#!/usr/bin/perl -w
#
# Get perl modules required by mindi and mondo and that should be on the restore media
#
use strict;

use File::Find;
use Cwd;

my $file = get_perl_modules(@ARGV) if (defined $ARGV[0]);

foreach my $f (sort keys %$file) {
	print "$f\n";
}

sub get_perl_modules {

my %files;

#print "Searching in ";
#print join "\n", @INC;

my $require = process_file(@_);

my @includes;

# Remove non exiting directories from @INC
# and thus avoid perl warnings
#
foreach my $d (@INC) {
	$d = read_all_link($d) if (-l $d);
	push @includes,$d if (-d $d);
}

find(
	sub {
		if ((-f $File::Find::name) 
			&& (/\.pm$/) 
			&& (not defined $files{$File::Find::name})) {
			foreach my $m (keys %$require,"warnings") {
				(my $mod = $m) =~ s|::|/|g;
				#print "Looking at $mod in $File::Find::name\n";
				if (index($File::Find::name,"$mod.pm") ne -1) {
					$files{$File::Find::name} = $mod;
					#push @files, $File::Find::name;
					#print "Found $mod in $File::Find::name\n";
					last;
				}
			}
		}
	},
	@includes);

return(\%files);
}

# Cf: http://www.stonehenge.com/merlyn/UnixReview/col27.html
sub read_all_link {

my $dir = cwd;
my $link;

find sub {
	return unless -l;
	my @right = split /\//, $File::Find::name;
	my @left = do {
		@right && ($right[0] eq "") ?
		shift @right :            # quick way
		split /\//, $dir;
	};    # first element always null
	while (@right) {
		my $item = shift @right;
		next if $item eq "." or $item eq "";
		if ($item eq "..") {
			pop @left if @left > 1;
			next;
		}
		my $link = readlink (join "/", @left, $item);
		if (defined $link) {
			my @parts = split /\//, $link;
			if (@parts && ($parts[0] eq "")) { # absolute
				@left = shift @parts;   # quick way
			}
		unshift @right, @parts;
		next;
		} else {
			push @left, $item;
			next;
		}
	}
	#print "$File::Find::name is ", join("/", @left), "\n";
	$link = join("/", @left);
}, @_;
return($link);
}

# Adapted From /usr/lib/rpm/mandriva/perl.req
# by Ken Estes Mail.com kestes@staff.mail.com

sub process_file {
  
	my %line;
	my %require;
	my $current_line;
	my $tag;

	foreach my $file (@_) {
  
  open(FILE, "<$file") || return(\%require);
  
  while (<FILE>) {
    
    # skip the "= <<" block

    if ( ( m/^\s*\$(.*)\s*=\s*<<\s*["'](.*)['"]/i) ||
         ( m/^\s*\$(.*)\s*=\s*<<\s*(.*);/i) ) {
      $tag = $2;
      while (<FILE>) {
        ( $_ =~ /^$tag/) && last;
      }
    }

    # skip the documentation

    # we should not need to have item in this if statement (it
    # properly belongs in the over/back section) but people do not
    # read the perldoc.

    if ( (m/^=(head1|head2|pod|item)/) .. (m/^=(cut)/) ) {
      next;
    }

    if ( (m/^=(over)/) .. (m/^=(back)/) ) {
      next;
    }
    
    # skip the data section
    if (m/^__(DATA|END)__$/) {
      last;
    }

    # Each keyword can appear multiple times.  Don't
    #  bother with datastructures to store these strings,
    #  if we need to print it print it now.
    
    if ( m/^\s*\$RPM_Requires\s*=\s*["'](.*)['"]/i) {
      foreach $_ (split(/\s+/, $1)) {
	print "$_\n";
      }
    }

    if ( 

# ouch could be in a eval, perhaps we do not want these since we catch
# an exception they must not be required

#   eval { require Term::ReadLine } or die $@;
#   eval "require Term::Rendezvous;" or die $@;
#   eval { require Carp } if defined $^S; # If error/warning during compilation,


	(m/^(\s*)         # we hope the inclusion starts the line
	 (require|use)\s+(?!\{)     # do not want 'do {' loops
	 # quotes around name are always legal
	 [\'\"]?([^\;\ \'\"\t]*)[\'\"]?[\t\;\ ]
	 # the syntax for 'use' allows version requirements
	 \s*([.0-9]*)
	 /x)
       ) {
      my ($whitespace, $statement, $module, $version) = ($1, $2, $3,$4);
      my $usebase;

      # we only consider require statements that are flush against
      # the left edge. any other require statements give too many
      # false positives, as they are usually inside of an if statement
      # as a fallback module or a rarely used option

      ($whitespace ne "" && $statement eq "require") && next;

      # if there is some interpolation of variables just skip this
      # dependency, we do not want
      #        do "$ENV{LOGDIR}/$rcfile";

      ($module =~ m/\$/) && next;

      # skip if the phrase was "use of" -- shows up in gimp-perl, et al
      next if $module eq 'of';

      # if the module ends in a comma we probaly caught some
      # documentation of the form 'check stuff,\n do stuff, clean
      # stuff.' there are several of these in the perl distribution

      ($module  =~ m/[,>]$/) && next;

      # if the module name starts in a dot it is not a module name.
      # Is this necessary?  Please give me an example if you turn this
      # back on.

      #      ($module =~ m/^\./) && next;

      # if the module ends with .pm strip it to leave only basename.
      # starts with /, which means its an absolute path to a file
      if ($module =~ m(^/)) {
        print "$module\n";
        next;
      }

      # as seen in some perl scripts
      # use base qw(App::CLI Class::Accessor::Chained::Fast App::CLI::Command);
      if ($module eq 'base') {
	  $require{$module} = $version;
	  $line{$module} = $current_line;
	  ($module = $_) =~ s/use\s*base\s*//;
	  $module =~ s/qw\((.*)\)\s*;/$1/;
	  $module =~ s/qw(.)(.*)\1\s*;/$2/;
	  $module =~ s/\s*;$//;
	  $module =~ s/#.*//;
	  $usebase = 1;
      }
      # sometimes people do use POSIX qw(foo), or use POSIX(qw(foo)) etc
      # we can strip qw.*$, as well as (.*$:
      $module =~ s/qw.*$//;
      $module =~ s/\(.*$//;

      $module =~ s/\.pm$//;

      # some perl programmers write 'require URI/URL;' when 
      # they mean 'require URI::URL;'

	  $module =~ s/\//::/;

      # trim off trailing parenthesis if any.  Sometimes people pass
      # the module an empty list.

      $module =~ s/\(\s*\)$//;

      # if module is a number then both require and use interpret that
      # to mean that a particular version of perl is specified. Don't
      # add a dependency, though, since the rpm will already require
      # perl-base at the build version (via find-requires)
      next if $module =~ /^v?\d/;

      # ph files do not use the package name inside the file.
      # perlmodlib  documentation says:
      #       the .ph files made by h2ph will probably end up as
      #       extension modules made by h2xs.
      # so do not spend much effort on these.

      # there is no easy way to find out if a file named systeminfo.ph
      # will be included with the name sys/systeminfo.ph so only use the
      # basename of *.ph files

      ($module  =~ m/\.ph$/) && next;

      # if the module was loaded trough base, we need to split the list
      if ($usebase) {
          my $current_line = $_;
          foreach (split(/\s+/, $module)) {
              next unless $_;
              $require{$_} = $version;
              $line{$_} = $current_line;
          }
      } else {
	  $require{$module}=$version;
	  $line{$module}=$current_line;
      }
    }
  }

  close(FILE) ||
    die("$0: Could not close file: '$file' : $!\n");
	}

  return(\%require);
}