package RolePlaying::Random;
use strict;
use warnings FATAL => qw(all);
use Exporter qw(import);
our @EXPORT_OK = qw(random tiny_rand instant_rand);

use List::Util qw(shuffle);

sub random {
  my ($list, $user_input, $opt) = @_;
  
  my $random_thing;
  if ($user_input && $user_input =~ /(?:help|options)/) {
    my $keys = join("\n\t", sort keys %{$list});
    $random_thing = "Your options are:
        $keys
        'by keys' to get a random key
        'data' to get the whole hash
        'keys' to get a list of the keys
        'all' to get a random item from any key on the list";
  }
  elsif ($user_input && $user_input eq 'data') {
    $random_thing = $list;
  }
  elsif ($user_input && $user_input eq 'keys') {
    $random_thing = [keys %$list];
  }
  else {
    my @random_list;
    if ($user_input && $user_input eq 'by keys') {
      @random_list = keys %{$list};
    }
    elsif (!$user_input || $user_input eq 'all' ) {
      @random_list = map { @$_ } values %{$list};
    }
    elsif ($list->{$user_input}) {
      @random_list = @{$list->{$user_input}};
    }
    else {
      my $caller = $opt->{caller} ? " in ".$opt->{caller} : '';
      die "Your option '$user_input' is not a list $caller.\n\tStopped
+$!"
    }
    push @random_list, @{$opt->{'additions'}} if $opt->{'additions'};
    @random_list = shuffle(@random_list);
    $random_thing = $random_list[rand @random_list];
  }
  
  return $random_thing;
}

sub random_from_list {
  my @rand_array = shuffle(@_);
  return $rand_array[rand @rand_array];
}
sub tiny_rand    { random_from_list(@_); }
sub instant_rand { random_from_list(@_); }

=head1 NAME

B<RolePlaying::Random> is a set of tools to generate randomness.

=head1 SYNOPSIS

  use RolePlaying::Random qw(random tiny_rand instant_rand);

  my $random_thing = random($hash_of_arrays, $selected_list, { additio
+ns => [@additional_items], caller => $caller });
  
  my $tiny_rand    = tiny_rand(qw(black white));
  my $instant_rand = instant_rand(qw(red yellow green cyan blue magent
+a));

=head1 DESCRIPTION

B<Random> has three tools to create randomness: C<random>, C<tiny_rand
+>, and C<instant_rand>.

=head2 random

C<random> takes a hash of arrays and returns a random result based on 
+the list selected from the hash. It is meant to be used in the creati
+on of other random subroutines.

  my %colors = (
    'eye'  => [qw(amber black blue brown gray green hazel red violet)]
+,
    'hair' => [qw(auburn brown black blond gray red white)],
    'rainbow'  => [qw(red orange yellow green blue indigo violet)],  
  );

  sub random_color {
    my ($selected_color_key, $color_additions) = @_;
    random(\%colors, $selected_color_key, {  additions => $color_addit
+ions, caller => 'random_color' });
  }

=head3 Selections

=head4 all or nothing

When C<all> or C<undef> is selected or nothing is entered, C<random> w
+ill flatten the hash and return any value from the hash.

Using C<random> by itself:

  my $random_color_one = random(\%colors);
  my $random_color_two = random(\%colors, undef);
  my $random_color_all = random(\%colors, 'all');

Using the newly created C<random_color>:

  my $random_color_one = random_color();
  my $random_color_two = random_color(undef);
  my $random_color_all = random_color('all');

All of the above will return any color in the hair, eye, and rainbow l
+ists.

=head4 a key

When a specific key is selected, C<random> will return an item from th
+e selected key.

Using C<random> by itself:

  my $random_hair_color = random(\%colors, 'hair');
  my $random_eyes_color = random(\%colors, 'eye');

Using the newly created C<random_color>:

  my $random_hair_color = random_color('hair');
  my $random_eyes_color = random_color('eye');

=head4 by keys

When C<by keys> is selected, C<random> will return a random key.

Using C<random> by itself:

  my $random_color_key = random(\%colors, 'by keys');

Using the newly created C<random_color>:

  my $random_color_key = random_color('by keys');
  
Both of the above will return a random key from C<%colors>: hair, eye,
+ rainbow.
  
=head4 keys

When C<keys> is selected, C<random> will return the list of keys from 
+the hash to help remind you of your key options.

Using C<random> by itself:

  my $random_color_keys = randon(\%colors, 'keys');

Using the newly created C<random_color>:

  my $random_color_keys = randon_color('keys');

Both of the above will return a list of the keys: C<['hair', 'eye', 'r
+ainbow']>.

=head4 data

When C<data> is selected, C<random> will return the entire hash so you
+ can refresh your memory of what is in the hash.

Using C<random> by itself:

  my $random_color_data = random(\%colors, 'data');

Using the newly created C<random_color>:

  my $random_color_data = random_color('data');

=head4 help or options

When C<help> or C<options> is selected, all of your options will be li
+sted.

Using C<random> by itself:

  my $random_color_help = random(\%colors, 'help');
  my $random_color_opts = random(\%colors, 'options');

Using the newly created C<random_color>:

  my $random_color_help = random_color('help');
  my $random_color_opts = random_color('options');

=head3 Optional parameters

There are two optional parameters you can use, C<additions> and C<call
+er>.

=head4 additions

C<additions> is a list (arrayref) that you want to add to the list you
+ have already selected.

You might want to add the colors pink, blue, and purple to the choices
+ of hair color or yellow and bloodshot to eye color.

Using C<random> by itself:

  my $random_hair_color = random(\%colors, 'hair', { additions => [qw(
+pink purple blue)] });
  my $random_eyes_color = random(\%colors, 'eye',  { additions => [qw(
+yellow bloodshot)] });

Using the newly created C<random_color>:

  my $random_hair_color = random_color('hair', [qw(pink purple blue)])
+;
  my $random_eyes_color = random_color('eye',  [qw(yellow bloodshot)])
+;

=head4 caller

C<caller> can be used to create an error message with the specific sub
+routine your are using random in.

Using C<random> by itself:

  my $random_color = random(\%colors, 'rainboe', { caller => 'random_c
+olor' });

Using the newly created C<random_color>:

  my $random_color = random(\%colors, 'rainboe');

If the user selects a list that will not produce a result, the error m
+essage from both of the above will read as follows.

  Your option 'rainboe' is not a list in random_color.
    Stopped at ...

=head2 random_from_list

C<random_from_list> takes an array and returns a random result. C<tiny
+_rand> and C<instant_rand> are aliases for C<random_from_list>.

  my $random_from_list = random_from_list(qw(black white red yellow gr
+een cyan blue magenta));
  my $tiny_rand        = tiny_rand(qw(black white));
  my $instant_rand     = instant_rand(qw(red yellow green cyan blue ma
+genta));

=head1 AUTHOR

Lady Aleena

=cut

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