discord-update.bash

#!/usr/bin/env bash

# ~/.local/libexec/discord-update.bash

which tar >/dev/null 2>/dev/null || (echo "missing command: 'tar'"; exit 1)
which wget >/dev/null 2>/dev/null || (echo "missing command: 'wget'"; exit 1)
which curl >/dev/null 2>/dev/null || (echo "missing command: 'curl'"; exit 1)
which jq >/dev/null 2>/dev/null || (echo "missing command: 'jq'"; exit 1)

if [[ "$EUID" == 0 ]]; then
    DEFAULT_PREFIX=/usr/local
else
    DEFAULT_PREFIX=$HOME/.local
fi

PREFIX=${PREFIX:-$DEFAULT_PREFIX}
SH=$PREFIX/share
D=$SH/discord

DEFAULT_DL_URL="https://discord.com/api/download?platform=linux&format=tar.gz"
DL_URL=${DL_URL:-$DEFAULT_DL_URL}

function notify() {
    if [[ -n "$NOTIFY_SEND" ]]; then
        NS_ID=$($NOTIFY_SEND -p $NS_REPLACE -a "Discord Update" "$1")
        NS_REPLACE="-r $NS_ID"
    fi
}

CURRENT=""
if [[ -f $D/resources/build_info.json ]]; then
    CURRENT=$(jq -r .version $D/resources/build_info.json)
    echo "* installed version: '$CURRENT'" 1>&2
fi

VER="$(curl -sI -H 'Cache-Control: no-cache' "$DL_URL" \
    | sed -ne 's/[Ll]ocation:.*discord-\(.*\)\.tar\.gz\r*/\1/p' \
)"

echo "* latest version: '$VER'" 1>&2

if [[ "$CURRENT" == "$VER" && -z "$FORCE" ]]; then
    echo "* already up to date"
    exit
fi

notify "Downloading Discord $VER..."

TMP=$(mktemp -d "/tmp/dl-discord-$VER.XXXXXXXXXXX")
trap 'rm -rf $TMP' EXIT

SRC=$TMP/Discord

if [[ -z "$ARCHIVE" ]]; then
    ARCHIVE=$TMP/discord.tar.gz
    echo "* downloading .tar.gz" 1>&2
    wget "$DL_URL" -O $ARCHIVE --no-verbose || exit 1
else
    ARCHIVE=$(realpath "$ARCHIVE")
fi

echo "* extracting .tar.gz" 1>&2
tar -C $TMP -xf "$ARCHIVE" Discord || exit 1

notify "Updating Discord $VER"

while pidof Discord >/dev/null; do
    echo "* stopping active discord process" 1>&2
    kill $(pidof Discord)
    sleep 1
done

if [[ -d $D ]]; then
    echo "* removing previous installation" 1>&2
    rm -f $SH/applications/discord.desktop $SH/pixmaps/discord.png $PREFIX/bin/discord
    rm -rf $D
fi

set -e

echo "* moving files into $PREFIX" 1>&2
mkdir -p $SH/applications $SH/pixmaps $PREFIX/bin
sed -se "s#/usr#$PREFIX#" -i $SRC/discord.desktop
mv $SRC/discord.desktop $SH/applications
mv $SRC $D
ln -s ../discord/discord.png $SH/pixmaps/discord.png
ln -s ../share/discord/Discord $PREFIX/bin/discord

set +e

which update-desktop-database >/dev/null 2>/dev/null && update-desktop-database $SH/applications

notify "Discord updated to $VER!"

discord-update.service

# ~/.config/systemd/user/discord-update.service

[Unit]
Description=Update Discord because it can't figure out how to do this on its own

[Service]
Type=oneshot
ExecStart=/bin/sh -c 'exec $HOME/.local/libexec/discord-update.bash'

# this line enables notification boxes
Environment=NOTIFY_SEND=notify-send

discord-update.timer

# ~/.config/systemd/user/discord-update.timer

[Unit]
Description=Try to update Discord daily

[Timer]
OnCalendar=daily
Persistent=true