#!/usr/bin/perl
# My super brilliant indexer. Just hollows out the content!
# Copyright       : http://www.fsf.org/copyleft/gpl.html
# Author          : Dan Jacobson -- http://jidanni.org/
# Created On      : Sun Dec 26 10:26:17 2021
# Last Modified On: Mon Dec 27 19:56:34 2021
# Update Count    : 53
use strict;
use warnings FATAL => 'all';
use XML::LibXML;
binmode STDERR, ":utf8";
my $basename = "@ARGV";
unless ( $basename =~ /^[\w.]+\.html$/ ) { die "Usage: $0 file.html" }
my $doc = XML::LibXML->load_html( location => $basename || die );
for ($doc) {
    for my $e (qw!p blockquote dd!) {
        $_->unbindNode() for $_->findnodes("//$e");
    }
    for my $e (qw!title h1!) {
        $_->appendText(" （目錄 Table of Contents）") for $_->findnodes("//$e");
    }
    for ( $_->findnodes('//*') ) {
        my $nodeName = $_->nodeName;
        my $id       = $_->getAttribute('id');
        if ( $_->nodeName ne 'a' ) {
            die "Not ready for $_, dude.Use <a id=\"$id\">...</a>" if $id;
        }
        else {
            next if $_->getAttribute('href');
            die "Where's the ID at $_, dude?" unless $id;
            $_->setAttribute( 'href', "#$id" );
            $_->removeAttribute('id');
        }
    }
    my $comment = $_->createComment("Made by $0. Do not edit by hand.");
    my $base    = $doc->createElement('base');
    $base->setAttribute( 'href', $basename );
    for ( $_->findnodes('/html/head') ) {
        $_->appendChild($comment);
        $_->appendChild($base);
    }
}
my $z = $doc->toString(1);
$z =~ s/^<\?xml [^\n]+\?>\n//;    # hack, yes.
print $z;