#! /usr/bin/env perl

use strict;
use warnings;

# test data
my @array = ({fname => 'bob',  last_name => 'smith'             },

             {fname => 'tony', last_name => 'jones', age => 23,
               kids =>
                 [
                   {first_name   => 'cheryl',
                    middle_name => 'karen',
                    age         => 23        },

                   {name         => 'jimmy',
                    age          => 17       }

                 ]                                                },
             {fname => 'janet', last_name => 'marcos',
               occupation => {
                 title => 'trucker',
                 years_on_job => 12}                              },


             {fname => 'Marge', last_name => 'Keefe',
                kids =>
                  [
                    {name => 'kate', age => 7, vaccinated => 'yes'},
                    {name => 'kim', age => 5}
                  ]
             });

my $out .= "var ";

my $out .= "var ";
my %giant_hash;

foreach my $array (@array) {
  %giant_hash = (%giant_hash, %$array);
}

my $s_values = 1;
introspect(\%giant_hash);

my $nest_level = 0;
# recursive function that traverses the data structure
sub introspect {
  my $data = shift;
  my $type = gtype ($data);

  if ($type eq 'ARRAY') {
    $nest_level++;
    $out .= "is an ARRAY with " . glen(@$data) . " elements:";
    my $count = 0;
    foreach my $elem (@$data) {
      $out .= "\n" . ("\t" x $nest_level) . "elem $count ";
      introspect (ref $elem ? $elem : \$elem);
      $count++;
    }
    $nest_level--;
  }

  if ($type eq 'HASH') {
    $nest_level++;
    $out .= "is a HASH with " . scalar (keys %$data) . " keys";
    $out .= "\n" . ("\t" x $nest_level) . "the keys are '" . join ("', '", sort keys %$data) . "'";
    my $last_key;
    foreach my $key (keys %$data) {
      $last_key = $key;
      $out .= "\n" . ("\t" x $nest_level) . "key '$key' ";
      introspect (ref $data->{$key} ? $data->{$key} : \$data->{$key});
    }
    $nest_level--;
  }

  # our base case
  if ($type eq 'SCALAR') {
    $out .= "is a SCALAR";
    if (!$s_values) {
      $out .= " with a value of '$$data'";
    }
  }
}

print $out;
print "\n";

sub glen {
  return scalar @_;
}

sub gtype {
  ref shift;
}