#!/usr/bin/perl

=head1 NAME

vidir - edit directory

=head1 SYNOPSIS

B<vidir> [--verbose] [directory|file|-] ...

=head1 DESCRIPTION

vidir allows editing of the contents of a directory in a text editor. If no
directory is specified, the current directory is edited. Each item in the
directory is listed. Delete items to remove them from the directory, or
edit their names to rename them.

Note that if "-" is specified as the directory to edit, it reads a list of
filenames from stdin and displays those for editing. Alternatively, a list
of files can be specified on the command line.

=head1 OPTIONS

=over 4

=item -v, --verbose

Verbosely display the actions taken by the program.

=back

=head1 ENVIRONMENT VARIABLES

=over 4

=item EDITOR

Editor to use. Defaults to vi if not set.

=item VISUAL

Also supported to determine what editor to use.

=back

=head1 BUGS

Does not support deletion of directories. Does not support recursive
editing of contents of a directory.

=head1 AUTHOR

Copyright 2006 by Joey Hess <joey@kitenet.net>

Licensed under the GNU GPL.

=cut

use File::Temp;
use Getopt::Long;

my $error=0;

my $verbose=0;
if (! GetOptions("verbose|v" => \$verbose)) {
	die "Usage: $0 [--verbose] [directory|file|-]\n";
}

my @dir;
if (! @ARGV) {
	push @ARGV, "."
}
foreach my $item (@ARGV) {
	if ($item eq "-") {
		push @dir, map { chomp; $_ } <STDIN>;
		close STDIN;
		open(STDIN, "/dev/tty") || die "reopen: $!\n";
	}
	elsif (-d $item) {
		opendir(DIR, $item) || die "$0: cannot read $item: $!\n";
		push @dir, sort readdir(DIR);
		closedir DIR;
	}
	else {
		push @dir, $item;
	}
}
	
my $tmp=File::Temp->new(template => "dirXXXXX");
open (OUT, ">".$tmp->filename) || die "$0: cannot write ".$tmp->filename.": $!\n";

my %item;
my $c=0;
foreach (@dir) {
	next if $_ eq '.' || $_ eq '..';
	$item{++$c}=$_;
	print OUT "$c.\t$_\n";
}
@dir=();
close OUT;

my $editor="vi";
if (exists $ENV{EDITOR}) {
	$editor=$ENV{EDITOR};
}
if (exists $ENV{VISUAL}) {
	$editor=$ENV{VISUAL};
}
$ret=system($editor, $tmp);
if ($ret != 0) {
	die "$editor exited nonzero, aborting\n";
}

open (IN, $tmp->filename) || die "$0: cannot read ".$tmp->filename.": $!\n";
while (<IN>) {
	chomp;
	if (/^(\d+)\.\t(.*)/) {
		my $num=$1;
		my $name=$2;
		if (! exists $item{$num}) {
			print STDERR "$0: unknown item number $num\n";
			$error=1;
		}
		elsif ($name ne $item{$num}) {
			my $src=$item{$num};
			
			# deal with swaps
			if (-e $name || -l $name) {
				my $tmp=$name."~";
				my $c=0;
				while (-e $tmp || -l $tmp) {
					$c++;
					$tmp=$name."~$c";
				}
				if (! rename($name, $tmp)) {
					print STDERR "$0: failed to rename $name to $tmp: $!\n";
					$error=1;
				}
				elsif ($verbose) {
					print "'$name' -> '$tmp'\n";
				}
				foreach my $item (keys %item) {
					if ($item{$item} eq $name) {
						$item{$item}=$tmp;
					}
				}
			}

			if (! rename($src, $name)) {
				print STDERR "$0: failed to rename $src to $name: $!\n";
				$error=1;
			}
			elsif ($verbose) {
				print "'$src' -> '$name'\n";
			}
		}
		delete $item{$num};
	}
	else {
		die "$0: unable to parse line \"$_\", aborting\n";
	}
}
close IN;
unlink($tmp.'~') if -e $tmp.'~';

foreach my $item (sort values %item) {
	if (! unlink($item)) {
		print STDERR "$0: failed to remove $item: $!\n";
		$error=1;
	}
	if ($verbose) {
		print "removed '$item'\n";
	}
}

exit $error;