#!/usr/bin/perl -w
require 5.008;
use bytes;
use strict;
use POSIX;
use Locale::PO;

use integer;

if (@ARGV == 0 || $ARGV[0] eq '--help') {
  print STDERR "Syntax: $0 PO_FILE...\n";
  exit (@ARGV != 0);
}

my %dropped;

my $pot = Locale::PO->load_file_asarray("survex.pot");
for my $po_file (@ARGV) {
  my ($lang) = ($po_file =~ m!([^/]+)\.po$!);
  my $po = Locale::PO->load_file_ashash($po_file);
  if (!defined $po) {
    print STDERR "$po_file: Bad!\n";
    next;
  }

  # Build a map from msgno to po msgid, so we can find the old translation when
  # a msgid has since changed in the pot file.
  my %msgno_to_po;
  foreach my $msgid (keys %{$po}) {
    my $ref = $po->{$msgid}->reference;
    if (defined $ref) {
      my ($msgno) = $ref =~ /\bn:(\d+)/;
      if (defined $msgno) {
	$msgno_to_po{$msgno} = [ $msgid, $po->{$msgid}->msgstr ];
      }
    }
  }

  my @fuzzy;
  open NEW, '>', "$po_file.tmp" or die $!;
  foreach my $pot_entry (@{$pot}) {
    my $msgid = $pot_entry->msgid;
    my $msgstr = '""';
    my $po_entry;
    if (exists $$po{$msgid}) {
	$po_entry = $$po{$msgid};
	$msgstr = $po_entry->msgstr;
	delete $$po{$msgid};
	if ($msgid eq '""') {
	    $msgstr =~ s/\\n(..)/\\n"\n"$1/g;
	    print NEW "msgid $msgid\nmsgstr \"\"\n$msgstr\n";
	    next;
	}
    } else {
	$po_entry = $pot_entry;
    }
    if (defined $pot_entry->automatic) {
	my $automatic = "\n" . $pot_entry->automatic;
	$automatic =~ s/\n/\n#. /g;
	while ($automatic =~ s/\n#. \n/\n#.\n/g) { }
	print NEW $automatic;
    }
    my $fuzzy = $po_entry->fuzzy;
    my $ref = $pot_entry->reference;
    if (defined $ref) {
	if ($msgstr eq '""') {
	    my ($msgno) = $ref =~ /\bn:(\d+)/;
	    if (exists $msgno_to_po{$msgno}) {
		my $old_msgid;
		($old_msgid, $msgstr) = @{$msgno_to_po{$msgno}};
		if ($msgstr ne '""') {
		    $fuzzy = 1;
		    print "$po_file: Fuzzifying translation $old_msgid / $msgid -> $msgstr\n";
		    push @fuzzy, $old_msgid;
		}
	    }
	}
	$ref = "\n" . $ref;
	$ref =~ s/\n/\n#: /mg;
	print NEW $ref;
    }
    my $c_format = $pot_entry->c_format;
    if ($fuzzy || $c_format) {
	print NEW "\n#";
	print NEW ", fuzzy" if $fuzzy;
	print NEW ", c-format" if $c_format;
    }
    print NEW "\n";
    print NEW "#~ " if $pot_entry->obsolete;
    print NEW "msgid $msgid\n";
    print NEW "#~ " if $pot_entry->obsolete;
    print NEW "msgstr $msgstr\n";
  }
  close NEW or die $!;
  unlink "$po_file.old";
  delete @$po{@fuzzy};
  for (sort keys %{$po}) {
    my $msgstr = $$po{$_}->msgstr;
    if ($msgstr ne '""') {
      print "$po_file: Dropping [$_] -> [$msgstr]\n";
      $dropped{$_}->{$lang} = $msgstr;
    }
  }
  link $po_file, "$po_file.old" or die $!;
  rename "$po_file.tmp", $po_file or die $!;
}

if (%dropped) {
    print "Saving dropped messages to deadmessages.txt\n";
    open DEAD, '>>deadmessages.txt' or die "Failed to open deadmessages.txt\n";
    for (sort keys %dropped) {
	print DEAD "\nmsgid \"$_\"\n";
	my $h = $dropped{$_};
	for my $lang (sort keys %$h) {
	    print DEAD "$lang $$h{$lang}\n";
	}
    }
    close DEAD;
}