use strict;
############################################################
#
#   depend.pl
#
#   Under the current directory, check all Java files
#   and see who is used by whom.
#
#   Caveat Emptor: this code calls DOS system commands
#   (I was being lazy in a bad way).
#
############################################################

#
#  I assume the workspace begins here.
#
my %uses = ();
my %user = ();
my %allkeys = ();

#
#  Here's one DOS system command.  Sorry 'bout that.
#
system( 'dir /b /s > files.tmp' );

open( IN, 'files.tmp' );
my @files = grep( /\.java$/, <IN> );
close IN;

chomp( @files );

#
#  Here's the other DOS system command.  No biggie to
#  just change it to 'unlink', I suppose.
#
system( 'del files.tmp' );

print "Processing files.\n";
my $file;
foreach $file (@files)
{
   #
   #  Glob the file
   #
   open( IN, $file ) || die "ERROR: cannot open $file\n";
   my @dat = <IN>;
   close IN;

   #
   #  Pull out the file name
   #
   my $filename = $file;
   $filename =~ s/^.*\\(\w+\.java).*$/$1/;
   
   #
   #  Pull out the package name
   #
   my ($pkg) = grep( /^package/, @dat );
   $pkg =~ s/^package (\S*);.*$/$1\.$filename/;
   chomp( $pkg );
  
   #
   #  Add the import dependency to our list.
   #
   foreach (grep( /^import/, @dat ))
   {
      /import (\S*);/;
      
      $uses{ $pkg }->{ $1   } ++;
      $user{ $1   }->{ $pkg } ++;  
      
      $allkeys{ $pkg } ++;
      $allkeys{ $1   } ++;    
   }
}

print "Writing uses.log file.\n";
open( OUT, ">uses.log" );

foreach ( sort keys %allkeys )
{
   if ( $uses{ $_ } )
   {
      print OUT "$_ uses:\n   "
              , join( "\n   ", keys %{$uses{$_}} )
              , "\n\n";
   }
   
   if ( $user{ $_ } )
   {
      print OUT "$_ is used by:\n   "
              , join( "\n   ", keys %{$user{$_}} )
              , "\n\n";
   }
}

close OUT;