use strict;
use 5.6.0;
use HTML::Stream;
use Pod::Tree;
use Pod::Tree::HTML;
use Pod::Tree::PerlUtil;

package Pod::Tree::PerlLib;

use base qw(Pod::Tree::PerlUtil);

use constant COLUMN_WIDTH => 30;


sub new
{
    my %defaults = (col_width => COLUMN_WIDTH,
		    bgcolor   => '#ffffff',
		    text      => '#000000');
    my($class, $perl_dir, $html_dir, $link_map, %options) = @_;
    my $options  = { %defaults, %options, link_map => $link_map };

    my %stop_files = map { $_ => 1 } qw(perllocal.pod);

    my $perl_lib = { perl_dir  =>  $perl_dir,
		     html_dir  =>  $html_dir,
		     lib_dir   =>  'lib',
		     top_page  =>  'lib.html',
		     stop_files => \%stop_files,
		     options   =>  $options };

    bless $perl_lib, $class
}


sub scan
{
    my($perl_lib, @dirs) = @_;
    $perl_lib->report1("scan");

    # Don't try to install PODs for modules on relative paths in @INC
    # (Typically `.')
    @dirs = grep { m(^/) } @dirs;

    $perl_lib->_stop_dirs(@dirs);

    for my $dir (@dirs)
    {
	$perl_lib->{find_dir} = $dir;
        File::Find::find({wanted   => sub {$perl_lib->_scan}, # Closures rock!
			  no_chdir => 1 },
			 $dir); 
    }
}


sub _stop_dirs
{
    my($perl_lib, @dirs) = @_;

    for my $dir (@dirs)
    {
	for my $stop_dir (@dirs)
	{
	    $stop_dir =~ /^$dir./ and 
		$perl_lib->{stop_dir}{$dir}{$stop_dir} = 1;
	}
    }
}


sub _scan
{
    my $perl_lib = shift;
    my $source   = $File::Find::name;

    -d $source and $perl_lib->_scan_dir ($source);
    -f $source and $perl_lib->_scan_file($source);
}


sub _scan_dir
{
    my($perl_lib, $dir) = @_;

    my $find_dir = $perl_lib->{find_dir};

    if ($perl_lib->{stop_dir}{$find_dir}{$dir} or $dir =~ /pod$/)
    {
	$File::Find::prune = 1;
	return;
    }

    my $html_dir = $perl_lib->{html_dir};
    my $lib_dir  = $perl_lib->{lib_dir};
       $dir      =~ s(^$find_dir)($html_dir/$lib_dir);

    $perl_lib->mkdir($dir);
}


sub _scan_file
{
    my($perl_lib, $source) = @_;

       $source   =~ m(\. (?: pl | pm | pod ) $ )x or  return;
    my $file     = (split m(/), $source)[-1];
       $perl_lib->{stop_files}{$file}             and return;
    my $module   = $source;
    my $find_dir = $perl_lib->{find_dir};
       $module   =~ s(^$find_dir/)();
       $module   =~ s( \.\w+$    )()x;    # Foo/Bar

    my $html_dir = $perl_lib->{html_dir};
    my $lib_dir  = $perl_lib->{lib_dir};
    my $dest     = "$html_dir/$lib_dir/$module.html"; 
    my($name, $description) = $perl_lib->get_name($source);

       $name or return;
       $perl_lib->report2($name);

    my $href = "$module.html";
    my $link = "$lib_dir/$module";

    my $entry = { source      => $source,       # .../Foo/Bar.pm
		  dest        => $dest,         # .../html/lib/Foo/Bar.html
		  href        => $href,         # Foo/Bar.html
		  description => $description };

    $perl_lib->{index}{$name} = $entry;
    $perl_lib->{options}{link_map}->add_page($name, $link);
}


sub index
{
    my $perl_lib = shift;
       $perl_lib->report1("index");
    my $html_dir = $perl_lib->{html_dir};
    my $top_page = $perl_lib->{top_page};
    my $dest     = "$html_dir/$top_page";

    my $fh       = new IO::File ">$dest";
    defined $fh or die "Pod::Tree::PerlLib::index: Can't open $dest: $!\n";
    my $stream   = new HTML::Stream $fh;

    my $options  = $perl_lib->{options};
    my $bgcolor  = $options->{bgcolor};
    my $text 	 = $options->{text};
    my $title    = "Perl Modules";

    $stream-> HTML->HEAD;
    $stream-> TITLE->text($title)->_TITLE;
    $stream->_HEAD
	   -> BODY(BGCOLOR => $bgcolor, TEXT => $text);
    $stream->H1->t($title)->_H1;

    $perl_lib->_emit_entries($stream);

    $stream->_BODY->_HTML;
}


sub get_top_entry
{
    my $perl_lib = shift;

    +{ URL         => $perl_lib->{top_page},
       description => 'Modules' }
}


sub _emit_entries
{
    my($perl_lib, $stream) = @_;

    my $lib_dir   = $perl_lib->{lib_dir};
    my $index     = $perl_lib->{index};
    my $options   = $perl_lib->{options};
    my $col_width = $options->{col_width};

    $stream->PRE;

    for my $name (sort keys %$index)
    {
	my $entry = $index->{$name};
	my $href  = $entry->{href};
	my $desc  = $entry->{description};
	my $pad   = $col_width - length $name;

	$stream->A(HREF => "$lib_dir/$href")->t($name)->_A;

	$pad < 1 and do
	{
	    $stream->nl;
	    $pad = $col_width;
	};

	$stream->t(' ' x $pad, $desc)->nl;
    }

    $stream->_PRE;
}


sub translate
{
    my $perl_lib = shift;
       $perl_lib->report1("translate");

    my $index    = $perl_lib->{index};
    my $options  = $perl_lib->{options};

    for my $name (sort keys %$index)
    {
	   $perl_lib->report2($name);
	my @path   = split m(::), $name;
	my $depth  = @path; # no -1 because they are all under /lib/
	   $options->{link_map}->set_depth($depth);
	
	my $entry  = $index->{$name};
	my $source = $entry->{source};
	my $dest   = $entry->{dest};
	my $html   = new Pod::Tree::HTML $source, $dest, %$options;
	   $html->translate;
    }
}

1

__END__

=head1 NAME

Pod::Tree::PerlLib - translate module PODs to HTML

=head1 SYNOPSIS

  $perl_map = new Pod::Tree::PerlMap;
  $perl_lib = new Pod::Tree::PerlLib $perl_dir, $HTML_dir, $perl_map, %opts;

  $perl_lib->scan(@INC);
  $perl_lib->index;
  $perl_lib->translate;

  $top = $perl_lib->get_top_entry;

=head1 DESCRIPTION

C<Pod::Tree::PerlLib> translates module PODs to HTML.
It does a recursive subdirectory search through a list of
directories (typically C<@INC>) to find PODs.

C<Pod::Tree::PerlLib> generates a top-level index of all the PODs
that it finds, and writes it to I<HTML_dir>C</lib.html>.

C<Pod::Tree::PerlLib> generates and uses an index of the PODs
that it finds to construct HTML links.
Other modules can also use this index.

=head1 METHODS

=over 4

=item I<$perl_lib> = C<new> C<Pod::Tree::PerlLib> I<$perl_dir>,
I<$HTML_dir>, I<$perl_map>, I<%options>

Creates and returns a new C<Pod::Tree::PerlLib> object.

I<$HTML_dir> is the directory where HTML files will be written.

I<$perl_map> maps module names to URLs.

I<%options> are passed through to C<Pod::Tree::HTML>.

The I<$perl_dir> argument is included for consistency with the
other C<Pod::Tree::Perl*> modules, but is currently unused.

=item I<$perl_lib>->C<scan>(I<@INC>)

Does a recursive subdirectory search through I<@INC> to locate module PODs.
Each module that is identified is entered into I<$perl_map>.

=item I<$perl_lib>->C<index>

Generates a top-level index of all the modules.
The index is written to I<HTML_dir>C</lib.html>.

=item I<$perl_lib>->C<translate>

Translates each module POD found by C<scan> to HTML.
The HTML pages are written to I<HTML_dir>C</lib/>,
in a subdirectory hierarchy that maps the module names.

=item I<$perl_lib>->C<get_top_entry>

Returns a hash reference of the form

  { URL         => $URL,
    description => $description }

C<Pod::Tree::PerlTop> uses this to build a top-level index of all the Perl PODs.

=back

=head1 LINKING

C<Pod::Tree::PerlLib> expects the second paragraph of the POD to have the form

    Foo::Bar - description

and enters I<Foo::Bar> into I<$perl_map>.
To link to a module POD, write

    L<Foo::Bar>

=head1 REQUIRES

    5.005;
    HTML::Stream;
    Pod::Tree;
    Pod::Tree::HTML;
    Pod::Tree::PerlUtil;

=head1 EXPORTS

Nothing.

=head1 SEE ALSO

L<C<Pod::Tree::HTML>>, L<C<Pod::Tree::PerlMap>>

=head1 AUTHOR

Steven McDougall, swmcd@world.std.com

=head1 COPYRIGHT

Copyright (c) 2000 by Steven McDougall.  This module is free software;
you can redistribute it and/or modify it under the same terms as Perl.