# Locale functions
#
# Copyright (C) 2012, 2018 Patrick McDermott
#
# This file is part of opkbuild.
#
# opkbuild is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# opkbuild is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with opkbuild.  If not, see <http://www.gnu.org/licenses/>.

_OB_DEFAULT_LOCALE='en_US'
_OB_INTERNAL_TEXT_DOMAIN="libopkbuild_${LIBOPKBUILD_SHSOVERSION}"
_OB_TEXT_DOMAIN=
_OB_LOCALE_PATH="${LOCALEDIR}/%s/LC_MESSAGES/%s.ms"

## @brief Get the current message domain
## @details \fBob_get_text_domain\fP prints the currently loaded message domain.
## @return Returns 0 on success or 125 if any arguments are given.
## @stdout Prints the name of the currently loaded message domain.
## @pure yes This function has no side effects.
ob_get_text_domain()
{
	if [ ${#} -ne 0 ]; then
		return 125
	fi

	echo "${_OB_TEXT_DOMAIN}"
	return 0
}

_ob_try_load_messages()
{
	local locale=
	local ms=

	locale="${1}"
	ms="$(printf "${_OB_LOCALE_PATH}" \
		"${locale}" "${_OB_TEXT_DOMAIN}")"

	if [ -f "${ms}" ]; then
		. "${ms}"
	else
		return 1
	fi

	return 0
}

## @brief Set and load the message domain
## @details \fBob_set_text_domain\fP() sets and loads the message domain for
##          future \fBob_get_msg\fP() calls.  A message domain is a catalog of
##          localized messages identified by message IDs.  Each application
##          should have its own message domain.  libopkbuild also has its own
##          message domain and temporarily switches to it when needed.
## @operand text_domain req The message domain to load.
## @return Returns 0 on success, 1 if the message domain cannot be loaded, or
##         125 if \fItext_domain\fP is missing.
## @stderr Prints a warning to stderr if the message domain cannot be loaded.
## @pure no This function sets an internal global variable and loads a message
##          catalog that sets numerous message variables.
ob_set_text_domain()
{
	if [ ${#} -eq 1 ]; then
		_OB_TEXT_DOMAIN="${1}"
	else
		return 125
	fi

	# Make sure LC_MESSAGES is set.
	if [ -z "${LC_MESSAGES}" ]; then
		if [ -n "${LC_ALL}" ]; then
			LC_MESSAGES="${LC_ALL}"
		elif [ -n "${LANG}" ]; then
			LC_MESSAGES="${LANG}"
		else
			LC_MESSAGES="${_OB_DEFAULT_LOCALE}"
		fi
	fi

	# TODO: Exit early if domain's messages have already been loaded.

	# Try to load the messages.
	if ! _ob_try_load_messages "${LC_MESSAGES%.*}"; then
		if ! _ob_try_load_messages "${LC_MESSAGES%_*}"; then
			if ! _ob_try_load_messages "${_OB_DEFAULT_LOCALE}"; then
				# TODO: Move this warning to the executables.
				# TODO: And use printf, since ob_warn() will be
				# internationalized.
				ob_warn 'Cannot load messages in "%s" domain.' \
					"${_OB_TEXT_DOMAIN}"
				return 1
			fi
		fi
	fi

	return 0
}

ob_set_locale_path()
{
	local format=

	if [ ${#} -eq 1 ]; then
		format="${1}"
	else
		return 125
	fi

	_OB_LOCALE_PATH="${format}"

	return 0
}

## @brief Get a message from the current message domain
## @details \fBob_get_msg\fP prints a message, identified by a message ID, from
##          the currently loaded message catalog.
## @operand msgid req The ID of the message to print
## @return Returns 0 on success or 125 if \fImsgid\fP is missing.
## @stdout Prints the requested message from the current message domain.
## @pure yes This function has no side effects.
ob_get_msg()
{
	local msgid=

	if [ ${#} -eq 1 ]; then
		msgid="${1}"
	else
		return 125
	fi

	IFS= eval echo \$\{"msg_${_OB_TEXT_DOMAIN}_${msgid}"\}

	return 0
}