# Blosxom Plugin: tagging
# Author: Gosuke Miyashita <miya@mizzy.org>
# Version: 2005-06-23
# Blosxom Home/Docs/Licensing: http://www.blosxom.com/

package tagging;

use strict;
use CGI qw(param url);
use vars qw($list $current_tag $find_tag $tags_in_this);
use Storable qw(store retrieve);
use Jcode;

## --- configurable variables ---
## What prefix should I expect prepended to each meta tag?
my $meta_prefix = 'meta-';
## character set for converting xmlhttprequest query
my $charset = "euc";
## cache file of mapping tags to entry files
my $tags_to_files_file = "$blosxom::plugin_state_dir/tagging_tags_to_files";
## cache file of mapping entry files to tags
my $files_to_tags_file = "$blosxom::plugin_state_dir/tagging_files_to_tags";
## cache of tags list
my $tags_list_file = "$blosxom::plugin_state_dir/tagging_tags_list";
## cache of tags list per category
my $tags_list_per_category_file = "$blosxom::plugin_state_dir/tagging_tags_list_per_category";


## read caches into hash ref
my ($tags_to_files, $files_to_tags, $tags_list, $tags_list_per_category);
eval { $tags_to_files = retrieve($tags_to_files_file); };
eval { $files_to_tags = retrieve($files_to_tags_file); };
eval { $tags_list = retrieve($tags_list_file); };
eval { $tags_list_per_category = retrieve($tags_list_per_category_file); };


sub start {
    ## create tags list
    my $url = url(-path_info => 1);
    $find_tag = Jcode->new(param('find_tag'))->$charset;


    $list = "<ul>\n";
    if(!$blosxom::path_info_yr and $blosxom::path_info){
	my $path = $blosxom::path_info;
	if($path =~ m|(.*?)/?\w+\.\w+$|){
	    $path = $1;
	}

	my %tags;
	foreach my $category (keys %$tags_list_per_category){
	    if($category =~ /$path/){
		foreach my $tag (keys %{$tags_list_per_category->{$category}}){
		    if(($find_tag and $tag =~ /^$find_tag/i) or !$find_tag){
			$tags{$tag} += $tags_list_per_category->{$category}->{$tag};
		    }
		}
	    }
	}
	
	foreach my $tag (sort keys %tags){
	    my $encoded_tag = $tag;
	    $encoded_tag =~ s/(\W)/sprintf("%%%02X", ord($1))/ego;
	    $list .= "<li><a href='$url?tag=$encoded_tag'>$tag</a> ($tags{$tag})</li>\n";
	}
	
    } else {
	foreach my $tag (sort keys %$tags_list){
	    if(($find_tag and $tag =~ /^$find_tag/i) or !$find_tag){
		my $encoded_tag = $tag;
		$encoded_tag =~ s/(\W)/sprintf("%%%02X", ord($1))/ego;
		$list .= "<li><a href='$url?tag=$encoded_tag'>$tag</a> ($tags_list->{$tag})</li>\n";
	    }
	}
    }
    $list .= "</ul>\n";


    ## return current tags;
    $current_tag = param('tag');

    return 1;
}

sub filter {
    my($pkg, $files) = @_;

    ## racache tags
    if(param('recache_tags') or !$tags_to_files or !$files_to_tags or !$tags_list or !$tags_list_per_category){
	## clear hash refs
	($tags_to_files, $files_to_tags, $tags_list, $tags_list_per_category) = ({}, {}, {}, {});
	## process each file
	foreach (sort keys %$files){
	    my($category, $file_tmp) = m!(.*)/(.*)!;
	    $category =~ s/$blosxom::datadir//;
	    $category =~ s!/!!;

	    my $file = $_;
	    open(IN, $file);
	    my @lines = <IN>;
	    close(IN);
	    my $in_header = 1;
	    ## process each line of a file and fine meta-tags
	    foreach my $line (@lines){
		$line =~ /^\s*$/ and $in_header = 0 and next;
		if($in_header){
		    ## get tags
		    my ($key, $value) = $line =~ m!^$meta_prefix(.+?):\s*(.+)$!;
		    if($key eq 'tags'){
			my @tags = split(/,/, $value);
			## convert characters of tags to small capital and remove heading and trailing spaces
			map { $_ = lc $_; $_ =~ s/^\s*//; $_ =~ s/\s*$//; } @tags;
			## asign tags to a file
			push @{$files_to_tags->{$file}}, @tags;
			## asign a file to tags
			map { push @{$tags_to_files->{$_}}, $file } @tags;
			## count up tags in the list
			map { $tags_list->{$_}++; } @tags;
                        ## count up tags per category in the list
			map { $tags_list_per_category->{$category}->{$_}++; } @tags;
			last;
		    }
		}
	    }
	}
	## store hash refs into files
	store $tags_to_files, "$tags_to_files_file";
	store $files_to_tags, "$files_to_tags_file";
	store $tags_list, "$tags_list_file";
	store $tags_list_per_category, "$tags_list_per_category_file";
    }


    ## find entries that have tags 
    if(param('tag')){
	my @tags = split(/,/, param('tag'));
	my ($files_have_tags, $cnt);
	
	foreach my $tag (@tags){
	    if(!$files_have_tags and !$cnt){
		%$files_have_tags = map { $_ => $files->{$_} } @{$tags_to_files->{$tag}};
	    } else {
		my $files_have_tags_tmp;
		foreach my $file (keys %$files_have_tags){
		    #%$files_have_tags_tmp = map { $file eq $_ and $_ => $files->{$_} } @{$tags_to_files->{$tag}};
		    foreach (@{$tags_to_files->{$tag}}){
			if($file eq $_){
			    $files_have_tags_tmp->{$_} = $files->{$_};
			}
		    }
		}
		$files_have_tags = $files_have_tags_tmp;
	    }
	    $cnt++;
	}

	%$files = %$files_have_tags;
    }

    return 1;
}

sub story {
    my($pkg, $path, $fn, $story_ref, $title_ref, $body_ref) = @_;
    $tags_in_this = '';
    my @tags;
    map { $_ = lc $_; $_ =~ s/^\s*//; $_ =~ s/\s*$//; push(@tags, $_); } split(/,/, $meta::tags);
    foreach (sort @tags) {
	my $encoded_tag = $_;
	$encoded_tag =~ s/(\W)/sprintf("%%%02X", ord($1))/ego;		    
	$tags_in_this .= "<a href='$blosxom::url/?tag=$encoded_tag'>$_</a> ";
    }
}

1;

__END__


=head1 NAME

Blosxom Plug-in: tagging