#!/bin/sh
# dist-tools/git-commit-po-updates.sh
# A helper script to commit translation updates into Git.
# Assumes translation updates are visible to git,
# and one directory above.
#
# © Copyright 2019 - 2020 by Matthias Andree.
# Licensed under the GNU General Public License V2 or,
# at your choice, any later version.
#
# Supported modes:
# -n:   dry-run, only print commands, but do not run them.
# -c:   commit, print commands and run them.
set -eu


cd "$(realpath $(dirname $0))/.."

# see if Perl has Carp::Always available,
# and implicitly fail (set -e) if it hasn't.
perl -MCarp::Always -e ''

usage() {
	printf 'Usage: %s {-n|-c}\n-n: dry-run; -c: commit\n' "$0"
	exit $1
}

dryrun_pfx=
docommit=
while getopts 'nc' opt ; do
  case $opt in
  n) dryrun_pfx=: ;;
  c) docommit=y ;;
  ?)
     usage 2 ;
  esac
done

if [ -z "$dryrun_pfx" -a -z "$docommit" ] ; then usage 2 ; fi

git diff -G '^"(Project-Id-Version|PO-Revision-Date):' --name-only po/*.po \
| while read pofile ; do
	if ! cmd="$(perl -WT - "$pofile" <<'_EOF'
use Encode::Locale;
use Encode;
use strict;
use Carp::Always ();
use warnings FATAL => 'uninitialized';
my ($ver, $dat, $translator, $lang, $lcod, $cset, $found);

while(<>)
{
	if (/^"Project-Id-Version: (.+)\\n"/)	{ $ver=$1; };
	if (/^"PO-Revision-Date: (.+)\\n"/)	{ $dat=$1; };
	if (/^"Last-Translator: (.+)\\n"/)	{ $translator=$1; };
	if (/^"Language-Team: ([^<]+?)\s+<.*>\\n"/)
						{ $lang=$1; };
	if (/^"Language: (.+)\\n"/)		{ $lcod=$1; };
	if (/^"Content-Type: text\/plain; charset=(.+)\\n"/)
						{ $cset = $1; };
	if ($ver and $dat and $translator and $lang and $lcod and $cset) {
		$found = 1;
		last;
	}
}

$translator = Encode::decode($cset, $translator);

if ($found) {
	print Encode::encode(locale => "git commit --author '$translator' --date '$dat' -m 'Update <$lcod> $lang translation to $ver'", Encode::FB_CROAK);
} else {
	exit(1);
}
_EOF
)"
	then
		echo >&2 "Parsing $pofile failed, skipping."
		continue
	fi
	cmd="$cmd '$pofile'"
	printf '+ %s\n' "$cmd"
	$dryrun_pfx eval "$cmd"
done