#!/usr/bin/perl_parallel -w
# For Emacs: -*- mode:cperl; mode:folding; -*-

# {{{ use block
use strict;

use File::Spec;


# }}}

my $wd = shift @ARGV;

$wd = '.' if(!defined $wd);
$wd = File::Spec->rel2abs($wd);

my %size   = map { $_ => -s $_ } @{&files($wd)};
my @fnames = sort { $size{$b} <=> $size{$a} ||
                           $a cmp $b } keys %size;


#
# The only speedup potential I see, is to replace the cmp system call with
# something faster ???
# And to get rid of the File::Spec->abs2rel with some leaner/faster code
#
while(@fnames) {
  my $f = shift @fnames;

  next if(-l $f);

  for my $f2 (@fnames) {
    next if(-l $f2);
    last if($size{$f} != $size{$f2});

    if(system("cmp -s '$f' '$f2'") == 0) {

      # $f is the file to be LINKED TO, so we need this as relative path
      # $f2 is the file to be evtl. LINKED FROM, this can/should be absolute

      $f2 =~ m|^ ( (?: .* / (?: \.\.?\Z(?!\n) )? )? ) ([^/]*) |xs;
      my $new = File::Spec->abs2rel($f,$1);

      `ln -sf '$new' '$f2'`;
    }
  }
}

# {{{ files
#
sub files {
  my $path = shift;
  my $f;
  my @files = ();

  opendir(DIR, $path);                     # open directory
  for $f (readdir(DIR)) {
    next if($f =~ /^\.|\..$/);    # skip . and ..

    if(-f "$path/$f") {
      push @files, "$path/$f";
    } elsif(-d "$path/$f") {
      push @files, @{&files("$path/$f")};
    }
  }
  closedir DIR;                            # close directory

  return \@files;
}
# }}}