#!/usr/bin/perl

use strict;
use warnings;
use Cwd;
use File::Find;
use Getopt::Long;

my @FORMATS = ("flac", "m4a", "aac", "alac", "mp3", "m3a", "ogg", "opus", "oga");
my $PATH_TO_REGAINER = "./regainer.py";
my $debug = 0;

# Parse command-line arguments
GetOptions("debug" => \$debug);

# Configure logging
if ($debug) {
    $| = 1; # Disable buffering for STDOUT
    print "Debug logs enabled\n";
}

my $workdir = getcwd();
print "regain.pl WorkDir: $workdir\n";

my @file_lists = find_files_by_extension($workdir);
print "Files for processing: ", countFiles(\@file_lists), "\n";

my @cmd = ("python", $PATH_TO_REGAINER, "-f");

foreach my $sublist (@file_lists) {
    push @cmd, "-a";
    push @cmd, @$_ foreach @$sublist;
}

print "Running command: @cmd\n";
print "Running regainer.py\n";

if ($debug) {
    open my $stdout_saved, ">&STDOUT";
    open my $stderr_saved, ">&STDERR";
    open STDOUT, ">", undef;
    open STDERR, ">", undef;

    my $result = system(@cmd);

    open STDOUT, ">&", $stdout_saved;
    open STDERR, ">&", $stderr_saved;

    print "regainer.py has exited with code $result\n";
    if ($result != 0) {
        print "You can re-run with --debug to view the output from regainer\n";
    } else {
        print "Files successfully tagged\n";
    }
} else {
    system(@cmd);
}

sub find_files_by_extension {
    my ($workdir) = @_;
    my @file_lists;

    find(sub {
        if (-f && /\.(@FORMATS)$/) {
            push @{$file_lists[-1]}, $File::Find::name;
        }
    }, $workdir);

    return \@file_lists;
}

sub countFiles {
    my ($file_list_of_lists) = @_;
    my $count = 0;

    foreach my $item (@$file_list_of_lists) {
        $count += scalar(@$item);
    }

    return $count;
}