#!/usr/bin/perl

=head1 NAME

metatrans - Perl/Tk frontend to MetaTrans

=head1 SYNOPSIS

    metatrans

=head1 CONFIGURATION

A configuration file of following structure is expected in
C</etc/metatrans.conf> or in C<$HOME/.metatrans>.

    # plug-ins to be used
    <modules>
      # for example
      add MetaTrans::SlovnikCz
      add MetaTrans::SeznamCz
      add MetaTrans::SmsCz
      add MetaTrans::WordbookCz
      add MetaTrans::UltralinguaNet
    </modules>

    # default language to translate from
    lang_from = eng

    # default language to translate to
    lang_to   = ger

    # should the matching be done at word boundaries only?
    # this is a default value (can be changed in "Filtering options")
    at_bounds = 1

    # default matching type (see help in "Filtering options")
    # 1 = exact match
    # 2 = match at start
    # 3 = match exprression
    # 4 = match words
    # 5 = no filtering
    matching  = 5

    # timeout in seconds
    timeout   = 15 

After the first run the C<~/.metatrans> is automatically overwritten
to take into account configuration changes made during apllication run.
This deletes all comments and makes the configuration file structure bit ugly.

=cut

use strict;
use warnings;

use MetaTrans;
use MetaTrans::Base qw(:match_consts);
use MetaTrans::Languages qw(get_lang_by_code get_code_by_lang);

use Tk;
use Tk::BrowseEntry;
use Tk::DialogBox;
use Tk::HList;
use Tk::ItemStyle;
use Tk::LabFrame;
use Tk::ROText;

use Config::Find;
use Config::General;
use Encode;

################################################################################
# initialization                                                               #
################################################################################

my $app_name = 'metatrans';

my $config_file = Config::Find->find(
    name  => $app_name,
    mode  => 'read',
);
    
die("can't find a configuration file\n")
    unless $config_file ne '';

my %config = ParseConfig(
    -ConfigFile           => $config_file,
    -AllowMultiOptions    => 1,
    -MergeDuplicateBlocks => 1,
);

$config{matching} = M_ALL
    unless exists $config{matching};

$config{at_bounds} = 1
    unless exists $config{at_bounds};

sub make_array
{
    my $scalar = shift;
    return ref($scalar) eq 'ARRAY' ? @{$scalar} : ($scalar);
}

no warnings;
my @modules  = make_array($config{modules}->{add});
my @disabled = make_array($config{modules}->{disable});
my %disabled_hash = map { ($_, 1) } @disabled;
use warnings;

my $MetaTrans = new MetaTrans;

foreach my $module (@modules)
{
    eval "require $module"
        or die("can't load '$module': $!");
    my $translator = new $module;
    $MetaTrans->add_translators($translator);
    $MetaTrans->disable_translator($translator)
        if $disabled_hash{$module};
}

$MetaTrans->set_timeout($config{timeout})
    if exists $config{timeout};

$MetaTrans->set_matching($config{matching});
$MetaTrans->set_match_at_bounds($config{at_bounds});

################################################################################
# gui design                                                                   #
################################################################################

my $nonbold_font = '-*-helvetica-medium-r-*-*-12-*-*-*-*-*-*-*';
my $unicode_font = '-*-fixed-medium-r-*-*-13-*-*-*-*-*-iso10646-1';

my $main = new MainWindow;
$main->configure(-title => 'Multilingual meta-translator');

my $left_f = $main->LabFrame(
    -label     => 'Translators search',
    -labelside => 'acrosstop',
);
$left_f->pack(-side => 'left', -fill => 'both', -expand => 1);

    my $top_left_f = $left_f->Frame;
    $top_left_f->pack(-side => 'top', -fill => 'x');

        my $Expression;
        my $Stop;
        my $expr_e = $top_left_f->Entry(
            -bg           => 'white',
            -textvariable => \$Expression,
        );
        $expr_e->bind('<Return>', sub { &run_translation; });
        $expr_e->bind('<Escape>', sub { $Stop = 1; });
        $expr_e->pack(-side => 'left', -fill => 'both', -expand => 1);

        my $trans_b = $top_left_f->Button(
            -text    => 'Translate',
            -width   => 8,
            -command => sub { &run_translation; },
        );
        $trans_b->pack(-side => 'left');

        my $stop_b = $top_left_f->Button(
            -text    => 'Stop',
            -width   => 8,
            -command => sub { $Stop = 1; },
        );
        $stop_b->pack(-side => 'left');

    my $bottom_left_f = $left_f->Frame;
    $bottom_left_f->pack(-side => 'top', -fill => 'both', -expand => 1);

        my $result_t = $bottom_left_f->Scrolled('ROText',
            -scrollbars => 'e',
            -relief     => 'sunken',
            -bd         => 2,
            -bg         => 'gray',
            -width      => 63,
            -height     => 20,
            -font       => $unicode_font,
        );
        $result_t->tag(qw/configure dark  -background/ => 'gray');
        $result_t->tag(qw/configure light -background/ => 'gray90');
        $result_t->pack(-fill => 'both', -expand => 1);

my $right_f = $main->Frame;
$right_f->pack(-side => 'left', -fill => 'y');

    my $dir_conf_f = $right_f->LabFrame(
        -label     => 'Translation direction',
        -labelside => 'acrosstop',
    );
    $dir_conf_f->pack(-side => 'top', -fill => 'x');

        my $src_l = $dir_conf_f->Label(-text => 'From');
        $src_l->grid(-column => 0, -row => 0);

        my $Src_Language;
        my $from_be = $dir_conf_f->BrowseEntry(
            -state     => 'readonly',
            -variable  => \$Src_Language,
            -browsecmd => sub {
                &populate_to_be;
                &enable_disable_swap;
                &refresh_trans_states;
            },
        );
        $from_be->grid(-column => 1, -row => 0);

        my $dest_l = $dir_conf_f->Label(-text => 'To');
        $dest_l->grid(-column => 0, -row => 1, -sticky => 'e');

        my $Old_Dest_Language;
        my $Dest_Language;
        my $to_be = $dir_conf_f->BrowseEntry(
            -state     => 'readonly',
            -variable  => \$Dest_Language,
            -browsecmd => sub {
                &enable_disable_swap;
                &refresh_trans_states;
            },
        );
        $to_be->grid(-column => 1, -row => 1);

        my $swap_b = $dir_conf_f->Button(
            -text    => 'Swap',
            -width   => 8,
            -command => sub {
                $Old_Dest_Language = get_code_by_lang($Src_Language);
                $Src_Language = $Dest_Language;
                &populate_to_be;
                &refresh_trans_states;
            },
        );
        $swap_b->grid(-column => 2, -row => 0, -rowspan => 2, -sticky => 'ns');

    my $dicts_f = $right_f->LabFrame(
        -label     => 'Translators',
        -labelside => 'acrosstop',
    );
    $dicts_f->pack(-side => 'top', -fill => 'x');

        my $dicts_t = $dicts_f->Frame(
            -bd     => 2,
            -bg     => 'black',
            -relief => 'sunken'
        );
        $dicts_t->pack(-side => 'top', -padx => 2);

        $dicts_t->Label(
            -text => 'Host',
            -relief => 'raised',
            -anchor => 'w',
            -width => 23,
        )->grid(-column => 0, -row => 0, -sticky => 'we');

        $dicts_t->Frame(
            -width => 1,
            -height => 1,
            -bg => 'black',
        )->grid(-column => 1, -row => 0);

        $dicts_t->Label(
            -text => 'State',
            -relief => 'raised',
            -anchor => 'w',
            -width  => 9,
        )->grid(-column => 2, -row => 0, -sticky => 'we');

        $dicts_t->Frame(
            -width => 1,
            -height => 1,
            -bg => 'black',
        )->grid(-column => 3, -row => 0);

        $dicts_t->Label(
            -text => 'Disable',
            -relief => 'raised',
            -anchor => 'w',
        )->grid(-column => 4, -row => 0, -sticky => 'we');

    my $filtering_f = $right_f->Frame;
    $filtering_f->pack(-side => 'top', -fill => 'x');
        
        my $filtering_b = $filtering_f->Button(
            -text    => 'Filtering options...',
            -command => sub {&filtering_options;},
        );
        $filtering_b->pack(-side => 'left', -fill => 'x', -expand => 1);

        $filtering_f->Canvas(
            -height => 1,
            -width  => 1,
        )->pack(-side => 'left');

    $right_f->Canvas(-height => 2, -width => 1)->pack(-side => 'top');

################################################################################
# dialogs                                                                      #
################################################################################

my $match_type;
my $at_bounds;
my $at_bounds_cb;

sub filtering_options
{
    my $filtering_dialog = $main->DialogBox(
        -title   => 'Filtering options',
        -buttons => ['OK', 'Cancel', 'Help'],
    );

    my $filter_conf_f = $filtering_dialog->Frame();
    $filter_conf_f->pack(-side => 'top', -padx => 10, -pady => 10);

        $match_type = $config{matching};

        $filter_conf_f->Radiobutton(
            -variable => \$match_type,
            -anchor   => 'w',
            -text     => 'Exact match',
            -value    => M_EXACT,
            -command  => sub { &enable_disable_at_bounds; },
        )->pack(-side => 'top', -fill => 'x');

        $filter_conf_f->Radiobutton(
            -variable => \$match_type,
            -anchor   => 'w',
            -text     => 'Match expression at start',
            -value    => M_START,
            -command  => sub { &enable_disable_at_bounds; },
        )->pack(-side => 'top', -fill => 'x');

        $filter_conf_f->Radiobutton(
            -variable => \$match_type,
            -anchor   => 'w',
            -text     => 'Match expression anywhere',
            -value    => M_EXPR,
            -command  => sub { &enable_disable_at_bounds; },
        )->pack(-side => 'top', -fill => 'x');

        $filter_conf_f->Radiobutton(
            -variable => \$match_type,
            -anchor   => 'w',
            -text     => 'Match words of expression',
            -value    => M_WORDS,
            -command  => sub { &enable_disable_at_bounds; },
        )->pack(-side => 'top', -fill => 'x');

        $filter_conf_f->Radiobutton(
            -variable => \$match_type,
            -anchor   => 'w',
            -text     => 'No filtering',
            -value    => M_ALL,
            -command  => sub { &enable_disable_at_bounds; },
        )->pack(-side => 'top', -fill => 'x');

        $filter_conf_f->Frame(
            -width  => 1,
            -height => 7,
        )->pack(-side => 'top');

        $at_bounds = $config{at_bounds};

        $at_bounds_cb = $filter_conf_f->Checkbutton(
            -anchor   => 'w',
            -text     => 'Match at word boundaries only',
            -command  => sub { $at_bounds = !$at_bounds; },
        )->pack(-side => 'top', -fill => 'x');
        $at_bounds ? $at_bounds_cb->select : $at_bounds_cb->deselect;

    &enable_disable_at_bounds;

    my $choice;
    do 
    {
        $choice = $filtering_dialog->Show(-popover => $main);
        &filtering_options_help() if $choice eq 'Help';
    }
    while ($choice eq 'Help');

    if ($choice eq 'OK')
    {
        $config{matching}  = $match_type;
        $config{at_bounds} = $at_bounds || 0;

        $MetaTrans->set_matching($match_type);
        $MetaTrans->set_match_at_bounds($at_bounds);
    }
}

sub enable_disable_at_bounds
{
    my $disable = $match_type == M_EXACT || $match_type == M_ALL;
    $at_bounds_cb->configure(-state => $disable ? 'disabled' : 'normal');
}

my $Filtering_Help_Window;
sub filtering_options_help
{
    $Filtering_Help_Window->destroy
        if Exists($Filtering_Help_Window);
    
    $Filtering_Help_Window = new MainWindow(
        -title   => 'Filtering options help',
    );

    my $help_text = $Filtering_Help_Window->Scrolled('ROText',
        -scrollbars => 'e',
        -width      => 75,
        -height     => 30,
        -bg         => 'gray',
    );
    $help_text->pack(
        -side   => 'top',
        -fill   => 'both',
        -expand => 1,
        -padx   => 10,
        -pady   => 10,
    );

    my $ok_b = $Filtering_Help_Window->Button(
        -text    => 'OK',
        -width   => 8,
        -command => sub {$Filtering_Help_Window->destroy;},
    );
    $ok_b->pack(-side => 'top', -pady => 5);

    $help_text->tag(qw/configure underline -underline on/);
    $help_text->insert('end', <<EOF);
Using filtering options one can affect the results of translation to be
shown. In most cases 'No filtering' will do just fine as long as the
sorting algorithm puts those results on the top, which are closest to the
searched keyword(s).
EOF
    $help_text->insert('end', "\nExact match\n", 'underline');
    $help_text->insert('end', <<EOF);
Matches only those expressions which are the same as the searched one.
Matching is incasesensitive and ignores grammar information, i.e.
everything in parenthesis or after semi-colon. The same applies bellow.

Examples:
'Dog'  matches        'dog'      (incasesensitive)
'Hund' matches        'Hund; r'  (grammar information ignored)
'dog'  does not match 'dog bite' (not an exact match)
EOF
    $help_text->insert('end', "\nMatch expression at start\n", 'underline');
    $help_text->insert('end', <<EOF);
Matches those expressions which are prefixed with the searched expression.

Examples:
'Dog'  matches        'dog bite'      (incasesensitive)
'Hund' matches        'Hund is los'
'Hund' does not match 'bissiger Hund' ('Hund' is not a prefix)
EOF
    $help_text->insert('end', "\nMatch expression anywhere\n", 'underline');
    $help_text->insert('end', <<EOF);
Matches those expressions which contain the searched expression, no matter
where.

Examples:
'Big Dog' matches        'very big dog'
'big dog' does not match 'big angry dog' ('big dog' is not a substring)
EOF
    $help_text->insert('end', "\nMatch expression words\n", 'underline');
    $help_text->insert('end', <<EOF);
Matches those expressions which contain all the words of the searched
expression.

Examples:
'big dog' matches        'big angry dog'
'big dog' does not match 'angry dog'     (not all words are contained)
EOF
    $help_text->insert('end', "\nNo filtering\n", 'underline');
    $help_text->insert('end', <<EOF);
Just no filtering at all :).
EOF
    $help_text->insert('end', "\nMatch at word boundaries only\n", 'underline');
    $help_text->insert('end', <<EOF);
This options makes matching behave in a slightly different way.
Subexpressions and words are matched at word boundaries only. In practice
this means that with 'Match expression words' the expression 'big dog'
won't be matched to 'big angry doggie' while it would be with
match-at-word-boundaries-only option disabled. The same applies to
'Match expression at start' and 'Match expression anywhere'. The option
has no effect with 'Exact match' and 'No filtering'.
EOF
}

################################################################################
# gui initialization                                                           #
################################################################################

&populate_from_be;
&populate_to_be;
&enable_disable_swap;

my %Status_Labels;

my $row = 1;
foreach my $translator ($MetaTrans->get_translators)
{
    $dicts_t->Label(
        -text   => $translator->host_server,
        -anchor => 'w',
        -bg     => 'white',
        -font   => $nonbold_font,
    )->grid(-column => 0, -row => $row, -sticky => 'wens');

    $Status_Labels{$translator} = $dicts_t->Label(
        -text => 'busy',
        -font => $nonbold_font,
    )->grid(-column => 2, -row => $row, -sticky => 'wens');
    
    my $cb = $dicts_t->Checkbutton(
        -bg       => 'white',
        -command  => sub {
            $MetaTrans->toggle_enabled_translator($translator);
            &populate_from_be;
            &populate_to_be;
            &refresh_trans_states;
        },
    )->grid(-column => 4, -row => $row, -sticky => 'we');
    $cb->select unless $MetaTrans->is_enabled_translator($translator);

    $row ++;

    $dicts_t->Frame(
        -width  => 1,
        -height => 1,
        -bg     => 'black',
    )->grid(-column => 0, -row => $row, -columnspan => 5);

    $row ++;
}

&refresh_trans_states;

################################################################################
# procedures                                                                   #
################################################################################

sub populate_from_be
{
    $from_be->delete(0, 'end');

    my @src_lang_codes = $MetaTrans->get_all_src_lang_codes;
    my %src_lang_codes_hash = map {($_, 1)} @src_lang_codes;

    foreach my $lang_code (@src_lang_codes)
        { $from_be->insert('end', get_lang_by_code($lang_code)); }

    unless (defined $Src_Language &&
        $src_lang_codes_hash{get_code_by_lang($Src_Language)})
    {
        $Src_Language = $src_lang_codes_hash{$config{lang_from}} ?
            get_lang_by_code($config{lang_from}) :
            get_lang_by_code($src_lang_codes[0]) ;
    }
}

sub populate_to_be
{
    $to_be->delete(0, 'end');
    
    $Old_Dest_Language = $config{lang_to}
        unless defined $Old_Dest_Language;
    undef $Dest_Language;

    my $src_lang_code = get_code_by_lang($Src_Language);
    foreach my $lang_code (
        $MetaTrans->get_dest_lang_codes_for_src_lang_code($src_lang_code))
    {
        $to_be->insert('end', get_lang_by_code($lang_code));
        $Dest_Language = get_lang_by_code($lang_code)
            unless defined $Dest_Language;
        $Dest_Language = get_lang_by_code($lang_code)
            if $lang_code eq $Old_Dest_Language;
    }

    $Old_Dest_Language = get_code_by_lang($Dest_Language)
        if defined $Dest_Language;
}

sub enable_disable_swap
{
    my $src_lang_code  = get_code_by_lang($Src_Language);
    my $dest_lang_code = get_code_by_lang($Dest_Language);
    my @translators    = $MetaTrans->get_translators_for_direction(
        $dest_lang_code, $src_lang_code);

    $swap_b->configure(-state => @translators > 0 ? 'normal' : 'disabled');
}

sub refresh_trans_states
{
    my $src_lang_code   = get_code_by_lang($Src_Language);
    my $dest_lang_code  = get_code_by_lang($Dest_Language);
    my @available_trans = $MetaTrans->get_translators_for_direction(
        $dest_lang_code, $src_lang_code);

    my %available_trans_hash;
    foreach my $translator (@available_trans)
        { $available_trans_hash{$translator} = 1; }

    my $ready_count = 0;
    foreach my $translator ($MetaTrans->get_translators)
    {
        my $label = $Status_Labels{$translator};

        unless ($MetaTrans->is_enabled_translator($translator))
        {
            $label->configure(-text => 'disabled', -bg => 'gray');
            next;
        }

        if ($available_trans_hash{$translator})
        {
            $label->configure(-text => 'ready', -bg => 'green');
            $ready_count++;
        }
        else
        {
            $label->configure(-text => 'N/A',   -bg => 'gray');
        }
    }

    $trans_b->configure(-state => $ready_count > 0 ? 'normal' : 'disabled');
}

sub run_translation
{
    $Expression =~ s/\s+/ /g;
    $Expression =~ s/^ //;
    $Expression =~ s/ $//;

    $expr_e->selectionRange(0, 'end');

    if ($Expression eq '')
    {
        &error_dialog('No expression to be translated specified.');
        return;
    }

    $Stop = 0;

    my $src_lang_code   = get_code_by_lang($Src_Language);
    my $dest_lang_code    = get_code_by_lang($Dest_Language);
    my @available_trans = $MetaTrans->get_translators_for_direction(
        $dest_lang_code, $src_lang_code);

    foreach my $translator (@available_trans)
    {
        my $label = $Status_Labels{$translator};
        $label->configure(-text => 'busy', -bg => 'LightSkyBlue2');
        $label->update;
    }

    $result_t->delete('1.0', 'end');
    $result_t->update;

    my @translations;
    $MetaTrans->run_translators($Expression, $src_lang_code, $dest_lang_code,
        tk_safe => 1) or return;

    OUTER: while (1)
    {
        do
        {
            $stop_b->update;
            if ($Stop)
            {
                $MetaTrans->stop_translators;
                foreach my $translator (@available_trans)
                {
                    my $label = $Status_Labels{$translator};
                    if ($MetaTrans->get_translators_state($translator) eq 'busy')
                    {
                        $label->configure(-text => 'interrupted', -bg => 'red');
                        $label->update;
                    }
                }
                last OUTER;
            }
        }
        until $MetaTrans->is_translation_available(0.01);
        
        my ($translation, $translator) = $MetaTrans->get_translation(
            return_translators => 1);
        last unless defined $translator;

        if ($translation eq '')
        {
            my $label = $Status_Labels{$translator};
            $label->configure(
                -text => $MetaTrans->get_translators_state($translator),
                -bg => $MetaTrans->get_translators_state($translator) eq 'ok' ?
                    'green' : 'red',
            );
            $label->update;

            &show_translations(MetaTrans::sort_translations(
                $Expression, @translations));
            next;
        }

        push @translations, $translation;
    }
}

sub show_translations
{
    my @translations    = @_;
    my $max_characters  = ($result_t->width - 31) / $result_t->fontMeasure(
        $unicode_font, '0');
    my $max_eq_sign_pos = 0;

    foreach my $trans (@translations)
    {
        $trans = Encode::decode_utf8($trans)
            unless Encode::is_utf8($trans);
        my $eq_sign_pos = index($trans, '=');
        $max_eq_sign_pos = $eq_sign_pos
            if $eq_sign_pos > $max_eq_sign_pos;
    }

    $max_eq_sign_pos = $max_characters / 2
        if $max_eq_sign_pos > $max_characters / 2;

    $result_t->delete('1.0', 'end');

    my $bg = @translations % 2 == 1 ? 'dark' : 'light';
    my $i  = 1;
    foreach my $trans (@translations)
    { 
        my $eq_sign_pos = index($trans, '=');
        $eq_sign_pos = $max_eq_sign_pos
            if $eq_sign_pos > $max_eq_sign_pos;
        my $blanks = ' ' x ($max_eq_sign_pos - $eq_sign_pos);
        $trans =~ s/=/$blanks=/;

        my $nl = @translations == $i ? "" : "\n";
        $result_t->insert('end', $trans . $nl, $bg);
        $bg = $bg eq 'dark' ? 'light' : 'dark';
    }
    continue { $i++; }

    $result_t->update;
}
            

sub error_dialog
{
    my $error = shift;
    $main->messageBox(
        -icon    => 'error',
        -type    => 'OK',
        -title   => 'Error',
        -message => $error,
    );
}

MainLoop();

################################################################################
# on exit                                                                      #
################################################################################

$config_file = Config::Find->find(
    name  => $app_name,
    mode  => 'write',
    scope => 'user',
);

$config{lang_from} = get_code_by_lang($Src_Language);
$config{lang_to}   = get_code_by_lang($Dest_Language);

undef @disabled;
foreach my $translator ($MetaTrans->get_translators)
{
    push @disabled, ref($translator)
        unless $MetaTrans->is_enabled_translator($translator);
}
$config{modules}->{disable} = \@disabled;

SaveConfig($config_file, \%config);

__END__

=head1 BUGS

Please report any bugs or feature requests to
C<bug-metatrans@rt.cpan.org>, or through the web interface at
L<http://rt.cpan.org>.  I will be notified, and then you'll automatically
be notified of progress on your bug as I make changes.

=head1 AUTHOR

Jan Pomikalek, C<< <xpomikal@fi.muni.cz> >>

=head1 COPYRIGHT & LICENSE

Copyright 2004 Jan Pomikalek, All Rights Reserved.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=head1 SEE ALSO

L<MetaTrans>, L<MetaTrans::Base>, L<Tk>