#!/usr/bin/env perl

use strict;
use warnings;

use FindBin qw($Bin);
use File::Find;
use File::Spec;

sub slurp_file {
    undef $/;
    open(my $fh, '<', shift);
    if(my $whole_file = <$fh>) {
        return $whole_file;
    } else {
        return;
    }
}

sub extract_synopsis {
    my $string = shift || return;
    my $head_or_cut = qr[head|cut]x;
    if($string=~m/^=head1 SYNOPSIS\n(.*?)^=$head_or_cut/sm) {
        return $1;
    } else {
        return;
    }
}

sub normalize_indent {
    my $extracted = shift || return;

    if($extracted=~m/([ \t]+)(\S+)/) {
        $extracted=~s/^$1//gsm;
        return $extracted;
    } else {
        return;
    }
}

sub create_test_string {
    my $extracted = shift || return;
    return <<TEST
use strict;
use warnings FATAL => 'all';
use Test::More qw(no_plan);
$extracted
TEST
}

sub create_test_path_from_lib {
    my $module_name = shift;
    $module_name =~s/\.pm$//;
    return File::Spec->catfile($Bin, '..', 't', 'synopsis', lc($module_name).'.t');
}

sub create_or_update_test {
    my ($string, $target) = @_;
    return unless $string && $target;
    print "Writing $target\n";
    open my $syn_test, '>', $target
      or die "Couldn't open $target - you screwed something up. Go fix it.\n";
    print $syn_test $string;
}

find(sub {
    return unless $_=~/pm$/;
    create_or_update_test(
        (create_test_string
        normalize_indent
        extract_synopsis
        slurp_file $File::Find::name),
        create_test_path_from_lib($_),
    );
}, File::Spec->catfile($Bin, '..', 'lib'));