#!/bin/sh

# name:     system-update
# summary:  - runs all relevant update commands for a machine
#           - automatically detects and handles apt, snap and flatpak
#           - fully POSIX shell compliant
# params:   none

# check if a command is available
has_command() { # $command
    command -v "$1" 1>/dev/null 2>/dev/null
}

# run self as root
if [ "$(id -u)" -ne 0 ]; then
    if has_command sudo; then
        # shellcheck disable=SC2068
        exec sudo "$(readlink -f "$0")" $@
    else
        echo "This script is designed to be run as root!"
        exit 1
    fi
fi

# handle apt packages
if has_command apt-get; then
    set -ex
    # update package sources
    apt-get --yes update
    # upgrade installed packages
    apt-get --yes dist-upgrade
    # remove unused dependencies
    apt-get --yes --purge autoremove
    # remove leftover local archives
    apt-get --yes autoclean
    # remove leftover config files
    apt-get --yes purge '?config-files'
    set +ex
fi

# handle snaps
if has_command snap; then
    set -ex
    # upgrade installed snaps
    snap refresh
    # remove disabled snaps: https://askubuntu.com/a/1040131
    set +x
    env LANG=en_US.UTF-8 snap list --all \
    | awk '/disabled/{print $1, $3}' \
    | while read -r snap_name snap_revision; do
            set -x
            snap remove "${snap_name}" --revision="${snap_revision}"
            set +x
    done
    set +ex
fi

# handle flatpaks
if has_command flatpak; then
    set -ex
    # upgrade installed flatpaks
    flatpak update --noninteractive
    # remove unused flatpaks
    flatpak uninstall --noninteractive --unused
    set +ex
fi