#!/usr/bin/env perl

use strict;
use warnings;
use autodie;

use File::Copy;

my $ref_file = 'ref.txt';
my $full_file = 'full.txt';
my $bu_file = "$full_file.BU";
#---------------------------------------------
# TODO - for demo only; remove for production
copy('original_full.txt', $full_file);
#---------------------------------------------
copy($full_file, $bu_file);

my %ref_paths;

_get_ref_paths($ref_file, \%ref_paths);

{
    open my $ifh, '<', $bu_file;
    open my $ofh, '>', $full_file;

    while (<$ifh>) {
        chomp;
        my $cmd = substr $_, 5, -1;
        my @possibles
            = @{_assess_full_path($cmd, \%ref_paths)};

        if (@possibles == 1) {
            $ofh->print(qq{CMD="$possibles[0]"\n});
        }
        elsif (@possibles > 1) {
            $ofh->print(qq{QRY($.)="$_"\n}) for @possibles;
        }
        else {
            $ofh->print(qq{WTF($.)="$cmd"\n});
        }
    }
}

#---------------------------------------------
# TODO - for demo only; remove for production
print "\n*** ref file: '$ref_file'\n";
system cat => $ref_file;
print "\n*** bu file: '$bu_file'\n";
system cat => $bu_file;
print "\n*** full file: '$full_file'\n";
system cat => $full_file;
#---------------------------------------------

sub _assess_full_path {
    my ($cmd, $ref_paths) = @_;

    my $possibles = [];

    my $pos = 1 + rindex $cmd, '/';
    my $start = substr $cmd, 0, $pos;
    my $end = substr $cmd, $pos;
    my $max = substr $cmd, 0, rindex($cmd, '.') - 1;

    if (exists $ref_paths->{$start}) {
        for my $key (keys %{$ref_paths->{$start}}) {
            my $dir = "$start$key";

            if (0 == index $max, $dir) {
                my $full_path
                    = join '/', $dir, substr $cmd, length $dir;
                $full_path =~ y{/}{/}s;
                push @$possibles, $full_path;
            }
        }
    }

    return $possibles;
}

sub _get_ref_paths {
    my ($ref_file, $ref_paths) = @_;

    open my $fh, '<', $ref_file;

    while (<$fh>) {
        chomp;
        my $end = substr $_, rindex($_, '/') + 1;
        substr $_, rindex($_, '/') + 1, length($_), '';
        $ref_paths->{$_}{$end} = 1;
        $ref_paths->{"$_$end/"}{''} = 1;
    }

    return;
}