# PreviousNextInCategory
# http://weblog.philringnalda.com/2004/02/05/previous-and-next-in-category
# Author: phil ringnalda
#
# Ported to Movable Type 4.x by Yujiro ARAKI.
# Release 0.01 (Mar 21, 2008) for Movable Type 4.1.
# Release 0.02 (Mar 22, 2008) correct comment.
# Release 0.10 (Nov 17, 2008) for Movable Type 4.2.

package MT::Plugin::PreviousNextInCategory;

use strict;
use warnings;
use base qw( MT::Plugin );

use MT;
use MT::Template::Context;

our $VERSION = '0.10';
my $plugin = __PACKAGE__->new({
    id          =>  'PreviousNextInCategory',
    name        =>  'PreviousNextInCategory',
    description =>  '<MT_TRANS phrase="Display previous entry or next entry in category.">',
    version     => $VERSION,
    doc_link => 'http://www.koikikukan.com/archives/2008/11/18-005555.php',
    author_name => 'Yujiro Araki',
    author_link => 'http://www.koikikukan.com/',
    l10n_class => 'PreviousNextInCategory::L10N',
});
MT->add_plugin($plugin);

sub init_registry {
    my $plugin = shift;
    $plugin->registry({
        tags => {
            block => {
                EntryPreviousInCategory => \&_hdlr_entry_previous_in_category,
                EntryNextInCategory => \&_hdlr_entry_next_in_category,
            }
        },
        callbacks => {
            'MT::App::CMS::CMSPostSave.entry'
                => sub { $plugin->runner('_rebuild', @_) },
        },
   });
}

sub _rebuild {
    my $plugin = shift;
    my ($eh, $app, $entry) = @_;
    my $cats = $entry->categories;
    for my $cat (@$cats) {
        my $prev = $entry->previous(1);
        while ($prev && !$prev->is_in_category($cat)) {
            $prev = $prev->previous(1);
        }
        $app->rebuild_entry(Entry => $prev->id) if $prev;
        my $next = $entry->next(1);
        while ($next && !$next->is_in_category($cat)) {
            $next = $next->next(1);
        }
        $app->rebuild_entry(Entry => $next->id) if $next;
    }
    return 1;
}
sub runner {
    my $plugin = shift;
    my $method = shift;
    return $_->($plugin, @_) if $_ = \&{"$method"};
}

sub _hdlr_entry_previous_in_category {
    my($ctx, $args, $cond) = @_;
    my $e = $ctx->stash('entry')
        or return $ctx->_no_entry_error('MTEntryPrevious');
    my $cat = $e->category
            or return '';
    if($ctx->stash('category') ne '') {
        $cat = $ctx->stash('category');
    }
    my $terms;
    $terms->{category_id} = $cat->id;
    my $prev = $e->previous(1, $terms);
    my $res = '';
        while ($prev && !$prev->is_in_category($cat)){
            $terms->{category_id} = $cat->id;
            $prev = $prev->previous(1, $terms);
    }
    if ($prev) {
        my $builder = $ctx->stash('builder');
        local $ctx->{__stash}->{entry} = $prev;
        local $ctx->{current_timestamp} = $prev->created_on;
        my %cond = %$cond;
        $cond{EntryIfAllowComments} = $prev->allow_comments;
        $cond{EntryIfCommentsOpen} = $prev->allow_comments eq '1';
        $cond{EntryIfAllowPings} = $prev->allow_pings;
        $cond{EntryIfExtended} = $prev->text_more ? 1 : 0;
        my $out = $builder->build($ctx, $ctx->stash('tokens'), \%cond);
        return $ctx->error( $builder->errstr ) unless defined $out;
        $res .= $out;
    }
    $res;
}

sub _hdlr_entry_next_in_category {
    my($ctx, $args, $cond) = @_;
    my $e = $ctx->stash('entry')
        or return $ctx->_no_entry_error('MTEntryNext');
    my $cat = $e->category
            or return '';
    if($ctx->stash('category') ne '') {
        $cat = $ctx->stash('category');
    }
    my $terms;
    $terms->{category_id} = $cat->id;
    my $next = $e->next(1, $terms);
    my $res = '';
        while ($next && !$next->is_in_category($cat)){
            $terms->{category_id} = $cat->id;
            $next = $next->next(1, $terms);
    }
    if ($next) {
        my $builder = $ctx->stash('builder');
        local $ctx->{__stash}->{entry} = $next;
        local $ctx->{current_timestamp} = $next->created_on;
        my %cond = %$cond;
        $cond{EntryIfAllowComments} = $next->allow_comments;
        $cond{EntryIfCommentsOpen} = $next->allow_comments eq '1';
        $cond{EntryIfAllowPings} = $next->allow_pings;
        $cond{EntryIfExtended} = $next->text_more ? 1 : 0;
        my $out = $builder->build($ctx, $ctx->stash('tokens'), \%cond);
        return $ctx->error( $builder->errstr ) unless defined $out;
        $res .= $out;
    }
    $res;
}

1;