path: root/src/modules/java-vm.eselect.in

# -*-eselect-*-  vim: ft=eselect
# Copyright 1999-2024 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

DESCRIPTION="Manage the Java system and user VM"
MAINTAINER="java@gentoo.org"
VERSION="@VERSION@"

VM_BASE="${EPREFIX}/usr/lib/jvm"
VM_SYSTEM="${EROOT}/etc/java-config-2/current-system-vm"
VM_USER="${HOME}/.gentoo${EPREFIX}/java-config-2/current-user-vm"
VM_CONFIG="${EROOT}/usr/share/java-config-2/vm"

find_targets() {
	local TARGETS=() target

	for target in "${ROOT}${VM_BASE}"/*; do
		[[ -L "${target}" ]] && TARGETS+=( ${target##*/} )
	done

	printf "%s\n" "${TARGETS[@]}" | sort -uV
}

sym_to_vm() {
	basename $(readlink "${1}")
}

### show action ###

describe_show() {
	echo "Show the current VM"
}

describe_show_parameters() {
	echo "[user|system]"
}

do_show() {
	if [[ ${1} == "system" ]]; then
		my_show "${VM_SYSTEM}" 'system-vm'
	elif [[ ${1} == "user" ]]; then
		my_show "${VM_USER}" 'user-vm'
	else
		my_show "${VM_SYSTEM}" 'system-vm'
		my_show "${VM_USER}" 'user-vm'
	fi
}

my_show() {
	local symlink=${1} vm_type=${2}
	write_list_start "Current ${vm_type}"
	if [[ -L "${symlink}" ]] ; then
		write_kv_list_entry "$(sym_to_vm ${symlink})" ""
	else
		write_kv_list_entry "(unset)" ""
	fi
}

### list action ###

describe_list() {
	echo "List Available Virtual Machines"
}

do_list() {
	targets=( $(find_targets) )
	write_list_start "Available Java Virtual Machines:"
	local found_build_only
	if [[ -n ${targets[@]} ]] ; then
		local i system_name user_name

		[[ -L ${VM_SYSTEM} ]] && system_name=$(sym_to_vm "${VM_SYSTEM}")
		[[ -L ${VM_USER} ]] && user_name=$(sym_to_vm "${VM_USER}")

		for (( i = 0 ; i < ${#targets[@]} ; i = i + 1 )) ; do
			local build_only=$(grep 'BUILD_ONLY' "${VM_CONFIG}/${targets[${i}]}" | cut -c 13-16 )
			local mark=""

			if [[ "${build_only}" == "TRUE" || "{build_only}" == "true" ]]; then
				mark="$(highlight_warning 'Build Only')"
				found_build_only="TRUE"
			fi

			if [[ ${targets[${i}]} == ${system_name} ]]; then
				mark="${mark} $(highlight 'system-vm')"
			fi
			if [[ ${targets[${i}]} == ${user_name} ]]; then
				mark="${mark} $(highlight 'user-vm' )"
			fi
			targets[${i}]="${targets[${i}]} ${mark}"
		done
		write_numbered_list "${targets[@]}"
	else
		write_kv_list_entry "(none found)" ""
	fi
	echo
	if [[ "${found_build_only}" == "TRUE" ]]; then
		write_warning_msg "VMs marked as Build Only may contain Security Vulnerabilities and/or be EOL."
		write_warning_msg "Gentoo recommends not setting these VMs as either your System or User VM."
		write_warning_msg "Please see https://wiki.gentoo.org/wiki/Java#Build_Only_VM for more information."
	fi
}

### set action ###

describe_set() {
	echo "Set a new system or user VM"
}

describe_set_options() {
	echo "--if-unset : do not change if already set"
}

describe_set_parameters() {
	echo "[user|system] <VM>"
}

do_set() {
	local usage="Usage [user|system] <VM>"
	local ifunset=0

	if [[ ${1} == "--if-unset" ]]; then
		ifunset=1
		shift
	fi

	# Automatically decide, based in the invoking user's UID, if the
	# user or system Java VM should be modified.
	if [[ ${#} -eq 1 ]]; then
		local kind
		if [[ ${UID} -eq 0 ]]; then
			kind="system"
		else
			kind="user"
		fi
		set -- ${kind} ${@}
	fi

	if [[ ${#} != 2 ]]; then
		die -q ${usage}
	elif [[ ${1} == "system" ]]; then
		if [[ -w ${VM_SYSTEM%/*} ]]; then
			my_set "${VM_SYSTEM}" "${2}" ${ifunset}
		else
			die -q "Sorry, you don't have enough permission to set system"
		fi
	elif [[ ${1} == "user" ]]; then
		if [[ ${UID} != 0 ]]; then
			my_set "${VM_USER}" "${2}" ${ifunset}
		else
			die -q "Sorry, you cannot set a user VM as root. Set the system VM instead"
		fi
	else
		die -q ${usage}
	fi
}

my_set() {
	local symlink=${1} target=${2} ifunset=${3}
	if [[ -z ${target} ]] ; then
		die -q "You didn't tell me what to set the symlink to"

	elif [[ -L "${symlink}" ]] ; then
		if [[ ${ifunset} == 0 || ! -d ${symlink} ]]; then
			set_symlink "${target}" "${symlink}"  || die -q "Couldn't set a new symlink"
		fi

	elif [[ -e ${symlink} ]] ; then
		die -q "Target file already exists and is not a symlink: ${symlink}"

	else
		set_symlink "${target}" "${symlink}" || die -q "Couldn't set a new symlink"
	fi
}

set_symlink() {
	local target=${1} symlink=${2}
	if is_number "${target}" ; then
		targets=( $(find_targets) )
		target=${targets[$(( ${target} - 1 ))]}
	fi
	if [[ -z ${target} ]] ; then
		die -q "Target \"${1}\" doesn't appear to be valid!"
	elif [[ -L ${ROOT}${VM_BASE}/${target} || -d ${ROOT}${VM_BASE}/${target} ]] ; then
		local sym_dir=${symlink%/*}
		mkdir -p "${sym_dir}" || die -q "Could not create ${sym_dir}"
		ln -snf "${VM_BASE}/${target}" "${symlink}"
	else
		die -q "Target \"${1}\" doesn't appear to be valid!"
	fi
}

describe_update() {
	echo "Automatically update the Java system VM"
}

do_update() {
	local targets
	targets=( $(find_targets) )

	if [[ ${#targets[@]} -eq 0 ]]; then
		echo "No installed Java VMs found, can not update"
		return
	fi

	if [[ -e "${VM_SYSTEM}" ]]; then
		local current_system_vm_name=$(sym_to_vm "${VM_SYSTEM}")
		echo "Current Java system VM ${current_system_vm_name} is valid, no need to update"
		return
	fi

	local new_target old_system_vm_name
	if [[ -L "${VM_SYSTEM}" ]]; then
		# There exists a Java system VM symlink that has become stale,
		# try to find another available VM with the same slot.
		old_system_vm_name=$(sym_to_vm "${VM_SYSTEM}")

		local old_system_vm_slot="${old_system_vm_name##*-}"

		local target
		for target in "${targets[@]}"; do
			local target_slot="${target##*-}"
			if [[ ${target_slot} -eq ${old_system_vm_slot} ]]; then
				new_target="${target}"
				break
			fi
		done
	fi

	if [[ -z "${new_target}" ]]; then
		# There is no Java system VM symlink or we could not find a
		# slot-matching replacement. But there are potential targets,
		# simply choose the first.
		# TODO: We could get more sophisticated here to select the "best"
		# target, but that is far from trivial.
		new_target="${targets[0]}"
	fi

	local from_vm_text=""
	if [[ -n "${old_system_vm_name}" ]]; then
		from_vm_text="from ${old_system_vm_name} "
	fi

	echo "Updating Java system VM ${from_vm_text}to ${new_target}"
	set_symlink "${new_target}" "${VM_SYSTEM}"
}