# Copyright 1999-2016 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: l10n.eclass
# @MAINTAINER:
# Ben de Groot <yngwin@gentoo.org>
# @BLURB: convenience functions to handle localizations
# @DESCRIPTION:
# The l10n (localization) eclass offers a number of functions to more
# conveniently handle localizations (translations) offered by packages.
# These are meant to prevent code duplication for such boring tasks as
# determining the cross-section between the user's set LINGUAS and what
# is offered by the package; and generating the right list of linguas_*
# USE flags.

# @ECLASS-VARIABLE: PLOCALES
# @DEFAULT_UNSET
# @DESCRIPTION:
# Variable listing the locales for which localizations are offered by
# the package. Check profiles/desc/linguas.desc to see if the locales
# are listed there. Add any missing ones there.
#
# Example: PLOCALES="cy de el_GR en_US pt_BR vi zh_CN"

# @ECLASS-VARIABLE: PLOCALE_BACKUP
# @DEFAULT_UNSET
# @DESCRIPTION:
# In some cases the package fails when none of the offered PLOCALES are
# selected by the user. In that case this variable should be set to a
# default locale (usually 'en' or 'en_US') as backup.
#
# Example: PLOCALE_BACKUP="en_US"

# Add linguas useflags
for u in ${PLOCALES}; do
	IUSE+=" linguas_${u}"
done

# @FUNCTION: l10n_for_each_locale_do
# @USAGE: <function>
# @DESCRIPTION:
# Convenience function for processing localizations. The parameter should
# be a function (defined in the consuming eclass or ebuild) which takes
# an individual localization as (last) parameter.
#
# Example: l10n_for_each_locale_do install_locale
l10n_for_each_locale_do() {
	local locs x
	locs=$(l10n_get_locales)
	for x in ${locs}; do
		"${@}" ${x} || die "failed to process enabled ${x} locale"
	done
}

# @FUNCTION: l10n_for_each_disabled_locale_do
# @USAGE: <function>
# @DESCRIPTION:
# Complementary to l10n_for_each_locale_do, this function will process
# locales that are disabled. This could be used for example to remove
# locales from a Makefile, to prevent them from being built needlessly.
l10n_for_each_disabled_locale_do() {
	local locs x
	locs=$(l10n_get_locales disabled)
	for x in ${locs}; do
		"${@}" ${x} || die "failed to process disabled ${x} locale"
	done
}

# @FUNCTION: l10n_find_plocales_changes
# @USAGE: <translations dir> <filename pre pattern> <filename post pattern>
# @DESCRIPTION:
# Ebuild maintenance helper function to find changes in package offered
# locales when doing a version bump. This could be added for example to
# src_prepare
#
# Example: l10n_find_plocales_changes "${S}/src/translations" "${PN}_" '.ts'
l10n_find_plocales_changes() {
	[[ $# -ne 3 ]] && die "Exactly 3 arguments are needed!"
	ebegin "Looking in ${1} for new locales"
	pushd "${1}" >/dev/null || die "Cannot access ${1}"
	local current= x=
	for x in ${2}*${3} ; do
		x=${x#"${2}"}
		x=${x%"${3}"}
		current+="${x} "
	done
	popd >/dev/null
	# RHS will be sorted with single spaces so ensure the LHS is too
	# before attempting to compare them for equality. See bug #513242.
	# Run them both through the same sorting algorithm so we don't have
	# to worry about them being the same.
	if [[ "$(printf '%s\n' ${PLOCALES} | LC_ALL=C sort)" != "$(printf '%s\n' ${current} | LC_ALL=C sort)" ]] ; then
		eend 1 "There are changes in locales! This ebuild should be updated to:"
		eerror "PLOCALES=\"${current%[[:space:]]}\""
		return 1
	else
		eend 0
	fi
}

# @FUNCTION: l10n_get_locales
# @USAGE: [disabled]
# @DESCRIPTION:
# Determine which LINGUAS USE flags the user has enabled that are offered
# by the package, as listed in PLOCALES, and return them. In case no locales
# are selected, fall back on PLOCALE_BACKUP. When the disabled argument is
# given, return the disabled useflags instead of the enabled ones.
l10n_get_locales() {
	local disabled_locales enabled_locales loc locs
	for loc in ${PLOCALES}; do
		if use linguas_${loc}; then
			enabled_locales+="${loc} "
		else
			disabled_locales+="${loc} "
		fi
	done
	if [[ ${1} == disabled ]]; then
		locs=${disabled_locales}
	else
		locs=${enabled_locales:-$PLOCALE_BACKUP}
	fi
	printf "%s" "${locs}"
}