#!/usr/bin/perl

use warnings;
use strict;

use feature qw(switch);
no if $] >= 5.018, warnings => "experimental::smartmatch";

use Pandoc::Filter 0.06;
use Pandoc::Elements 0.12;

my ( $frontmatter_seen, $mainmatter_seen, $backmatter_seen, $toc_seen);

pandoc_filter(
    \&matter,
    \&toc,
);

sub matter {
    my $self = shift;
    return unless ( $self->name eq 'Header' );
    return unless ( $self->level == 1 );
    my (@replace, @prepend);
#   push @prepend, RawBlock( 'latex', '\\frontmatter' )
#       unless ($toc_seen++);
    given ($self->string) {
        when ( /^Table/ and not $frontmatter_seen++ ) {
            push @replace, RawBlock( 'latex',
                '{\\hypersetup{linkcolor=black}\\setcounter{tocdepth}{3}\\cleartorecto\\tableofcontents}'
            );
        };
        when ( /^Scope/ and not $mainmatter_seen++ ) {
            push @prepend, RawBlock( 'latex', '\\mainmatter' );
        };
        when ( /^Notes/ and not $backmatter_seen++ ) {
            push @prepend, RawBlock( 'latex', '\\backmatter' );
            push @replace, Header( 1, attributes {},
                [ Str 'References' ] );
        };
        default { return };
    }

    return unless ( @replace or @prepend );
    return [ @prepend, $self ] unless (@replace);
    return [ @prepend, @replace ];
}

sub toc {
    my $self = shift;
    return []
        if ( $self->name eq 'Para' and $self->string =~ /__TOC__/ );
    return;
}