package TaskManager;

use Task;

sub new {
  # create.
  # receive task objects or task names, store them via add_task.
}

sub add_task {
  # receive task objects or task names
  my $self = shift;
  push @{$self->{_tasks}}, map {
    ref $_ ? $_ : Task::find_task($_)
  } @_;
}

sub execute_tasks {
  my $self = shift;

  # do we need to do them?
  my @tasks = grep {
    $_->needed()
  } @{$self->{_tasks}}

  for my $t (@tasks)
  {
    $t->perform_task();
  }
}

1;

##</code><code>##

package Task;

sub new {
  # creation of generic object.
}

my %task_cache;
sub find_task {
  my $task = shift;
  $task = shift if $task eq __PACKAGE__; # can call as Task-> or Task::

  return $task_cache{$task} if $task_cache{$task};

  (my $mod_name = $task . '.pm') =~ s{::}{/};
  eval { require $mod_name };
  if ($@) { 
    # handle error - return error, die, whatever.
  }
  $task_cache{$task} = $mod_name->new(@_);
}

sub needed
{
  #default - yes.
  1
}

sub perform_task
{
  # default... can't.
  my $self = shift;
  die "Forgot to override perform_task in " . ref($self) . "\n";
}

1;

##</code><code>##

package Task::WWW;

use WWW::Mechanize;

sub perform_task
{
  my $self = shift;
  # set up proxy, ...
  my $www = WWW::Mechanize->new($self->get_hostname());
  $self->handle_page($www);
}
1;