#!/usr/bin/perl
# backlink.pl -- script to rewrite .ic files by adding backlink text.
use strict;
use warnings;
use English;
use Prosaix;
use Data::Dumper::Simple;

my %hrefs;
my $url;
my $re_url   = qr/^\/url: (.*)/;
my $re_end   = qr/^\/endtext/;
my $re_wc    = qr/^\/wc: (.*)/;
my $notfound = 0;
my $total    = 0;
my $success  = '_____found_____';
my $count = 1;
my $base_file = $ARGV[0] or die "Missing input file name\n";
(my $output_file = $base_file) =~ s/\.txt/\+bl.txt/;

open( my $fh_HREF, '<', $base_file . '.links' )
  or die "Couldn't open '$base_file.links': $OS_ERROR\n";
open( my $fh_IN, '<', $base_file )
  or die "Couldn't open '$base_file': $OS_ERROR\n";
open( my $fh_OUT, '>', $output_file )
  or die "Couldn't open 'base_file.backlnked': $OS_ERROR\n";
open( my $fh_ERR, '>', $base_file . '.unlinked' )
  or die "Couldn't open 'base_file.unlinked': $OS_ERROR\n";
binmode $fh_OUT;
start();
while (<$fh_HREF>) {
    chomp;
    my ( $key, $value ) = split(/\|/);
    unless ( defined( $hrefs{$key} ) ) {
        $hrefs{$key} = [];
    }
    push( @{ $hrefs{$key} }, $value );
}
while (<$fh_IN>) {
    print $fh_OUT $_;
    if (/$re_url/) {
        $url = $1;
    }
    if (/$re_wc/) {
        print "wc $count $1\n";
        $count++;
    }
    elsif (/$re_end/) {
        print $fh_OUT "/backlinks\n";
        if ( defined( $hrefs{$url} ) ) {
            my $s = $hrefs{$url};
            if (defined($s->[0])) {
                my @text = collapse(@$s);
                print $fh_OUT join( ".\n", @text ), ".\n";
                print join( ".\n", @text ), ".\n";
            }
            push( @{ $hrefs{$url} }, $success );
        }
    }
}
while ( my ( $url, $text ) = each(%hrefs) ) {
    if ( !defined( $text->[-1] ) ) {
        print $fh_ERR "$url|_____NO_TEXT_____\n";
    }
    elsif ( $text->[-1] ne $success ) {
        $notfound++;
        if (defined($text->[0])) {
            my @text = collapse(@$text);
            print $fh_ERR "$url|", join( ",", @text ), "\n";
        }
        else {
            print $fh_ERR "$url|\n";
        }
    }
    $total++;
}
close($fh_HREF);
close($fh_IN);
close($fh_OUT);
close($fh_ERR);
print "$notfound URLs (of $total) pointing to about.com pages not\n";
print "in this IC ($base_file) written to $base_file.unlinked\n";
finish();

sub collapse {
    my @s = @_;
    my @t;
    for (@s) {
        next unless defined($_);
        push(@t,$_);
    }
    return @t;
}