package MT::Plugin::ModTextFilter;
use strict;

use MT;
use MT::Plugin;
use MT::Util qw( encode_html );

use vars qw( @ncv_tags @ncv_br_tags );

@ncv_tags = qw( pre textarea table ol dl ul menu dir );
@ncv_br_tags = qw ( blockquote div p h1 h2 h3 h4 h5 h6 form address );

# show plugin information to main menu
eval("use Storable;");
if (!$@ && MT->can('add_plugin')) {
    my $plugin = MT::Plugin->new;
    $plugin->description('Modified text filter.');
    if (MT->version_number >= 3.2) {
        $plugin->name('Modified Text Filter');
        $plugin->version('1.0');
    }
    else {
        $plugin->name('Modified Text Filter 1.0');
    }
    MT->add_plugin($plugin);
}

MT->add_text_filter('ModTextFilter' => {
    label => '改良テキストフィルター',
    on_format => \&modified_text_filter
});

sub modified_text_filter
{
    my $str = shift;
    my ($pattern, $found, $replace, $tag, $attr, $inner, $tags);

    $str ||= '';

    # convert to html entities
    while ($str =~ /(<enchtml>(\r?\n)?(.*?)(\r?\n)?<\/enchtml>)/s) {
        $found = quotemeta($1);
        $replace = encode_html($3);
        $str =~ s/$found/$replace/;
    }

    # pre convert
    push @ncv_tags, "noconv";
    push @ncv_br_tags, "convbr";
    my @c_tags;
    push @c_tags, @ncv_tags;
    push @c_tags, @ncv_br_tags;
    $tags = join "|", @c_tags;
    $pattern = "(<($tags)(.*?)>(.*?)</\\2>)";
    while ($str =~ /$pattern/s) {
        $found = quotemeta($1);
        $tag = $2;
        $attr = $3;
        $inner = $4;
        $inner =~ s/\r?\n/\@\$\@cr\@\$\@/sg;
        $inner =~ s/^\@\$\@cr\@\$\@/\@\$\@fcr\@\$\@/;
        $inner =~ s/\@\$\@cr\@\$\@$/\@\$\@ecr\@\$\@/;
        $inner =~ s/<(.*?)>/<IT$1>/sg;
        $replace = "<T${tag}${attr}>${inner}</T${tag}>";
        $str =~ s/$found/$replace/;
    }

    # convert
    my @paras = split /\r?\n\r?\n/, $str;
    for my $p (@paras) {
        if ($p !~ /<\/T($tags)>/g) {
            $p =~ s/\r?\n/<br \/>\n/g;
            $p = "<p>\n$p\n</p>";
        } 
    }
    $str = join "\n\n", @paras;
    
    # after convert
    $tags = join "|", @ncv_tags;
    $pattern = "(<T($tags)(.*?)>(.*?)</T\\2>)";
    while ($str =~ /$pattern/s) {
        $found = quotemeta($1);
        $tag = $2;
        $attr = $3;
        $inner = $4;
        $inner =~ s/\@\$\@cr\@\$\@/\n/g;
        $inner =~ s/<IT(.*?)>/<$1>/sg;
        $replace = "<${tag}${attr}>${inner}</${tag}>";
        $str =~ s/$found/$replace/s;
    }

    $tags = join "|", @ncv_br_tags;
    $pattern = "(<T($tags)(.*?)>(.*?)</T\\2>)";
    while ($str =~ /$pattern/s) {
        $found = quotemeta($1);
        $tag = $2;
        $attr = $3;
        $inner = $4;
        $inner =~ s/\@\$\@cr\@\$\@/<br \/>\n/g;
        $inner =~ s/<IT(.*?)>/<$1>/sg;
        $replace = "<${tag}${attr}>${inner}</${tag}>";
        $str =~ s/$found/$replace/s;
    }
    
    $str =~ s/\@\$\@fcr\@\$\@/\n/sg;
    $str =~ s/\@\$\@ecr\@\$\@/\n/sg;
    $str =~ s/<\/?noconv>\n?//sg;
    $str =~ s/<\/?convbr>\n?//sg;

    $str;
}

1;