#!/usr/bin/perl

use strict;
use Options;

my (@files_to_convert, @dir_of_files);
my $output_dir;

my %input_map = ('shn' => ['shorten -x "', '" -'],
				  'ogg' => ['oggdec -o - "', '"'],
				  'flac' => ['flac -s -d -c "', '"']);
my %output_map = ('mp3' => ['ffmpeg -i - -f mp3 -acodec mp3 -ab 256 "', '"']);

my @inout = ($0 =~ m/(\w+?)2(\w+)/);

unless(defined $input_map{$inout[0]}){
	print "$inout[0] is not a supported input type.\n";
	exit(1);
}
unless(defined $output_map{$inout[1]}){
	print "$inout[1] is not a supported output type.\n";
	exit(1);
}

if(-d $ARGV[0]){
	$ARGV[0] =~ s/\/$//;
	opendir(DIR, $ARGV[0]);
	@dir_of_files = readdir DIR;
	closedir DIR;

	if(-e "$ARGV[0]/.converted"){
		print "This directory has been converted already. (Delete the .converted file if you wish to convert again.)\n";
		exit(1);
	}

	if(grep /DO_NOT_EDIT/, @dir_of_files){
		print "This is an incomplete Furthur directory.\n";
		exit(1);
	}

	@files_to_convert = grep /.$inout[0]$/, map "$ARGV[0]/$_", @dir_of_files;
	unless(@files_to_convert){
		print "There are no .$inout[0] files in the specified directory.\n";
		exit(1);
	}
}
elsif(-e $ARGV[0] && $ARGV[0] =~ m/\.$inout[0]$/){
	@files_to_convert = ($ARGV[0]);
}
else{
	print "You must specify a .$inout[0] file, or a directory of files to convert.\n";
	exit(1);
}

if($ARGV[1] && -d $ARGV[1]){
	$output_dir = $ARGV[1];
}

foreach my $file (@files_to_convert){
	$file =~ m/(.*?)\.$inout[0]$/;
	my $output_file = "$1.$inout[1]";
	if($output_dir){
		if($output_file =~ /\//){
			($output_file) = ($output_file =~ m/\/([^\/]*)$/);
		}
		if($output_dir =~ /\/$/){
			chop($output_dir);
		}
		$output_file = "$output_dir/$output_file";
	}
	print "Output file is $output_file\n";
	my $command = $input_map{$inout[0]}->[0] . $file . $input_map{$inout[0]}->[1] . ' | ' .
				  $output_map{$inout[1]}->[0] . $output_file . $output_map{$inout[1]}->[1];
	my $result = system($command);
	if($result != 0){
		print "Subprocess ended with non-zero result: $result...exiting.\n";
		exit(1);
	}
}

if(-d $ARGV[0]){
	open(FILE, ">$ARGV[0]/.converted");
	print FILE "DONE";
	close(FILE);
}