#!/usr/bin/perl

use strict;

binmode(STDERR, ':utf8');

my $intro_file = 'helpers/intro';
my $intro_template = 'helpers/intro-template';

my $notebook_file = $ARGV[0];

my $number;

if (($number) = ($notebook_file =~ m{^(\d+)_})) {

} else {
    die "????";
}

my $org_file = $notebook_file;
$org_file =~ s{\.ipynb}{\.org};

my $title = undef;

open(my $org_fh, '<', $org_file);
binmode($org_fh, ':utf8');

LOOP:
while (my $line=<$org_fh>) {
    chomp $line;

    if ($line =~ m{^\* (.*)}) {
        $title = $1;
        last LOOP;
    } elsif ($line =~ /\S/) {
        last LOOP;
    }
}

if (not defined($title)) {
    die '???? TITLE';
}

print STDERR "NUMBER: $number\n";
print STDERR "TITLE: $title\n";

my $intro = '';

open(my $intro_ih, '<', $intro_template);
binmode($intro_ih, ':utf8');
while(my $line=<$intro_ih>) {
    $line =~ s{NUMBER}{$number};
    $line =~ s{TITLE}{$title};
    $intro .= $line;
}
close($intro_ih);

open(my $intro_oh, '>', $intro_file);
binmode($intro_oh, ':utf8');
print $intro_oh $intro;
close($intro_oh);