# Copyright (c) 2017 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Johnny C. Lam.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# NAME
#	groups.subr -- group management for packages
#
# SYNOPSIS
#	task_groups [-s] add | remove
#	task_groups check-add | check-remove
#
# DESCRIPTION
#	The task_groups function supports four actions: "add", "remove",
#	"check-add", and "check-remove".
#
#	The available options are as follows:
#
#	-s	Silent; don't write to standard output.
#
#	The task_groups function reads standard input line by line and
#	looks for lines of the form:
#
#	    # GROUP: <name>[:<groupid>]
#
#	Only the group is required; the groupid is optional.
#
#	The "add" action creates the group with the given name if it is
#	missing, with the given group ID, if ${PKG_CREATE_USERGROUP} is
#	"yes".  A reference count for the group will be error for the
#	package.
#
#	The "remove" action removes a reference count for the group by
#	the package.  This function shall not remove any group on the
#	system.
#
#	The "check-add" action will check whether the groups exist with
#	the optional group IDs if they are given, or otherwise writes a
#	message to standard output noting the missing groups.
#
#	The "check-remove" action will check whether the groups have been
#	removed, or otherwise writes a message to standard output noting
#	the groups still exists.
#
# RETURN VALUES
#	The "add" and "remove" actions return 0 if they are successful
#	for all groups, and >0 if an error occurs.
#
#	The "check-add" and "check-remove" actions return >0 if they
#	write informative messages, and return 0 otherwise.
#
# ENVIRONMENT
#	The following variables are used if they are set:
#
#	PKGNAME
#		The name of the package.
#
#	PKG_CREATE_USERGROUP
#		If ${PKG_CREATE_USERGROUP} is a "truthy" value, then the
#		"add" and "remove" actions are allowed to create and
#		remove groups from the system.
#
#	TASK_MSG
#		String prepended to all normal message written to
#		standard output.
#

__task_groups__="yes"
__task_groups_init__="_task_groups_init"

task_load cleanup
task_load echo
task_load quote
task_load refcount
task_load truthy
task_load usergroup
task_load usergroup_exists

task_groups()
{
	: ${PKGNAME:=${0##*/}}
	: ${PKG_CREATE_USERGROUP:=yes}
	: ${TASK_MSG:=""}

	local arg
	local echo="task_echo"
	local OPTIND=1
	while getopts ":s" arg "$@"; do
		case $arg in
		s)	echo=":" ;;
		*)	return 127 ;;
		esac
	done
	shift $(( ${OPTIND} - 1 ))
	[ $# -gt 0 ] || return 127

	local action="$1"; shift
	case $action in
	add|remove|check-add|check-remove)
		: "valid action" ;;
	*)	return 0 ;;
	esac

	local create="yes"
	task_is_truthy "${PKG_CREATE_USERGROUP}" || create=

	local result line_result
	local save_IFS group gid msg

	result=0
	local hash tag entry
	while read hash tag entry; do
		# Filter for "# GROUP:".
		case $hash/$tag in
		"#/GROUP:")
			: "use this line" ;;
		*)	continue ;;
		esac

		save_IFS=$IFS; IFS=:
		set -o noglob; set -- $entry; set +o noglob
		group=$1; gid=$2
		IFS=$save_IFS
		[ -n "$group" ] || continue

		if [ -n "$gid" ]; then
			msg="$group (gid = $gid)"
		else
			msg="$group"
		fi

		line_result=0
		case $action in
		add)	if task_refcount add groups "$group"; then
				task_group_exists "$group" "$gid"
				case $? in
				0)	# $group exists and has gid $gid
					$echo "${TASK_MSG}! group already exists: $group" ;;
				1)	# neither $group nor $gid exist
					if [ -z "$create" ]; then
						$echo "${TASK_MSG}! group creation skipped: $msg"
					elif task_addgroup "$group" "$gid"; then
						$echo "${TASK_MSG}> group created: $msg"
						# Keep track of groups added in case of error later.
						task_quote "$group"
						__task_groups_error__="$__task_groups_error__ $_quoted"
					else
						$echo "${TASK_MSG}! group not created: $msg"
						line_result=1
					fi ;;
				2)	$echo "${TASK_MSG}! group conflict: $msg"
					result=1
					break ;;
				*)	$echo "${TASK_MSG}! group not created: $msg"
					line_result=1 ;;
				esac
			else
				# add refcount failed; skip to next line
				$echo "${TASK_MSG}! refcount add failure: groups $group"
				result=1
				continue
			fi ;;
		remove)	if task_refcount remove groups "$group"; then
				if task_refcount exists groups "$group"; then
					: "refcount is not zero"
				else
					# delete the reference count
					task_refcount delete groups "$group"
				fi
			else
				# remove refcount failed
				$echo "${TASK_MSG}! refcount remove failure: groups $group"
				line_result=1
			fi ;;
		check-add)
			if task_group_exists "$group" "$gid"; then
				: "group already exists"
			else
				task_echo "!!! INFO: ${PKGNAME}: Create group: $msg"
				line_result=1
			fi ;;
		check-remove)
			if task_group_exists "$group" "$gid"; then
				task_echo "!!! INFO: ${PKGNAME}: Remove group if unused: $group"
				line_result=1
			fi ;;
		esac
		[ $line_result -eq 0 ] || result=1
	done

	# Clear groups to remove in case of error if all groups added
	# successfully.
	#
	[ $result -gt 0 ] || __task_groups_error__=

	return $result
}


_task_groups_cleanup()
{
	eval set -- $__task_groups_error__
	local group
	for group; do
		if task_group_exists "$group"; then
			task_echo "!!! ERROR: ${PKGNAME}: Group created before error: $group"
		fi
	done
	__task_groups_error__=
}

_task_groups_init()
{
	task_cleanup_add_hook _task_groups_cleanup
}

# Static variable for groups that should be removed if an error occurs.
__task_groups_error__=