "$ver_current" = "$ver_available" ] ; then
	echo "Discord is up to date!"
	exit 0
fi

echo "Discord is not up to date, editing $DISCORD_BUILD_INFO_PATH"

jq ".version = \"$ver_available\"" $DISCORD_BUILD_INFO_PATH > discord_build_info_tmp.json
chmod 644 discord_build_info_tmp.json
mv discord_build_info_tmp.json "$DISCORD_BUILD_INFO_PATH"

killall Discord