DEBIAN_CODENAME="$(
	grep "VERSION_CODENAME" "/etc/os-release" |
		cut --delimiter "=" --fields "2"
)"

apt_clean() {
	apt-get \
		clean
}

apt_conf_write() {
	printf "\
Acquire::AllowInsecureRepositories False;
Acquire::AllowWeakRepositories False;
Acquire::AllowDowngradeToInsecureRepositories False;
Acquire::Check-Valid-Until True;
APT::Install-Recommends False;
APT::Install-Suggests False;
APT::Get::Show-Versions True;
Dir::Etc::SourceParts \"\";
Dpkg::Progress True;
" >"/etc/apt/apt.conf.d/apt.conf"
}

apt_install_backports() {
	apt_install_target "${DEBIAN_CODENAME}-backports" "${@}"
}

apt_install_release() {
	apt_install_target "${DEBIAN_CODENAME}" "${@}"
}

apt_install_target() {
	local target="${1}"
	shift
	local package
	for package in "${@}"; do
		log_info
		log_info "${package} ← ${target}"
		apt-get \
			install \
			--assume-yes \
			--target-release "${target}" \
			"${package}"
		apt_clean
	done
}

apt_sources_write() {
	printf "%s" "\
deb https://deb.debian.org/debian \
${DEBIAN_CODENAME} main non-free-firmware contrib non-free
deb https://deb.debian.org/debian \
${DEBIAN_CODENAME}-backports main non-free-firmware contrib non-free
deb https://deb.debian.org/debian \
${DEBIAN_CODENAME}-updates main non-free-firmware contrib non-free
deb https://deb.debian.org/debian-security \
${DEBIAN_CODENAME}-security main non-free-firmware contrib non-free
" >"/etc/apt/sources.list"
}

apt_update() {
	apt-get \
		update
}

apt_upgrade() {
	apt-get \
		upgrade \
		--assume-yes
	apt_clean
}

debian_disable_frontend() {
	export DEBIAN_FRONTEND="noninteractive"
}